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* [PATCH v2 00/37] KVM: PPC: Book3S: C-ify the P9 entry/exit code
@ 2021-02-25 13:46 ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Since last posting, fixed a bunch of bugs, tidied things up, and
ironed out a few issues with XIVE.

I also got HPT guest and also host working on the new P9 path, which
allows major simplifications to the old path and moving P9 off it
completely, so I think that is really worth posting (I thought it
would be much more difficult).

Thanks,
Nick

Nicholas Piggin (37):
  KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
  KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls
  powerpc/64s: Remove KVM handler support from CBE_RAS interrupts
  powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
  KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
  KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
  KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
  KVM: PPC: Book3S 64: add hcall interrupt handler
  KVM: PPC: Book3S 64: Move hcall early register setup to KVM
  KVM: PPC: Book3S 64: Move interrupt early register setup to KVM
  KVM: PPC: Book3S 64: move bad_host_intr check to HV handler
  KVM: PPC: Book3S 64: Minimise hcall handler calling convention
    differences
  KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
  KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C
  KVM: PPC: Book3S HV P9: Move xive vcpu context management into
    kvmhv_p9_guest_entry
  KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9
    path
  KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest
    LPCR
  KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
  KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer
    read
  KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit
  powerpc: add set_dec_or_work API for safely updating decrementer
  KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races
  KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
  KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into
    __kvmhv_vcpu_entry_p9
  KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is
    0
  KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage
  KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check
  KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
  KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as
    possible
  KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling
    MMU
  KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9
  KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path
  KVM: PPC: Book3S HV: small pseries_do_hcall cleanup
  KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page
    faults
  KVM: PPC: Book3S HV P9: implement hash guest support
  KVM: PPC: Book3S HV P9: implement hash host / hash guest support
  KVM: PPC: Book3S HV: remove POWER9 support from P7/8 paths

 arch/powerpc/include/asm/asm-prototypes.h |   3 +-
 arch/powerpc/include/asm/exception-64s.h  |  13 +
 arch/powerpc/include/asm/kvm_asm.h        |   3 +-
 arch/powerpc/include/asm/kvm_book3s_64.h  |   8 +
 arch/powerpc/include/asm/kvm_host.h       |   1 -
 arch/powerpc/include/asm/kvm_ppc.h        |  10 +-
 arch/powerpc/include/asm/mmu_context.h    |   6 -
 arch/powerpc/include/asm/paca.h           |   1 +
 arch/powerpc/include/asm/time.h           |  16 +
 arch/powerpc/kernel/exceptions-64s.S      | 257 ++-------
 arch/powerpc/kernel/security.c            |   5 +-
 arch/powerpc/kernel/time.c                |  20 +-
 arch/powerpc/kvm/Makefile                 |   6 +
 arch/powerpc/kvm/book3s_64_entry.S        | 297 ++++++++++
 arch/powerpc/kvm/book3s_hv.c              | 590 ++++++++++----------
 arch/powerpc/kvm/book3s_hv_builtin.c      |   7 +
 arch/powerpc/kvm/book3s_hv_interrupt.c    | 493 +++++++++++++++++
 arch/powerpc/kvm/book3s_hv_interrupts.S   |   9 +-
 arch/powerpc/kvm/book3s_hv_nested.c       |   1 +
 arch/powerpc/kvm/book3s_hv_ras.c          |   5 +
 arch/powerpc/kvm/book3s_hv_rm_mmu.c       |   7 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 625 +---------------------
 arch/powerpc/kvm/book3s_segment.S         |   7 +
 arch/powerpc/kvm/book3s_xive.c            |  93 ++++
 arch/powerpc/mm/book3s64/radix_pgtable.c  |  27 +-
 arch/powerpc/mm/book3s64/radix_tlb.c      |  46 --
 arch/powerpc/mm/mmu_context.c             |   4 +-
 arch/powerpc/platforms/powernv/idle.c     |  52 +-
 28 files changed, 1342 insertions(+), 1270 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_64_entry.S
 create mode 100644 arch/powerpc/kvm/book3s_hv_interrupt.c

-- 
2.23.0


^ permalink raw reply	[flat|nested] 134+ messages in thread
* [PATCH v2 00/37] KVM: PPC: Book3S: C-ify the P9 entry/exit code
@ 2021-02-25 13:46 ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Since last posting, fixed a bunch of bugs, tidied things up, and
ironed out a few issues with XIVE.

I also got HPT guest and also host working on the new P9 path, which
allows major simplifications to the old path and moving P9 off it
completely, so I think that is really worth posting (I thought it
would be much more difficult).

Thanks,
Nick

Nicholas Piggin (37):
  KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
  KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls
  powerpc/64s: Remove KVM handler support from CBE_RAS interrupts
  powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
  KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
  KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
  KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
  KVM: PPC: Book3S 64: add hcall interrupt handler
  KVM: PPC: Book3S 64: Move hcall early register setup to KVM
  KVM: PPC: Book3S 64: Move interrupt early register setup to KVM
  KVM: PPC: Book3S 64: move bad_host_intr check to HV handler
  KVM: PPC: Book3S 64: Minimise hcall handler calling convention
    differences
  KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
  KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C
  KVM: PPC: Book3S HV P9: Move xive vcpu context management into
    kvmhv_p9_guest_entry
  KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9
    path
  KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest
    LPCR
  KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
  KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer
    read
  KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit
  powerpc: add set_dec_or_work API for safely updating decrementer
  KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races
  KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
  KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into
    __kvmhv_vcpu_entry_p9
  KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is
    0
  KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage
  KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check
  KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
  KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as
    possible
  KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling
    MMU
  KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9
  KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path
  KVM: PPC: Book3S HV: small pseries_do_hcall cleanup
  KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page
    faults
  KVM: PPC: Book3S HV P9: implement hash guest support
  KVM: PPC: Book3S HV P9: implement hash host / hash guest support
  KVM: PPC: Book3S HV: remove POWER9 support from P7/8 paths

 arch/powerpc/include/asm/asm-prototypes.h |   3 +-
 arch/powerpc/include/asm/exception-64s.h  |  13 +
 arch/powerpc/include/asm/kvm_asm.h        |   3 +-
 arch/powerpc/include/asm/kvm_book3s_64.h  |   8 +
 arch/powerpc/include/asm/kvm_host.h       |   1 -
 arch/powerpc/include/asm/kvm_ppc.h        |  10 +-
 arch/powerpc/include/asm/mmu_context.h    |   6 -
 arch/powerpc/include/asm/paca.h           |   1 +
 arch/powerpc/include/asm/time.h           |  16 +
 arch/powerpc/kernel/exceptions-64s.S      | 257 ++-------
 arch/powerpc/kernel/security.c            |   5 +-
 arch/powerpc/kernel/time.c                |  20 +-
 arch/powerpc/kvm/Makefile                 |   6 +
 arch/powerpc/kvm/book3s_64_entry.S        | 297 ++++++++++
 arch/powerpc/kvm/book3s_hv.c              | 590 ++++++++++----------
 arch/powerpc/kvm/book3s_hv_builtin.c      |   7 +
 arch/powerpc/kvm/book3s_hv_interrupt.c    | 493 +++++++++++++++++
 arch/powerpc/kvm/book3s_hv_interrupts.S   |   9 +-
 arch/powerpc/kvm/book3s_hv_nested.c       |   1 +
 arch/powerpc/kvm/book3s_hv_ras.c          |   5 +
 arch/powerpc/kvm/book3s_hv_rm_mmu.c       |   7 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 625 +---------------------
 arch/powerpc/kvm/book3s_segment.S         |   7 +
 arch/powerpc/kvm/book3s_xive.c            |  93 ++++
 arch/powerpc/mm/book3s64/radix_pgtable.c  |  27 +-
 arch/powerpc/mm/book3s64/radix_tlb.c      |  46 --
 arch/powerpc/mm/mmu_context.c             |   4 +-
 arch/powerpc/platforms/powernv/idle.c     |  52 +-
 28 files changed, 1342 insertions(+), 1270 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_64_entry.S
 create mode 100644 arch/powerpc/kvm/book3s_hv_interrupt.c

-- 
2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

The va argument is not used in the function or set by its asm caller,
so remove it to be safe.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h  | 3 +--
 arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 8aacd76bb702..9531b1c1b190 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
                      unsigned long pte_index, unsigned long avpn);
 long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
-                      unsigned long pte_index, unsigned long avpn,
-                      unsigned long va);
+                      unsigned long pte_index, unsigned long avpn);
 long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
                    unsigned long pte_index);
 long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 88da2764c1bb..7af7c70f1468 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
 }
 
 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
-		      unsigned long pte_index, unsigned long avpn,
-		      unsigned long va)
+		      unsigned long pte_index, unsigned long avpn)
 {
 	struct kvm *kvm = vcpu->kvm;
 	__be64 *hpte;
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

The va argument is not used in the function or set by its asm caller,
so remove it to be safe.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h  | 3 +--
 arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 8aacd76bb702..9531b1c1b190 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
                      unsigned long pte_index, unsigned long avpn);
 long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
-                      unsigned long pte_index, unsigned long avpn,
-                      unsigned long va);
+                      unsigned long pte_index, unsigned long avpn);
 long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
                    unsigned long pte_index);
 long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 88da2764c1bb..7af7c70f1468 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
 }
 
 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
-		      unsigned long pte_index, unsigned long avpn,
-		      unsigned long va)
+		      unsigned long pte_index, unsigned long avpn)
 {
 	struct kvm *kvm = vcpu->kvm;
 	__be64 *hpte;
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 02/37] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This config option causes the warning in init_default_hcalls to fire
because the TCE handlers are in the default hcall list but not
implemented.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 13bad6bf4c95..895090636295 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -5369,8 +5369,10 @@ static unsigned int default_hcall_list[] = {
 	H_READ,
 	H_PROTECT,
 	H_BULK_REMOVE,
+#ifdef CONFIG_SPAPR_TCE_IOMMU
 	H_GET_TCE,
 	H_PUT_TCE,
+#endif
 	H_SET_DABR,
 	H_SET_XDABR,
 	H_CEDE,
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 02/37] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This config option causes the warning in init_default_hcalls to fire
because the TCE handlers are in the default hcall list but not
implemented.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 13bad6bf4c95..895090636295 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -5369,8 +5369,10 @@ static unsigned int default_hcall_list[] = {
 	H_READ,
 	H_PROTECT,
 	H_BULK_REMOVE,
+#ifdef CONFIG_SPAPR_TCE_IOMMU
 	H_GET_TCE,
 	H_PUT_TCE,
+#endif
 	H_SET_DABR,
 	H_SET_XDABR,
 	H_CEDE,
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 03/37] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Cell does not support KVM.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 60d3051a8bc8..a027600beeb1 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2530,8 +2530,6 @@ EXC_VIRT_NONE(0x5100, 0x100)
 INT_DEFINE_BEGIN(cbe_system_error)
 	IVEC=0x1200
 	IHSRR=1
-	IKVM_SKIP=1
-	IKVM_REAL=1
 INT_DEFINE_END(cbe_system_error)
 
 EXC_REAL_BEGIN(cbe_system_error, 0x1200, 0x100)
@@ -2701,8 +2699,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
 INT_DEFINE_BEGIN(cbe_maintenance)
 	IVEC=0x1600
 	IHSRR=1
-	IKVM_SKIP=1
-	IKVM_REAL=1
 INT_DEFINE_END(cbe_maintenance)
 
 EXC_REAL_BEGIN(cbe_maintenance, 0x1600, 0x100)
@@ -2754,8 +2750,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
 INT_DEFINE_BEGIN(cbe_thermal)
 	IVEC=0x1800
 	IHSRR=1
-	IKVM_SKIP=1
-	IKVM_REAL=1
 INT_DEFINE_END(cbe_thermal)
 
 EXC_REAL_BEGIN(cbe_thermal, 0x1800, 0x100)
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 03/37] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Cell does not support KVM.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 60d3051a8bc8..a027600beeb1 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2530,8 +2530,6 @@ EXC_VIRT_NONE(0x5100, 0x100)
 INT_DEFINE_BEGIN(cbe_system_error)
 	IVEC=0x1200
 	IHSRR=1
-	IKVM_SKIP=1
-	IKVM_REAL=1
 INT_DEFINE_END(cbe_system_error)
 
 EXC_REAL_BEGIN(cbe_system_error, 0x1200, 0x100)
@@ -2701,8 +2699,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
 INT_DEFINE_BEGIN(cbe_maintenance)
 	IVEC=0x1600
 	IHSRR=1
-	IKVM_SKIP=1
-	IKVM_REAL=1
 INT_DEFINE_END(cbe_maintenance)
 
 EXC_REAL_BEGIN(cbe_maintenance, 0x1600, 0x100)
@@ -2754,8 +2750,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
 INT_DEFINE_BEGIN(cbe_thermal)
 	IVEC=0x1800
 	IHSRR=1
-	IKVM_SKIP=1
-	IKVM_REAL=1
 INT_DEFINE_END(cbe_thermal)
 
 EXC_REAL_BEGIN(cbe_thermal, 0x1800, 0x100)
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
MSR[IR]=0, so the faults of concern are the d-side ones caused by access
to guest context by the hypervisor.

Instruction breakpoint interrupts are not a concern here. It's unlikely
any good would come of causing breaks in this code, but skipping the
instruction that caused it won't help matters (e.g., skip the mtmsr that
sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a027600beeb1..0097e0676ed7 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
 INT_DEFINE_BEGIN(instruction_breakpoint)
 	IVEC=0x1300
 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
-	IKVM_SKIP=1
 	IKVM_REAL=1
 #endif
 INT_DEFINE_END(instruction_breakpoint)
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
MSR[IR]=0, so the faults of concern are the d-side ones caused by access
to guest context by the hypervisor.

Instruction breakpoint interrupts are not a concern here. It's unlikely
any good would come of causing breaks in this code, but skipping the
instruction that caused it won't help matters (e.g., skip the mtmsr that
sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a027600beeb1..0097e0676ed7 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
 INT_DEFINE_BEGIN(instruction_breakpoint)
 	IVEC=0x1300
 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
-	IKVM_SKIP=1
 	IKVM_REAL=1
 #endif
 INT_DEFINE_END(instruction_breakpoint)
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Rather than add the ME bit to the MSR when the guest is entered, make
it clear that the hypervisor does not allow the guest to clear the bit.

The ME addition is kept in the code for now, but a future patch will
warn if it's not present.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_builtin.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 158d309b42a3..1ca484160636 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -662,6 +662,13 @@ static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
 
 void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
 {
+	/*
+	 * Guest must always run with machine check interrupt
+	 * enabled.
+	 */
+	if (!(msr & MSR_ME))
+		msr |= MSR_ME;
+
 	/*
 	 * Check for illegal transactional state bit combination
 	 * and if we find it, force the TS field to a safe state.
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Rather than add the ME bit to the MSR when the guest is entered, make
it clear that the hypervisor does not allow the guest to clear the bit.

The ME addition is kept in the code for now, but a future patch will
warn if it's not present.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_builtin.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 158d309b42a3..1ca484160636 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -662,6 +662,13 @@ static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
 
 void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
 {
+	/*
+	 * Guest must always run with machine check interrupt
+	 * enabled.
+	 */
+	if (!(msr & MSR_ME))
+		msr |= MSR_ME;
+
 	/*
 	 * Check for illegal transactional state bit combination
 	 * and if we find it, force the TS field to a safe state.
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 06/37] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Rather than bifurcate the call depending on whether or not HV is
possible, and have the HV entry test for PR, just make a single
common point which does the demultiplexing. This makes it simpler
to add another type of exit handler.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S    |  8 +-----
 arch/powerpc/kvm/Makefile               |  3 +++
 arch/powerpc/kvm/book3s_64_entry.S      | 35 +++++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 ++------
 4 files changed, 41 insertions(+), 16 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_64_entry.S

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 0097e0676ed7..ba13d749d203 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -208,7 +208,6 @@ do_define_int n
 .endm
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 /*
  * All interrupts which set HSRR registers, as well as SRESET and MCE and
  * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
@@ -238,13 +237,8 @@ do_define_int n
 
 /*
  * If an interrupt is taken while a guest is running, it is immediately routed
- * to KVM to handle. If both HV and PR KVM arepossible, KVM interrupts go first
- * to kvmppc_interrupt_hv, which handles the PR guest case.
+ * to KVM to handle.
  */
-#define kvmppc_interrupt kvmppc_interrupt_hv
-#else
-#define kvmppc_interrupt kvmppc_interrupt_pr
-#endif
 
 .macro KVMTEST name
 	lbz	r10,HSTATE_IN_GUEST(r13)
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 2bfeaa13befb..cdd119028f64 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -59,6 +59,9 @@ kvm-pr-y := \
 kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
 	tm.o
 
+kvm-book3s_64-builtin-objs-y += \
+	book3s_64_entry.o
+
 ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
 kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
 	book3s_rmhandlers.o
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
new file mode 100644
index 000000000000..e9a6a8fbb164
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -0,0 +1,35 @@
+#include <asm/asm-offsets.h>
+#include <asm/cache.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_book3s_asm.h>
+#include <asm/ppc_asm.h>
+#include <asm/reg.h>
+
+/*
+ * This is branched to from interrupt handlers in exception-64s.S which set
+ * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
+ */
+.global	kvmppc_interrupt
+.balign IFETCH_ALIGN_BYTES
+kvmppc_interrupt:
+	/*
+	 * Register contents:
+	 * R12		= (guest CR << 32) | interrupt vector
+	 * R13		= PACA
+	 * guest R12 saved in shadow VCPU SCRATCH0
+	 * guest R13 saved in SPRN_SCRATCH0
+	 */
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	std	r9,HSTATE_SCRATCH2(r13)
+	lbz	r9,HSTATE_IN_GUEST(r13)
+	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
+	beq	kvmppc_bad_host_intr
+#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
+	cmpwi	r9,KVM_GUEST_MODE_GUEST
+	ld	r9,HSTATE_SCRATCH2(r13)
+	beq	kvmppc_interrupt_pr
+#endif
+	b	kvmppc_interrupt_hv
+#else
+	b	kvmppc_interrupt_pr
+#endif
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 5e634db4809b..f976efb7e4a9 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1269,16 +1269,8 @@ kvmppc_interrupt_hv:
 	 * R13		= PACA
 	 * guest R12 saved in shadow VCPU SCRATCH0
 	 * guest R13 saved in SPRN_SCRATCH0
+	 * guest R9 saved in HSTATE_SCRATCH2
 	 */
-	std	r9, HSTATE_SCRATCH2(r13)
-	lbz	r9, HSTATE_IN_GUEST(r13)
-	cmpwi	r9, KVM_GUEST_MODE_HOST_HV
-	beq	kvmppc_bad_host_intr
-#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
-	cmpwi	r9, KVM_GUEST_MODE_GUEST
-	ld	r9, HSTATE_SCRATCH2(r13)
-	beq	kvmppc_interrupt_pr
-#endif
 	/* We're now back in the host but in guest MMU context */
 	li	r9, KVM_GUEST_MODE_HOST_HV
 	stb	r9, HSTATE_IN_GUEST(r13)
@@ -3280,6 +3272,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
  * cfar is saved in HSTATE_CFAR(r13)
  * ppr is saved in HSTATE_PPR(r13)
  */
+.global kvmppc_bad_host_intr
 kvmppc_bad_host_intr:
 	/*
 	 * Switch to the emergency stack, but start half-way down in
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 06/37] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Rather than bifurcate the call depending on whether or not HV is
possible, and have the HV entry test for PR, just make a single
common point which does the demultiplexing. This makes it simpler
to add another type of exit handler.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S    |  8 +-----
 arch/powerpc/kvm/Makefile               |  3 +++
 arch/powerpc/kvm/book3s_64_entry.S      | 35 +++++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 ++------
 4 files changed, 41 insertions(+), 16 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_64_entry.S

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 0097e0676ed7..ba13d749d203 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -208,7 +208,6 @@ do_define_int n
 .endm
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 /*
  * All interrupts which set HSRR registers, as well as SRESET and MCE and
  * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
@@ -238,13 +237,8 @@ do_define_int n
 
 /*
  * If an interrupt is taken while a guest is running, it is immediately routed
- * to KVM to handle. If both HV and PR KVM arepossible, KVM interrupts go first
- * to kvmppc_interrupt_hv, which handles the PR guest case.
+ * to KVM to handle.
  */
-#define kvmppc_interrupt kvmppc_interrupt_hv
-#else
-#define kvmppc_interrupt kvmppc_interrupt_pr
-#endif
 
 .macro KVMTEST name
 	lbz	r10,HSTATE_IN_GUEST(r13)
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 2bfeaa13befb..cdd119028f64 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -59,6 +59,9 @@ kvm-pr-y := \
 kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
 	tm.o
 
+kvm-book3s_64-builtin-objs-y += \
+	book3s_64_entry.o
+
 ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
 kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
 	book3s_rmhandlers.o
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
new file mode 100644
index 000000000000..e9a6a8fbb164
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -0,0 +1,35 @@
+#include <asm/asm-offsets.h>
+#include <asm/cache.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_book3s_asm.h>
+#include <asm/ppc_asm.h>
+#include <asm/reg.h>
+
+/*
+ * This is branched to from interrupt handlers in exception-64s.S which set
+ * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
+ */
+.global	kvmppc_interrupt
+.balign IFETCH_ALIGN_BYTES
+kvmppc_interrupt:
+	/*
+	 * Register contents:
+	 * R12		= (guest CR << 32) | interrupt vector
+	 * R13		= PACA
+	 * guest R12 saved in shadow VCPU SCRATCH0
+	 * guest R13 saved in SPRN_SCRATCH0
+	 */
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	std	r9,HSTATE_SCRATCH2(r13)
+	lbz	r9,HSTATE_IN_GUEST(r13)
+	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
+	beq	kvmppc_bad_host_intr
+#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
+	cmpwi	r9,KVM_GUEST_MODE_GUEST
+	ld	r9,HSTATE_SCRATCH2(r13)
+	beq	kvmppc_interrupt_pr
+#endif
+	b	kvmppc_interrupt_hv
+#else
+	b	kvmppc_interrupt_pr
+#endif
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 5e634db4809b..f976efb7e4a9 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1269,16 +1269,8 @@ kvmppc_interrupt_hv:
 	 * R13		= PACA
 	 * guest R12 saved in shadow VCPU SCRATCH0
 	 * guest R13 saved in SPRN_SCRATCH0
+	 * guest R9 saved in HSTATE_SCRATCH2
 	 */
-	std	r9, HSTATE_SCRATCH2(r13)
-	lbz	r9, HSTATE_IN_GUEST(r13)
-	cmpwi	r9, KVM_GUEST_MODE_HOST_HV
-	beq	kvmppc_bad_host_intr
-#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
-	cmpwi	r9, KVM_GUEST_MODE_GUEST
-	ld	r9, HSTATE_SCRATCH2(r13)
-	beq	kvmppc_interrupt_pr
-#endif
 	/* We're now back in the host but in guest MMU context */
 	li	r9, KVM_GUEST_MODE_HOST_HV
 	stb	r9, HSTATE_IN_GUEST(r13)
@@ -3280,6 +3272,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
  * cfar is saved in HSTATE_CFAR(r13)
  * ppr is saved in HSTATE_PPR(r13)
  */
+.global kvmppc_bad_host_intr
 kvmppc_bad_host_intr:
 	/*
 	 * Switch to the emergency stack, but start half-way down in
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 07/37] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Move the GUEST_MODE_SKIP logic into KVM code. This is quite a KVM
internal detail that has no real need to be in common handlers.

Also add a comment explaining why this thing exists.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 60 ----------------------------
 arch/powerpc/kvm/book3s_64_entry.S   | 51 ++++++++++++++++++++++-
 2 files changed, 50 insertions(+), 61 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index ba13d749d203..d956dd9ed61f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -133,7 +133,6 @@ name:
 #define IBRANCH_TO_COMMON	.L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
 #define IREALMODE_COMMON	.L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
 #define IMASK		.L_IMASK_\name\()	/* IRQ soft-mask bit */
-#define IKVM_SKIP	.L_IKVM_SKIP_\name\()	/* Generate KVM skip handler */
 #define IKVM_REAL	.L_IKVM_REAL_\name\()	/* Real entry tests KVM */
 #define __IKVM_REAL(name)	.L_IKVM_REAL_ ## name
 #define IKVM_VIRT	.L_IKVM_VIRT_\name\()	/* Virt entry tests KVM */
@@ -190,9 +189,6 @@ do_define_int n
 	.ifndef IMASK
 		IMASK=0
 	.endif
-	.ifndef IKVM_SKIP
-		IKVM_SKIP=0
-	.endif
 	.ifndef IKVM_REAL
 		IKVM_REAL=0
 	.endif
@@ -250,15 +246,10 @@ do_define_int n
 	.balign IFETCH_ALIGN_BYTES
 \name\()_kvm:
 
-	.if IKVM_SKIP
-	cmpwi	r10,KVM_GUEST_MODE_SKIP
-	beq	89f
-	.else
 BEGIN_FTR_SECTION
 	ld	r10,IAREA+EX_CFAR(r13)
 	std	r10,HSTATE_CFAR(r13)
 END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
-	.endif
 
 	ld	r10,IAREA+EX_CTR(r13)
 	mtctr	r10
@@ -285,27 +276,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ori	r12,r12,(IVEC)
 	.endif
 	b	kvmppc_interrupt
-
-	.if IKVM_SKIP
-89:	mtocrf	0x80,r9
-	ld	r10,IAREA+EX_CTR(r13)
-	mtctr	r10
-	ld	r9,IAREA+EX_R9(r13)
-	ld	r10,IAREA+EX_R10(r13)
-	ld	r11,IAREA+EX_R11(r13)
-	ld	r12,IAREA+EX_R12(r13)
-	.if IHSRR_IF_HVMODE
-	BEGIN_FTR_SECTION
-	b	kvmppc_skip_Hinterrupt
-	FTR_SECTION_ELSE
-	b	kvmppc_skip_interrupt
-	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
-	.elseif IHSRR
-	b	kvmppc_skip_Hinterrupt
-	.else
-	b	kvmppc_skip_interrupt
-	.endif
-	.endif
 .endm
 
 #else
@@ -1083,7 +1053,6 @@ INT_DEFINE_BEGIN(machine_check)
 	ISET_RI=0
 	IDAR=1
 	IDSISR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 INT_DEFINE_END(machine_check)
 
@@ -1356,7 +1325,6 @@ INT_DEFINE_BEGIN(data_access)
 	IVEC=0x300
 	IDAR=1
 	IDSISR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 INT_DEFINE_END(data_access)
 
@@ -1410,7 +1378,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 INT_DEFINE_BEGIN(data_access_slb)
 	IVEC=0x380
 	IDAR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 INT_DEFINE_END(data_access_slb)
 
@@ -2080,7 +2047,6 @@ INT_DEFINE_BEGIN(h_data_storage)
 	IHSRR=1
 	IDAR=1
 	IDSISR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 	IKVM_VIRT=1
 INT_DEFINE_END(h_data_storage)
@@ -3024,32 +2990,6 @@ EXPORT_SYMBOL(do_uaccess_flush)
 MASKED_INTERRUPT
 MASKED_INTERRUPT hsrr=1
 
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-kvmppc_skip_interrupt:
-	/*
-	 * Here all GPRs are unchanged from when the interrupt happened
-	 * except for r13, which is saved in SPRG_SCRATCH0.
-	 */
-	mfspr	r13, SPRN_SRR0
-	addi	r13, r13, 4
-	mtspr	SPRN_SRR0, r13
-	GET_SCRATCH0(r13)
-	RFI_TO_KERNEL
-	b	.
-
-kvmppc_skip_Hinterrupt:
-	/*
-	 * Here all GPRs are unchanged from when the interrupt happened
-	 * except for r13, which is saved in SPRG_SCRATCH0.
-	 */
-	mfspr	r13, SPRN_HSRR0
-	addi	r13, r13, 4
-	mtspr	SPRN_HSRR0, r13
-	GET_SCRATCH0(r13)
-	HRFI_TO_KERNEL
-	b	.
-#endif
-
 	/*
 	 * Relocation-on interrupts: A subset of the interrupts can be delivered
 	 * with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index e9a6a8fbb164..c1276f616af4 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -1,5 +1,6 @@
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
+#include <asm/exception-64s.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_book3s_asm.h>
 #include <asm/ppc_asm.h>
@@ -19,9 +20,12 @@ kvmppc_interrupt:
 	 * guest R12 saved in shadow VCPU SCRATCH0
 	 * guest R13 saved in SPRN_SCRATCH0
 	 */
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 	std	r9,HSTATE_SCRATCH2(r13)
 	lbz	r9,HSTATE_IN_GUEST(r13)
+	cmpwi	r9,KVM_GUEST_MODE_SKIP
+	beq-	.Lmaybe_skip
+.Lno_skip:
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
 	beq	kvmppc_bad_host_intr
 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
@@ -33,3 +37,48 @@ kvmppc_interrupt:
 #else
 	b	kvmppc_interrupt_pr
 #endif
+
+/*
+ * KVM uses a trick where it is running in MSR[HV]=1 mode in real-mode with the
+ * guest MMU context loaded, and it sets KVM_GUEST_MODE_SKIP and enables
+ * MSR[DR]=1 while leaving MSR[IR]=0, so it continues to fetch HV instructions
+ * but loads and stores will access the guest context. This is used to load
+ * the faulting instruction without walking page tables.
+ *
+ * However the guest context may not be able to translate, or it may cause a
+ * machine check or other issue, which will result in a fault in the host
+ * (even with KVM-HV).
+ *
+ * These faults are caught here and if the fault was (or was likely) due to
+ * that load, then we just return with the PC advanced +4 and skip the load,
+ * which then goes via the slow path.
+ */
+.Lmaybe_skip:
+	cmpwi	r12,BOOK3S_INTERRUPT_MACHINE_CHECK
+	beq	1f
+	cmpwi	r12,BOOK3S_INTERRUPT_DATA_STORAGE
+	beq	1f
+	cmpwi	r12,BOOK3S_INTERRUPT_DATA_SEGMENT
+	beq	1f
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* HSRR interrupts have 2 added to trap vector */
+	cmpwi	r12,BOOK3S_INTERRUPT_H_DATA_STORAGE | 0x2
+	beq	2f
+#endif
+	b	.Lno_skip
+1:	mfspr	r9,SPRN_SRR0
+	addi	r9,r9,4
+	mtspr	SPRN_SRR0,r9
+	ld	r12,HSTATE_SCRATCH0(r13)
+	ld	r9,HSTATE_SCRATCH2(r13)
+	GET_SCRATCH0(r13)
+	RFI_TO_KERNEL
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+2:	mfspr	r9,SPRN_HSRR0
+	addi	r9,r9,4
+	mtspr	SPRN_HSRR0,r9
+	ld	r12,HSTATE_SCRATCH0(r13)
+	ld	r9,HSTATE_SCRATCH2(r13)
+	GET_SCRATCH0(r13)
+	HRFI_TO_KERNEL
+#endif
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 07/37] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Move the GUEST_MODE_SKIP logic into KVM code. This is quite a KVM
internal detail that has no real need to be in common handlers.

Also add a comment explaining why this thing exists.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 60 ----------------------------
 arch/powerpc/kvm/book3s_64_entry.S   | 51 ++++++++++++++++++++++-
 2 files changed, 50 insertions(+), 61 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index ba13d749d203..d956dd9ed61f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -133,7 +133,6 @@ name:
 #define IBRANCH_TO_COMMON	.L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
 #define IREALMODE_COMMON	.L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
 #define IMASK		.L_IMASK_\name\()	/* IRQ soft-mask bit */
-#define IKVM_SKIP	.L_IKVM_SKIP_\name\()	/* Generate KVM skip handler */
 #define IKVM_REAL	.L_IKVM_REAL_\name\()	/* Real entry tests KVM */
 #define __IKVM_REAL(name)	.L_IKVM_REAL_ ## name
 #define IKVM_VIRT	.L_IKVM_VIRT_\name\()	/* Virt entry tests KVM */
@@ -190,9 +189,6 @@ do_define_int n
 	.ifndef IMASK
 		IMASK=0
 	.endif
-	.ifndef IKVM_SKIP
-		IKVM_SKIP=0
-	.endif
 	.ifndef IKVM_REAL
 		IKVM_REAL=0
 	.endif
@@ -250,15 +246,10 @@ do_define_int n
 	.balign IFETCH_ALIGN_BYTES
 \name\()_kvm:
 
-	.if IKVM_SKIP
-	cmpwi	r10,KVM_GUEST_MODE_SKIP
-	beq	89f
-	.else
 BEGIN_FTR_SECTION
 	ld	r10,IAREA+EX_CFAR(r13)
 	std	r10,HSTATE_CFAR(r13)
 END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
-	.endif
 
 	ld	r10,IAREA+EX_CTR(r13)
 	mtctr	r10
@@ -285,27 +276,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ori	r12,r12,(IVEC)
 	.endif
 	b	kvmppc_interrupt
-
-	.if IKVM_SKIP
-89:	mtocrf	0x80,r9
-	ld	r10,IAREA+EX_CTR(r13)
-	mtctr	r10
-	ld	r9,IAREA+EX_R9(r13)
-	ld	r10,IAREA+EX_R10(r13)
-	ld	r11,IAREA+EX_R11(r13)
-	ld	r12,IAREA+EX_R12(r13)
-	.if IHSRR_IF_HVMODE
-	BEGIN_FTR_SECTION
-	b	kvmppc_skip_Hinterrupt
-	FTR_SECTION_ELSE
-	b	kvmppc_skip_interrupt
-	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
-	.elseif IHSRR
-	b	kvmppc_skip_Hinterrupt
-	.else
-	b	kvmppc_skip_interrupt
-	.endif
-	.endif
 .endm
 
 #else
@@ -1083,7 +1053,6 @@ INT_DEFINE_BEGIN(machine_check)
 	ISET_RI=0
 	IDAR=1
 	IDSISR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 INT_DEFINE_END(machine_check)
 
@@ -1356,7 +1325,6 @@ INT_DEFINE_BEGIN(data_access)
 	IVEC=0x300
 	IDAR=1
 	IDSISR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 INT_DEFINE_END(data_access)
 
@@ -1410,7 +1378,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 INT_DEFINE_BEGIN(data_access_slb)
 	IVEC=0x380
 	IDAR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 INT_DEFINE_END(data_access_slb)
 
@@ -2080,7 +2047,6 @@ INT_DEFINE_BEGIN(h_data_storage)
 	IHSRR=1
 	IDAR=1
 	IDSISR=1
-	IKVM_SKIP=1
 	IKVM_REAL=1
 	IKVM_VIRT=1
 INT_DEFINE_END(h_data_storage)
@@ -3024,32 +2990,6 @@ EXPORT_SYMBOL(do_uaccess_flush)
 MASKED_INTERRUPT
 MASKED_INTERRUPT hsrr=1
 
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-kvmppc_skip_interrupt:
-	/*
-	 * Here all GPRs are unchanged from when the interrupt happened
-	 * except for r13, which is saved in SPRG_SCRATCH0.
-	 */
-	mfspr	r13, SPRN_SRR0
-	addi	r13, r13, 4
-	mtspr	SPRN_SRR0, r13
-	GET_SCRATCH0(r13)
-	RFI_TO_KERNEL
-	b	.
-
-kvmppc_skip_Hinterrupt:
-	/*
-	 * Here all GPRs are unchanged from when the interrupt happened
-	 * except for r13, which is saved in SPRG_SCRATCH0.
-	 */
-	mfspr	r13, SPRN_HSRR0
-	addi	r13, r13, 4
-	mtspr	SPRN_HSRR0, r13
-	GET_SCRATCH0(r13)
-	HRFI_TO_KERNEL
-	b	.
-#endif
-
 	/*
 	 * Relocation-on interrupts: A subset of the interrupts can be delivered
 	 * with IR=1/DR=1, if AIL=2 and MSR.HV won't be changed by delivering
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index e9a6a8fbb164..c1276f616af4 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -1,5 +1,6 @@
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
+#include <asm/exception-64s.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_book3s_asm.h>
 #include <asm/ppc_asm.h>
@@ -19,9 +20,12 @@ kvmppc_interrupt:
 	 * guest R12 saved in shadow VCPU SCRATCH0
 	 * guest R13 saved in SPRN_SCRATCH0
 	 */
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 	std	r9,HSTATE_SCRATCH2(r13)
 	lbz	r9,HSTATE_IN_GUEST(r13)
+	cmpwi	r9,KVM_GUEST_MODE_SKIP
+	beq-	.Lmaybe_skip
+.Lno_skip:
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
 	beq	kvmppc_bad_host_intr
 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
@@ -33,3 +37,48 @@ kvmppc_interrupt:
 #else
 	b	kvmppc_interrupt_pr
 #endif
+
+/*
+ * KVM uses a trick where it is running in MSR[HV]=1 mode in real-mode with the
+ * guest MMU context loaded, and it sets KVM_GUEST_MODE_SKIP and enables
+ * MSR[DR]=1 while leaving MSR[IR]=0, so it continues to fetch HV instructions
+ * but loads and stores will access the guest context. This is used to load
+ * the faulting instruction without walking page tables.
+ *
+ * However the guest context may not be able to translate, or it may cause a
+ * machine check or other issue, which will result in a fault in the host
+ * (even with KVM-HV).
+ *
+ * These faults are caught here and if the fault was (or was likely) due to
+ * that load, then we just return with the PC advanced +4 and skip the load,
+ * which then goes via the slow path.
+ */
+.Lmaybe_skip:
+	cmpwi	r12,BOOK3S_INTERRUPT_MACHINE_CHECK
+	beq	1f
+	cmpwi	r12,BOOK3S_INTERRUPT_DATA_STORAGE
+	beq	1f
+	cmpwi	r12,BOOK3S_INTERRUPT_DATA_SEGMENT
+	beq	1f
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* HSRR interrupts have 2 added to trap vector */
+	cmpwi	r12,BOOK3S_INTERRUPT_H_DATA_STORAGE | 0x2
+	beq	2f
+#endif
+	b	.Lno_skip
+1:	mfspr	r9,SPRN_SRR0
+	addi	r9,r9,4
+	mtspr	SPRN_SRR0,r9
+	ld	r12,HSTATE_SCRATCH0(r13)
+	ld	r9,HSTATE_SCRATCH2(r13)
+	GET_SCRATCH0(r13)
+	RFI_TO_KERNEL
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+2:	mfspr	r9,SPRN_HSRR0
+	addi	r9,r9,4
+	mtspr	SPRN_HSRR0,r9
+	ld	r12,HSTATE_SCRATCH0(r13)
+	ld	r9,HSTATE_SCRATCH2(r13)
+	GET_SCRATCH0(r13)
+	HRFI_TO_KERNEL
+#endif
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 08/37] KVM: PPC: Book3S 64: add hcall interrupt handler
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Add a separate hcall entry point. This can be used to deal with the
different calling convention.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 4 ++--
 arch/powerpc/kvm/book3s_64_entry.S   | 6 +++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index d956dd9ed61f..9ae463e8522b 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1992,13 +1992,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
 	 * outside the head section.
 	 */
-	__LOAD_FAR_HANDLER(r10, kvmppc_interrupt)
+	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
 	mtctr   r10
 	ld	r10,PACA_EXGEN+EX_R10(r13)
 	bctr
 #else
 	ld	r10,PACA_EXGEN+EX_R10(r13)
-	b       kvmppc_interrupt
+	b       kvmppc_hcall
 #endif
 #endif
 
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index c1276f616af4..9572f759255c 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -7,9 +7,13 @@
 #include <asm/reg.h>
 
 /*
- * This is branched to from interrupt handlers in exception-64s.S which set
+ * These are branched to from interrupt handlers in exception-64s.S which set
  * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
  */
+.global	kvmppc_hcall
+.balign IFETCH_ALIGN_BYTES
+kvmppc_hcall:
+
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
 kvmppc_interrupt:
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 08/37] KVM: PPC: Book3S 64: add hcall interrupt handler
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Add a separate hcall entry point. This can be used to deal with the
different calling convention.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 4 ++--
 arch/powerpc/kvm/book3s_64_entry.S   | 6 +++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index d956dd9ed61f..9ae463e8522b 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1992,13 +1992,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
 	 * outside the head section.
 	 */
-	__LOAD_FAR_HANDLER(r10, kvmppc_interrupt)
+	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
 	mtctr   r10
 	ld	r10,PACA_EXGEN+EX_R10(r13)
 	bctr
 #else
 	ld	r10,PACA_EXGEN+EX_R10(r13)
-	b       kvmppc_interrupt
+	b       kvmppc_hcall
 #endif
 #endif
 
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index c1276f616af4..9572f759255c 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -7,9 +7,13 @@
 #include <asm/reg.h>
 
 /*
- * This is branched to from interrupt handlers in exception-64s.S which set
+ * These are branched to from interrupt handlers in exception-64s.S which set
  * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
  */
+.global	kvmppc_hcall
+.balign IFETCH_ALIGN_BYTES
+kvmppc_hcall:
+
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
 kvmppc_interrupt:
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 09/37] KVM: PPC: Book3S 64: Move hcall early register setup to KVM
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

System calls / hcalls have a different calling convention than
other interrupts, so there is code in the KVMTEST to massage these
into the same form as other interrupt handlers.

Move this work into the KVM hcall handler. This means teaching KVM
a little more about the low level interrupt handler setup, PACA save
areas, etc., although that's not obviously worse than the current
approach of coming up with an entirely different interrupt register
/ save convention.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/exception-64s.h | 13 +++++++
 arch/powerpc/kernel/exceptions-64s.S     | 44 ++----------------------
 arch/powerpc/kvm/book3s_64_entry.S       | 17 +++++++++
 3 files changed, 32 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index c1a8aac01cf9..bb6f78fcf981 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -35,6 +35,19 @@
 /* PACA save area size in u64 units (exgen, exmc, etc) */
 #define EX_SIZE		10
 
+/* PACA save area offsets */
+#define EX_R9		0
+#define EX_R10		8
+#define EX_R11		16
+#define EX_R12		24
+#define EX_R13		32
+#define EX_DAR		40
+#define EX_DSISR	48
+#define EX_CCR		52
+#define EX_CFAR		56
+#define EX_PPR		64
+#define EX_CTR		72
+
 /*
  * maximum recursive depth of MCE exceptions
  */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 9ae463e8522b..b7092ba87da8 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -21,22 +21,6 @@
 #include <asm/feature-fixups.h>
 #include <asm/kup.h>
 
-/* PACA save area offsets (exgen, exmc, etc) */
-#define EX_R9		0
-#define EX_R10		8
-#define EX_R11		16
-#define EX_R12		24
-#define EX_R13		32
-#define EX_DAR		40
-#define EX_DSISR	48
-#define EX_CCR		52
-#define EX_CFAR		56
-#define EX_PPR		64
-#define EX_CTR		72
-.if EX_SIZE != 10
-	.error "EX_SIZE is wrong"
-.endif
-
 /*
  * Following are fixed section helper macros.
  *
@@ -1964,45 +1948,21 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 TRAMP_REAL_BEGIN(system_call_kvm)
-	/*
-	 * This is a hcall, so register convention is as above, with these
-	 * differences:
-	 * r13 = PACA
-	 * ctr = orig r13
-	 * orig r10 saved in PACA
-	 */
-	 /*
-	  * Save the PPR (on systems that support it) before changing to
-	  * HMT_MEDIUM. That allows the KVM code to save that value into the
-	  * guest state (it is the guest's PPR value).
-	  */
-BEGIN_FTR_SECTION
-	mfspr	r10,SPRN_PPR
-	std	r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	HMT_MEDIUM
 	mfctr	r10
-	SET_SCRATCH0(r10)
-	mfcr	r10
-	std	r12,HSTATE_SCRATCH0(r13)
-	sldi	r12,r10,32
-	ori	r12,r12,0xc00
+	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
 #ifdef CONFIG_RELOCATABLE
 	/*
-	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
+	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
 	 * outside the head section.
 	 */
 	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
 	mtctr   r10
-	ld	r10,PACA_EXGEN+EX_R10(r13)
 	bctr
 #else
-	ld	r10,PACA_EXGEN+EX_R10(r13)
 	b       kvmppc_hcall
 #endif
 #endif
 
-
 /**
  * Interrupt 0xd00 - Trace Interrupt.
  * This is a synchronous interrupt in response to instruction step or
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 9572f759255c..1c9518ab7d96 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -13,6 +13,23 @@
 .global	kvmppc_hcall
 .balign IFETCH_ALIGN_BYTES
 kvmppc_hcall:
+	/*
+	 * This is a hcall, so register convention is as
+	 * Documentation/powerpc/papr_hcalls.rst, with these additions:
+	 * R13		= PACA
+	 * guest R13 saved in SPRN_SCRATCH0
+	 * R10		= free
+	 */
+BEGIN_FTR_SECTION
+	mfspr	r10,SPRN_PPR
+	std	r10,HSTATE_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	HMT_MEDIUM
+	mfcr	r10
+	std	r12,HSTATE_SCRATCH0(r13)
+	sldi	r12,r10,32
+	ori	r12,r12,0xc00
+	ld	r10,PACA_EXGEN+EX_R10(r13)
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 09/37] KVM: PPC: Book3S 64: Move hcall early register setup to KVM
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

System calls / hcalls have a different calling convention than
other interrupts, so there is code in the KVMTEST to massage these
into the same form as other interrupt handlers.

Move this work into the KVM hcall handler. This means teaching KVM
a little more about the low level interrupt handler setup, PACA save
areas, etc., although that's not obviously worse than the current
approach of coming up with an entirely different interrupt register
/ save convention.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/exception-64s.h | 13 +++++++
 arch/powerpc/kernel/exceptions-64s.S     | 44 ++----------------------
 arch/powerpc/kvm/book3s_64_entry.S       | 17 +++++++++
 3 files changed, 32 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index c1a8aac01cf9..bb6f78fcf981 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -35,6 +35,19 @@
 /* PACA save area size in u64 units (exgen, exmc, etc) */
 #define EX_SIZE		10
 
+/* PACA save area offsets */
+#define EX_R9		0
+#define EX_R10		8
+#define EX_R11		16
+#define EX_R12		24
+#define EX_R13		32
+#define EX_DAR		40
+#define EX_DSISR	48
+#define EX_CCR		52
+#define EX_CFAR		56
+#define EX_PPR		64
+#define EX_CTR		72
+
 /*
  * maximum recursive depth of MCE exceptions
  */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 9ae463e8522b..b7092ba87da8 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -21,22 +21,6 @@
 #include <asm/feature-fixups.h>
 #include <asm/kup.h>
 
-/* PACA save area offsets (exgen, exmc, etc) */
-#define EX_R9		0
-#define EX_R10		8
-#define EX_R11		16
-#define EX_R12		24
-#define EX_R13		32
-#define EX_DAR		40
-#define EX_DSISR	48
-#define EX_CCR		52
-#define EX_CFAR		56
-#define EX_PPR		64
-#define EX_CTR		72
-.if EX_SIZE != 10
-	.error "EX_SIZE is wrong"
-.endif
-
 /*
  * Following are fixed section helper macros.
  *
@@ -1964,45 +1948,21 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 TRAMP_REAL_BEGIN(system_call_kvm)
-	/*
-	 * This is a hcall, so register convention is as above, with these
-	 * differences:
-	 * r13 = PACA
-	 * ctr = orig r13
-	 * orig r10 saved in PACA
-	 */
-	 /*
-	  * Save the PPR (on systems that support it) before changing to
-	  * HMT_MEDIUM. That allows the KVM code to save that value into the
-	  * guest state (it is the guest's PPR value).
-	  */
-BEGIN_FTR_SECTION
-	mfspr	r10,SPRN_PPR
-	std	r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	HMT_MEDIUM
 	mfctr	r10
-	SET_SCRATCH0(r10)
-	mfcr	r10
-	std	r12,HSTATE_SCRATCH0(r13)
-	sldi	r12,r10,32
-	ori	r12,r12,0xc00
+	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
 #ifdef CONFIG_RELOCATABLE
 	/*
-	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
+	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
 	 * outside the head section.
 	 */
 	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
 	mtctr   r10
-	ld	r10,PACA_EXGEN+EX_R10(r13)
 	bctr
 #else
-	ld	r10,PACA_EXGEN+EX_R10(r13)
 	b       kvmppc_hcall
 #endif
 #endif
 
-
 /**
  * Interrupt 0xd00 - Trace Interrupt.
  * This is a synchronous interrupt in response to instruction step or
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 9572f759255c..1c9518ab7d96 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -13,6 +13,23 @@
 .global	kvmppc_hcall
 .balign IFETCH_ALIGN_BYTES
 kvmppc_hcall:
+	/*
+	 * This is a hcall, so register convention is as
+	 * Documentation/powerpc/papr_hcalls.rst, with these additions:
+	 * R13		= PACA
+	 * guest R13 saved in SPRN_SCRATCH0
+	 * R10		= free
+	 */
+BEGIN_FTR_SECTION
+	mfspr	r10,SPRN_PPR
+	std	r10,HSTATE_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	HMT_MEDIUM
+	mfcr	r10
+	std	r12,HSTATE_SCRATCH0(r13)
+	sldi	r12,r10,32
+	ori	r12,r12,0xc00
+	ld	r10,PACA_EXGEN+EX_R10(r13)
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 10/37] KVM: PPC: Book3S 64: Move interrupt early register setup to KVM
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Like the earlier patch for hcalls, KVM interrupt entry requires a
different calling convention than the Linux interrupt handlers
set up. Move the code that converts from one to the other into KVM.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 126 ++++-----------------------
 arch/powerpc/kvm/book3s_64_entry.S   |  34 +++++++-
 2 files changed, 50 insertions(+), 110 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b7092ba87da8..bbda628ab344 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -187,7 +187,6 @@ do_define_int n
 	.endif
 .endm
 
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 /*
  * All interrupts which set HSRR registers, as well as SRESET and MCE and
  * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
@@ -220,54 +219,25 @@ do_define_int n
  * to KVM to handle.
  */
 
-.macro KVMTEST name
+.macro KVMTEST name handler
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 	lbz	r10,HSTATE_IN_GUEST(r13)
 	cmpwi	r10,0
-	bne	\name\()_kvm
-.endm
-
-.macro GEN_KVM name
-	.balign IFETCH_ALIGN_BYTES
-\name\()_kvm:
-
-BEGIN_FTR_SECTION
-	ld	r10,IAREA+EX_CFAR(r13)
-	std	r10,HSTATE_CFAR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
-
-	ld	r10,IAREA+EX_CTR(r13)
-	mtctr	r10
-BEGIN_FTR_SECTION
-	ld	r10,IAREA+EX_PPR(r13)
-	std	r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	ld	r11,IAREA+EX_R11(r13)
-	ld	r12,IAREA+EX_R12(r13)
-	std	r12,HSTATE_SCRATCH0(r13)
-	sldi	r12,r9,32
-	ld	r9,IAREA+EX_R9(r13)
-	ld	r10,IAREA+EX_R10(r13)
 	/* HSRR variants have the 0x2 bit added to their trap number */
 	.if IHSRR_IF_HVMODE
 	BEGIN_FTR_SECTION
-	ori	r12,r12,(IVEC + 0x2)
+	li	r10,(IVEC + 0x2)
 	FTR_SECTION_ELSE
-	ori	r12,r12,(IVEC)
+	li	r10,(IVEC)
 	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
 	.elseif IHSRR
-	ori	r12,r12,(IVEC+ 0x2)
+	li	r10,(IVEC + 0x2)
 	.else
-	ori	r12,r12,(IVEC)
+	li	r10,(IVEC)
 	.endif
-	b	kvmppc_interrupt
-.endm
-
-#else
-.macro KVMTEST name
-.endm
-.macro GEN_KVM name
-.endm
+	bne	\handler
 #endif
+.endm
 
 /*
  * This is the BOOK3S interrupt entry code macro.
@@ -409,7 +379,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 DEFINE_FIXED_SYMBOL(\name\()_common_real)
 \name\()_common_real:
 	.if IKVM_REAL
-		KVMTEST \name
+		KVMTEST \name kvm_interrupt
 	.endif
 
 	ld	r10,PACAKMSR(r13)	/* get MSR value for kernel */
@@ -432,7 +402,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
 DEFINE_FIXED_SYMBOL(\name\()_common_virt)
 \name\()_common_virt:
 	.if IKVM_VIRT
-		KVMTEST \name
+		KVMTEST \name kvm_interrupt
 1:
 	.endif
 	.endif /* IVIRT */
@@ -446,7 +416,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
 DEFINE_FIXED_SYMBOL(\name\()_common_real)
 \name\()_common_real:
 	.if IKVM_REAL
-		KVMTEST \name
+		KVMTEST \name kvm_interrupt
 	.endif
 .endm
 
@@ -967,8 +937,6 @@ EXC_COMMON_BEGIN(system_reset_common)
 	EXCEPTION_RESTORE_REGS
 	RFI_TO_USER_OR_KERNEL
 
-	GEN_KVM system_reset
-
 
 /**
  * Interrupt 0x200 - Machine Check Interrupt (MCE).
@@ -1132,7 +1100,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
 	/*
 	 * Check if we are coming from guest. If yes, then run the normal
 	 * exception handler which will take the
-	 * machine_check_kvm->kvmppc_interrupt branch to deliver the MC event
+	 * machine_check_kvm->kvm_interrupt branch to deliver the MC event
 	 * to guest.
 	 */
 	lbz	r11,HSTATE_IN_GUEST(r13)
@@ -1203,8 +1171,6 @@ EXC_COMMON_BEGIN(machine_check_common)
 	bl	machine_check_exception
 	b	interrupt_return
 
-	GEN_KVM machine_check
-
 
 #ifdef CONFIG_PPC_P7_NAP
 /*
@@ -1339,8 +1305,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	REST_NVGPRS(r1)
 	b	interrupt_return
 
-	GEN_KVM data_access
-
 
 /**
  * Interrupt 0x380 - Data Segment Interrupt (DSLB).
@@ -1390,8 +1354,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	bl	do_bad_slb_fault
 	b	interrupt_return
 
-	GEN_KVM data_access_slb
-
 
 /**
  * Interrupt 0x400 - Instruction Storage Interrupt (ISI).
@@ -1428,8 +1390,6 @@ MMU_FTR_SECTION_ELSE
 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	b	interrupt_return
 
-	GEN_KVM instruction_access
-
 
 /**
  * Interrupt 0x480 - Instruction Segment Interrupt (ISLB).
@@ -1474,8 +1434,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	bl	do_bad_slb_fault
 	b	interrupt_return
 
-	GEN_KVM instruction_access_slb
-
 
 /**
  * Interrupt 0x500 - External Interrupt.
@@ -1521,8 +1479,6 @@ EXC_COMMON_BEGIN(hardware_interrupt_common)
 	bl	do_IRQ
 	b	interrupt_return
 
-	GEN_KVM hardware_interrupt
-
 
 /**
  * Interrupt 0x600 - Alignment Interrupt
@@ -1550,8 +1506,6 @@ EXC_COMMON_BEGIN(alignment_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM alignment
-
 
 /**
  * Interrupt 0x700 - Program Interrupt (program check).
@@ -1659,8 +1613,6 @@ EXC_COMMON_BEGIN(program_check_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM program_check
-
 
 /*
  * Interrupt 0x800 - Floating-Point Unavailable Interrupt.
@@ -1710,8 +1662,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
 	b	interrupt_return
 #endif
 
-	GEN_KVM fp_unavailable
-
 
 /**
  * Interrupt 0x900 - Decrementer Interrupt.
@@ -1751,8 +1701,6 @@ EXC_COMMON_BEGIN(decrementer_common)
 	bl	timer_interrupt
 	b	interrupt_return
 
-	GEN_KVM decrementer
-
 
 /**
  * Interrupt 0x980 - Hypervisor Decrementer Interrupt.
@@ -1798,8 +1746,6 @@ EXC_COMMON_BEGIN(hdecrementer_common)
 	ld	r13,PACA_EXGEN+EX_R13(r13)
 	HRFI_TO_KERNEL
 
-	GEN_KVM hdecrementer
-
 
 /**
  * Interrupt 0xa00 - Directed Privileged Doorbell Interrupt.
@@ -1840,8 +1786,6 @@ EXC_COMMON_BEGIN(doorbell_super_common)
 #endif
 	b	interrupt_return
 
-	GEN_KVM doorbell_super
-
 
 EXC_REAL_NONE(0xb00, 0x100)
 EXC_VIRT_NONE(0x4b00, 0x100)
@@ -1891,7 +1835,7 @@ INT_DEFINE_END(system_call)
 	GET_PACA(r13)
 	std	r10,PACA_EXGEN+EX_R10(r13)
 	INTERRUPT_TO_KERNEL
-	KVMTEST system_call /* uses r10, branch to system_call_kvm */
+	KVMTEST system_call kvm_hcall /* uses r10, branch to kvm_hcall */
 	mfctr	r9
 #else
 	mr	r9,r13
@@ -1947,7 +1891,7 @@ EXC_VIRT_BEGIN(system_call, 0x4c00, 0x100)
 EXC_VIRT_END(system_call, 0x4c00, 0x100)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-TRAMP_REAL_BEGIN(system_call_kvm)
+TRAMP_REAL_BEGIN(kvm_hcall)
 	mfctr	r10
 	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
 #ifdef CONFIG_RELOCATABLE
@@ -1987,8 +1931,6 @@ EXC_COMMON_BEGIN(single_step_common)
 	bl	single_step_exception
 	b	interrupt_return
 
-	GEN_KVM single_step
-
 
 /**
  * Interrupt 0xe00 - Hypervisor Data Storage Interrupt (HDSI).
@@ -2027,8 +1969,6 @@ MMU_FTR_SECTION_ELSE
 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
 	b       interrupt_return
 
-	GEN_KVM h_data_storage
-
 
 /**
  * Interrupt 0xe20 - Hypervisor Instruction Storage Interrupt (HISI).
@@ -2054,8 +1994,6 @@ EXC_COMMON_BEGIN(h_instr_storage_common)
 	bl	unknown_exception
 	b	interrupt_return
 
-	GEN_KVM h_instr_storage
-
 
 /**
  * Interrupt 0xe40 - Hypervisor Emulation Assistance Interrupt.
@@ -2080,8 +2018,6 @@ EXC_COMMON_BEGIN(emulation_assist_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM emulation_assist
-
 
 /**
  * Interrupt 0xe60 - Hypervisor Maintenance Interrupt (HMI).
@@ -2153,8 +2089,6 @@ EXC_COMMON_BEGIN(hmi_exception_early_common)
 	EXCEPTION_RESTORE_REGS hsrr=1
 	GEN_INT_ENTRY hmi_exception, virt=0
 
-	GEN_KVM hmi_exception_early
-
 EXC_COMMON_BEGIN(hmi_exception_common)
 	GEN_COMMON hmi_exception
 	FINISH_NAP
@@ -2162,8 +2096,6 @@ EXC_COMMON_BEGIN(hmi_exception_common)
 	bl	handle_hmi_exception
 	b	interrupt_return
 
-	GEN_KVM hmi_exception
-
 
 /**
  * Interrupt 0xe80 - Directed Hypervisor Doorbell Interrupt.
@@ -2195,8 +2127,6 @@ EXC_COMMON_BEGIN(h_doorbell_common)
 #endif
 	b	interrupt_return
 
-	GEN_KVM h_doorbell
-
 
 /**
  * Interrupt 0xea0 - Hypervisor Virtualization Interrupt.
@@ -2224,8 +2154,6 @@ EXC_COMMON_BEGIN(h_virt_irq_common)
 	bl	do_IRQ
 	b	interrupt_return
 
-	GEN_KVM h_virt_irq
-
 
 EXC_REAL_NONE(0xec0, 0x20)
 EXC_VIRT_NONE(0x4ec0, 0x20)
@@ -2270,8 +2198,6 @@ EXC_COMMON_BEGIN(performance_monitor_common)
 	bl	performance_monitor_exception
 	b	interrupt_return
 
-	GEN_KVM performance_monitor
-
 
 /**
  * Interrupt 0xf20 - Vector Unavailable Interrupt.
@@ -2321,8 +2247,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	bl	altivec_unavailable_exception
 	b	interrupt_return
 
-	GEN_KVM altivec_unavailable
-
 
 /**
  * Interrupt 0xf40 - VSX Unavailable Interrupt.
@@ -2371,8 +2295,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	bl	vsx_unavailable_exception
 	b	interrupt_return
 
-	GEN_KVM vsx_unavailable
-
 
 /**
  * Interrupt 0xf60 - Facility Unavailable Interrupt.
@@ -2401,8 +2323,6 @@ EXC_COMMON_BEGIN(facility_unavailable_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM facility_unavailable
-
 
 /**
  * Interrupt 0xf60 - Hypervisor Facility Unavailable Interrupt.
@@ -2431,8 +2351,6 @@ EXC_COMMON_BEGIN(h_facility_unavailable_common)
 	REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
 	b	interrupt_return
 
-	GEN_KVM h_facility_unavailable
-
 
 EXC_REAL_NONE(0xfa0, 0x20)
 EXC_VIRT_NONE(0x4fa0, 0x20)
@@ -2462,8 +2380,6 @@ EXC_COMMON_BEGIN(cbe_system_error_common)
 	bl	cbe_system_error_exception
 	b	interrupt_return
 
-	GEN_KVM cbe_system_error
-
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1200, 0x100)
 EXC_VIRT_NONE(0x5200, 0x100)
@@ -2489,8 +2405,6 @@ EXC_COMMON_BEGIN(instruction_breakpoint_common)
 	bl	instruction_breakpoint_exception
 	b	interrupt_return
 
-	GEN_KVM instruction_breakpoint
-
 
 EXC_REAL_NONE(0x1400, 0x100)
 EXC_VIRT_NONE(0x5400, 0x100)
@@ -2611,8 +2525,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
 	bl	unknown_exception
 	b	interrupt_return
 
-	GEN_KVM denorm_exception
-
 
 #ifdef CONFIG_CBE_RAS
 INT_DEFINE_BEGIN(cbe_maintenance)
@@ -2630,8 +2542,6 @@ EXC_COMMON_BEGIN(cbe_maintenance_common)
 	bl	cbe_maintenance_exception
 	b	interrupt_return
 
-	GEN_KVM cbe_maintenance
-
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1600, 0x100)
 EXC_VIRT_NONE(0x5600, 0x100)
@@ -2662,8 +2572,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
 #endif
 	b	interrupt_return
 
-	GEN_KVM altivec_assist
-
 
 #ifdef CONFIG_CBE_RAS
 INT_DEFINE_BEGIN(cbe_thermal)
@@ -2681,8 +2589,6 @@ EXC_COMMON_BEGIN(cbe_thermal_common)
 	bl	cbe_thermal_exception
 	b	interrupt_return
 
-	GEN_KVM cbe_thermal
-
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1800, 0x100)
 EXC_VIRT_NONE(0x5800, 0x100)
@@ -2935,6 +2841,10 @@ TRAMP_REAL_BEGIN(rfscv_flush_fallback)
 
 USE_TEXT_SECTION()
 
+	/* conditional branch in KVMTEST can't reach all the way, make a stub */
+kvm_interrupt:
+	b	kvmppc_interrupt
+
 _GLOBAL(do_uaccess_flush)
 	UACCESS_FLUSH_FIXUP_SECTION
 	nop
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 1c9518ab7d96..4603c0709ae3 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -30,15 +30,45 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	sldi	r12,r10,32
 	ori	r12,r12,0xc00
 	ld	r10,PACA_EXGEN+EX_R10(r13)
+	b	do_kvm_interrupt
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
 kvmppc_interrupt:
+	li	r11,PACA_EXGEN
+	cmpdi	r10,0x200
+	bgt+	1f
+	li	r11,PACA_EXMC
+	beq	1f
+	li	r11,PACA_EXNMI
+1:	add	r11,r11,r13
+
+BEGIN_FTR_SECTION
+	ld	r12,EX_CFAR(r11)
+	std	r12,HSTATE_CFAR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+	ld	r12,EX_CTR(r11)
+	mtctr	r12
+BEGIN_FTR_SECTION
+	ld	r12,EX_PPR(r11)
+	std	r12,HSTATE_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	ld	r12,EX_R12(r11)
+	std	r12,HSTATE_SCRATCH0(r13)
+	sldi	r12,r9,32
+	or	r12,r12,r10
+	ld	r9,EX_R9(r11)
+	ld	r10,EX_R10(r11)
+	ld	r11,EX_R11(r11)
+
+do_kvm_interrupt:
 	/*
-	 * Register contents:
+	 * Hcalls and other interrupts come here after normalising register
+	 * contents and save locations:
+	 *
 	 * R12		= (guest CR << 32) | interrupt vector
 	 * R13		= PACA
-	 * guest R12 saved in shadow VCPU SCRATCH0
+	 * guest R12 saved in shadow HSTATE_SCRATCH0
 	 * guest R13 saved in SPRN_SCRATCH0
 	 */
 	std	r9,HSTATE_SCRATCH2(r13)
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 10/37] KVM: PPC: Book3S 64: Move interrupt early register setup to KVM
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Like the earlier patch for hcalls, KVM interrupt entry requires a
different calling convention than the Linux interrupt handlers
set up. Move the code that converts from one to the other into KVM.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 126 ++++-----------------------
 arch/powerpc/kvm/book3s_64_entry.S   |  34 +++++++-
 2 files changed, 50 insertions(+), 110 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b7092ba87da8..bbda628ab344 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -187,7 +187,6 @@ do_define_int n
 	.endif
 .endm
 
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 /*
  * All interrupts which set HSRR registers, as well as SRESET and MCE and
  * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
@@ -220,54 +219,25 @@ do_define_int n
  * to KVM to handle.
  */
 
-.macro KVMTEST name
+.macro KVMTEST name handler
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 	lbz	r10,HSTATE_IN_GUEST(r13)
 	cmpwi	r10,0
-	bne	\name\()_kvm
-.endm
-
-.macro GEN_KVM name
-	.balign IFETCH_ALIGN_BYTES
-\name\()_kvm:
-
-BEGIN_FTR_SECTION
-	ld	r10,IAREA+EX_CFAR(r13)
-	std	r10,HSTATE_CFAR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
-
-	ld	r10,IAREA+EX_CTR(r13)
-	mtctr	r10
-BEGIN_FTR_SECTION
-	ld	r10,IAREA+EX_PPR(r13)
-	std	r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	ld	r11,IAREA+EX_R11(r13)
-	ld	r12,IAREA+EX_R12(r13)
-	std	r12,HSTATE_SCRATCH0(r13)
-	sldi	r12,r9,32
-	ld	r9,IAREA+EX_R9(r13)
-	ld	r10,IAREA+EX_R10(r13)
 	/* HSRR variants have the 0x2 bit added to their trap number */
 	.if IHSRR_IF_HVMODE
 	BEGIN_FTR_SECTION
-	ori	r12,r12,(IVEC + 0x2)
+	li	r10,(IVEC + 0x2)
 	FTR_SECTION_ELSE
-	ori	r12,r12,(IVEC)
+	li	r10,(IVEC)
 	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
 	.elseif IHSRR
-	ori	r12,r12,(IVEC+ 0x2)
+	li	r10,(IVEC + 0x2)
 	.else
-	ori	r12,r12,(IVEC)
+	li	r10,(IVEC)
 	.endif
-	b	kvmppc_interrupt
-.endm
-
-#else
-.macro KVMTEST name
-.endm
-.macro GEN_KVM name
-.endm
+	bne	\handler
 #endif
+.endm
 
 /*
  * This is the BOOK3S interrupt entry code macro.
@@ -409,7 +379,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 DEFINE_FIXED_SYMBOL(\name\()_common_real)
 \name\()_common_real:
 	.if IKVM_REAL
-		KVMTEST \name
+		KVMTEST \name kvm_interrupt
 	.endif
 
 	ld	r10,PACAKMSR(r13)	/* get MSR value for kernel */
@@ -432,7 +402,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
 DEFINE_FIXED_SYMBOL(\name\()_common_virt)
 \name\()_common_virt:
 	.if IKVM_VIRT
-		KVMTEST \name
+		KVMTEST \name kvm_interrupt
 1:
 	.endif
 	.endif /* IVIRT */
@@ -446,7 +416,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
 DEFINE_FIXED_SYMBOL(\name\()_common_real)
 \name\()_common_real:
 	.if IKVM_REAL
-		KVMTEST \name
+		KVMTEST \name kvm_interrupt
 	.endif
 .endm
 
@@ -967,8 +937,6 @@ EXC_COMMON_BEGIN(system_reset_common)
 	EXCEPTION_RESTORE_REGS
 	RFI_TO_USER_OR_KERNEL
 
-	GEN_KVM system_reset
-
 
 /**
  * Interrupt 0x200 - Machine Check Interrupt (MCE).
@@ -1132,7 +1100,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
 	/*
 	 * Check if we are coming from guest. If yes, then run the normal
 	 * exception handler which will take the
-	 * machine_check_kvm->kvmppc_interrupt branch to deliver the MC event
+	 * machine_check_kvm->kvm_interrupt branch to deliver the MC event
 	 * to guest.
 	 */
 	lbz	r11,HSTATE_IN_GUEST(r13)
@@ -1203,8 +1171,6 @@ EXC_COMMON_BEGIN(machine_check_common)
 	bl	machine_check_exception
 	b	interrupt_return
 
-	GEN_KVM machine_check
-
 
 #ifdef CONFIG_PPC_P7_NAP
 /*
@@ -1339,8 +1305,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	REST_NVGPRS(r1)
 	b	interrupt_return
 
-	GEN_KVM data_access
-
 
 /**
  * Interrupt 0x380 - Data Segment Interrupt (DSLB).
@@ -1390,8 +1354,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	bl	do_bad_slb_fault
 	b	interrupt_return
 
-	GEN_KVM data_access_slb
-
 
 /**
  * Interrupt 0x400 - Instruction Storage Interrupt (ISI).
@@ -1428,8 +1390,6 @@ MMU_FTR_SECTION_ELSE
 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	b	interrupt_return
 
-	GEN_KVM instruction_access
-
 
 /**
  * Interrupt 0x480 - Instruction Segment Interrupt (ISLB).
@@ -1474,8 +1434,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	bl	do_bad_slb_fault
 	b	interrupt_return
 
-	GEN_KVM instruction_access_slb
-
 
 /**
  * Interrupt 0x500 - External Interrupt.
@@ -1521,8 +1479,6 @@ EXC_COMMON_BEGIN(hardware_interrupt_common)
 	bl	do_IRQ
 	b	interrupt_return
 
-	GEN_KVM hardware_interrupt
-
 
 /**
  * Interrupt 0x600 - Alignment Interrupt
@@ -1550,8 +1506,6 @@ EXC_COMMON_BEGIN(alignment_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM alignment
-
 
 /**
  * Interrupt 0x700 - Program Interrupt (program check).
@@ -1659,8 +1613,6 @@ EXC_COMMON_BEGIN(program_check_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM program_check
-
 
 /*
  * Interrupt 0x800 - Floating-Point Unavailable Interrupt.
@@ -1710,8 +1662,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
 	b	interrupt_return
 #endif
 
-	GEN_KVM fp_unavailable
-
 
 /**
  * Interrupt 0x900 - Decrementer Interrupt.
@@ -1751,8 +1701,6 @@ EXC_COMMON_BEGIN(decrementer_common)
 	bl	timer_interrupt
 	b	interrupt_return
 
-	GEN_KVM decrementer
-
 
 /**
  * Interrupt 0x980 - Hypervisor Decrementer Interrupt.
@@ -1798,8 +1746,6 @@ EXC_COMMON_BEGIN(hdecrementer_common)
 	ld	r13,PACA_EXGEN+EX_R13(r13)
 	HRFI_TO_KERNEL
 
-	GEN_KVM hdecrementer
-
 
 /**
  * Interrupt 0xa00 - Directed Privileged Doorbell Interrupt.
@@ -1840,8 +1786,6 @@ EXC_COMMON_BEGIN(doorbell_super_common)
 #endif
 	b	interrupt_return
 
-	GEN_KVM doorbell_super
-
 
 EXC_REAL_NONE(0xb00, 0x100)
 EXC_VIRT_NONE(0x4b00, 0x100)
@@ -1891,7 +1835,7 @@ INT_DEFINE_END(system_call)
 	GET_PACA(r13)
 	std	r10,PACA_EXGEN+EX_R10(r13)
 	INTERRUPT_TO_KERNEL
-	KVMTEST system_call /* uses r10, branch to system_call_kvm */
+	KVMTEST system_call kvm_hcall /* uses r10, branch to kvm_hcall */
 	mfctr	r9
 #else
 	mr	r9,r13
@@ -1947,7 +1891,7 @@ EXC_VIRT_BEGIN(system_call, 0x4c00, 0x100)
 EXC_VIRT_END(system_call, 0x4c00, 0x100)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-TRAMP_REAL_BEGIN(system_call_kvm)
+TRAMP_REAL_BEGIN(kvm_hcall)
 	mfctr	r10
 	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
 #ifdef CONFIG_RELOCATABLE
@@ -1987,8 +1931,6 @@ EXC_COMMON_BEGIN(single_step_common)
 	bl	single_step_exception
 	b	interrupt_return
 
-	GEN_KVM single_step
-
 
 /**
  * Interrupt 0xe00 - Hypervisor Data Storage Interrupt (HDSI).
@@ -2027,8 +1969,6 @@ MMU_FTR_SECTION_ELSE
 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
 	b       interrupt_return
 
-	GEN_KVM h_data_storage
-
 
 /**
  * Interrupt 0xe20 - Hypervisor Instruction Storage Interrupt (HISI).
@@ -2054,8 +1994,6 @@ EXC_COMMON_BEGIN(h_instr_storage_common)
 	bl	unknown_exception
 	b	interrupt_return
 
-	GEN_KVM h_instr_storage
-
 
 /**
  * Interrupt 0xe40 - Hypervisor Emulation Assistance Interrupt.
@@ -2080,8 +2018,6 @@ EXC_COMMON_BEGIN(emulation_assist_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM emulation_assist
-
 
 /**
  * Interrupt 0xe60 - Hypervisor Maintenance Interrupt (HMI).
@@ -2153,8 +2089,6 @@ EXC_COMMON_BEGIN(hmi_exception_early_common)
 	EXCEPTION_RESTORE_REGS hsrr=1
 	GEN_INT_ENTRY hmi_exception, virt=0
 
-	GEN_KVM hmi_exception_early
-
 EXC_COMMON_BEGIN(hmi_exception_common)
 	GEN_COMMON hmi_exception
 	FINISH_NAP
@@ -2162,8 +2096,6 @@ EXC_COMMON_BEGIN(hmi_exception_common)
 	bl	handle_hmi_exception
 	b	interrupt_return
 
-	GEN_KVM hmi_exception
-
 
 /**
  * Interrupt 0xe80 - Directed Hypervisor Doorbell Interrupt.
@@ -2195,8 +2127,6 @@ EXC_COMMON_BEGIN(h_doorbell_common)
 #endif
 	b	interrupt_return
 
-	GEN_KVM h_doorbell
-
 
 /**
  * Interrupt 0xea0 - Hypervisor Virtualization Interrupt.
@@ -2224,8 +2154,6 @@ EXC_COMMON_BEGIN(h_virt_irq_common)
 	bl	do_IRQ
 	b	interrupt_return
 
-	GEN_KVM h_virt_irq
-
 
 EXC_REAL_NONE(0xec0, 0x20)
 EXC_VIRT_NONE(0x4ec0, 0x20)
@@ -2270,8 +2198,6 @@ EXC_COMMON_BEGIN(performance_monitor_common)
 	bl	performance_monitor_exception
 	b	interrupt_return
 
-	GEN_KVM performance_monitor
-
 
 /**
  * Interrupt 0xf20 - Vector Unavailable Interrupt.
@@ -2321,8 +2247,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	bl	altivec_unavailable_exception
 	b	interrupt_return
 
-	GEN_KVM altivec_unavailable
-
 
 /**
  * Interrupt 0xf40 - VSX Unavailable Interrupt.
@@ -2371,8 +2295,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	bl	vsx_unavailable_exception
 	b	interrupt_return
 
-	GEN_KVM vsx_unavailable
-
 
 /**
  * Interrupt 0xf60 - Facility Unavailable Interrupt.
@@ -2401,8 +2323,6 @@ EXC_COMMON_BEGIN(facility_unavailable_common)
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return
 
-	GEN_KVM facility_unavailable
-
 
 /**
  * Interrupt 0xf60 - Hypervisor Facility Unavailable Interrupt.
@@ -2431,8 +2351,6 @@ EXC_COMMON_BEGIN(h_facility_unavailable_common)
 	REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
 	b	interrupt_return
 
-	GEN_KVM h_facility_unavailable
-
 
 EXC_REAL_NONE(0xfa0, 0x20)
 EXC_VIRT_NONE(0x4fa0, 0x20)
@@ -2462,8 +2380,6 @@ EXC_COMMON_BEGIN(cbe_system_error_common)
 	bl	cbe_system_error_exception
 	b	interrupt_return
 
-	GEN_KVM cbe_system_error
-
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1200, 0x100)
 EXC_VIRT_NONE(0x5200, 0x100)
@@ -2489,8 +2405,6 @@ EXC_COMMON_BEGIN(instruction_breakpoint_common)
 	bl	instruction_breakpoint_exception
 	b	interrupt_return
 
-	GEN_KVM instruction_breakpoint
-
 
 EXC_REAL_NONE(0x1400, 0x100)
 EXC_VIRT_NONE(0x5400, 0x100)
@@ -2611,8 +2525,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
 	bl	unknown_exception
 	b	interrupt_return
 
-	GEN_KVM denorm_exception
-
 
 #ifdef CONFIG_CBE_RAS
 INT_DEFINE_BEGIN(cbe_maintenance)
@@ -2630,8 +2542,6 @@ EXC_COMMON_BEGIN(cbe_maintenance_common)
 	bl	cbe_maintenance_exception
 	b	interrupt_return
 
-	GEN_KVM cbe_maintenance
-
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1600, 0x100)
 EXC_VIRT_NONE(0x5600, 0x100)
@@ -2662,8 +2572,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
 #endif
 	b	interrupt_return
 
-	GEN_KVM altivec_assist
-
 
 #ifdef CONFIG_CBE_RAS
 INT_DEFINE_BEGIN(cbe_thermal)
@@ -2681,8 +2589,6 @@ EXC_COMMON_BEGIN(cbe_thermal_common)
 	bl	cbe_thermal_exception
 	b	interrupt_return
 
-	GEN_KVM cbe_thermal
-
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1800, 0x100)
 EXC_VIRT_NONE(0x5800, 0x100)
@@ -2935,6 +2841,10 @@ TRAMP_REAL_BEGIN(rfscv_flush_fallback)
 
 USE_TEXT_SECTION()
 
+	/* conditional branch in KVMTEST can't reach all the way, make a stub */
+kvm_interrupt:
+	b	kvmppc_interrupt
+
 _GLOBAL(do_uaccess_flush)
 	UACCESS_FLUSH_FIXUP_SECTION
 	nop
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 1c9518ab7d96..4603c0709ae3 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -30,15 +30,45 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	sldi	r12,r10,32
 	ori	r12,r12,0xc00
 	ld	r10,PACA_EXGEN+EX_R10(r13)
+	b	do_kvm_interrupt
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
 kvmppc_interrupt:
+	li	r11,PACA_EXGEN
+	cmpdi	r10,0x200
+	bgt+	1f
+	li	r11,PACA_EXMC
+	beq	1f
+	li	r11,PACA_EXNMI
+1:	add	r11,r11,r13
+
+BEGIN_FTR_SECTION
+	ld	r12,EX_CFAR(r11)
+	std	r12,HSTATE_CFAR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+	ld	r12,EX_CTR(r11)
+	mtctr	r12
+BEGIN_FTR_SECTION
+	ld	r12,EX_PPR(r11)
+	std	r12,HSTATE_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	ld	r12,EX_R12(r11)
+	std	r12,HSTATE_SCRATCH0(r13)
+	sldi	r12,r9,32
+	or	r12,r12,r10
+	ld	r9,EX_R9(r11)
+	ld	r10,EX_R10(r11)
+	ld	r11,EX_R11(r11)
+
+do_kvm_interrupt:
 	/*
-	 * Register contents:
+	 * Hcalls and other interrupts come here after normalising register
+	 * contents and save locations:
+	 *
 	 * R12		= (guest CR << 32) | interrupt vector
 	 * R13		= PACA
-	 * guest R12 saved in shadow VCPU SCRATCH0
+	 * guest R12 saved in shadow HSTATE_SCRATCH0
 	 * guest R13 saved in SPRN_SCRATCH0
 	 */
 	std	r9,HSTATE_SCRATCH2(r13)
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 11/37] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is not used by PR KVM.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_64_entry.S      | 3 ---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 +++-
 arch/powerpc/kvm/book3s_segment.S       | 7 +++++++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 4603c0709ae3..75accb1321c9 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -77,11 +77,8 @@ do_kvm_interrupt:
 	beq-	.Lmaybe_skip
 .Lno_skip:
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
-	beq	kvmppc_bad_host_intr
 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
 	cmpwi	r9,KVM_GUEST_MODE_GUEST
-	ld	r9,HSTATE_SCRATCH2(r13)
 	beq	kvmppc_interrupt_pr
 #endif
 	b	kvmppc_interrupt_hv
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index f976efb7e4a9..75405ef53238 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1265,6 +1265,7 @@ hdec_soon:
 kvmppc_interrupt_hv:
 	/*
 	 * Register contents:
+	 * R9		= HSTATE_IN_GUEST
 	 * R12		= (guest CR << 32) | interrupt vector
 	 * R13		= PACA
 	 * guest R12 saved in shadow VCPU SCRATCH0
@@ -1272,6 +1273,8 @@ kvmppc_interrupt_hv:
 	 * guest R9 saved in HSTATE_SCRATCH2
 	 */
 	/* We're now back in the host but in guest MMU context */
+	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
+	beq	kvmppc_bad_host_intr
 	li	r9, KVM_GUEST_MODE_HOST_HV
 	stb	r9, HSTATE_IN_GUEST(r13)
 
@@ -3272,7 +3275,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
  * cfar is saved in HSTATE_CFAR(r13)
  * ppr is saved in HSTATE_PPR(r13)
  */
-.global kvmppc_bad_host_intr
 kvmppc_bad_host_intr:
 	/*
 	 * Switch to the emergency stack, but start half-way down in
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index 1f492aa4c8d6..ef1d88b869bf 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -167,8 +167,15 @@ kvmppc_interrupt_pr:
 	 * R12             = (guest CR << 32) | exit handler id
 	 * R13             = PACA
 	 * HSTATE.SCRATCH0 = guest R12
+	 *
+	 * If HV is possible, additionally:
+	 * R9              = HSTATE_IN_GUEST
+	 * HSTATE.SCRATCH2 = guest R9
 	 */
 #ifdef CONFIG_PPC64
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	ld	r9,HSTATE_SCRATCH2(r13)
+#endif
 	/* Match 32-bit entry */
 	rotldi	r12, r12, 32		  /* Flip R12 halves for stw */
 	stw	r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 11/37] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is not used by PR KVM.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_64_entry.S      | 3 ---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 +++-
 arch/powerpc/kvm/book3s_segment.S       | 7 +++++++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 4603c0709ae3..75accb1321c9 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -77,11 +77,8 @@ do_kvm_interrupt:
 	beq-	.Lmaybe_skip
 .Lno_skip:
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
-	beq	kvmppc_bad_host_intr
 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
 	cmpwi	r9,KVM_GUEST_MODE_GUEST
-	ld	r9,HSTATE_SCRATCH2(r13)
 	beq	kvmppc_interrupt_pr
 #endif
 	b	kvmppc_interrupt_hv
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index f976efb7e4a9..75405ef53238 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1265,6 +1265,7 @@ hdec_soon:
 kvmppc_interrupt_hv:
 	/*
 	 * Register contents:
+	 * R9		= HSTATE_IN_GUEST
 	 * R12		= (guest CR << 32) | interrupt vector
 	 * R13		= PACA
 	 * guest R12 saved in shadow VCPU SCRATCH0
@@ -1272,6 +1273,8 @@ kvmppc_interrupt_hv:
 	 * guest R9 saved in HSTATE_SCRATCH2
 	 */
 	/* We're now back in the host but in guest MMU context */
+	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
+	beq	kvmppc_bad_host_intr
 	li	r9, KVM_GUEST_MODE_HOST_HV
 	stb	r9, HSTATE_IN_GUEST(r13)
 
@@ -3272,7 +3275,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
  * cfar is saved in HSTATE_CFAR(r13)
  * ppr is saved in HSTATE_PPR(r13)
  */
-.global kvmppc_bad_host_intr
 kvmppc_bad_host_intr:
 	/*
 	 * Switch to the emergency stack, but start half-way down in
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index 1f492aa4c8d6..ef1d88b869bf 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -167,8 +167,15 @@ kvmppc_interrupt_pr:
 	 * R12             = (guest CR << 32) | exit handler id
 	 * R13             = PACA
 	 * HSTATE.SCRATCH0 = guest R12
+	 *
+	 * If HV is possible, additionally:
+	 * R9              = HSTATE_IN_GUEST
+	 * HSTATE.SCRATCH2 = guest R9
 	 */
 #ifdef CONFIG_PPC64
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	ld	r9,HSTATE_SCRATCH2(r13)
+#endif
 	/* Match 32-bit entry */
 	rotldi	r12, r12, 32		  /* Flip R12 halves for stw */
 	stw	r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 12/37] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This sets up the same calling convention from interrupt entry to
KVM interrupt handler for system calls as exists for other interrupt
types.

This is a better API, it uses a save area rather than SPR, and it has
more registers free to use. Using a single common API helps maintain
it, and it becomes easier to use in C in a later patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 16 +++++++++++++++-
 arch/powerpc/kvm/book3s_64_entry.S   | 22 +++-------------------
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index bbda628ab344..dcd71d9e7913 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1892,8 +1892,22 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 TRAMP_REAL_BEGIN(kvm_hcall)
+	std	r9,PACA_EXGEN+EX_R9(r13)
+	std	r11,PACA_EXGEN+EX_R11(r13)
+	std	r12,PACA_EXGEN+EX_R12(r13)
+	mfcr	r9
 	mfctr	r10
-	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
+	std	r10,PACA_EXGEN+EX_R13(r13)
+	li	r10,0
+	std	r10,PACA_EXGEN+EX_CFAR(r13)
+	std	r10,PACA_EXGEN+EX_CTR(r13)
+BEGIN_FTR_SECTION
+	mfspr	r10,SPRN_PPR
+	std	r10,PACA_EXGEN+EX_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	HMT_MEDIUM
+
 #ifdef CONFIG_RELOCATABLE
 	/*
 	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 75accb1321c9..f826c8dc2e19 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -13,24 +13,9 @@
 .global	kvmppc_hcall
 .balign IFETCH_ALIGN_BYTES
 kvmppc_hcall:
-	/*
-	 * This is a hcall, so register convention is as
-	 * Documentation/powerpc/papr_hcalls.rst, with these additions:
-	 * R13		= PACA
-	 * guest R13 saved in SPRN_SCRATCH0
-	 * R10		= free
-	 */
-BEGIN_FTR_SECTION
-	mfspr	r10,SPRN_PPR
-	std	r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	HMT_MEDIUM
-	mfcr	r10
-	std	r12,HSTATE_SCRATCH0(r13)
-	sldi	r12,r10,32
-	ori	r12,r12,0xc00
-	ld	r10,PACA_EXGEN+EX_R10(r13)
-	b	do_kvm_interrupt
+	ld	r10,PACA_EXGEN+EX_R13(r13)
+	SET_SCRATCH0(r10)
+	li	r10,0xc00
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
@@ -61,7 +46,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ld	r10,EX_R10(r11)
 	ld	r11,EX_R11(r11)
 
-do_kvm_interrupt:
 	/*
 	 * Hcalls and other interrupts come here after normalising register
 	 * contents and save locations:
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 12/37] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This sets up the same calling convention from interrupt entry to
KVM interrupt handler for system calls as exists for other interrupt
types.

This is a better API, it uses a save area rather than SPR, and it has
more registers free to use. Using a single common API helps maintain
it, and it becomes easier to use in C in a later patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 16 +++++++++++++++-
 arch/powerpc/kvm/book3s_64_entry.S   | 22 +++-------------------
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index bbda628ab344..dcd71d9e7913 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1892,8 +1892,22 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 TRAMP_REAL_BEGIN(kvm_hcall)
+	std	r9,PACA_EXGEN+EX_R9(r13)
+	std	r11,PACA_EXGEN+EX_R11(r13)
+	std	r12,PACA_EXGEN+EX_R12(r13)
+	mfcr	r9
 	mfctr	r10
-	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
+	std	r10,PACA_EXGEN+EX_R13(r13)
+	li	r10,0
+	std	r10,PACA_EXGEN+EX_CFAR(r13)
+	std	r10,PACA_EXGEN+EX_CTR(r13)
+BEGIN_FTR_SECTION
+	mfspr	r10,SPRN_PPR
+	std	r10,PACA_EXGEN+EX_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	HMT_MEDIUM
+
 #ifdef CONFIG_RELOCATABLE
 	/*
 	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 75accb1321c9..f826c8dc2e19 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -13,24 +13,9 @@
 .global	kvmppc_hcall
 .balign IFETCH_ALIGN_BYTES
 kvmppc_hcall:
-	/*
-	 * This is a hcall, so register convention is as
-	 * Documentation/powerpc/papr_hcalls.rst, with these additions:
-	 * R13		= PACA
-	 * guest R13 saved in SPRN_SCRATCH0
-	 * R10		= free
-	 */
-BEGIN_FTR_SECTION
-	mfspr	r10,SPRN_PPR
-	std	r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	HMT_MEDIUM
-	mfcr	r10
-	std	r12,HSTATE_SCRATCH0(r13)
-	sldi	r12,r10,32
-	ori	r12,r12,0xc00
-	ld	r10,PACA_EXGEN+EX_R10(r13)
-	b	do_kvm_interrupt
+	ld	r10,PACA_EXGEN+EX_R13(r13)
+	SET_SCRATCH0(r10)
+	li	r10,0xc00
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
@@ -61,7 +46,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ld	r10,EX_R10(r11)
 	ld	r11,EX_R11(r11)
 
-do_kvm_interrupt:
 	/*
 	 * Hcalls and other interrupts come here after normalising register
 	 * contents and save locations:
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Switching the MMU from radix<->radix mode is tricky particularly as the
MMU can remain enabled and requires a certain sequence of SPR updates.
Move these together into their own functions.

This also includes the radix TLB check / flush because it's tied in to
MMU switching due to tlbiel getting LPID from LPIDR.

(XXX: isync / hwsync synchronisation TBD)

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 55 +++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 895090636295..23d6dc04b0e9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3440,12 +3440,38 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+
+	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+	isync();
+
+	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
+	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+}
+
+static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+{
+	mtspr(SPRN_PID, pid);
+	mtspr(SPRN_LPID, kvm->arch.host_lpid);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+	isync();
+}
+
 /*
  * Load up hypervisor-mode registers on P9.
  */
 static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 				     unsigned long lpcr)
 {
+	struct kvm *kvm = vcpu->kvm;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	s64 hdec;
 	u64 tb, purr, spurr;
@@ -3468,12 +3494,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
 	 * so set HDICE before writing HDEC.
 	 */
-	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr | LPCR_HDICE);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
 	isync();
 
 	hdec = time_limit - mftb();
 	if (hdec < 0) {
-		mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
+		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
 		isync();
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 	}
@@ -3508,7 +3534,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
 	mtspr(SPRN_IC, vcpu->arch.ic);
-	mtspr(SPRN_PID, vcpu->arch.pid);
 
 	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
 	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
@@ -3522,8 +3547,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	mtspr(SPRN_AMOR, ~0UL);
 
-	mtspr(SPRN_LPCR, lpcr);
-	isync();
+	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
 	kvmppc_xive_push_vcpu(vcpu);
 
@@ -3562,7 +3586,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 		mtspr(SPRN_DAWR1, host_dawr1);
 		mtspr(SPRN_DAWRX1, host_dawrx1);
 	}
-	mtspr(SPRN_PID, host_pidr);
 
 	/*
 	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
@@ -3577,9 +3600,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
 		asm volatile(PPC_CP_ABORT);
 
-	mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid);	/* restore host LPID */
-	isync();
-
 	vc->dpdes = mfspr(SPRN_DPDES);
 	vc->vtb = mfspr(SPRN_VTB);
 	mtspr(SPRN_DPDES, 0);
@@ -3596,7 +3616,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 
 	mtspr(SPRN_HDEC, 0x7fffffff);
-	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
+
+	switch_mmu_to_host_radix(kvm, host_pidr);
 
 	return trap;
 }
@@ -4130,7 +4151,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 {
 	struct kvm_run *run = vcpu->run;
 	int trap, r, pcpu;
-	int srcu_idx, lpid;
+	int srcu_idx;
 	struct kvmppc_vcore *vc;
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
@@ -4204,13 +4225,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->vcore_state = VCORE_RUNNING;
 	trace_kvmppc_run_core(vc, 0);
 
-	if (cpu_has_feature(CPU_FTR_HVMODE)) {
-		lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
-		mtspr(SPRN_LPID, lpid);
-		isync();
-		kvmppc_check_need_tlb_flush(kvm, pcpu, nested);
-	}
-
 	guest_enter_irqoff();
 
 	srcu_idx = srcu_read_lock(&kvm->srcu);
@@ -4229,11 +4243,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	srcu_read_unlock(&kvm->srcu, srcu_idx);
 
-	if (cpu_has_feature(CPU_FTR_HVMODE)) {
-		mtspr(SPRN_LPID, kvm->arch.host_lpid);
-		isync();
-	}
-
 	set_irq_happened(trap);
 
 	kvmppc_set_host_core(pcpu);
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Switching the MMU from radix<->radix mode is tricky particularly as the
MMU can remain enabled and requires a certain sequence of SPR updates.
Move these together into their own functions.

This also includes the radix TLB check / flush because it's tied in to
MMU switching due to tlbiel getting LPID from LPIDR.

(XXX: isync / hwsync synchronisation TBD)

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 55 +++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 895090636295..23d6dc04b0e9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3440,12 +3440,38 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+
+	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+	isync();
+
+	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
+	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+}
+
+static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+{
+	mtspr(SPRN_PID, pid);
+	mtspr(SPRN_LPID, kvm->arch.host_lpid);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+	isync();
+}
+
 /*
  * Load up hypervisor-mode registers on P9.
  */
 static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 				     unsigned long lpcr)
 {
+	struct kvm *kvm = vcpu->kvm;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	s64 hdec;
 	u64 tb, purr, spurr;
@@ -3468,12 +3494,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
 	 * so set HDICE before writing HDEC.
 	 */
-	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr | LPCR_HDICE);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
 	isync();
 
 	hdec = time_limit - mftb();
 	if (hdec < 0) {
-		mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
+		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
 		isync();
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 	}
@@ -3508,7 +3534,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
 	mtspr(SPRN_IC, vcpu->arch.ic);
-	mtspr(SPRN_PID, vcpu->arch.pid);
 
 	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
 	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
@@ -3522,8 +3547,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	mtspr(SPRN_AMOR, ~0UL);
 
-	mtspr(SPRN_LPCR, lpcr);
-	isync();
+	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
 	kvmppc_xive_push_vcpu(vcpu);
 
@@ -3562,7 +3586,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 		mtspr(SPRN_DAWR1, host_dawr1);
 		mtspr(SPRN_DAWRX1, host_dawrx1);
 	}
-	mtspr(SPRN_PID, host_pidr);
 
 	/*
 	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
@@ -3577,9 +3600,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
 		asm volatile(PPC_CP_ABORT);
 
-	mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid);	/* restore host LPID */
-	isync();
-
 	vc->dpdes = mfspr(SPRN_DPDES);
 	vc->vtb = mfspr(SPRN_VTB);
 	mtspr(SPRN_DPDES, 0);
@@ -3596,7 +3616,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 
 	mtspr(SPRN_HDEC, 0x7fffffff);
-	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
+
+	switch_mmu_to_host_radix(kvm, host_pidr);
 
 	return trap;
 }
@@ -4130,7 +4151,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 {
 	struct kvm_run *run = vcpu->run;
 	int trap, r, pcpu;
-	int srcu_idx, lpid;
+	int srcu_idx;
 	struct kvmppc_vcore *vc;
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
@@ -4204,13 +4225,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->vcore_state = VCORE_RUNNING;
 	trace_kvmppc_run_core(vc, 0);
 
-	if (cpu_has_feature(CPU_FTR_HVMODE)) {
-		lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
-		mtspr(SPRN_LPID, lpid);
-		isync();
-		kvmppc_check_need_tlb_flush(kvm, pcpu, nested);
-	}
-
 	guest_enter_irqoff();
 
 	srcu_idx = srcu_read_lock(&kvm->srcu);
@@ -4229,11 +4243,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	srcu_read_unlock(&kvm->srcu, srcu_idx);
 
-	if (cpu_has_feature(CPU_FTR_HVMODE)) {
-		mtspr(SPRN_LPID, kvm->arch.host_lpid);
-		isync();
-	}
-
 	set_irq_happened(trap);
 
 	kvmppc_set_host_core(pcpu);
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 14/37] KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is more symmetric with kvmppc_xive_push_vcpu. The extra test in
the asm will go away in a later change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h      |  2 ++
 arch/powerpc/kvm/book3s_hv.c            |  2 ++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 ++++
 arch/powerpc/kvm/book3s_xive.c          | 34 +++++++++++++++++++++++++
 4 files changed, 43 insertions(+)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 9531b1c1b190..73b1ca5a6471 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -672,6 +672,7 @@ extern int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
 extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
 			       int level, bool line_status);
 extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
+extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 {
@@ -712,6 +713,7 @@ static inline int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval) { retur
 static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
 				      int level, bool line_status) { return -ENODEV; }
 static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
+static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 	{ return 0; }
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 23d6dc04b0e9..e3344d58537d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3556,6 +3556,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	trap = __kvmhv_vcpu_entry_p9(vcpu);
 
+	kvmppc_xive_pull_vcpu(vcpu);
+
 	/* Advance host PURR/SPURR by the amount used by guest */
 	purr = mfspr(SPRN_PURR);
 	spurr = mfspr(SPRN_SPURR);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 75405ef53238..c11597f815e4 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1442,6 +1442,11 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	bl	kvmhv_accumulate_time
 #endif
 #ifdef CONFIG_KVM_XICS
+	/* If we came in through the P9 short path, xive pull is done in C */
+	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
+	cmpwi	r0, 0
+	bne	1f
+
 	/* We are exiting, pull the VP from the XIVE */
 	lbz	r0, VCPU_XIVE_PUSHED(r9)
 	cmpwi	cr0, r0, 0
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index e7219b6f5f9a..8632fb998a55 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -127,6 +127,40 @@ void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvmppc_xive_push_vcpu);
 
+/*
+ * Pull a vcpu's context from the XIVE on guest exit.
+ * This assumes we are in virtual mode (MMU on)
+ */
+void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu)
+{
+	void __iomem *tima = local_paca->kvm_hstate.xive_tima_virt;
+
+	BUG_ON(!(mfmsr() & MSR_IR));
+	BUG_ON(!(mfmsr() & MSR_DR));
+
+	if (!vcpu->arch.xive_pushed)
+		return;
+
+	/*
+	 * Sould not have been pushed if there is no tima
+	 */
+	if (WARN_ON(!tima))
+		return;
+
+	eieio();
+	/* First load to pull the context, we ignore the value */
+	__raw_readl(tima + TM_SPC_PULL_OS_CTX);
+	/* Second load to recover the context state (Words 0 and 1) */
+	vcpu->arch.xive_saved_state.w01 = __raw_readq(tima + TM_QW1_OS);
+
+	/* Fixup some of the state for the next load */
+	vcpu->arch.xive_saved_state.lsmfb = 0;
+	vcpu->arch.xive_saved_state.ack = 0xff;
+	vcpu->arch.xive_pushed = 0;
+	eieio();
+}
+EXPORT_SYMBOL_GPL(kvmppc_xive_pull_vcpu);
+
 /*
  * This is a simple trigger for a generic XIVE IRQ. This must
  * only be called for interrupts that support a trigger page
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 14/37] KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is more symmetric with kvmppc_xive_push_vcpu. The extra test in
the asm will go away in a later change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h      |  2 ++
 arch/powerpc/kvm/book3s_hv.c            |  2 ++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 ++++
 arch/powerpc/kvm/book3s_xive.c          | 34 +++++++++++++++++++++++++
 4 files changed, 43 insertions(+)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 9531b1c1b190..73b1ca5a6471 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -672,6 +672,7 @@ extern int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
 extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
 			       int level, bool line_status);
 extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
+extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 {
@@ -712,6 +713,7 @@ static inline int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval) { retur
 static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
 				      int level, bool line_status) { return -ENODEV; }
 static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
+static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 	{ return 0; }
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 23d6dc04b0e9..e3344d58537d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3556,6 +3556,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	trap = __kvmhv_vcpu_entry_p9(vcpu);
 
+	kvmppc_xive_pull_vcpu(vcpu);
+
 	/* Advance host PURR/SPURR by the amount used by guest */
 	purr = mfspr(SPRN_PURR);
 	spurr = mfspr(SPRN_SPURR);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 75405ef53238..c11597f815e4 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1442,6 +1442,11 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	bl	kvmhv_accumulate_time
 #endif
 #ifdef CONFIG_KVM_XICS
+	/* If we came in through the P9 short path, xive pull is done in C */
+	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
+	cmpwi	r0, 0
+	bne	1f
+
 	/* We are exiting, pull the VP from the XIVE */
 	lbz	r0, VCPU_XIVE_PUSHED(r9)
 	cmpwi	cr0, r0, 0
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index e7219b6f5f9a..8632fb998a55 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -127,6 +127,40 @@ void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvmppc_xive_push_vcpu);
 
+/*
+ * Pull a vcpu's context from the XIVE on guest exit.
+ * This assumes we are in virtual mode (MMU on)
+ */
+void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu)
+{
+	void __iomem *tima = local_paca->kvm_hstate.xive_tima_virt;
+
+	BUG_ON(!(mfmsr() & MSR_IR));
+	BUG_ON(!(mfmsr() & MSR_DR));
+
+	if (!vcpu->arch.xive_pushed)
+		return;
+
+	/*
+	 * Sould not have been pushed if there is no tima
+	 */
+	if (WARN_ON(!tima))
+		return;
+
+	eieio();
+	/* First load to pull the context, we ignore the value */
+	__raw_readl(tima + TM_SPC_PULL_OS_CTX);
+	/* Second load to recover the context state (Words 0 and 1) */
+	vcpu->arch.xive_saved_state.w01 = __raw_readq(tima + TM_QW1_OS);
+
+	/* Fixup some of the state for the next load */
+	vcpu->arch.xive_saved_state.lsmfb = 0;
+	vcpu->arch.xive_saved_state.ack = 0xff;
+	vcpu->arch.xive_pushed = 0;
+	eieio();
+}
+EXPORT_SYMBOL_GPL(kvmppc_xive_pull_vcpu);
+
 /*
  * This is a simple trigger for a generic XIVE IRQ. This must
  * only be called for interrupts that support a trigger page
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 15/37] KVM: PPC: Book3S HV P9: Move xive vcpu context management into kvmhv_p9_guest_entry
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Move the xive management up so the low level register switching can be
pushed further down in a later patch. XIVE MMIO CI operations can run in
higher level code with machine checks, tracing, etc., available.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e3344d58537d..7e23838b7f9b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3549,15 +3549,11 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
-	kvmppc_xive_push_vcpu(vcpu);
-
 	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
 	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
 
 	trap = __kvmhv_vcpu_entry_p9(vcpu);
 
-	kvmppc_xive_pull_vcpu(vcpu);
-
 	/* Advance host PURR/SPURR by the amount used by guest */
 	purr = mfspr(SPRN_PURR);
 	spurr = mfspr(SPRN_SPURR);
@@ -3740,7 +3736,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			trap = 0;
 		}
 	} else {
+		kvmppc_xive_push_vcpu(vcpu);
 		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
+		kvmppc_xive_pull_vcpu(vcpu);
+
 	}
 
 	vcpu->arch.slb_max = 0;
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 15/37] KVM: PPC: Book3S HV P9: Move xive vcpu context management into kvmhv_p9_guest_entry
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Move the xive management up so the low level register switching can be
pushed further down in a later patch. XIVE MMIO CI operations can run in
higher level code with machine checks, tracing, etc., available.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e3344d58537d..7e23838b7f9b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3549,15 +3549,11 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
-	kvmppc_xive_push_vcpu(vcpu);
-
 	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
 	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
 
 	trap = __kvmhv_vcpu_entry_p9(vcpu);
 
-	kvmppc_xive_pull_vcpu(vcpu);
-
 	/* Advance host PURR/SPURR by the amount used by guest */
 	purr = mfspr(SPRN_PURR);
 	spurr = mfspr(SPRN_SPURR);
@@ -3740,7 +3736,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			trap = 0;
 		}
 	} else {
+		kvmppc_xive_push_vcpu(vcpu);
 		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
+		kvmppc_xive_pull_vcpu(vcpu);
+
 	}
 
 	vcpu->arch.slb_max = 0;
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

In the interest of minimising the amount of code that is run in
"real-mode", don't handle hcalls in real mode in the P9 path.

POWER8 and earlier are much more expensive to exit from HV real mode
and switch to host mode, because on those processors HV interrupts get
to the hypervisor with the MMU off, and the other threads in the core
need to be pulled out of the guest, and SLBs all need to be saved,
ERATs invalidated, and host SLB reloaded before the MMU is re-enabled
in host mode. Hash guests also require a lot of hcalls to run. The
XICS interrupt controller requires hcalls to run.

By contrast, POWER9 has independent thread switching, and in radix mode
the hypervisor is already in a host virtual memory mode when the HV
interrupt is taken. Radix + xive guests don't need hcalls to handle
interrupts or manage translations.

So it's much less important to handle hcalls in real mode in P9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h      |  5 +++++
 arch/powerpc/kvm/book3s_hv.c            | 25 ++++++++++++++++++++++---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 +++++
 arch/powerpc/kvm/book3s_xive.c          | 25 +++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 73b1ca5a6471..db6646c2ade2 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -607,6 +607,7 @@ extern void kvmppc_free_pimap(struct kvm *kvm);
 extern int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall);
 extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
 extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
+extern int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req);
 extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
 extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
 extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
@@ -639,6 +640,8 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
 static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
 static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
 	{ return 0; }
+static inline int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
+	{ return 0; }
 #endif
 
 #ifdef CONFIG_KVM_XIVE
@@ -673,6 +676,7 @@ extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
 			       int level, bool line_status);
 extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
 extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
+extern void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu);
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 {
@@ -714,6 +718,7 @@ static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 ir
 				      int level, bool line_status) { return -ENODEV; }
 static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
 static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
+static inline void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu) { }
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 	{ return 0; }
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7e23838b7f9b..d4770b222d7e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1144,7 +1144,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
  * This has to be done early, not in kvmppc_pseries_do_hcall(), so
  * that the cede logic in kvmppc_run_single_vcpu() works properly.
  */
-static void kvmppc_nested_cede(struct kvm_vcpu *vcpu)
+static void kvmppc_cede(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.shregs.msr |= MSR_EE;
 	vcpu->arch.ceded = 1;
@@ -3731,15 +3731,34 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		/* H_CEDE has to be handled now, not later */
 		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
 		    kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
-			kvmppc_nested_cede(vcpu);
+			kvmppc_cede(vcpu);
 			kvmppc_set_gpr(vcpu, 3, 0);
 			trap = 0;
 		}
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
 		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
-		kvmppc_xive_pull_vcpu(vcpu);
+		/* H_CEDE has to be handled now, not later */
+		/* XICS hcalls must be handled before xive is pulled */
+		if (trap == BOOK3S_INTERRUPT_SYSCALL &&
+		    !(vcpu->arch.shregs.msr & MSR_PR)) {
+			unsigned long req = kvmppc_get_gpr(vcpu, 3);
 
+			if (req == H_CEDE) {
+				kvmppc_cede(vcpu);
+				kvmppc_xive_cede_vcpu(vcpu); /* may un-cede */
+				kvmppc_set_gpr(vcpu, 3, 0);
+				trap = 0;
+			}
+			if (req == H_EOI || req == H_CPPR || req == H_IPI ||
+			    req == H_IPOLL || req == H_XIRR || req == H_XIRR_X) {
+				unsigned long ret;
+				ret = kvmppc_xive_xics_hcall(vcpu, req);
+				kvmppc_set_gpr(vcpu, 3, ret);
+				trap = 0;
+			}
+		}
+		kvmppc_xive_pull_vcpu(vcpu);
 	}
 
 	vcpu->arch.slb_max = 0;
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index c11597f815e4..2d0d14ed1d92 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1397,9 +1397,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	mr	r4,r9
 	bge	fast_guest_return
 2:
+	/* If we came in through the P9 short path, no real mode hcalls */
+	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
+	cmpwi	r0, 0
+	bne	no_try_real
 	/* See if this is an hcall we can handle in real mode */
 	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
 	beq	hcall_try_real_mode
+no_try_real:
 
 	/* Hypervisor doorbell - exit only if host IPI flag set */
 	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 8632fb998a55..d2266d36a7c7 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -2109,6 +2109,31 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
 	return 0;
 }
 
+int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+
+	switch (req) {
+	case H_XIRR:
+		return xive_vm_h_xirr(vcpu);
+	case H_CPPR:
+		return xive_vm_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
+	case H_EOI:
+		return xive_vm_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
+	case H_IPI:
+		return xive_vm_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
+					  kvmppc_get_gpr(vcpu, 5));
+	case H_IPOLL:
+		return xive_vm_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
+	case H_XIRR_X:
+		xive_vm_h_xirr(vcpu);
+		kvmppc_set_gpr(vcpu, 5, get_tb() + vc->tb_offset);
+		return H_SUCCESS;
+	}
+
+	return H_UNSUPPORTED;
+}
+
 int kvmppc_xive_debug_show_queues(struct seq_file *m, struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

In the interest of minimising the amount of code that is run in
"real-mode", don't handle hcalls in real mode in the P9 path.

POWER8 and earlier are much more expensive to exit from HV real mode
and switch to host mode, because on those processors HV interrupts get
to the hypervisor with the MMU off, and the other threads in the core
need to be pulled out of the guest, and SLBs all need to be saved,
ERATs invalidated, and host SLB reloaded before the MMU is re-enabled
in host mode. Hash guests also require a lot of hcalls to run. The
XICS interrupt controller requires hcalls to run.

By contrast, POWER9 has independent thread switching, and in radix mode
the hypervisor is already in a host virtual memory mode when the HV
interrupt is taken. Radix + xive guests don't need hcalls to handle
interrupts or manage translations.

So it's much less important to handle hcalls in real mode in P9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h      |  5 +++++
 arch/powerpc/kvm/book3s_hv.c            | 25 ++++++++++++++++++++++---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 +++++
 arch/powerpc/kvm/book3s_xive.c          | 25 +++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 73b1ca5a6471..db6646c2ade2 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -607,6 +607,7 @@ extern void kvmppc_free_pimap(struct kvm *kvm);
 extern int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall);
 extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
 extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
+extern int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req);
 extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
 extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
 extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
@@ -639,6 +640,8 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
 static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
 static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
 	{ return 0; }
+static inline int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
+	{ return 0; }
 #endif
 
 #ifdef CONFIG_KVM_XIVE
@@ -673,6 +676,7 @@ extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
 			       int level, bool line_status);
 extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
 extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
+extern void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu);
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 {
@@ -714,6 +718,7 @@ static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 ir
 				      int level, bool line_status) { return -ENODEV; }
 static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
 static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
+static inline void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu) { }
 
 static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
 	{ return 0; }
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7e23838b7f9b..d4770b222d7e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1144,7 +1144,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
  * This has to be done early, not in kvmppc_pseries_do_hcall(), so
  * that the cede logic in kvmppc_run_single_vcpu() works properly.
  */
-static void kvmppc_nested_cede(struct kvm_vcpu *vcpu)
+static void kvmppc_cede(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.shregs.msr |= MSR_EE;
 	vcpu->arch.ceded = 1;
@@ -3731,15 +3731,34 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		/* H_CEDE has to be handled now, not later */
 		if (trap = BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
 		    kvmppc_get_gpr(vcpu, 3) = H_CEDE) {
-			kvmppc_nested_cede(vcpu);
+			kvmppc_cede(vcpu);
 			kvmppc_set_gpr(vcpu, 3, 0);
 			trap = 0;
 		}
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
 		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
-		kvmppc_xive_pull_vcpu(vcpu);
+		/* H_CEDE has to be handled now, not later */
+		/* XICS hcalls must be handled before xive is pulled */
+		if (trap = BOOK3S_INTERRUPT_SYSCALL &&
+		    !(vcpu->arch.shregs.msr & MSR_PR)) {
+			unsigned long req = kvmppc_get_gpr(vcpu, 3);
 
+			if (req = H_CEDE) {
+				kvmppc_cede(vcpu);
+				kvmppc_xive_cede_vcpu(vcpu); /* may un-cede */
+				kvmppc_set_gpr(vcpu, 3, 0);
+				trap = 0;
+			}
+			if (req = H_EOI || req = H_CPPR || req = H_IPI ||
+			    req = H_IPOLL || req = H_XIRR || req = H_XIRR_X) {
+				unsigned long ret;
+				ret = kvmppc_xive_xics_hcall(vcpu, req);
+				kvmppc_set_gpr(vcpu, 3, ret);
+				trap = 0;
+			}
+		}
+		kvmppc_xive_pull_vcpu(vcpu);
 	}
 
 	vcpu->arch.slb_max = 0;
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index c11597f815e4..2d0d14ed1d92 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1397,9 +1397,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	mr	r4,r9
 	bge	fast_guest_return
 2:
+	/* If we came in through the P9 short path, no real mode hcalls */
+	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
+	cmpwi	r0, 0
+	bne	no_try_real
 	/* See if this is an hcall we can handle in real mode */
 	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
 	beq	hcall_try_real_mode
+no_try_real:
 
 	/* Hypervisor doorbell - exit only if host IPI flag set */
 	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 8632fb998a55..d2266d36a7c7 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -2109,6 +2109,31 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
 	return 0;
 }
 
+int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+
+	switch (req) {
+	case H_XIRR:
+		return xive_vm_h_xirr(vcpu);
+	case H_CPPR:
+		return xive_vm_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
+	case H_EOI:
+		return xive_vm_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
+	case H_IPI:
+		return xive_vm_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
+					  kvmppc_get_gpr(vcpu, 5));
+	case H_IPOLL:
+		return xive_vm_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
+	case H_XIRR_X:
+		xive_vm_h_xirr(vcpu);
+		kvmppc_set_gpr(vcpu, 5, get_tb() + vc->tb_offset);
+		return H_SUCCESS;
+	}
+
+	return H_UNSUPPORTED;
+}
+
 int kvmppc_xive_debug_show_queues(struct seq_file *m, struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
processors, so it must be enabled before HDEC is set.

Rather than set it in the host LPCR then setting HDEC, move the HDEC
update to after the guest MMU context (including LPCR) is loaded.
There shouldn't be much concern with delaying HDEC by some 10s or 100s
of nanoseconds by setting it a bit later.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d4770b222d7e..63cc92c45c5d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3490,23 +3490,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 		host_dawrx1 = mfspr(SPRN_DAWRX1);
 	}
 
-	/*
-	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
-	 * so set HDICE before writing HDEC.
-	 */
-	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
-	isync();
-
-	hdec = time_limit - mftb();
-	if (hdec < 0) {
-		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
-		isync();
+	tb = mftb();
+	hdec = time_limit - tb;
+	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
-	}
-	mtspr(SPRN_HDEC, hdec);
 
 	if (vc->tb_offset) {
-		u64 new_tb = mftb() + vc->tb_offset;
+		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
 		tb = mftb();
 		if ((tb & 0xffffff) < (new_tb & 0xffffff))
@@ -3549,6 +3539,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
+	/*
+	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+	 * so set guest LPCR (with HDICE) before writing HDEC.
+	 */
+	mtspr(SPRN_HDEC, hdec);
+
 	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
 	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
 
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
processors, so it must be enabled before HDEC is set.

Rather than set it in the host LPCR then setting HDEC, move the HDEC
update to after the guest MMU context (including LPCR) is loaded.
There shouldn't be much concern with delaying HDEC by some 10s or 100s
of nanoseconds by setting it a bit later.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d4770b222d7e..63cc92c45c5d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3490,23 +3490,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 		host_dawrx1 = mfspr(SPRN_DAWRX1);
 	}
 
-	/*
-	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
-	 * so set HDICE before writing HDEC.
-	 */
-	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
-	isync();
-
-	hdec = time_limit - mftb();
-	if (hdec < 0) {
-		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
-		isync();
+	tb = mftb();
+	hdec = time_limit - tb;
+	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
-	}
-	mtspr(SPRN_HDEC, hdec);
 
 	if (vc->tb_offset) {
-		u64 new_tb = mftb() + vc->tb_offset;
+		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
 		tb = mftb();
 		if ((tb & 0xffffff) < (new_tb & 0xffffff))
@@ -3549,6 +3539,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
+	/*
+	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+	 * so set guest LPCR (with HDICE) before writing HDEC.
+	 */
+	mtspr(SPRN_HDEC, hdec);
+
 	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
 	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
 
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 18/37] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0,
this could help reduce needless guest exits due to leftover exceptions on
entering the guest.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h | 2 ++
 arch/powerpc/kvm/book3s_hv.c    | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 8dd3cdb25338..68d94711811e 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -18,6 +18,8 @@
 #include <asm/vdso/timebase.h>
 
 /* time.c */
+extern u64 decrementer_max;
+
 extern unsigned long tb_ticks_per_jiffy;
 extern unsigned long tb_ticks_per_usec;
 extern unsigned long tb_ticks_per_sec;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 63cc92c45c5d..913582bd848f 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3609,7 +3609,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 		vc->tb_offset_applied = 0;
 	}
 
-	mtspr(SPRN_HDEC, 0x7fffffff);
+	/* HDEC must be at least as large as DEC, so decrementer_max fits */
+	mtspr(SPRN_HDEC, decrementer_max);
 
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 18/37] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0,
this could help reduce needless guest exits due to leftover exceptions on
entering the guest.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h | 2 ++
 arch/powerpc/kvm/book3s_hv.c    | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 8dd3cdb25338..68d94711811e 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -18,6 +18,8 @@
 #include <asm/vdso/timebase.h>
 
 /* time.c */
+extern u64 decrementer_max;
+
 extern unsigned long tb_ticks_per_jiffy;
 extern unsigned long tb_ticks_per_usec;
 extern unsigned long tb_ticks_per_sec;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 63cc92c45c5d..913582bd848f 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3609,7 +3609,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 		vc->tb_offset_applied = 0;
 	}
 
-	mtspr(SPRN_HDEC, 0x7fffffff);
+	/* HDEC must be at least as large as DEC, so decrementer_max fits */
+	mtspr(SPRN_HDEC, decrementer_max);
 
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 19/37] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

There is no need to save away the host DEC value, as it is derived
from the host timer subsystem, which maintains the next timer time.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h |  5 +++++
 arch/powerpc/kvm/book3s_hv.c    | 12 ++++++------
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 68d94711811e..0128cd9769bc 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -101,6 +101,11 @@ extern void __init time_init(void);
 
 DECLARE_PER_CPU(u64, decrementers_next_tb);
 
+static inline u64 timer_get_next_tb(void)
+{
+	return __this_cpu_read(decrementers_next_tb);
+}
+
 /* Convert timebase ticks to nanoseconds */
 unsigned long long tb_to_ns(unsigned long long tb_ticks);
 
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 913582bd848f..735ec40ece86 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3631,16 +3631,16 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	unsigned long host_amr = mfspr(SPRN_AMR);
 	unsigned long host_fscr = mfspr(SPRN_FSCR);
 	s64 dec;
-	u64 tb;
+	u64 tb, next_timer;
 	int trap, save_pmu;
 
-	dec = mfspr(SPRN_DEC);
 	tb = mftb();
-	if (dec < 0)
+	next_timer = timer_get_next_tb();
+	if (tb >= next_timer)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
-	local_paca->kvm_hstate.dec_expires = dec + tb;
-	if (local_paca->kvm_hstate.dec_expires < time_limit)
-		time_limit = local_paca->kvm_hstate.dec_expires;
+	local_paca->kvm_hstate.dec_expires = next_timer;
+	if (next_timer < time_limit)
+		time_limit = next_timer;
 
 	vcpu->arch.ceded = 0;
 
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 19/37] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

There is no need to save away the host DEC value, as it is derived
from the host timer subsystem, which maintains the next timer time.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h |  5 +++++
 arch/powerpc/kvm/book3s_hv.c    | 12 ++++++------
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 68d94711811e..0128cd9769bc 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -101,6 +101,11 @@ extern void __init time_init(void);
 
 DECLARE_PER_CPU(u64, decrementers_next_tb);
 
+static inline u64 timer_get_next_tb(void)
+{
+	return __this_cpu_read(decrementers_next_tb);
+}
+
 /* Convert timebase ticks to nanoseconds */
 unsigned long long tb_to_ns(unsigned long long tb_ticks);
 
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 913582bd848f..735ec40ece86 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3631,16 +3631,16 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	unsigned long host_amr = mfspr(SPRN_AMR);
 	unsigned long host_fscr = mfspr(SPRN_FSCR);
 	s64 dec;
-	u64 tb;
+	u64 tb, next_timer;
 	int trap, save_pmu;
 
-	dec = mfspr(SPRN_DEC);
 	tb = mftb();
-	if (dec < 0)
+	next_timer = timer_get_next_tb();
+	if (tb >= next_timer)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
-	local_paca->kvm_hstate.dec_expires = dec + tb;
-	if (local_paca->kvm_hstate.dec_expires < time_limit)
-		time_limit = local_paca->kvm_hstate.dec_expires;
+	local_paca->kvm_hstate.dec_expires = next_timer;
+	if (next_timer < time_limit)
+		time_limit = next_timer;
 
 	vcpu->arch.ceded = 0;
 
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 20/37] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

mftb is serialising (dispatch next-to-complete) so it is heavy weight
for a mfspr. Avoid reading it multiple times in the entry or exit paths.
A small number of cycles delay to timers is tolerable.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 735ec40ece86..d98958b78830 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3689,7 +3689,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (!(vcpu->arch.ctrl & 1))
 		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
 
-	mtspr(SPRN_DEC, vcpu->arch.dec_expires - mftb());
+	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
 
 	if (kvmhv_on_pseries()) {
 		/*
@@ -3822,7 +3822,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - mftb());
+	mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - tb);
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
 	kvmhv_load_host_pmu();
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 20/37] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

mftb is serialising (dispatch next-to-complete) so it is heavy weight
for a mfspr. Avoid reading it multiple times in the entry or exit paths.
A small number of cycles delay to timers is tolerable.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 735ec40ece86..d98958b78830 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3689,7 +3689,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (!(vcpu->arch.ctrl & 1))
 		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
 
-	mtspr(SPRN_DEC, vcpu->arch.dec_expires - mftb());
+	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
 
 	if (kvmhv_on_pseries()) {
 		/*
@@ -3822,7 +3822,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - mftb());
+	mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - tb);
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
 	kvmhv_load_host_pmu();
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 21/37] powerpc: add set_dec_or_work API for safely updating decrementer
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Decrementer updates must always check for new irq work to avoid an
irq work decrementer interrupt being lost.

Add an API for this in the timer code so callers don't have to care
about details.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h |  9 +++++++++
 arch/powerpc/kernel/time.c      | 20 +++++++++++---------
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 0128cd9769bc..d62bde57bf02 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -78,6 +78,15 @@ static inline void set_dec(u64 val)
 		mtspr(SPRN_DEC, val - 1);
 }
 
+#ifdef CONFIG_IRQ_WORK
+void set_dec_or_work(u64 val);
+#else
+static inline void set_dec_or_work(u64 val)
+{
+	set_dec(val);
+}
+#endif
+
 static inline unsigned long tb_ticks_since(unsigned long tstamp)
 {
 	return mftb() - tstamp;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index b67d93a609a2..e35156858e6e 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -561,6 +561,15 @@ void arch_irq_work_raise(void)
 	preempt_enable();
 }
 
+void set_dec_or_work(u64 val)
+{
+	set_dec(val);
+	/* We may have raced with new irq work */
+	if (unlikely(test_irq_work_pending()))
+		set_dec(1);
+}
+EXPORT_SYMBOL_GPL(set_dec_or_work);
+
 #else  /* CONFIG_IRQ_WORK */
 
 #define test_irq_work_pending()	0
@@ -628,10 +637,7 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(timer_interrupt)
 	} else {
 		now = *next_tb - now;
 		if (now <= decrementer_max)
-			set_dec(now);
-		/* We may have raced with new irq work */
-		if (test_irq_work_pending())
-			set_dec(1);
+			set_dec_or_work(now);
 		__this_cpu_inc(irq_stat.timer_irqs_others);
 	}
 
@@ -873,11 +879,7 @@ static int decrementer_set_next_event(unsigned long evt,
 				      struct clock_event_device *dev)
 {
 	__this_cpu_write(decrementers_next_tb, get_tb() + evt);
-	set_dec(evt);
-
-	/* We may have raced with new irq work */
-	if (test_irq_work_pending())
-		set_dec(1);
+	set_dec_or_work(evt);
 
 	return 0;
 }
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 21/37] powerpc: add set_dec_or_work API for safely updating decrementer
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Decrementer updates must always check for new irq work to avoid an
irq work decrementer interrupt being lost.

Add an API for this in the timer code so callers don't have to care
about details.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h |  9 +++++++++
 arch/powerpc/kernel/time.c      | 20 +++++++++++---------
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 0128cd9769bc..d62bde57bf02 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -78,6 +78,15 @@ static inline void set_dec(u64 val)
 		mtspr(SPRN_DEC, val - 1);
 }
 
+#ifdef CONFIG_IRQ_WORK
+void set_dec_or_work(u64 val);
+#else
+static inline void set_dec_or_work(u64 val)
+{
+	set_dec(val);
+}
+#endif
+
 static inline unsigned long tb_ticks_since(unsigned long tstamp)
 {
 	return mftb() - tstamp;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index b67d93a609a2..e35156858e6e 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -561,6 +561,15 @@ void arch_irq_work_raise(void)
 	preempt_enable();
 }
 
+void set_dec_or_work(u64 val)
+{
+	set_dec(val);
+	/* We may have raced with new irq work */
+	if (unlikely(test_irq_work_pending()))
+		set_dec(1);
+}
+EXPORT_SYMBOL_GPL(set_dec_or_work);
+
 #else  /* CONFIG_IRQ_WORK */
 
 #define test_irq_work_pending()	0
@@ -628,10 +637,7 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(timer_interrupt)
 	} else {
 		now = *next_tb - now;
 		if (now <= decrementer_max)
-			set_dec(now);
-		/* We may have raced with new irq work */
-		if (test_irq_work_pending())
-			set_dec(1);
+			set_dec_or_work(now);
 		__this_cpu_inc(irq_stat.timer_irqs_others);
 	}
 
@@ -873,11 +879,7 @@ static int decrementer_set_next_event(unsigned long evt,
 				      struct clock_event_device *dev)
 {
 	__this_cpu_write(decrementers_next_tb, get_tb() + evt);
-	set_dec(evt);
-
-	/* We may have raced with new irq work */
-	if (test_irq_work_pending())
-		set_dec(1);
+	set_dec_or_work(evt);
 
 	return 0;
 }
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 22/37] KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

irq_work's use of the DEC SPR is racy with guest<->host switch and guest
entry which flips the DEC interrupt to guest, which could lose a host
work interrupt.

This patch closes one race, and attempts to comment several others.

(XXX: should think a bit harder about this)

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/paca.h |  1 +
 arch/powerpc/kvm/book3s_hv.c    | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index ec18ac818e3a..23c12048fbc9 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -174,6 +174,7 @@ struct paca_struct {
 	u8 irq_happened;		/* irq happened while soft-disabled */
 	u8 irq_work_pending;		/* IRQ_WORK interrupt while soft-disable */
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* Could have irq_work_using_hdec here, but what about nested HV entry modifying DEC? Could have a pointer to the hv struct time limit */
 	u8 pmcregs_in_use;		/* pseries puts this in lppaca */
 #endif
 	u64 sprg_vdso;			/* Saved user-visible sprg */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d98958b78830..1997cf347d3e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3689,6 +3689,18 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (!(vcpu->arch.ctrl & 1))
 		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
 
+	/*
+	 * XXX: must always deal with irq_work_raise via NMI vs setting DEC.
+	 * The problem occurs right as we switch into guest mode if a NMI
+	 * hits and sets pending work and sets DEC, then that will apply to
+	 * the guest and not bring us back to the host.
+	 *
+	 * irq_work_raise could check a flag (or possibly LPCR[HDICE] for
+	 * example) and set HDEC to 1? That wouldn't solve the nested hv
+	 * case which needs to abort the hcall or zero the time limit.
+	 *
+	 * Another day's problem.
+	 */
 	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
 
 	if (kvmhv_on_pseries()) {
@@ -3822,7 +3834,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - tb);
+	set_dec_or_work(local_paca->kvm_hstate.dec_expires - tb);
+
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
 	kvmhv_load_host_pmu();
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 22/37] KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

irq_work's use of the DEC SPR is racy with guest<->host switch and guest
entry which flips the DEC interrupt to guest, which could lose a host
work interrupt.

This patch closes one race, and attempts to comment several others.

(XXX: should think a bit harder about this)

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/paca.h |  1 +
 arch/powerpc/kvm/book3s_hv.c    | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index ec18ac818e3a..23c12048fbc9 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -174,6 +174,7 @@ struct paca_struct {
 	u8 irq_happened;		/* irq happened while soft-disabled */
 	u8 irq_work_pending;		/* IRQ_WORK interrupt while soft-disable */
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* Could have irq_work_using_hdec here, but what about nested HV entry modifying DEC? Could have a pointer to the hv struct time limit */
 	u8 pmcregs_in_use;		/* pseries puts this in lppaca */
 #endif
 	u64 sprg_vdso;			/* Saved user-visible sprg */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d98958b78830..1997cf347d3e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3689,6 +3689,18 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (!(vcpu->arch.ctrl & 1))
 		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
 
+	/*
+	 * XXX: must always deal with irq_work_raise via NMI vs setting DEC.
+	 * The problem occurs right as we switch into guest mode if a NMI
+	 * hits and sets pending work and sets DEC, then that will apply to
+	 * the guest and not bring us back to the host.
+	 *
+	 * irq_work_raise could check a flag (or possibly LPCR[HDICE] for
+	 * example) and set HDEC to 1? That wouldn't solve the nested hv
+	 * case which needs to abort the hcall or zero the time limit.
+	 *
+	 * Another day's problem.
+	 */
 	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
 
 	if (kvmhv_on_pseries()) {
@@ -3822,7 +3834,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - tb);
+	set_dec_or_work(local_paca->kvm_hstate.dec_expires - tb);
+
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
 	kvmhv_load_host_pmu();
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Almost all logic is moved to C, by introducing a new in_guest mode that
selects and branches very early in the interrupt handler to the P9 exit
code.

The remaining assembly is only about 160 lines of low level stack setup,
with VCPU vs host register save and restore, plus a small shim to the
legacy paths in the interrupt handler.

There are two motivations for this, the first is just make the code more
maintainable being in C. The second is to reduce the amount of code
running in a special KVM mode, "realmode". I put that in quotes because
with radix it is no longer necessarily real-mode in the MMU, but it
still has to be treated specially because it may be in real-mode, and
has various important registers like PID, DEC, TB, etc set to guest.
This is hostile to the rest of Linux and can't use arbitrary kernel
functionality or be instrumented well.

This initial patch is a reasonably faithful conversion of the asm code.
It does lack any loop to return quickly back into the guest without
switching out of realmode in the case of unimportant or easily handled
interrupts, as explained in the previous change, handling HV interrupts
in real mode is not so important for P9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/asm-prototypes.h |   3 +-
 arch/powerpc/include/asm/kvm_asm.h        |   3 +-
 arch/powerpc/include/asm/kvm_book3s_64.h  |   8 +
 arch/powerpc/kernel/security.c            |   5 +-
 arch/powerpc/kvm/Makefile                 |   3 +
 arch/powerpc/kvm/book3s_64_entry.S        | 181 ++++++++++++++++++
 arch/powerpc/kvm/book3s_hv.c              |  27 ++-
 arch/powerpc/kvm/book3s_hv_interrupt.c    | 221 ++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 123 +-----------
 arch/powerpc/kvm/book3s_xive.c            |  34 ++++
 10 files changed, 480 insertions(+), 128 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_hv_interrupt.c

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 939f3c94c8f3..8677d27929fe 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -122,6 +122,7 @@ extern s32 patch__call_flush_branch_caches3;
 extern s32 patch__flush_count_cache_return;
 extern s32 patch__flush_link_stack_return;
 extern s32 patch__call_kvm_flush_link_stack;
+extern s32 patch__call_kvm_flush_link_stack_2;
 extern s32 patch__memset_nocache, patch__memcpy_nocache;
 
 extern long flush_branch_caches;
@@ -142,7 +143,7 @@ void kvmhv_load_host_pmu(void);
 void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use);
 void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu);
 
-int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+void kvmppc_p9_enter_guest(struct kvm_vcpu *vcpu);
 
 long kvmppc_h_set_dabr(struct kvm_vcpu *vcpu, unsigned long dabr);
 long kvmppc_h_set_xdabr(struct kvm_vcpu *vcpu, unsigned long dabr,
diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index a3633560493b..b4f9996bd331 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -146,7 +146,8 @@
 #define KVM_GUEST_MODE_GUEST	1
 #define KVM_GUEST_MODE_SKIP	2
 #define KVM_GUEST_MODE_GUEST_HV	3
-#define KVM_GUEST_MODE_HOST_HV	4
+#define KVM_GUEST_MODE_GUEST_HV_FAST	4 /* ISA v3.0 with host radix mode */
+#define KVM_GUEST_MODE_HOST_HV	5
 
 #define KVM_INST_FETCH_FAILED	-1
 
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 9bb9bb370b53..c214bcffb441 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -153,9 +153,17 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
 	return radix;
 }
 
+int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+
 #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
 #endif
 
+/*
+ * Invalid HDSISR value which is used to indicate when HW has not set the reg.
+ * Used to work around an errata.
+ */
+#define HDSISR_CANARY	0x7fff
+
 /*
  * We use a lock bit in HPTE dword 0 to synchronize updates and
  * accesses to each HPTE, and another bit to indicate non-present
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index e4e1a94ccf6a..6c37aeed0650 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -430,16 +430,19 @@ device_initcall(stf_barrier_debugfs_init);
 
 static void update_branch_cache_flush(void)
 {
-	u32 *site;
+	u32 *site, __maybe_unused *site2;
 
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 	site = &patch__call_kvm_flush_link_stack;
+	site2 = &patch__call_kvm_flush_link_stack_2;
 	// This controls the branch from guest_exit_cont to kvm_flush_link_stack
 	if (link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE) {
 		patch_instruction_site(site, ppc_inst(PPC_INST_NOP));
+		patch_instruction_site(site2, ppc_inst(PPC_INST_NOP));
 	} else {
 		// Could use HW flush, but that could also flush count cache
 		patch_branch_site(site, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
+		patch_branch_site(site2, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
 	}
 #endif
 
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index cdd119028f64..40a55a5ba4ff 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -43,6 +43,9 @@ kvm-objs-$(CONFIG_KVM_E500MC) := $(kvm-e500mc-objs)
 kvm-book3s_64-builtin-objs-$(CONFIG_SPAPR_TCE_IOMMU) := \
 	book3s_64_vio_hv.o
 
+kvm-book3s_64-builtin-objs-y += \
+	book3s_hv_interrupt.o
+
 kvm-pr-y := \
 	fpu.o \
 	emulate.o \
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index f826c8dc2e19..cc7b76865a16 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -1,10 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
+#include <asm/code-patching-asm.h>
 #include <asm/exception-64s.h>
+#include <asm/export.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_book3s_asm.h>
 #include <asm/ppc_asm.h>
 #include <asm/reg.h>
+#include <asm/ultravisor-api.h>
 
 /*
  * These are branched to from interrupt handlers in exception-64s.S which set
@@ -13,13 +17,24 @@
 .global	kvmppc_hcall
 .balign IFETCH_ALIGN_BYTES
 kvmppc_hcall:
+	lbz	r10,HSTATE_IN_GUEST(r13)
+	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
+	beq	kvmppc_p9_exit_hcall
 	ld	r10,PACA_EXGEN+EX_R13(r13)
 	SET_SCRATCH0(r10)
 	li	r10,0xc00
+	li	r11,PACA_EXGEN
+	b	1f
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
 kvmppc_interrupt:
+	std	r10,HSTATE_SCRATCH0(r13)
+	lbz	r10,HSTATE_IN_GUEST(r13)
+	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
+	beq	kvmppc_p9_exit_interrupt
+	ld	r10,HSTATE_SCRATCH0(r13)
+	lbz	r11,HSTATE_IN_GUEST(r13)
 	li	r11,PACA_EXGEN
 	cmpdi	r10,0x200
 	bgt+	1f
@@ -114,3 +129,169 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	GET_SCRATCH0(r13)
 	HRFI_TO_KERNEL
 #endif
+
+/* Stack frame offsets for kvmppc_hv_entry */
+#define SFS			208
+#define STACK_SLOT_VCPU		(SFS-8)
+#define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
+
+/*
+ * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
+ *
+ * Enter the guest on a ISAv3.0 or later system where we have exactly
+ * one vcpu per vcore, and both the host and guest are radix, and threads
+ * are set to "indepdent mode".
+ */
+.balign	IFETCH_ALIGN_BYTES
+_GLOBAL(kvmppc_p9_enter_guest)
+EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
+	mflr	r0
+	std	r0,PPC_LR_STKOFF(r1)
+	stdu	r1,-SFS(r1)
+
+	std	r1,HSTATE_HOST_R1(r13)
+	std	r3,STACK_SLOT_VCPU(r1)
+
+	mfcr	r4
+	stw	r4,SFS+8(r1)
+
+	reg = 14
+	.rept	18
+	std	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
+	reg = reg + 1
+	.endr
+
+	ld	r4,VCPU_LR(r3)
+	mtlr	r4
+	ld	r4,VCPU_CTR(r3)
+	mtctr	r4
+	ld	r4,VCPU_XER(r3)
+	mtspr	SPRN_XER,r4
+
+	ld	r1,VCPU_CR(r3)
+
+BEGIN_FTR_SECTION
+	ld	r4,VCPU_CFAR(r3)
+	mtspr	SPRN_CFAR,r4
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+BEGIN_FTR_SECTION
+	ld	r4,VCPU_PPR(r3)
+	mtspr	SPRN_PPR,r4
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	reg = 4
+	.rept	28
+	ld	reg,__VCPU_GPR(reg)(r3)
+	reg = reg + 1
+	.endr
+
+	ld	r4,VCPU_KVM(r3)
+	lbz	r4,KVM_SECURE_GUEST(r4)
+	cmpdi	r4,0
+	ld	r4,VCPU_GPR(R4)(r3)
+	bne	.Lret_to_ultra
+
+	mtcr	r1
+
+	ld	r0,VCPU_GPR(R0)(r3)
+	ld	r1,VCPU_GPR(R1)(r3)
+	ld	r2,VCPU_GPR(R2)(r3)
+	ld	r3,VCPU_GPR(R3)(r3)
+
+	HRFI_TO_GUEST
+	b	.
+
+	/*
+	 * Use UV_RETURN ultracall to return control back to the Ultravisor
+	 * after processing an hypercall or interrupt that was forwarded
+	 * (a.k.a. reflected) to the Hypervisor.
+	 *
+	 * All registers have already been reloaded except the ucall requires:
+	 *   R0 = hcall result
+	 *   R2 = SRR1, so UV can detect a synthesized interrupt (if any)
+	 *   R3 = UV_RETURN
+	 */
+.Lret_to_ultra:
+	mtcr	r1
+	ld	r1,VCPU_GPR(R1)(r3)
+
+	ld	r0,VCPU_GPR(R3)(r3)
+	mfspr	r2,SPRN_SRR1
+	LOAD_REG_IMMEDIATE(r3, UV_RETURN)
+	sc	2
+
+/*
+ * kvmppc_p9_exit_hcall and kvmppc_p9_exit_interrupt are branched to from
+ * above if the interrupt was taken for a guest that was entered via
+ * kvmppc_p9_enter_guest().
+ *
+ * This code recovers the host stack and vcpu pointer, saves all GPRs and
+ * CR, LR, CTR, XER as well as guest MSR and NIA into the VCPU, then re-
+ * establishes the host stack and registers to return from  the
+ * kvmppc_p9_enter_guest() function.
+ */
+.balign	IFETCH_ALIGN_BYTES
+kvmppc_p9_exit_hcall:
+	mfspr	r11,SPRN_SRR0
+	mfspr	r12,SPRN_SRR1
+	li	r10,0xc00
+	std	r10,HSTATE_SCRATCH0(r13)
+
+.balign	IFETCH_ALIGN_BYTES
+kvmppc_p9_exit_interrupt:
+	std     r1,HSTATE_SCRATCH1(r13)
+	std     r3,HSTATE_SCRATCH2(r13)
+	ld	r1,HSTATE_HOST_R1(r13)
+	ld	r3,STACK_SLOT_VCPU(r1)
+
+	std	r9,VCPU_CR(r3)
+
+1:
+	std	r11,VCPU_PC(r3)
+	std	r12,VCPU_MSR(r3)
+
+	reg = 14
+	.rept	18
+	std	reg,__VCPU_GPR(reg)(r3)
+	reg = reg + 1
+	.endr
+
+	/* r1, r3, r9-r13 are saved to vcpu by C code */
+	std	r0,VCPU_GPR(R0)(r3)
+	std	r2,VCPU_GPR(R2)(r3)
+	reg = 4
+	.rept	5
+	std	reg,__VCPU_GPR(reg)(r3)
+	reg = reg + 1
+	.endr
+
+	ld	r2,PACATOC(r13)
+
+	mflr	r4
+	std	r4,VCPU_LR(r3)
+	mfspr	r4,SPRN_XER
+	std	r4,VCPU_XER(r3)
+
+	reg = 14
+	.rept	18
+	ld	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
+	reg = reg + 1
+	.endr
+
+	lwz	r4,SFS+8(r1)
+	mtcr	r4
+
+	/*
+	 * Flush the link stack here, before executing the first blr on the
+	 * way out of the guest.
+	 *
+	 * The link stack won't match coming out of the guest anyway so the
+	 * only cost is the flush itself. The call clobbers r0.
+	 */
+1:	nop
+	patch_site 1b patch__call_kvm_flush_link_stack_2
+
+	addi	r1,r1,SFS
+	ld	r0,PPC_LR_STKOFF(r1)
+	mtlr	r0
+	blr
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1997cf347d3e..28a2761515e3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1421,6 +1421,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 	 */
 	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
 		r = RESUME_PAGE_FAULT;
+		if (vcpu->arch.fault_dsisr == HDSISR_CANARY)
+			r = RESUME_GUEST; /* Just retry if it's the canary */
 		break;
 	case BOOK3S_INTERRUPT_H_INST_STORAGE:
 		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
@@ -3736,14 +3738,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
 		vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
 		mtspr(SPRN_PSSCR_PR, host_psscr);
-
 		/* H_CEDE has to be handled now, not later */
-		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
+		if (trap == BOOK3S_INTERRUPT_SYSCALL &&
 		    kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
 			kvmppc_cede(vcpu);
 			kvmppc_set_gpr(vcpu, 3, 0);
 			trap = 0;
 		}
+
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
 		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
@@ -3768,9 +3770,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			}
 		}
 		kvmppc_xive_pull_vcpu(vcpu);
+
+		vcpu->arch.slb_max = 0;
 	}
 
-	vcpu->arch.slb_max = 0;
 	dec = mfspr(SPRN_DEC);
 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 		dec = (s32) dec;
@@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		else
 			r = kvmppc_run_vcpu(vcpu);
 
-		if (run->exit_reason == KVM_EXIT_PAPR_HCALL &&
-		    !(vcpu->arch.shregs.msr & MSR_PR)) {
-			trace_kvm_hcall_enter(vcpu);
-			r = kvmppc_pseries_do_hcall(vcpu);
-			trace_kvm_hcall_exit(vcpu, r);
+		if (run->exit_reason == KVM_EXIT_PAPR_HCALL) {
+			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
+				/*
+				 * Guest userspace executed sc 1, reflect it
+				 * back as a privileged program check interrupt.
+				 */
+				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
+				r = RESUME_GUEST;
+			} else {
+				trace_kvm_hcall_enter(vcpu);
+				r = kvmppc_pseries_do_hcall(vcpu);
+				trace_kvm_hcall_exit(vcpu, r);
+			}
 			kvmppc_core_prepare_to_enter(vcpu);
 		} else if (r == RESUME_PAGE_FAULT) {
 			srcu_idx = srcu_read_lock(&kvm->srcu);
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
new file mode 100644
index 000000000000..5a7b036c447f
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <asm/asm-prototypes.h>
+#include <asm/dbell.h>
+#include <asm/kvm_ppc.h>
+
+#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
+static void __start_timing(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	u64 tb = mftb() - vc->tb_offset_applied;
+
+	vcpu->arch.cur_activity = next;
+	vcpu->arch.cur_tb_start = tb;
+}
+
+static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvmhv_tb_accumulator *curr;
+	u64 tb = mftb() - vc->tb_offset_applied;
+	u64 prev_tb;
+	u64 delta;
+	u64 seq;
+
+	curr = vcpu->arch.cur_activity;
+	vcpu->arch.cur_activity = next;
+	prev_tb = vcpu->arch.cur_tb_start;
+	vcpu->arch.cur_tb_start = tb;
+
+	if (!curr)
+		return;
+
+	delta = tb - prev_tb;
+
+	seq = curr->seqcount;
+	curr->seqcount = seq + 1;
+	smp_wmb();
+	curr->tb_total += delta;
+	if (seq == 0 || delta < curr->tb_min)
+		curr->tb_min = delta;
+	if (delta > curr->tb_max)
+		curr->tb_max = delta;
+	smp_wmb();
+	curr->seqcount = seq + 2;
+}
+
+#define start_timing(vcpu, next) __start_timing(vcpu, next)
+#define end_timing(vcpu) __start_timing(vcpu, NULL)
+#define accumulate_time(vcpu, next) __accumulate_time(vcpu, next)
+#else
+#define start_timing(vcpu, next) do {} while (0)
+#define end_timing(vcpu) do {} while (0)
+#define accumulate_time(vcpu, next) do {} while (0)
+#endif
+
+static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
+{
+	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
+	asm volatile("slbmfee  %0,%1" : "=r" (*slbee) : "r" (idx));
+}
+
+static inline void mtslb(unsigned int idx, u64 slbee, u64 slbev)
+{
+	BUG_ON((slbee & 0xfff) != idx);
+
+	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+}
+
+static inline void slb_invalidate(unsigned int ih)
+{
+	asm volatile("slbia %0" :: "i"(ih));
+}
+
+/*
+ * Malicious or buggy radix guests may have inserted SLB entries
+ * (only 0..3 because radix always runs with UPRT=1), so these must
+ * be cleared here to avoid side-channels. slbmte is used rather
+ * than slbia, as it won't clear cached translations.
+ */
+static void radix_clear_slb(void)
+{
+	u64 slbee, slbev;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		mfslb(i, &slbee, &slbev);
+		if (unlikely(slbee || slbev)) {
+			slbee = i;
+			slbev = 0;
+			mtslb(i, slbee, slbev);
+		}
+	}
+}
+
+int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
+{
+	u64 *exsave;
+	unsigned long msr = mfmsr();
+	int trap;
+
+	start_timing(vcpu, &vcpu->arch.rm_entry);
+
+	vcpu->arch.ceded = 0;
+
+	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
+	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
+
+	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
+	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
+
+	/*
+	 * On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage
+	 * Interrupt (HDSI) the HDSISR is not be updated at all.
+	 *
+	 * To work around this we put a canary value into the HDSISR before
+	 * returning to a guest and then check for this canary when we take a
+	 * HDSI. If we find the canary on a HDSI, we know the hardware didn't
+	 * update the HDSISR. In this case we return to the guest to retake the
+	 * HDSI which should correctly update the HDSISR the second time HDSI
+	 * entry.
+	 *
+	 * Just do this on all p9 processors for now.
+	 */
+	mtspr(SPRN_HDSISR, HDSISR_CANARY);
+
+	accumulate_time(vcpu, &vcpu->arch.guest_time);
+
+	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
+	kvmppc_p9_enter_guest(vcpu);
+	// Radix host and guest means host never runs with guest MMU state
+	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
+
+	accumulate_time(vcpu, &vcpu->arch.rm_intr);
+
+	/* Get these from r11/12 and paca exsave */
+	vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
+	vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
+	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
+	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
+
+	trap = local_paca->kvm_hstate.scratch0 & ~0x2;
+	if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+		exsave = local_paca->exgen;
+	} else if (trap == BOOK3S_INTERRUPT_SYSTEM_RESET) {
+		exsave = local_paca->exnmi;
+	} else { /* trap == 0x200 */
+		exsave = local_paca->exmc;
+	}
+
+	vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
+	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
+	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
+	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
+	vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
+	vcpu->arch.regs.gpr[12] = exsave[EX_R12/sizeof(u64)];
+	vcpu->arch.regs.gpr[13] = exsave[EX_R13/sizeof(u64)];
+	vcpu->arch.ppr = exsave[EX_PPR/sizeof(u64)];
+	vcpu->arch.cfar = exsave[EX_CFAR/sizeof(u64)];
+	vcpu->arch.regs.ctr = exsave[EX_CTR/sizeof(u64)];
+
+	vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
+
+	if (unlikely(trap == BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+		kvmppc_realmode_machine_check(vcpu);
+
+	} else if (unlikely(trap == BOOK3S_INTERRUPT_HMI)) {
+		kvmppc_realmode_hmi_handler();
+
+	} else if (trap == BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
+		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+	} else if (trap == BOOK3S_INTERRUPT_H_DATA_STORAGE) {
+		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+	} else if (trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
+		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+	} else if (trap == BOOK3S_INTERRUPT_H_FAC_UNAVAIL) {
+		vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/*
+	 * Softpatch interrupt for transactional memory emulation cases
+	 * on POWER9 DD2.2.  This is early in the guest exit path - we
+	 * haven't saved registers or done a treclaim yet.
+	 */
+	} else if (trap == BOOK3S_INTERRUPT_HV_SOFTPATCH) {
+		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+		/*
+		 * The cases we want to handle here are those where the guest
+		 * is in real suspend mode and is trying to transition to
+		 * transactional mode.
+		 */
+		if (local_paca->kvm_hstate.fake_suspend &&
+				(vcpu->arch.shregs.msr & MSR_TS_S)) {
+			if (kvmhv_p9_tm_emulation_early(vcpu)) {
+				/* Prevent it being handled again. */
+				trap = 0;
+			}
+		}
+#endif
+	}
+
+	radix_clear_slb();
+
+	__mtmsrd(msr, 0);
+
+	accumulate_time(vcpu, &vcpu->arch.rm_exit);
+
+	end_timing(vcpu);
+
+	return trap;
+}
+EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 2d0d14ed1d92..6118e8a97ddd 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -44,9 +44,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define NAPPING_UNSPLIT	3
 
 /* Stack frame offsets for kvmppc_hv_entry */
-#define SFS			208
+#define SFS			160
 #define STACK_SLOT_TRAP		(SFS-4)
-#define STACK_SLOT_SHORT_PATH	(SFS-8)
 #define STACK_SLOT_TID		(SFS-16)
 #define STACK_SLOT_PSSCR	(SFS-24)
 #define STACK_SLOT_PID		(SFS-32)
@@ -59,8 +58,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define STACK_SLOT_UAMOR	(SFS-88)
 #define STACK_SLOT_DAWR1	(SFS-96)
 #define STACK_SLOT_DAWRX1	(SFS-104)
-/* the following is used by the P9 short path */
-#define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
 
 /*
  * Call kvmppc_hv_entry in real mode.
@@ -1008,9 +1005,6 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
 no_xive:
 #endif /* CONFIG_KVM_XICS */
 
-	li	r0, 0
-	stw	r0, STACK_SLOT_SHORT_PATH(r1)
-
 deliver_guest_interrupt:	/* r4 = vcpu, r13 = paca */
 	/* Check if we can deliver an external or decrementer interrupt now */
 	ld	r0, VCPU_PENDING_EXC(r4)
@@ -1030,7 +1024,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	mtspr	SPRN_SRR0, r6
 	mtspr	SPRN_SRR1, r7
 
-fast_guest_entry_c:
 	ld	r10, VCPU_PC(r4)
 	ld	r11, VCPU_MSR(r4)
 	/* r11 = vcpu->arch.msr & ~MSR_HV */
@@ -1135,97 +1128,6 @@ ret_to_ultra:
 	ld	r4, VCPU_GPR(R4)(r4)
 	sc	2
 
-/*
- * Enter the guest on a P9 or later system where we have exactly
- * one vcpu per vcore and we don't need to go to real mode
- * (which implies that host and guest are both using radix MMU mode).
- * r3 = vcpu pointer
- * Most SPRs and all the VSRs have been loaded already.
- */
-_GLOBAL(__kvmhv_vcpu_entry_p9)
-EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9)
-	mflr	r0
-	std	r0, PPC_LR_STKOFF(r1)
-	stdu	r1, -SFS(r1)
-
-	li	r0, 1
-	stw	r0, STACK_SLOT_SHORT_PATH(r1)
-
-	std	r3, HSTATE_KVM_VCPU(r13)
-	mfcr	r4
-	stw	r4, SFS+8(r1)
-
-	std	r1, HSTATE_HOST_R1(r13)
-
-	reg = 14
-	.rept	18
-	std	reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
-	reg = reg + 1
-	.endr
-
-	reg = 14
-	.rept	18
-	ld	reg, __VCPU_GPR(reg)(r3)
-	reg = reg + 1
-	.endr
-
-	mfmsr	r10
-	std	r10, HSTATE_HOST_MSR(r13)
-
-	mr	r4, r3
-	b	fast_guest_entry_c
-guest_exit_short_path:
-	/*
-	 * Malicious or buggy radix guests may have inserted SLB entries
-	 * (only 0..3 because radix always runs with UPRT=1), so these must
-	 * be cleared here to avoid side-channels. slbmte is used rather
-	 * than slbia, as it won't clear cached translations.
-	 */
-	li	r0,0
-	slbmte	r0,r0
-	li	r4,1
-	slbmte	r0,r4
-	li	r4,2
-	slbmte	r0,r4
-	li	r4,3
-	slbmte	r0,r4
-
-	li	r0, KVM_GUEST_MODE_NONE
-	stb	r0, HSTATE_IN_GUEST(r13)
-
-	reg = 14
-	.rept	18
-	std	reg, __VCPU_GPR(reg)(r9)
-	reg = reg + 1
-	.endr
-
-	reg = 14
-	.rept	18
-	ld	reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
-	reg = reg + 1
-	.endr
-
-	lwz	r4, SFS+8(r1)
-	mtcr	r4
-
-	mr	r3, r12		/* trap number */
-
-	addi	r1, r1, SFS
-	ld	r0, PPC_LR_STKOFF(r1)
-	mtlr	r0
-
-	/* If we are in real mode, do a rfid to get back to the caller */
-	mfmsr	r4
-	andi.	r5, r4, MSR_IR
-	bnelr
-	rldicl	r5, r4, 64 - MSR_TS_S_LG, 62	/* extract TS field */
-	mtspr	SPRN_SRR0, r0
-	ld	r10, HSTATE_HOST_MSR(r13)
-	rldimi	r10, r5, MSR_TS_S_LG, 63 - MSR_TS_T_LG
-	mtspr	SPRN_SRR1, r10
-	RFI_TO_KERNEL
-	b	.
-
 secondary_too_late:
 	li	r12, 0
 	stw	r12, STACK_SLOT_TRAP(r1)
@@ -1397,14 +1299,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	mr	r4,r9
 	bge	fast_guest_return
 2:
-	/* If we came in through the P9 short path, no real mode hcalls */
-	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
-	cmpwi	r0, 0
-	bne	no_try_real
 	/* See if this is an hcall we can handle in real mode */
 	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
 	beq	hcall_try_real_mode
-no_try_real:
 
 	/* Hypervisor doorbell - exit only if host IPI flag set */
 	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
@@ -1447,11 +1344,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	bl	kvmhv_accumulate_time
 #endif
 #ifdef CONFIG_KVM_XICS
-	/* If we came in through the P9 short path, xive pull is done in C */
-	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
-	cmpwi	r0, 0
-	bne	1f
-
 	/* We are exiting, pull the VP from the XIVE */
 	lbz	r0, VCPU_XIVE_PUSHED(r9)
 	cmpwi	cr0, r0, 0
@@ -1496,11 +1388,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 1:	nop
 	patch_site 1b patch__call_kvm_flush_link_stack
 
-	/* If we came in through the P9 short path, go back out to C now */
-	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
-	cmpwi	r0, 0
-	bne	guest_exit_short_path
-
 	/* For hash guest, read the guest SLB and save it away */
 	ld	r5, VCPU_KVM(r9)
 	lbz	r0, KVM_RADIX(r5)
@@ -1548,8 +1435,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 	b	guest_bypass
 
 0:	/*
-	 * Sanitise radix guest SLB, see guest_exit_short_path comment.
-	 * We clear vcpu->arch.slb_max to match earlier behaviour.
+	 * Malicious or buggy radix guests may have inserted SLB entries
+	 * (only 0..3 because radix always runs with UPRT=1), so these must
+	 * be cleared here to avoid side-channels. slbmte is used rather
+	 * than slbia, as it won't clear cached translations.
 	 */
 	li	r0,0
 	stw	r0,VCPU_SLB_MAX(r9)
@@ -3362,7 +3251,7 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWRX1, r0
 END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 
-	/* Clear hash and radix guest SLB, see guest_exit_short_path comment. */
+	/* Clear hash and radix guest SLB. */
 	slbmte	r0, r0
 	PPC_SLBIA(6)
 
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index d2266d36a7c7..cb03ed147b42 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -161,6 +161,40 @@ void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvmppc_xive_pull_vcpu);
 
+void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu)
+{
+	void __iomem *esc_vaddr = (void __iomem *)vcpu->arch.xive_esc_vaddr;
+
+	if (!esc_vaddr)
+		return;
+
+	/* we are using XIVE with single escalation */
+
+	if (vcpu->arch.xive_esc_on) {
+		/*
+		 * If we still have a pending escalation, abort the cede,
+		 * and we must set PQ to 10 rather than 00 so that we don't
+		 * potentially end up with two entries for the escalation
+		 * interrupt in the XIVE interrupt queue.  In that case
+		 * we also don't want to set xive_esc_on to 1 here in
+		 * case we race with xive_esc_irq().
+		 */
+		vcpu->arch.ceded = 0;
+		/*
+		 * The escalation interrupts are special as we don't EOI them.
+		 * There is no need to use the load-after-store ordering offset
+		 * to set PQ to 10 as we won't use StoreEOI.
+		 */
+		__raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_10);
+	} else {
+		vcpu->arch.xive_esc_on = true;
+		mb();
+		__raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_00);
+	}
+	mb();
+}
+EXPORT_SYMBOL_GPL(kvmppc_xive_cede_vcpu);
+
 /*
  * This is a simple trigger for a generic XIVE IRQ. This must
  * only be called for interrupts that support a trigger page
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Almost all logic is moved to C, by introducing a new in_guest mode that
selects and branches very early in the interrupt handler to the P9 exit
code.

The remaining assembly is only about 160 lines of low level stack setup,
with VCPU vs host register save and restore, plus a small shim to the
legacy paths in the interrupt handler.

There are two motivations for this, the first is just make the code more
maintainable being in C. The second is to reduce the amount of code
running in a special KVM mode, "realmode". I put that in quotes because
with radix it is no longer necessarily real-mode in the MMU, but it
still has to be treated specially because it may be in real-mode, and
has various important registers like PID, DEC, TB, etc set to guest.
This is hostile to the rest of Linux and can't use arbitrary kernel
functionality or be instrumented well.

This initial patch is a reasonably faithful conversion of the asm code.
It does lack any loop to return quickly back into the guest without
switching out of realmode in the case of unimportant or easily handled
interrupts, as explained in the previous change, handling HV interrupts
in real mode is not so important for P9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/asm-prototypes.h |   3 +-
 arch/powerpc/include/asm/kvm_asm.h        |   3 +-
 arch/powerpc/include/asm/kvm_book3s_64.h  |   8 +
 arch/powerpc/kernel/security.c            |   5 +-
 arch/powerpc/kvm/Makefile                 |   3 +
 arch/powerpc/kvm/book3s_64_entry.S        | 181 ++++++++++++++++++
 arch/powerpc/kvm/book3s_hv.c              |  27 ++-
 arch/powerpc/kvm/book3s_hv_interrupt.c    | 221 ++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 123 +-----------
 arch/powerpc/kvm/book3s_xive.c            |  34 ++++
 10 files changed, 480 insertions(+), 128 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_hv_interrupt.c

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 939f3c94c8f3..8677d27929fe 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -122,6 +122,7 @@ extern s32 patch__call_flush_branch_caches3;
 extern s32 patch__flush_count_cache_return;
 extern s32 patch__flush_link_stack_return;
 extern s32 patch__call_kvm_flush_link_stack;
+extern s32 patch__call_kvm_flush_link_stack_2;
 extern s32 patch__memset_nocache, patch__memcpy_nocache;
 
 extern long flush_branch_caches;
@@ -142,7 +143,7 @@ void kvmhv_load_host_pmu(void);
 void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use);
 void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu);
 
-int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+void kvmppc_p9_enter_guest(struct kvm_vcpu *vcpu);
 
 long kvmppc_h_set_dabr(struct kvm_vcpu *vcpu, unsigned long dabr);
 long kvmppc_h_set_xdabr(struct kvm_vcpu *vcpu, unsigned long dabr,
diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index a3633560493b..b4f9996bd331 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -146,7 +146,8 @@
 #define KVM_GUEST_MODE_GUEST	1
 #define KVM_GUEST_MODE_SKIP	2
 #define KVM_GUEST_MODE_GUEST_HV	3
-#define KVM_GUEST_MODE_HOST_HV	4
+#define KVM_GUEST_MODE_GUEST_HV_FAST	4 /* ISA v3.0 with host radix mode */
+#define KVM_GUEST_MODE_HOST_HV	5
 
 #define KVM_INST_FETCH_FAILED	-1
 
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 9bb9bb370b53..c214bcffb441 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -153,9 +153,17 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
 	return radix;
 }
 
+int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+
 #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
 #endif
 
+/*
+ * Invalid HDSISR value which is used to indicate when HW has not set the reg.
+ * Used to work around an errata.
+ */
+#define HDSISR_CANARY	0x7fff
+
 /*
  * We use a lock bit in HPTE dword 0 to synchronize updates and
  * accesses to each HPTE, and another bit to indicate non-present
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index e4e1a94ccf6a..6c37aeed0650 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -430,16 +430,19 @@ device_initcall(stf_barrier_debugfs_init);
 
 static void update_branch_cache_flush(void)
 {
-	u32 *site;
+	u32 *site, __maybe_unused *site2;
 
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 	site = &patch__call_kvm_flush_link_stack;
+	site2 = &patch__call_kvm_flush_link_stack_2;
 	// This controls the branch from guest_exit_cont to kvm_flush_link_stack
 	if (link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE) {
 		patch_instruction_site(site, ppc_inst(PPC_INST_NOP));
+		patch_instruction_site(site2, ppc_inst(PPC_INST_NOP));
 	} else {
 		// Could use HW flush, but that could also flush count cache
 		patch_branch_site(site, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
+		patch_branch_site(site2, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
 	}
 #endif
 
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index cdd119028f64..40a55a5ba4ff 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -43,6 +43,9 @@ kvm-objs-$(CONFIG_KVM_E500MC) := $(kvm-e500mc-objs)
 kvm-book3s_64-builtin-objs-$(CONFIG_SPAPR_TCE_IOMMU) := \
 	book3s_64_vio_hv.o
 
+kvm-book3s_64-builtin-objs-y += \
+	book3s_hv_interrupt.o
+
 kvm-pr-y := \
 	fpu.o \
 	emulate.o \
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index f826c8dc2e19..cc7b76865a16 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -1,10 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
+#include <asm/code-patching-asm.h>
 #include <asm/exception-64s.h>
+#include <asm/export.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_book3s_asm.h>
 #include <asm/ppc_asm.h>
 #include <asm/reg.h>
+#include <asm/ultravisor-api.h>
 
 /*
  * These are branched to from interrupt handlers in exception-64s.S which set
@@ -13,13 +17,24 @@
 .global	kvmppc_hcall
 .balign IFETCH_ALIGN_BYTES
 kvmppc_hcall:
+	lbz	r10,HSTATE_IN_GUEST(r13)
+	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
+	beq	kvmppc_p9_exit_hcall
 	ld	r10,PACA_EXGEN+EX_R13(r13)
 	SET_SCRATCH0(r10)
 	li	r10,0xc00
+	li	r11,PACA_EXGEN
+	b	1f
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
 kvmppc_interrupt:
+	std	r10,HSTATE_SCRATCH0(r13)
+	lbz	r10,HSTATE_IN_GUEST(r13)
+	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
+	beq	kvmppc_p9_exit_interrupt
+	ld	r10,HSTATE_SCRATCH0(r13)
+	lbz	r11,HSTATE_IN_GUEST(r13)
 	li	r11,PACA_EXGEN
 	cmpdi	r10,0x200
 	bgt+	1f
@@ -114,3 +129,169 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	GET_SCRATCH0(r13)
 	HRFI_TO_KERNEL
 #endif
+
+/* Stack frame offsets for kvmppc_hv_entry */
+#define SFS			208
+#define STACK_SLOT_VCPU		(SFS-8)
+#define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
+
+/*
+ * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
+ *
+ * Enter the guest on a ISAv3.0 or later system where we have exactly
+ * one vcpu per vcore, and both the host and guest are radix, and threads
+ * are set to "indepdent mode".
+ */
+.balign	IFETCH_ALIGN_BYTES
+_GLOBAL(kvmppc_p9_enter_guest)
+EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
+	mflr	r0
+	std	r0,PPC_LR_STKOFF(r1)
+	stdu	r1,-SFS(r1)
+
+	std	r1,HSTATE_HOST_R1(r13)
+	std	r3,STACK_SLOT_VCPU(r1)
+
+	mfcr	r4
+	stw	r4,SFS+8(r1)
+
+	reg = 14
+	.rept	18
+	std	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
+	reg = reg + 1
+	.endr
+
+	ld	r4,VCPU_LR(r3)
+	mtlr	r4
+	ld	r4,VCPU_CTR(r3)
+	mtctr	r4
+	ld	r4,VCPU_XER(r3)
+	mtspr	SPRN_XER,r4
+
+	ld	r1,VCPU_CR(r3)
+
+BEGIN_FTR_SECTION
+	ld	r4,VCPU_CFAR(r3)
+	mtspr	SPRN_CFAR,r4
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+BEGIN_FTR_SECTION
+	ld	r4,VCPU_PPR(r3)
+	mtspr	SPRN_PPR,r4
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	reg = 4
+	.rept	28
+	ld	reg,__VCPU_GPR(reg)(r3)
+	reg = reg + 1
+	.endr
+
+	ld	r4,VCPU_KVM(r3)
+	lbz	r4,KVM_SECURE_GUEST(r4)
+	cmpdi	r4,0
+	ld	r4,VCPU_GPR(R4)(r3)
+	bne	.Lret_to_ultra
+
+	mtcr	r1
+
+	ld	r0,VCPU_GPR(R0)(r3)
+	ld	r1,VCPU_GPR(R1)(r3)
+	ld	r2,VCPU_GPR(R2)(r3)
+	ld	r3,VCPU_GPR(R3)(r3)
+
+	HRFI_TO_GUEST
+	b	.
+
+	/*
+	 * Use UV_RETURN ultracall to return control back to the Ultravisor
+	 * after processing an hypercall or interrupt that was forwarded
+	 * (a.k.a. reflected) to the Hypervisor.
+	 *
+	 * All registers have already been reloaded except the ucall requires:
+	 *   R0 = hcall result
+	 *   R2 = SRR1, so UV can detect a synthesized interrupt (if any)
+	 *   R3 = UV_RETURN
+	 */
+.Lret_to_ultra:
+	mtcr	r1
+	ld	r1,VCPU_GPR(R1)(r3)
+
+	ld	r0,VCPU_GPR(R3)(r3)
+	mfspr	r2,SPRN_SRR1
+	LOAD_REG_IMMEDIATE(r3, UV_RETURN)
+	sc	2
+
+/*
+ * kvmppc_p9_exit_hcall and kvmppc_p9_exit_interrupt are branched to from
+ * above if the interrupt was taken for a guest that was entered via
+ * kvmppc_p9_enter_guest().
+ *
+ * This code recovers the host stack and vcpu pointer, saves all GPRs and
+ * CR, LR, CTR, XER as well as guest MSR and NIA into the VCPU, then re-
+ * establishes the host stack and registers to return from  the
+ * kvmppc_p9_enter_guest() function.
+ */
+.balign	IFETCH_ALIGN_BYTES
+kvmppc_p9_exit_hcall:
+	mfspr	r11,SPRN_SRR0
+	mfspr	r12,SPRN_SRR1
+	li	r10,0xc00
+	std	r10,HSTATE_SCRATCH0(r13)
+
+.balign	IFETCH_ALIGN_BYTES
+kvmppc_p9_exit_interrupt:
+	std     r1,HSTATE_SCRATCH1(r13)
+	std     r3,HSTATE_SCRATCH2(r13)
+	ld	r1,HSTATE_HOST_R1(r13)
+	ld	r3,STACK_SLOT_VCPU(r1)
+
+	std	r9,VCPU_CR(r3)
+
+1:
+	std	r11,VCPU_PC(r3)
+	std	r12,VCPU_MSR(r3)
+
+	reg = 14
+	.rept	18
+	std	reg,__VCPU_GPR(reg)(r3)
+	reg = reg + 1
+	.endr
+
+	/* r1, r3, r9-r13 are saved to vcpu by C code */
+	std	r0,VCPU_GPR(R0)(r3)
+	std	r2,VCPU_GPR(R2)(r3)
+	reg = 4
+	.rept	5
+	std	reg,__VCPU_GPR(reg)(r3)
+	reg = reg + 1
+	.endr
+
+	ld	r2,PACATOC(r13)
+
+	mflr	r4
+	std	r4,VCPU_LR(r3)
+	mfspr	r4,SPRN_XER
+	std	r4,VCPU_XER(r3)
+
+	reg = 14
+	.rept	18
+	ld	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
+	reg = reg + 1
+	.endr
+
+	lwz	r4,SFS+8(r1)
+	mtcr	r4
+
+	/*
+	 * Flush the link stack here, before executing the first blr on the
+	 * way out of the guest.
+	 *
+	 * The link stack won't match coming out of the guest anyway so the
+	 * only cost is the flush itself. The call clobbers r0.
+	 */
+1:	nop
+	patch_site 1b patch__call_kvm_flush_link_stack_2
+
+	addi	r1,r1,SFS
+	ld	r0,PPC_LR_STKOFF(r1)
+	mtlr	r0
+	blr
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1997cf347d3e..28a2761515e3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1421,6 +1421,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 	 */
 	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
 		r = RESUME_PAGE_FAULT;
+		if (vcpu->arch.fault_dsisr = HDSISR_CANARY)
+			r = RESUME_GUEST; /* Just retry if it's the canary */
 		break;
 	case BOOK3S_INTERRUPT_H_INST_STORAGE:
 		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
@@ -3736,14 +3738,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
 		vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
 		mtspr(SPRN_PSSCR_PR, host_psscr);
-
 		/* H_CEDE has to be handled now, not later */
-		if (trap = BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
+		if (trap = BOOK3S_INTERRUPT_SYSCALL &&
 		    kvmppc_get_gpr(vcpu, 3) = H_CEDE) {
 			kvmppc_cede(vcpu);
 			kvmppc_set_gpr(vcpu, 3, 0);
 			trap = 0;
 		}
+
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
 		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
@@ -3768,9 +3770,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			}
 		}
 		kvmppc_xive_pull_vcpu(vcpu);
+
+		vcpu->arch.slb_max = 0;
 	}
 
-	vcpu->arch.slb_max = 0;
 	dec = mfspr(SPRN_DEC);
 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 		dec = (s32) dec;
@@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		else
 			r = kvmppc_run_vcpu(vcpu);
 
-		if (run->exit_reason = KVM_EXIT_PAPR_HCALL &&
-		    !(vcpu->arch.shregs.msr & MSR_PR)) {
-			trace_kvm_hcall_enter(vcpu);
-			r = kvmppc_pseries_do_hcall(vcpu);
-			trace_kvm_hcall_exit(vcpu, r);
+		if (run->exit_reason = KVM_EXIT_PAPR_HCALL) {
+			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
+				/*
+				 * Guest userspace executed sc 1, reflect it
+				 * back as a privileged program check interrupt.
+				 */
+				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
+				r = RESUME_GUEST;
+			} else {
+				trace_kvm_hcall_enter(vcpu);
+				r = kvmppc_pseries_do_hcall(vcpu);
+				trace_kvm_hcall_exit(vcpu, r);
+			}
 			kvmppc_core_prepare_to_enter(vcpu);
 		} else if (r = RESUME_PAGE_FAULT) {
 			srcu_idx = srcu_read_lock(&kvm->srcu);
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
new file mode 100644
index 000000000000..5a7b036c447f
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <asm/asm-prototypes.h>
+#include <asm/dbell.h>
+#include <asm/kvm_ppc.h>
+
+#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
+static void __start_timing(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	u64 tb = mftb() - vc->tb_offset_applied;
+
+	vcpu->arch.cur_activity = next;
+	vcpu->arch.cur_tb_start = tb;
+}
+
+static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvmhv_tb_accumulator *curr;
+	u64 tb = mftb() - vc->tb_offset_applied;
+	u64 prev_tb;
+	u64 delta;
+	u64 seq;
+
+	curr = vcpu->arch.cur_activity;
+	vcpu->arch.cur_activity = next;
+	prev_tb = vcpu->arch.cur_tb_start;
+	vcpu->arch.cur_tb_start = tb;
+
+	if (!curr)
+		return;
+
+	delta = tb - prev_tb;
+
+	seq = curr->seqcount;
+	curr->seqcount = seq + 1;
+	smp_wmb();
+	curr->tb_total += delta;
+	if (seq = 0 || delta < curr->tb_min)
+		curr->tb_min = delta;
+	if (delta > curr->tb_max)
+		curr->tb_max = delta;
+	smp_wmb();
+	curr->seqcount = seq + 2;
+}
+
+#define start_timing(vcpu, next) __start_timing(vcpu, next)
+#define end_timing(vcpu) __start_timing(vcpu, NULL)
+#define accumulate_time(vcpu, next) __accumulate_time(vcpu, next)
+#else
+#define start_timing(vcpu, next) do {} while (0)
+#define end_timing(vcpu) do {} while (0)
+#define accumulate_time(vcpu, next) do {} while (0)
+#endif
+
+static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
+{
+	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
+	asm volatile("slbmfee  %0,%1" : "=r" (*slbee) : "r" (idx));
+}
+
+static inline void mtslb(unsigned int idx, u64 slbee, u64 slbev)
+{
+	BUG_ON((slbee & 0xfff) != idx);
+
+	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+}
+
+static inline void slb_invalidate(unsigned int ih)
+{
+	asm volatile("slbia %0" :: "i"(ih));
+}
+
+/*
+ * Malicious or buggy radix guests may have inserted SLB entries
+ * (only 0..3 because radix always runs with UPRT=1), so these must
+ * be cleared here to avoid side-channels. slbmte is used rather
+ * than slbia, as it won't clear cached translations.
+ */
+static void radix_clear_slb(void)
+{
+	u64 slbee, slbev;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		mfslb(i, &slbee, &slbev);
+		if (unlikely(slbee || slbev)) {
+			slbee = i;
+			slbev = 0;
+			mtslb(i, slbee, slbev);
+		}
+	}
+}
+
+int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
+{
+	u64 *exsave;
+	unsigned long msr = mfmsr();
+	int trap;
+
+	start_timing(vcpu, &vcpu->arch.rm_entry);
+
+	vcpu->arch.ceded = 0;
+
+	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
+	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
+
+	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
+	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
+
+	/*
+	 * On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage
+	 * Interrupt (HDSI) the HDSISR is not be updated at all.
+	 *
+	 * To work around this we put a canary value into the HDSISR before
+	 * returning to a guest and then check for this canary when we take a
+	 * HDSI. If we find the canary on a HDSI, we know the hardware didn't
+	 * update the HDSISR. In this case we return to the guest to retake the
+	 * HDSI which should correctly update the HDSISR the second time HDSI
+	 * entry.
+	 *
+	 * Just do this on all p9 processors for now.
+	 */
+	mtspr(SPRN_HDSISR, HDSISR_CANARY);
+
+	accumulate_time(vcpu, &vcpu->arch.guest_time);
+
+	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
+	kvmppc_p9_enter_guest(vcpu);
+	// Radix host and guest means host never runs with guest MMU state
+	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
+
+	accumulate_time(vcpu, &vcpu->arch.rm_intr);
+
+	/* Get these from r11/12 and paca exsave */
+	vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
+	vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
+	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
+	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
+
+	trap = local_paca->kvm_hstate.scratch0 & ~0x2;
+	if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+		exsave = local_paca->exgen;
+	} else if (trap = BOOK3S_INTERRUPT_SYSTEM_RESET) {
+		exsave = local_paca->exnmi;
+	} else { /* trap = 0x200 */
+		exsave = local_paca->exmc;
+	}
+
+	vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
+	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
+	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
+	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
+	vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
+	vcpu->arch.regs.gpr[12] = exsave[EX_R12/sizeof(u64)];
+	vcpu->arch.regs.gpr[13] = exsave[EX_R13/sizeof(u64)];
+	vcpu->arch.ppr = exsave[EX_PPR/sizeof(u64)];
+	vcpu->arch.cfar = exsave[EX_CFAR/sizeof(u64)];
+	vcpu->arch.regs.ctr = exsave[EX_CTR/sizeof(u64)];
+
+	vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
+
+	if (unlikely(trap = BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+		kvmppc_realmode_machine_check(vcpu);
+
+	} else if (unlikely(trap = BOOK3S_INTERRUPT_HMI)) {
+		kvmppc_realmode_hmi_handler();
+
+	} else if (trap = BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
+		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+	} else if (trap = BOOK3S_INTERRUPT_H_DATA_STORAGE) {
+		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+	} else if (trap = BOOK3S_INTERRUPT_H_INST_STORAGE) {
+		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+	} else if (trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL) {
+		vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/*
+	 * Softpatch interrupt for transactional memory emulation cases
+	 * on POWER9 DD2.2.  This is early in the guest exit path - we
+	 * haven't saved registers or done a treclaim yet.
+	 */
+	} else if (trap = BOOK3S_INTERRUPT_HV_SOFTPATCH) {
+		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+		/*
+		 * The cases we want to handle here are those where the guest
+		 * is in real suspend mode and is trying to transition to
+		 * transactional mode.
+		 */
+		if (local_paca->kvm_hstate.fake_suspend &&
+				(vcpu->arch.shregs.msr & MSR_TS_S)) {
+			if (kvmhv_p9_tm_emulation_early(vcpu)) {
+				/* Prevent it being handled again. */
+				trap = 0;
+			}
+		}
+#endif
+	}
+
+	radix_clear_slb();
+
+	__mtmsrd(msr, 0);
+
+	accumulate_time(vcpu, &vcpu->arch.rm_exit);
+
+	end_timing(vcpu);
+
+	return trap;
+}
+EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 2d0d14ed1d92..6118e8a97ddd 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -44,9 +44,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define NAPPING_UNSPLIT	3
 
 /* Stack frame offsets for kvmppc_hv_entry */
-#define SFS			208
+#define SFS			160
 #define STACK_SLOT_TRAP		(SFS-4)
-#define STACK_SLOT_SHORT_PATH	(SFS-8)
 #define STACK_SLOT_TID		(SFS-16)
 #define STACK_SLOT_PSSCR	(SFS-24)
 #define STACK_SLOT_PID		(SFS-32)
@@ -59,8 +58,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define STACK_SLOT_UAMOR	(SFS-88)
 #define STACK_SLOT_DAWR1	(SFS-96)
 #define STACK_SLOT_DAWRX1	(SFS-104)
-/* the following is used by the P9 short path */
-#define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
 
 /*
  * Call kvmppc_hv_entry in real mode.
@@ -1008,9 +1005,6 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
 no_xive:
 #endif /* CONFIG_KVM_XICS */
 
-	li	r0, 0
-	stw	r0, STACK_SLOT_SHORT_PATH(r1)
-
 deliver_guest_interrupt:	/* r4 = vcpu, r13 = paca */
 	/* Check if we can deliver an external or decrementer interrupt now */
 	ld	r0, VCPU_PENDING_EXC(r4)
@@ -1030,7 +1024,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	mtspr	SPRN_SRR0, r6
 	mtspr	SPRN_SRR1, r7
 
-fast_guest_entry_c:
 	ld	r10, VCPU_PC(r4)
 	ld	r11, VCPU_MSR(r4)
 	/* r11 = vcpu->arch.msr & ~MSR_HV */
@@ -1135,97 +1128,6 @@ ret_to_ultra:
 	ld	r4, VCPU_GPR(R4)(r4)
 	sc	2
 
-/*
- * Enter the guest on a P9 or later system where we have exactly
- * one vcpu per vcore and we don't need to go to real mode
- * (which implies that host and guest are both using radix MMU mode).
- * r3 = vcpu pointer
- * Most SPRs and all the VSRs have been loaded already.
- */
-_GLOBAL(__kvmhv_vcpu_entry_p9)
-EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9)
-	mflr	r0
-	std	r0, PPC_LR_STKOFF(r1)
-	stdu	r1, -SFS(r1)
-
-	li	r0, 1
-	stw	r0, STACK_SLOT_SHORT_PATH(r1)
-
-	std	r3, HSTATE_KVM_VCPU(r13)
-	mfcr	r4
-	stw	r4, SFS+8(r1)
-
-	std	r1, HSTATE_HOST_R1(r13)
-
-	reg = 14
-	.rept	18
-	std	reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
-	reg = reg + 1
-	.endr
-
-	reg = 14
-	.rept	18
-	ld	reg, __VCPU_GPR(reg)(r3)
-	reg = reg + 1
-	.endr
-
-	mfmsr	r10
-	std	r10, HSTATE_HOST_MSR(r13)
-
-	mr	r4, r3
-	b	fast_guest_entry_c
-guest_exit_short_path:
-	/*
-	 * Malicious or buggy radix guests may have inserted SLB entries
-	 * (only 0..3 because radix always runs with UPRT=1), so these must
-	 * be cleared here to avoid side-channels. slbmte is used rather
-	 * than slbia, as it won't clear cached translations.
-	 */
-	li	r0,0
-	slbmte	r0,r0
-	li	r4,1
-	slbmte	r0,r4
-	li	r4,2
-	slbmte	r0,r4
-	li	r4,3
-	slbmte	r0,r4
-
-	li	r0, KVM_GUEST_MODE_NONE
-	stb	r0, HSTATE_IN_GUEST(r13)
-
-	reg = 14
-	.rept	18
-	std	reg, __VCPU_GPR(reg)(r9)
-	reg = reg + 1
-	.endr
-
-	reg = 14
-	.rept	18
-	ld	reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
-	reg = reg + 1
-	.endr
-
-	lwz	r4, SFS+8(r1)
-	mtcr	r4
-
-	mr	r3, r12		/* trap number */
-
-	addi	r1, r1, SFS
-	ld	r0, PPC_LR_STKOFF(r1)
-	mtlr	r0
-
-	/* If we are in real mode, do a rfid to get back to the caller */
-	mfmsr	r4
-	andi.	r5, r4, MSR_IR
-	bnelr
-	rldicl	r5, r4, 64 - MSR_TS_S_LG, 62	/* extract TS field */
-	mtspr	SPRN_SRR0, r0
-	ld	r10, HSTATE_HOST_MSR(r13)
-	rldimi	r10, r5, MSR_TS_S_LG, 63 - MSR_TS_T_LG
-	mtspr	SPRN_SRR1, r10
-	RFI_TO_KERNEL
-	b	.
-
 secondary_too_late:
 	li	r12, 0
 	stw	r12, STACK_SLOT_TRAP(r1)
@@ -1397,14 +1299,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	mr	r4,r9
 	bge	fast_guest_return
 2:
-	/* If we came in through the P9 short path, no real mode hcalls */
-	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
-	cmpwi	r0, 0
-	bne	no_try_real
 	/* See if this is an hcall we can handle in real mode */
 	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
 	beq	hcall_try_real_mode
-no_try_real:
 
 	/* Hypervisor doorbell - exit only if host IPI flag set */
 	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
@@ -1447,11 +1344,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	bl	kvmhv_accumulate_time
 #endif
 #ifdef CONFIG_KVM_XICS
-	/* If we came in through the P9 short path, xive pull is done in C */
-	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
-	cmpwi	r0, 0
-	bne	1f
-
 	/* We are exiting, pull the VP from the XIVE */
 	lbz	r0, VCPU_XIVE_PUSHED(r9)
 	cmpwi	cr0, r0, 0
@@ -1496,11 +1388,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 1:	nop
 	patch_site 1b patch__call_kvm_flush_link_stack
 
-	/* If we came in through the P9 short path, go back out to C now */
-	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
-	cmpwi	r0, 0
-	bne	guest_exit_short_path
-
 	/* For hash guest, read the guest SLB and save it away */
 	ld	r5, VCPU_KVM(r9)
 	lbz	r0, KVM_RADIX(r5)
@@ -1548,8 +1435,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 	b	guest_bypass
 
 0:	/*
-	 * Sanitise radix guest SLB, see guest_exit_short_path comment.
-	 * We clear vcpu->arch.slb_max to match earlier behaviour.
+	 * Malicious or buggy radix guests may have inserted SLB entries
+	 * (only 0..3 because radix always runs with UPRT=1), so these must
+	 * be cleared here to avoid side-channels. slbmte is used rather
+	 * than slbia, as it won't clear cached translations.
 	 */
 	li	r0,0
 	stw	r0,VCPU_SLB_MAX(r9)
@@ -3362,7 +3251,7 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWRX1, r0
 END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 
-	/* Clear hash and radix guest SLB, see guest_exit_short_path comment. */
+	/* Clear hash and radix guest SLB. */
 	slbmte	r0, r0
 	PPC_SLBIA(6)
 
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index d2266d36a7c7..cb03ed147b42 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -161,6 +161,40 @@ void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvmppc_xive_pull_vcpu);
 
+void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu)
+{
+	void __iomem *esc_vaddr = (void __iomem *)vcpu->arch.xive_esc_vaddr;
+
+	if (!esc_vaddr)
+		return;
+
+	/* we are using XIVE with single escalation */
+
+	if (vcpu->arch.xive_esc_on) {
+		/*
+		 * If we still have a pending escalation, abort the cede,
+		 * and we must set PQ to 10 rather than 00 so that we don't
+		 * potentially end up with two entries for the escalation
+		 * interrupt in the XIVE interrupt queue.  In that case
+		 * we also don't want to set xive_esc_on to 1 here in
+		 * case we race with xive_esc_irq().
+		 */
+		vcpu->arch.ceded = 0;
+		/*
+		 * The escalation interrupts are special as we don't EOI them.
+		 * There is no need to use the load-after-store ordering offset
+		 * to set PQ to 10 as we won't use StoreEOI.
+		 */
+		__raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_10);
+	} else {
+		vcpu->arch.xive_esc_on = true;
+		mb();
+		__raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_00);
+	}
+	mb();
+}
+EXPORT_SYMBOL_GPL(kvmppc_xive_cede_vcpu);
+
 /*
  * This is a simple trigger for a generic XIVE IRQ. This must
  * only be called for interrupts that support a trigger page
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entry_p9
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Now the initial C implementation is done, inline more HV code to make
rearranging things easier.

And rename __kvmhv_vcpu_entry_p9 to drop the leading underscores as it's
now C, and is now a more complete vcpu entry.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_book3s_64.h |   2 +-
 arch/powerpc/kvm/book3s_hv.c             | 181 +----------------------
 arch/powerpc/kvm/book3s_hv_interrupt.c   | 168 ++++++++++++++++++++-
 3 files changed, 169 insertions(+), 182 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index c214bcffb441..eaf3a562bf1e 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -153,7 +153,7 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
 	return radix;
 }
 
-int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr);
 
 #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
 #endif
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 28a2761515e3..f99503acdda5 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3442,183 +3442,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
-static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
-{
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	struct kvm_nested_guest *nested = vcpu->arch.nested;
-	u32 lpid;
-
-	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
-
-	mtspr(SPRN_LPID, lpid);
-	mtspr(SPRN_LPCR, lpcr);
-	mtspr(SPRN_PID, vcpu->arch.pid);
-	isync();
-
-	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
-	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
-}
-
-static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
-{
-	mtspr(SPRN_PID, pid);
-	mtspr(SPRN_LPID, kvm->arch.host_lpid);
-	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
-	isync();
-}
-
-/*
- * Load up hypervisor-mode registers on P9.
- */
-static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
-				     unsigned long lpcr)
-{
-	struct kvm *kvm = vcpu->kvm;
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	s64 hdec;
-	u64 tb, purr, spurr;
-	int trap;
-	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
-	unsigned long host_ciabr = mfspr(SPRN_CIABR);
-	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
-	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
-	unsigned long host_psscr = mfspr(SPRN_PSSCR);
-	unsigned long host_pidr = mfspr(SPRN_PID);
-	unsigned long host_dawr1 = 0;
-	unsigned long host_dawrx1 = 0;
-
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		host_dawr1 = mfspr(SPRN_DAWR1);
-		host_dawrx1 = mfspr(SPRN_DAWRX1);
-	}
-
-	tb = mftb();
-	hdec = time_limit - tb;
-	if (hdec < 0)
-		return BOOK3S_INTERRUPT_HV_DECREMENTER;
-
-	if (vc->tb_offset) {
-		u64 new_tb = tb + vc->tb_offset;
-		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
-		vc->tb_offset_applied = vc->tb_offset;
-	}
-
-	if (vc->pcr)
-		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
-	mtspr(SPRN_DPDES, vc->dpdes);
-	mtspr(SPRN_VTB, vc->vtb);
-
-	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
-	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
-	mtspr(SPRN_PURR, vcpu->arch.purr);
-	mtspr(SPRN_SPURR, vcpu->arch.spurr);
-
-	if (dawr_enabled()) {
-		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
-		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
-		if (cpu_has_feature(CPU_FTR_DAWR1)) {
-			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
-			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
-		}
-	}
-	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
-	mtspr(SPRN_IC, vcpu->arch.ic);
-
-	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
-	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
-
-	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
-
-	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
-	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
-	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
-	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
-
-	mtspr(SPRN_AMOR, ~0UL);
-
-	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
-
-	/*
-	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
-	 * so set guest LPCR (with HDICE) before writing HDEC.
-	 */
-	mtspr(SPRN_HDEC, hdec);
-
-	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
-	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
-
-	trap = __kvmhv_vcpu_entry_p9(vcpu);
-
-	/* Advance host PURR/SPURR by the amount used by guest */
-	purr = mfspr(SPRN_PURR);
-	spurr = mfspr(SPRN_SPURR);
-	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
-	      purr - vcpu->arch.purr);
-	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
-	      spurr - vcpu->arch.spurr);
-	vcpu->arch.purr = purr;
-	vcpu->arch.spurr = spurr;
-
-	vcpu->arch.ic = mfspr(SPRN_IC);
-	vcpu->arch.pid = mfspr(SPRN_PID);
-	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
-
-	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
-	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
-	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
-	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
-
-	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
-	mtspr(SPRN_PSSCR, host_psscr |
-	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
-	mtspr(SPRN_HFSCR, host_hfscr);
-	mtspr(SPRN_CIABR, host_ciabr);
-	mtspr(SPRN_DAWR0, host_dawr0);
-	mtspr(SPRN_DAWRX0, host_dawrx0);
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		mtspr(SPRN_DAWR1, host_dawr1);
-		mtspr(SPRN_DAWRX1, host_dawrx1);
-	}
-
-	/*
-	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
-	 * case we interrupted the guest between a tlbie and a ptesync.
-	 */
-	asm volatile("eieio; tlbsync; ptesync");
-
-	/*
-	 * cp_abort is required if the processor supports local copy-paste
-	 * to clear the copy buffer that was under control of the guest.
-	 */
-	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		asm volatile(PPC_CP_ABORT);
-
-	vc->dpdes = mfspr(SPRN_DPDES);
-	vc->vtb = mfspr(SPRN_VTB);
-	mtspr(SPRN_DPDES, 0);
-	if (vc->pcr)
-		mtspr(SPRN_PCR, PCR_MASK);
-
-	if (vc->tb_offset_applied) {
-		u64 new_tb = mftb() - vc->tb_offset_applied;
-		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
-		vc->tb_offset_applied = 0;
-	}
-
-	/* HDEC must be at least as large as DEC, so decrementer_max fits */
-	mtspr(SPRN_HDEC, decrementer_max);
-
-	switch_mmu_to_host_radix(kvm, host_pidr);
-
-	return trap;
-}
-
 /*
  * Virtual-mode guest entry for POWER9 and later when the host and
  * guest are both using the radix MMU.  The LPIDR has already been set.
@@ -3710,7 +3533,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		 * We need to save and restore the guest visible part of the
 		 * psscr (i.e. using SPRN_PSSCR_PR) since the hypervisor
 		 * doesn't do this for us. Note only required if pseries since
-		 * this is done in kvmhv_load_hv_regs_and_go() below otherwise.
+		 * this is done in kvmhv_vcpu_entry_p9() below otherwise.
 		 */
 		unsigned long host_psscr;
 		/* call our hypervisor to load up HV regs and go */
@@ -3748,7 +3571,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
-		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
+		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr);
 		/* H_CEDE has to be handled now, not later */
 		/* XICS hcalls must be handled before xive is pulled */
 		if (trap == BOOK3S_INTERRUPT_SYSCALL &&
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index 5a7b036c447f..dea3eca3648a 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -55,6 +55,31 @@ static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator
 #define accumulate_time(vcpu, next) do {} while (0)
 #endif
 
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+
+	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+	isync();
+
+	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
+	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+}
+
+static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+{
+	mtspr(SPRN_PID, pid);
+	mtspr(SPRN_LPID, kvm->arch.host_lpid);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+	isync();
+}
+
 static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
 {
 	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
@@ -94,11 +119,86 @@ static void radix_clear_slb(void)
 	}
 }
 
-int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
+int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
 {
+	struct kvm *kvm = vcpu->kvm;
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	s64 hdec;
+	u64 tb, purr, spurr;
 	u64 *exsave;
 	unsigned long msr = mfmsr();
 	int trap;
+	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
+	unsigned long host_ciabr = mfspr(SPRN_CIABR);
+	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
+	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
+	unsigned long host_psscr = mfspr(SPRN_PSSCR);
+	unsigned long host_pidr = mfspr(SPRN_PID);
+	unsigned long host_dawr1 = 0;
+	unsigned long host_dawrx1 = 0;
+
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		host_dawr1 = mfspr(SPRN_DAWR1);
+		host_dawrx1 = mfspr(SPRN_DAWRX1);
+	}
+
+	tb = mftb();
+	hdec = time_limit - tb;
+	if (hdec < 0)
+		return BOOK3S_INTERRUPT_HV_DECREMENTER;
+
+	if (vc->tb_offset) {
+		u64 new_tb = tb + vc->tb_offset;
+		mtspr(SPRN_TBU40, new_tb);
+		tb = mftb();
+		if ((tb & 0xffffff) < (new_tb & 0xffffff))
+			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		vc->tb_offset_applied = vc->tb_offset;
+	}
+
+	if (vc->pcr)
+		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
+	mtspr(SPRN_DPDES, vc->dpdes);
+	mtspr(SPRN_VTB, vc->vtb);
+
+	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
+	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
+	mtspr(SPRN_PURR, vcpu->arch.purr);
+	mtspr(SPRN_SPURR, vcpu->arch.spurr);
+
+	if (dawr_enabled()) {
+		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
+		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
+		if (cpu_has_feature(CPU_FTR_DAWR1)) {
+			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
+			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
+		}
+	}
+	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
+	mtspr(SPRN_IC, vcpu->arch.ic);
+
+	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
+	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+
+	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
+
+	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
+	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
+	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
+	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
+
+	mtspr(SPRN_AMOR, ~0UL);
+
+	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+
+	/*
+	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+	 * so set guest LPCR (with HDICE) before writing HDEC.
+	 */
+	mtspr(SPRN_HDEC, hdec);
+
+	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
+	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
 
 	start_timing(vcpu, &vcpu->arch.rm_entry);
 
@@ -216,6 +316,70 @@ int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
 
 	end_timing(vcpu);
 
+	/* Advance host PURR/SPURR by the amount used by guest */
+	purr = mfspr(SPRN_PURR);
+	spurr = mfspr(SPRN_SPURR);
+	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
+	      purr - vcpu->arch.purr);
+	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
+	      spurr - vcpu->arch.spurr);
+	vcpu->arch.purr = purr;
+	vcpu->arch.spurr = spurr;
+
+	vcpu->arch.ic = mfspr(SPRN_IC);
+	vcpu->arch.pid = mfspr(SPRN_PID);
+	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
+
+	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
+	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
+	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
+	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
+
+	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
+	mtspr(SPRN_PSSCR, host_psscr |
+	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+	mtspr(SPRN_HFSCR, host_hfscr);
+	mtspr(SPRN_CIABR, host_ciabr);
+	mtspr(SPRN_DAWR0, host_dawr0);
+	mtspr(SPRN_DAWRX0, host_dawrx0);
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		mtspr(SPRN_DAWR1, host_dawr1);
+		mtspr(SPRN_DAWRX1, host_dawrx1);
+	}
+
+	/*
+	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
+	 * case we interrupted the guest between a tlbie and a ptesync.
+	 */
+	asm volatile("eieio; tlbsync; ptesync");
+
+	/*
+	 * cp_abort is required if the processor supports local copy-paste
+	 * to clear the copy buffer that was under control of the guest.
+	 */
+	if (cpu_has_feature(CPU_FTR_ARCH_31))
+		asm volatile(PPC_CP_ABORT);
+
+	vc->dpdes = mfspr(SPRN_DPDES);
+	vc->vtb = mfspr(SPRN_VTB);
+	mtspr(SPRN_DPDES, 0);
+	if (vc->pcr)
+		mtspr(SPRN_PCR, PCR_MASK);
+
+	if (vc->tb_offset_applied) {
+		u64 new_tb = mftb() - vc->tb_offset_applied;
+		mtspr(SPRN_TBU40, new_tb);
+		tb = mftb();
+		if ((tb & 0xffffff) < (new_tb & 0xffffff))
+			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		vc->tb_offset_applied = 0;
+	}
+
+	/* HDEC must be at least as large as DEC, so decrementer_max fits */
+	mtspr(SPRN_HDEC, decrementer_max);
+
+	switch_mmu_to_host_radix(kvm, host_pidr);
+
 	return trap;
 }
-EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
+EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entry_p9
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Now the initial C implementation is done, inline more HV code to make
rearranging things easier.

And rename __kvmhv_vcpu_entry_p9 to drop the leading underscores as it's
now C, and is now a more complete vcpu entry.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_book3s_64.h |   2 +-
 arch/powerpc/kvm/book3s_hv.c             | 181 +----------------------
 arch/powerpc/kvm/book3s_hv_interrupt.c   | 168 ++++++++++++++++++++-
 3 files changed, 169 insertions(+), 182 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index c214bcffb441..eaf3a562bf1e 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -153,7 +153,7 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
 	return radix;
 }
 
-int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr);
 
 #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
 #endif
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 28a2761515e3..f99503acdda5 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3442,183 +3442,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
-static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
-{
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	struct kvm_nested_guest *nested = vcpu->arch.nested;
-	u32 lpid;
-
-	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
-
-	mtspr(SPRN_LPID, lpid);
-	mtspr(SPRN_LPCR, lpcr);
-	mtspr(SPRN_PID, vcpu->arch.pid);
-	isync();
-
-	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
-	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
-}
-
-static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
-{
-	mtspr(SPRN_PID, pid);
-	mtspr(SPRN_LPID, kvm->arch.host_lpid);
-	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
-	isync();
-}
-
-/*
- * Load up hypervisor-mode registers on P9.
- */
-static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
-				     unsigned long lpcr)
-{
-	struct kvm *kvm = vcpu->kvm;
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	s64 hdec;
-	u64 tb, purr, spurr;
-	int trap;
-	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
-	unsigned long host_ciabr = mfspr(SPRN_CIABR);
-	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
-	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
-	unsigned long host_psscr = mfspr(SPRN_PSSCR);
-	unsigned long host_pidr = mfspr(SPRN_PID);
-	unsigned long host_dawr1 = 0;
-	unsigned long host_dawrx1 = 0;
-
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		host_dawr1 = mfspr(SPRN_DAWR1);
-		host_dawrx1 = mfspr(SPRN_DAWRX1);
-	}
-
-	tb = mftb();
-	hdec = time_limit - tb;
-	if (hdec < 0)
-		return BOOK3S_INTERRUPT_HV_DECREMENTER;
-
-	if (vc->tb_offset) {
-		u64 new_tb = tb + vc->tb_offset;
-		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
-		vc->tb_offset_applied = vc->tb_offset;
-	}
-
-	if (vc->pcr)
-		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
-	mtspr(SPRN_DPDES, vc->dpdes);
-	mtspr(SPRN_VTB, vc->vtb);
-
-	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
-	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
-	mtspr(SPRN_PURR, vcpu->arch.purr);
-	mtspr(SPRN_SPURR, vcpu->arch.spurr);
-
-	if (dawr_enabled()) {
-		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
-		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
-		if (cpu_has_feature(CPU_FTR_DAWR1)) {
-			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
-			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
-		}
-	}
-	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
-	mtspr(SPRN_IC, vcpu->arch.ic);
-
-	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
-	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
-
-	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
-
-	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
-	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
-	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
-	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
-
-	mtspr(SPRN_AMOR, ~0UL);
-
-	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
-
-	/*
-	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
-	 * so set guest LPCR (with HDICE) before writing HDEC.
-	 */
-	mtspr(SPRN_HDEC, hdec);
-
-	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
-	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
-
-	trap = __kvmhv_vcpu_entry_p9(vcpu);
-
-	/* Advance host PURR/SPURR by the amount used by guest */
-	purr = mfspr(SPRN_PURR);
-	spurr = mfspr(SPRN_SPURR);
-	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
-	      purr - vcpu->arch.purr);
-	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
-	      spurr - vcpu->arch.spurr);
-	vcpu->arch.purr = purr;
-	vcpu->arch.spurr = spurr;
-
-	vcpu->arch.ic = mfspr(SPRN_IC);
-	vcpu->arch.pid = mfspr(SPRN_PID);
-	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
-
-	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
-	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
-	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
-	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
-
-	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
-	mtspr(SPRN_PSSCR, host_psscr |
-	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
-	mtspr(SPRN_HFSCR, host_hfscr);
-	mtspr(SPRN_CIABR, host_ciabr);
-	mtspr(SPRN_DAWR0, host_dawr0);
-	mtspr(SPRN_DAWRX0, host_dawrx0);
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		mtspr(SPRN_DAWR1, host_dawr1);
-		mtspr(SPRN_DAWRX1, host_dawrx1);
-	}
-
-	/*
-	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
-	 * case we interrupted the guest between a tlbie and a ptesync.
-	 */
-	asm volatile("eieio; tlbsync; ptesync");
-
-	/*
-	 * cp_abort is required if the processor supports local copy-paste
-	 * to clear the copy buffer that was under control of the guest.
-	 */
-	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		asm volatile(PPC_CP_ABORT);
-
-	vc->dpdes = mfspr(SPRN_DPDES);
-	vc->vtb = mfspr(SPRN_VTB);
-	mtspr(SPRN_DPDES, 0);
-	if (vc->pcr)
-		mtspr(SPRN_PCR, PCR_MASK);
-
-	if (vc->tb_offset_applied) {
-		u64 new_tb = mftb() - vc->tb_offset_applied;
-		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
-		vc->tb_offset_applied = 0;
-	}
-
-	/* HDEC must be at least as large as DEC, so decrementer_max fits */
-	mtspr(SPRN_HDEC, decrementer_max);
-
-	switch_mmu_to_host_radix(kvm, host_pidr);
-
-	return trap;
-}
-
 /*
  * Virtual-mode guest entry for POWER9 and later when the host and
  * guest are both using the radix MMU.  The LPIDR has already been set.
@@ -3710,7 +3533,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		 * We need to save and restore the guest visible part of the
 		 * psscr (i.e. using SPRN_PSSCR_PR) since the hypervisor
 		 * doesn't do this for us. Note only required if pseries since
-		 * this is done in kvmhv_load_hv_regs_and_go() below otherwise.
+		 * this is done in kvmhv_vcpu_entry_p9() below otherwise.
 		 */
 		unsigned long host_psscr;
 		/* call our hypervisor to load up HV regs and go */
@@ -3748,7 +3571,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
-		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
+		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr);
 		/* H_CEDE has to be handled now, not later */
 		/* XICS hcalls must be handled before xive is pulled */
 		if (trap = BOOK3S_INTERRUPT_SYSCALL &&
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index 5a7b036c447f..dea3eca3648a 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -55,6 +55,31 @@ static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator
 #define accumulate_time(vcpu, next) do {} while (0)
 #endif
 
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+
+	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+	isync();
+
+	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
+	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+}
+
+static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+{
+	mtspr(SPRN_PID, pid);
+	mtspr(SPRN_LPID, kvm->arch.host_lpid);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+	isync();
+}
+
 static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
 {
 	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
@@ -94,11 +119,86 @@ static void radix_clear_slb(void)
 	}
 }
 
-int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
+int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
 {
+	struct kvm *kvm = vcpu->kvm;
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	s64 hdec;
+	u64 tb, purr, spurr;
 	u64 *exsave;
 	unsigned long msr = mfmsr();
 	int trap;
+	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
+	unsigned long host_ciabr = mfspr(SPRN_CIABR);
+	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
+	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
+	unsigned long host_psscr = mfspr(SPRN_PSSCR);
+	unsigned long host_pidr = mfspr(SPRN_PID);
+	unsigned long host_dawr1 = 0;
+	unsigned long host_dawrx1 = 0;
+
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		host_dawr1 = mfspr(SPRN_DAWR1);
+		host_dawrx1 = mfspr(SPRN_DAWRX1);
+	}
+
+	tb = mftb();
+	hdec = time_limit - tb;
+	if (hdec < 0)
+		return BOOK3S_INTERRUPT_HV_DECREMENTER;
+
+	if (vc->tb_offset) {
+		u64 new_tb = tb + vc->tb_offset;
+		mtspr(SPRN_TBU40, new_tb);
+		tb = mftb();
+		if ((tb & 0xffffff) < (new_tb & 0xffffff))
+			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		vc->tb_offset_applied = vc->tb_offset;
+	}
+
+	if (vc->pcr)
+		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
+	mtspr(SPRN_DPDES, vc->dpdes);
+	mtspr(SPRN_VTB, vc->vtb);
+
+	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
+	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
+	mtspr(SPRN_PURR, vcpu->arch.purr);
+	mtspr(SPRN_SPURR, vcpu->arch.spurr);
+
+	if (dawr_enabled()) {
+		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
+		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
+		if (cpu_has_feature(CPU_FTR_DAWR1)) {
+			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
+			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
+		}
+	}
+	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
+	mtspr(SPRN_IC, vcpu->arch.ic);
+
+	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
+	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+
+	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
+
+	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
+	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
+	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
+	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
+
+	mtspr(SPRN_AMOR, ~0UL);
+
+	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+
+	/*
+	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+	 * so set guest LPCR (with HDICE) before writing HDEC.
+	 */
+	mtspr(SPRN_HDEC, hdec);
+
+	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
+	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
 
 	start_timing(vcpu, &vcpu->arch.rm_entry);
 
@@ -216,6 +316,70 @@ int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
 
 	end_timing(vcpu);
 
+	/* Advance host PURR/SPURR by the amount used by guest */
+	purr = mfspr(SPRN_PURR);
+	spurr = mfspr(SPRN_SPURR);
+	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
+	      purr - vcpu->arch.purr);
+	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
+	      spurr - vcpu->arch.spurr);
+	vcpu->arch.purr = purr;
+	vcpu->arch.spurr = spurr;
+
+	vcpu->arch.ic = mfspr(SPRN_IC);
+	vcpu->arch.pid = mfspr(SPRN_PID);
+	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
+
+	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
+	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
+	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
+	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
+
+	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
+	mtspr(SPRN_PSSCR, host_psscr |
+	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+	mtspr(SPRN_HFSCR, host_hfscr);
+	mtspr(SPRN_CIABR, host_ciabr);
+	mtspr(SPRN_DAWR0, host_dawr0);
+	mtspr(SPRN_DAWRX0, host_dawrx0);
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		mtspr(SPRN_DAWR1, host_dawr1);
+		mtspr(SPRN_DAWRX1, host_dawrx1);
+	}
+
+	/*
+	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
+	 * case we interrupted the guest between a tlbie and a ptesync.
+	 */
+	asm volatile("eieio; tlbsync; ptesync");
+
+	/*
+	 * cp_abort is required if the processor supports local copy-paste
+	 * to clear the copy buffer that was under control of the guest.
+	 */
+	if (cpu_has_feature(CPU_FTR_ARCH_31))
+		asm volatile(PPC_CP_ABORT);
+
+	vc->dpdes = mfspr(SPRN_DPDES);
+	vc->vtb = mfspr(SPRN_VTB);
+	mtspr(SPRN_DPDES, 0);
+	if (vc->pcr)
+		mtspr(SPRN_PCR, PCR_MASK);
+
+	if (vc->tb_offset_applied) {
+		u64 new_tb = mftb() - vc->tb_offset_applied;
+		mtspr(SPRN_TBU40, new_tb);
+		tb = mftb();
+		if ((tb & 0xffffff) < (new_tb & 0xffffff))
+			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		vc->tb_offset_applied = 0;
+	}
+
+	/* HDEC must be at least as large as DEC, so decrementer_max fits */
+	mtspr(SPRN_HDEC, decrementer_max);
+
+	switch_mmu_to_host_radix(kvm, host_pidr);
+
 	return trap;
 }
-EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
+EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 25/37] KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

SRR0/1, DAR, DSISR must all be protected from machine check which can
clobber them. Ensure MSR[RI] is clear while they are live.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c           |  5 +++--
 arch/powerpc/kvm/book3s_hv_interrupt.c | 26 +++++++++++++++++++++++---
 arch/powerpc/kvm/book3s_hv_ras.c       |  5 +++++
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index f99503acdda5..94989fe2fdfe 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3506,8 +3506,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	mtspr(SPRN_BESCR, vcpu->arch.bescr);
 	mtspr(SPRN_WORT, vcpu->arch.wort);
 	mtspr(SPRN_TIDR, vcpu->arch.tid);
-	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
-	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
+	/* XXX: DAR, DSISR must be set with MSR[RI] clear (or hstate as appropriate) */
 	mtspr(SPRN_AMR, vcpu->arch.amr);
 	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
 
@@ -3553,6 +3552,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			hvregs.vcpu_token = vcpu->vcpu_id;
 		}
 		hvregs.hdec_expiry = time_limit;
+		mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
+		mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
 		trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs),
 					  __pa(&vcpu->arch.regs));
 		kvmhv_restore_hv_return_state(vcpu, &hvregs);
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index dea3eca3648a..f5fef7398e37 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -126,6 +126,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	s64 hdec;
 	u64 tb, purr, spurr;
 	u64 *exsave;
+	bool ri_clear;
 	unsigned long msr = mfmsr();
 	int trap;
 	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
@@ -197,9 +198,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
-	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
-
 	start_timing(vcpu, &vcpu->arch.rm_entry);
 
 	vcpu->arch.ceded = 0;
@@ -225,6 +223,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDSISR, HDSISR_CANARY);
 
+	__mtmsrd(0, 1); /* clear RI */
+
+	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
+	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
+	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
+	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
+
 	accumulate_time(vcpu, &vcpu->arch.guest_time);
 
 	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
@@ -240,6 +245,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
 	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
 
+	/* HSRR interrupts leave MSR[RI] unchanged, SRR interrupts clear it. */
+	if ((local_paca->kvm_hstate.scratch0 & 0x2) &&
+				(vcpu->arch.shregs.msr & MSR_RI))
+		ri_clear = false;
+	else
+		ri_clear = true;
+
 	trap = local_paca->kvm_hstate.scratch0 & ~0x2;
 	if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
 		exsave = local_paca->exgen;
@@ -251,6 +263,14 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
 	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
+
+	if (ri_clear) {
+/// XXX this fires maybe on syscalls on mambo		WARN_ON((mfmsr() & MSR_RI));
+		__mtmsrd(MSR_RI, 1); /* set RI after reading machine check regs (DAR, DSISR, SRR0/1) and hstate scratch (which we need to move into exsave) */
+	} else {
+		WARN_ON(!(mfmsr() & MSR_RI));
+	}
+
 	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
 	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
 	vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
diff --git a/arch/powerpc/kvm/book3s_hv_ras.c b/arch/powerpc/kvm/book3s_hv_ras.c
index d4bca93b79f6..7a645f4428c2 100644
--- a/arch/powerpc/kvm/book3s_hv_ras.c
+++ b/arch/powerpc/kvm/book3s_hv_ras.c
@@ -198,6 +198,7 @@ static void kvmppc_tb_resync_done(void)
  * value. Hence the idea is to resync the TB on every HMI, so that we
  * know about the exact state of the TB value. Resync TB call will
  * restore TB to host timebase.
+ *  XXX: could use new opal hmi handler flags for this
  *
  * Things to consider:
  * - On TB error, HMI interrupt is reported on all the threads of the core
@@ -290,6 +291,10 @@ long kvmppc_realmode_hmi_handler(void)
 	 */
 	wait_for_subcore_guest_exit();
 
+	/*
+	 * XXX: Is this safe with independent threads mode?
+	 */
+
 	/*
 	 * At this point we are sure that primary threads from each
 	 * subcore on this core have completed guest->host partition
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 25/37] KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

SRR0/1, DAR, DSISR must all be protected from machine check which can
clobber them. Ensure MSR[RI] is clear while they are live.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c           |  5 +++--
 arch/powerpc/kvm/book3s_hv_interrupt.c | 26 +++++++++++++++++++++++---
 arch/powerpc/kvm/book3s_hv_ras.c       |  5 +++++
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index f99503acdda5..94989fe2fdfe 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3506,8 +3506,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	mtspr(SPRN_BESCR, vcpu->arch.bescr);
 	mtspr(SPRN_WORT, vcpu->arch.wort);
 	mtspr(SPRN_TIDR, vcpu->arch.tid);
-	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
-	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
+	/* XXX: DAR, DSISR must be set with MSR[RI] clear (or hstate as appropriate) */
 	mtspr(SPRN_AMR, vcpu->arch.amr);
 	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
 
@@ -3553,6 +3552,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			hvregs.vcpu_token = vcpu->vcpu_id;
 		}
 		hvregs.hdec_expiry = time_limit;
+		mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
+		mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
 		trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs),
 					  __pa(&vcpu->arch.regs));
 		kvmhv_restore_hv_return_state(vcpu, &hvregs);
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index dea3eca3648a..f5fef7398e37 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -126,6 +126,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	s64 hdec;
 	u64 tb, purr, spurr;
 	u64 *exsave;
+	bool ri_clear;
 	unsigned long msr = mfmsr();
 	int trap;
 	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
@@ -197,9 +198,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
-	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
-
 	start_timing(vcpu, &vcpu->arch.rm_entry);
 
 	vcpu->arch.ceded = 0;
@@ -225,6 +223,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDSISR, HDSISR_CANARY);
 
+	__mtmsrd(0, 1); /* clear RI */
+
+	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
+	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
+	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
+	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
+
 	accumulate_time(vcpu, &vcpu->arch.guest_time);
 
 	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
@@ -240,6 +245,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
 	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
 
+	/* HSRR interrupts leave MSR[RI] unchanged, SRR interrupts clear it. */
+	if ((local_paca->kvm_hstate.scratch0 & 0x2) &&
+				(vcpu->arch.shregs.msr & MSR_RI))
+		ri_clear = false;
+	else
+		ri_clear = true;
+
 	trap = local_paca->kvm_hstate.scratch0 & ~0x2;
 	if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
 		exsave = local_paca->exgen;
@@ -251,6 +263,14 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
 	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
+
+	if (ri_clear) {
+/// XXX this fires maybe on syscalls on mambo		WARN_ON((mfmsr() & MSR_RI));
+		__mtmsrd(MSR_RI, 1); /* set RI after reading machine check regs (DAR, DSISR, SRR0/1) and hstate scratch (which we need to move into exsave) */
+	} else {
+		WARN_ON(!(mfmsr() & MSR_RI));
+	}
+
 	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
 	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
 	vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
diff --git a/arch/powerpc/kvm/book3s_hv_ras.c b/arch/powerpc/kvm/book3s_hv_ras.c
index d4bca93b79f6..7a645f4428c2 100644
--- a/arch/powerpc/kvm/book3s_hv_ras.c
+++ b/arch/powerpc/kvm/book3s_hv_ras.c
@@ -198,6 +198,7 @@ static void kvmppc_tb_resync_done(void)
  * value. Hence the idea is to resync the TB on every HMI, so that we
  * know about the exact state of the TB value. Resync TB call will
  * restore TB to host timebase.
+ *  XXX: could use new opal hmi handler flags for this
  *
  * Things to consider:
  * - On TB error, HMI interrupt is reported on all the threads of the core
@@ -290,6 +291,10 @@ long kvmppc_realmode_hmi_handler(void)
 	 */
 	wait_for_subcore_guest_exit();
 
+	/*
+	 * XXX: Is this safe with independent threads mode?
+	 */
+
 	/*
 	 * At this point we are sure that primary threads from each
 	 * subcore on this core have completed guest->host partition
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 26/37] KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

The C conversion caused exit timing to become a bit cramped. Expand it
to cover more of the entry and exit code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_interrupt.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index f5fef7398e37..4a158c8fc0bc 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -148,6 +148,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 
+	start_timing(vcpu, &vcpu->arch.rm_entry);
+
 	if (vc->tb_offset) {
 		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
@@ -198,8 +200,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	start_timing(vcpu, &vcpu->arch.rm_entry);
-
 	vcpu->arch.ceded = 0;
 
 	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
@@ -334,8 +334,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	accumulate_time(vcpu, &vcpu->arch.rm_exit);
 
-	end_timing(vcpu);
-
 	/* Advance host PURR/SPURR by the amount used by guest */
 	purr = mfspr(SPRN_PURR);
 	spurr = mfspr(SPRN_SPURR);
@@ -400,6 +398,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
+	end_timing(vcpu);
+
 	return trap;
 }
 EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 26/37] KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

The C conversion caused exit timing to become a bit cramped. Expand it
to cover more of the entry and exit code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_interrupt.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index f5fef7398e37..4a158c8fc0bc 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -148,6 +148,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 
+	start_timing(vcpu, &vcpu->arch.rm_entry);
+
 	if (vc->tb_offset) {
 		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
@@ -198,8 +200,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	start_timing(vcpu, &vcpu->arch.rm_entry);
-
 	vcpu->arch.ceded = 0;
 
 	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
@@ -334,8 +334,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	accumulate_time(vcpu, &vcpu->arch.rm_exit);
 
-	end_timing(vcpu);
-
 	/* Advance host PURR/SPURR by the amount used by guest */
 	purr = mfspr(SPRN_PURR);
 	spurr = mfspr(SPRN_SPURR);
@@ -400,6 +398,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
+	end_timing(vcpu);
+
 	return trap;
 }
 EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 27/37] KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is wasted work if the time limit is exceeded.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_interrupt.c | 38 ++++++++++++++++----------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index 4a158c8fc0bc..dd0a78a69f49 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -126,22 +126,17 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	s64 hdec;
 	u64 tb, purr, spurr;
 	u64 *exsave;
-	bool ri_clear;
-	unsigned long msr = mfmsr();
 	int trap;
-	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
-	unsigned long host_ciabr = mfspr(SPRN_CIABR);
-	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
-	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
-	unsigned long host_psscr = mfspr(SPRN_PSSCR);
-	unsigned long host_pidr = mfspr(SPRN_PID);
-	unsigned long host_dawr1 = 0;
-	unsigned long host_dawrx1 = 0;
-
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		host_dawr1 = mfspr(SPRN_DAWR1);
-		host_dawrx1 = mfspr(SPRN_DAWRX1);
-	}
+	bool ri_clear;
+	unsigned long msr;
+	unsigned long host_hfscr;
+	unsigned long host_ciabr;
+	unsigned long host_dawr0;
+	unsigned long host_dawrx0;
+	unsigned long host_psscr;
+	unsigned long host_pidr;
+	unsigned long host_dawr1;
+	unsigned long host_dawrx1;
 
 	tb = mftb();
 	hdec = time_limit - tb;
@@ -159,6 +154,19 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		vc->tb_offset_applied = vc->tb_offset;
 	}
 
+	msr = mfmsr();
+
+	host_hfscr = mfspr(SPRN_HFSCR);
+	host_ciabr = mfspr(SPRN_CIABR);
+	host_dawr0 = mfspr(SPRN_DAWR0);
+	host_dawrx0 = mfspr(SPRN_DAWRX0);
+	host_psscr = mfspr(SPRN_PSSCR);
+	host_pidr = mfspr(SPRN_PID);
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		host_dawr1 = mfspr(SPRN_DAWR1);
+		host_dawrx1 = mfspr(SPRN_DAWRX1);
+	}
+
 	if (vc->pcr)
 		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
 	mtspr(SPRN_DPDES, vc->dpdes);
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 27/37] KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is wasted work if the time limit is exceeded.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_interrupt.c | 38 ++++++++++++++++----------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index 4a158c8fc0bc..dd0a78a69f49 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -126,22 +126,17 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	s64 hdec;
 	u64 tb, purr, spurr;
 	u64 *exsave;
-	bool ri_clear;
-	unsigned long msr = mfmsr();
 	int trap;
-	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
-	unsigned long host_ciabr = mfspr(SPRN_CIABR);
-	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
-	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
-	unsigned long host_psscr = mfspr(SPRN_PSSCR);
-	unsigned long host_pidr = mfspr(SPRN_PID);
-	unsigned long host_dawr1 = 0;
-	unsigned long host_dawrx1 = 0;
-
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		host_dawr1 = mfspr(SPRN_DAWR1);
-		host_dawrx1 = mfspr(SPRN_DAWRX1);
-	}
+	bool ri_clear;
+	unsigned long msr;
+	unsigned long host_hfscr;
+	unsigned long host_ciabr;
+	unsigned long host_dawr0;
+	unsigned long host_dawrx0;
+	unsigned long host_psscr;
+	unsigned long host_pidr;
+	unsigned long host_dawr1;
+	unsigned long host_dawrx1;
 
 	tb = mftb();
 	hdec = time_limit - tb;
@@ -159,6 +154,19 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		vc->tb_offset_applied = vc->tb_offset;
 	}
 
+	msr = mfmsr();
+
+	host_hfscr = mfspr(SPRN_HFSCR);
+	host_ciabr = mfspr(SPRN_CIABR);
+	host_dawr0 = mfspr(SPRN_DAWR0);
+	host_dawrx0 = mfspr(SPRN_DAWRX0);
+	host_psscr = mfspr(SPRN_PSSCR);
+	host_pidr = mfspr(SPRN_PID);
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		host_dawr1 = mfspr(SPRN_DAWR1);
+		host_dawrx1 = mfspr(SPRN_DAWRX1);
+	}
+
 	if (vc->pcr)
 		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
 	mtspr(SPRN_DPDES, vc->dpdes);
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is a first step to wrapping supervisor and user SPR saving and
loading up into helpers, which will then be called independently in
bare metal and nested HV cases in order to optimise SPR access.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 131 ++++++++++++++++++++++-------------
 1 file changed, 84 insertions(+), 47 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 94989fe2fdfe..ad16331c3370 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3442,6 +3442,84 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
+static void load_spr_state(struct kvm_vcpu *vcpu)
+{
+	mtspr(SPRN_DSCR, vcpu->arch.dscr);
+	mtspr(SPRN_IAMR, vcpu->arch.iamr);
+	mtspr(SPRN_PSPB, vcpu->arch.pspb);
+	mtspr(SPRN_FSCR, vcpu->arch.fscr);
+	mtspr(SPRN_TAR, vcpu->arch.tar);
+	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
+	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
+	mtspr(SPRN_BESCR, vcpu->arch.bescr);
+	mtspr(SPRN_WORT, vcpu->arch.wort);
+	mtspr(SPRN_TIDR, vcpu->arch.tid);
+	/* XXX: DAR, DSISR must be set with MSR[RI] clear (or hstate as appropriate) */
+	mtspr(SPRN_AMR, vcpu->arch.amr);
+	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
+
+	if (!(vcpu->arch.ctrl & 1))
+		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
+}
+
+static void store_spr_state(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
+
+	vcpu->arch.iamr = mfspr(SPRN_IAMR);
+	vcpu->arch.pspb = mfspr(SPRN_PSPB);
+	vcpu->arch.fscr = mfspr(SPRN_FSCR);
+	vcpu->arch.tar = mfspr(SPRN_TAR);
+	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
+	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
+	vcpu->arch.bescr = mfspr(SPRN_BESCR);
+	vcpu->arch.wort = mfspr(SPRN_WORT);
+	vcpu->arch.tid = mfspr(SPRN_TIDR);
+	vcpu->arch.amr = mfspr(SPRN_AMR);
+	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
+	vcpu->arch.dscr = mfspr(SPRN_DSCR);
+}
+
+/*
+ * Privileged (non-hypervisor) host registers to save.
+ */
+struct p9_host_os_sprs {
+	unsigned long dscr;
+	unsigned long tidr;
+	unsigned long iamr;
+	unsigned long amr;
+	unsigned long fscr;
+};
+
+static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
+{
+	host_os_sprs->dscr = mfspr(SPRN_DSCR);
+	host_os_sprs->tidr = mfspr(SPRN_TIDR);
+	host_os_sprs->iamr = mfspr(SPRN_IAMR);
+	host_os_sprs->amr = mfspr(SPRN_AMR);
+	host_os_sprs->fscr = mfspr(SPRN_FSCR);
+}
+
+/* vcpu guest regs must already be saved */
+static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
+				    struct p9_host_os_sprs *host_os_sprs)
+{
+	mtspr(SPRN_PSPB, 0);
+	mtspr(SPRN_WORT, 0);
+	mtspr(SPRN_UAMOR, 0);
+	mtspr(SPRN_PSPB, 0);
+
+	mtspr(SPRN_DSCR, host_os_sprs->dscr);
+	mtspr(SPRN_TIDR, host_os_sprs->tidr);
+	mtspr(SPRN_IAMR, host_os_sprs->iamr);
+
+	if (host_os_sprs->amr != vcpu->arch.amr)
+		mtspr(SPRN_AMR, host_os_sprs->amr);
+
+	if (host_os_sprs->fscr != vcpu->arch.fscr)
+		mtspr(SPRN_FSCR, host_os_sprs->fscr);
+}
+
 /*
  * Virtual-mode guest entry for POWER9 and later when the host and
  * guest are both using the radix MMU.  The LPIDR has already been set.
@@ -3450,11 +3528,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			 unsigned long lpcr)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	unsigned long host_dscr = mfspr(SPRN_DSCR);
-	unsigned long host_tidr = mfspr(SPRN_TIDR);
-	unsigned long host_iamr = mfspr(SPRN_IAMR);
-	unsigned long host_amr = mfspr(SPRN_AMR);
-	unsigned long host_fscr = mfspr(SPRN_FSCR);
+	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
 	u64 tb, next_timer;
 	int trap, save_pmu;
@@ -3469,6 +3543,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu->arch.ceded = 0;
 
+	save_p9_host_os_sprs(&host_os_sprs);
+
 	kvmhv_save_host_pmu();		/* saves it to PACA kvm_hstate */
 
 	kvmppc_subcore_enter_guest();
@@ -3496,22 +3572,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 #endif
 	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
 
-	mtspr(SPRN_DSCR, vcpu->arch.dscr);
-	mtspr(SPRN_IAMR, vcpu->arch.iamr);
-	mtspr(SPRN_PSPB, vcpu->arch.pspb);
-	mtspr(SPRN_FSCR, vcpu->arch.fscr);
-	mtspr(SPRN_TAR, vcpu->arch.tar);
-	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
-	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
-	mtspr(SPRN_BESCR, vcpu->arch.bescr);
-	mtspr(SPRN_WORT, vcpu->arch.wort);
-	mtspr(SPRN_TIDR, vcpu->arch.tid);
-	/* XXX: DAR, DSISR must be set with MSR[RI] clear (or hstate as appropriate) */
-	mtspr(SPRN_AMR, vcpu->arch.amr);
-	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
-
-	if (!(vcpu->arch.ctrl & 1))
-		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
+	load_spr_state(vcpu);
 
 	/*
 	 * XXX: must always deal with irq_work_raise via NMI vs setting DEC.
@@ -3605,34 +3666,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vcpu->arch.dec_expires = dec + tb;
 	vcpu->cpu = -1;
 	vcpu->arch.thread_cpu = -1;
-	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
-
-	vcpu->arch.iamr = mfspr(SPRN_IAMR);
-	vcpu->arch.pspb = mfspr(SPRN_PSPB);
-	vcpu->arch.fscr = mfspr(SPRN_FSCR);
-	vcpu->arch.tar = mfspr(SPRN_TAR);
-	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
-	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
-	vcpu->arch.bescr = mfspr(SPRN_BESCR);
-	vcpu->arch.wort = mfspr(SPRN_WORT);
-	vcpu->arch.tid = mfspr(SPRN_TIDR);
-	vcpu->arch.amr = mfspr(SPRN_AMR);
-	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
-	vcpu->arch.dscr = mfspr(SPRN_DSCR);
-
-	mtspr(SPRN_PSPB, 0);
-	mtspr(SPRN_WORT, 0);
-	mtspr(SPRN_UAMOR, 0);
-	mtspr(SPRN_DSCR, host_dscr);
-	mtspr(SPRN_TIDR, host_tidr);
-	mtspr(SPRN_IAMR, host_iamr);
-	mtspr(SPRN_PSPB, 0);
 
-	if (host_amr != vcpu->arch.amr)
-		mtspr(SPRN_AMR, host_amr);
+	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
 
-	if (host_fscr != vcpu->arch.fscr)
-		mtspr(SPRN_FSCR, host_fscr);
+	store_spr_state(vcpu);
 
 	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	store_fp_state(&vcpu->arch.fp);
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is a first step to wrapping supervisor and user SPR saving and
loading up into helpers, which will then be called independently in
bare metal and nested HV cases in order to optimise SPR access.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 131 ++++++++++++++++++++++-------------
 1 file changed, 84 insertions(+), 47 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 94989fe2fdfe..ad16331c3370 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3442,6 +3442,84 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
+static void load_spr_state(struct kvm_vcpu *vcpu)
+{
+	mtspr(SPRN_DSCR, vcpu->arch.dscr);
+	mtspr(SPRN_IAMR, vcpu->arch.iamr);
+	mtspr(SPRN_PSPB, vcpu->arch.pspb);
+	mtspr(SPRN_FSCR, vcpu->arch.fscr);
+	mtspr(SPRN_TAR, vcpu->arch.tar);
+	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
+	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
+	mtspr(SPRN_BESCR, vcpu->arch.bescr);
+	mtspr(SPRN_WORT, vcpu->arch.wort);
+	mtspr(SPRN_TIDR, vcpu->arch.tid);
+	/* XXX: DAR, DSISR must be set with MSR[RI] clear (or hstate as appropriate) */
+	mtspr(SPRN_AMR, vcpu->arch.amr);
+	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
+
+	if (!(vcpu->arch.ctrl & 1))
+		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
+}
+
+static void store_spr_state(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
+
+	vcpu->arch.iamr = mfspr(SPRN_IAMR);
+	vcpu->arch.pspb = mfspr(SPRN_PSPB);
+	vcpu->arch.fscr = mfspr(SPRN_FSCR);
+	vcpu->arch.tar = mfspr(SPRN_TAR);
+	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
+	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
+	vcpu->arch.bescr = mfspr(SPRN_BESCR);
+	vcpu->arch.wort = mfspr(SPRN_WORT);
+	vcpu->arch.tid = mfspr(SPRN_TIDR);
+	vcpu->arch.amr = mfspr(SPRN_AMR);
+	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
+	vcpu->arch.dscr = mfspr(SPRN_DSCR);
+}
+
+/*
+ * Privileged (non-hypervisor) host registers to save.
+ */
+struct p9_host_os_sprs {
+	unsigned long dscr;
+	unsigned long tidr;
+	unsigned long iamr;
+	unsigned long amr;
+	unsigned long fscr;
+};
+
+static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
+{
+	host_os_sprs->dscr = mfspr(SPRN_DSCR);
+	host_os_sprs->tidr = mfspr(SPRN_TIDR);
+	host_os_sprs->iamr = mfspr(SPRN_IAMR);
+	host_os_sprs->amr = mfspr(SPRN_AMR);
+	host_os_sprs->fscr = mfspr(SPRN_FSCR);
+}
+
+/* vcpu guest regs must already be saved */
+static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
+				    struct p9_host_os_sprs *host_os_sprs)
+{
+	mtspr(SPRN_PSPB, 0);
+	mtspr(SPRN_WORT, 0);
+	mtspr(SPRN_UAMOR, 0);
+	mtspr(SPRN_PSPB, 0);
+
+	mtspr(SPRN_DSCR, host_os_sprs->dscr);
+	mtspr(SPRN_TIDR, host_os_sprs->tidr);
+	mtspr(SPRN_IAMR, host_os_sprs->iamr);
+
+	if (host_os_sprs->amr != vcpu->arch.amr)
+		mtspr(SPRN_AMR, host_os_sprs->amr);
+
+	if (host_os_sprs->fscr != vcpu->arch.fscr)
+		mtspr(SPRN_FSCR, host_os_sprs->fscr);
+}
+
 /*
  * Virtual-mode guest entry for POWER9 and later when the host and
  * guest are both using the radix MMU.  The LPIDR has already been set.
@@ -3450,11 +3528,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			 unsigned long lpcr)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	unsigned long host_dscr = mfspr(SPRN_DSCR);
-	unsigned long host_tidr = mfspr(SPRN_TIDR);
-	unsigned long host_iamr = mfspr(SPRN_IAMR);
-	unsigned long host_amr = mfspr(SPRN_AMR);
-	unsigned long host_fscr = mfspr(SPRN_FSCR);
+	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
 	u64 tb, next_timer;
 	int trap, save_pmu;
@@ -3469,6 +3543,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu->arch.ceded = 0;
 
+	save_p9_host_os_sprs(&host_os_sprs);
+
 	kvmhv_save_host_pmu();		/* saves it to PACA kvm_hstate */
 
 	kvmppc_subcore_enter_guest();
@@ -3496,22 +3572,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 #endif
 	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
 
-	mtspr(SPRN_DSCR, vcpu->arch.dscr);
-	mtspr(SPRN_IAMR, vcpu->arch.iamr);
-	mtspr(SPRN_PSPB, vcpu->arch.pspb);
-	mtspr(SPRN_FSCR, vcpu->arch.fscr);
-	mtspr(SPRN_TAR, vcpu->arch.tar);
-	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
-	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
-	mtspr(SPRN_BESCR, vcpu->arch.bescr);
-	mtspr(SPRN_WORT, vcpu->arch.wort);
-	mtspr(SPRN_TIDR, vcpu->arch.tid);
-	/* XXX: DAR, DSISR must be set with MSR[RI] clear (or hstate as appropriate) */
-	mtspr(SPRN_AMR, vcpu->arch.amr);
-	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
-
-	if (!(vcpu->arch.ctrl & 1))
-		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
+	load_spr_state(vcpu);
 
 	/*
 	 * XXX: must always deal with irq_work_raise via NMI vs setting DEC.
@@ -3605,34 +3666,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vcpu->arch.dec_expires = dec + tb;
 	vcpu->cpu = -1;
 	vcpu->arch.thread_cpu = -1;
-	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
-
-	vcpu->arch.iamr = mfspr(SPRN_IAMR);
-	vcpu->arch.pspb = mfspr(SPRN_PSPB);
-	vcpu->arch.fscr = mfspr(SPRN_FSCR);
-	vcpu->arch.tar = mfspr(SPRN_TAR);
-	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
-	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
-	vcpu->arch.bescr = mfspr(SPRN_BESCR);
-	vcpu->arch.wort = mfspr(SPRN_WORT);
-	vcpu->arch.tid = mfspr(SPRN_TIDR);
-	vcpu->arch.amr = mfspr(SPRN_AMR);
-	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
-	vcpu->arch.dscr = mfspr(SPRN_DSCR);
-
-	mtspr(SPRN_PSPB, 0);
-	mtspr(SPRN_WORT, 0);
-	mtspr(SPRN_UAMOR, 0);
-	mtspr(SPRN_DSCR, host_dscr);
-	mtspr(SPRN_TIDR, host_tidr);
-	mtspr(SPRN_IAMR, host_iamr);
-	mtspr(SPRN_PSPB, 0);
 
-	if (host_amr != vcpu->arch.amr)
-		mtspr(SPRN_AMR, host_amr);
+	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
 
-	if (host_fscr != vcpu->arch.fscr)
-		mtspr(SPRN_FSCR, host_fscr);
+	store_spr_state(vcpu);
 
 	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	store_fp_state(&vcpu->arch.fp);
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 29/37] KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as possible
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Move WARN_ON traps early so they are less likely to get tangled
on CPU switching to guest. Move MMU context switch as late as
reasonably possible to minimise code running with guest context
switched in. This becomes more important when this code may run
in real-mode, with later changes.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_interrupt.c | 40 +++++++++++++-------------
 arch/powerpc/kvm/book3s_hv_nested.c    |  1 +
 2 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index dd0a78a69f49..b93d861d8538 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -143,8 +143,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 
+	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
+	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
+
 	start_timing(vcpu, &vcpu->arch.rm_entry);
 
+	vcpu->arch.ceded = 0;
+
 	if (vc->tb_offset) {
 		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
@@ -193,26 +198,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
 
-	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
-	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
-	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
-	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
-
-	mtspr(SPRN_AMOR, ~0UL);
-
-	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
-
-	/*
-	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
-	 * so set guest LPCR (with HDICE) before writing HDEC.
-	 */
-	mtspr(SPRN_HDEC, hdec);
-
-	vcpu->arch.ceded = 0;
-
-	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
-	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
-
 	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
 	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
 
@@ -231,6 +216,21 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDSISR, HDSISR_CANARY);
 
+	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
+	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
+	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
+	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
+
+	mtspr(SPRN_AMOR, ~0UL);
+
+	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+
+	/*
+	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+	 * so set guest LPCR (with HDICE) before writing HDEC.
+	 */
+	mtspr(SPRN_HDEC, hdec);
+
 	__mtmsrd(0, 1); /* clear RI */
 
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 0cd0e7aad588..cdf3ee2145ab 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -323,6 +323,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 	vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
 	mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
 		LPCR_LPES | LPCR_MER;
+	/* XXX: set lpcr in sanitise hv regs? Why is it plumbed through? */
 	lpcr = (vc->lpcr & ~mask) | (l2_hv.lpcr & mask);
 	sanitise_hv_regs(vcpu, &l2_hv);
 	restore_hv_regs(vcpu, &l2_hv);
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 29/37] KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as possible
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Move WARN_ON traps early so they are less likely to get tangled
on CPU switching to guest. Move MMU context switch as late as
reasonably possible to minimise code running with guest context
switched in. This becomes more important when this code may run
in real-mode, with later changes.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_interrupt.c | 40 +++++++++++++-------------
 arch/powerpc/kvm/book3s_hv_nested.c    |  1 +
 2 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index dd0a78a69f49..b93d861d8538 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -143,8 +143,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 
+	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
+	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
+
 	start_timing(vcpu, &vcpu->arch.rm_entry);
 
+	vcpu->arch.ceded = 0;
+
 	if (vc->tb_offset) {
 		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
@@ -193,26 +198,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
 
-	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
-	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
-	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
-	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
-
-	mtspr(SPRN_AMOR, ~0UL);
-
-	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
-
-	/*
-	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
-	 * so set guest LPCR (with HDICE) before writing HDEC.
-	 */
-	mtspr(SPRN_HDEC, hdec);
-
-	vcpu->arch.ceded = 0;
-
-	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
-	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
-
 	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
 	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
 
@@ -231,6 +216,21 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDSISR, HDSISR_CANARY);
 
+	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
+	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
+	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
+	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
+
+	mtspr(SPRN_AMOR, ~0UL);
+
+	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+
+	/*
+	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+	 * so set guest LPCR (with HDICE) before writing HDEC.
+	 */
+	mtspr(SPRN_HDEC, hdec);
+
 	__mtmsrd(0, 1); /* clear RI */
 
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 0cd0e7aad588..cdf3ee2145ab 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -323,6 +323,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 	vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
 	mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
 		LPCR_LPES | LPCR_MER;
+	/* XXX: set lpcr in sanitise hv regs? Why is it plumbed through? */
 	lpcr = (vc->lpcr & ~mask) | (l2_hv.lpcr & mask);
 	sanitise_hv_regs(vcpu, &l2_hv);
 	restore_hv_regs(vcpu, &l2_hv);
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Rather than partition the guest PID space and catch and flush a rogue
guest, instead work around this issue by ensuring the MMU is always
disabled in HV mode while the guest MMU context is switched in.

This may be a bit less efficient, but it is a lot less complicated and
allows the P9 path to trivally implement the workaround too. Newer CPUs
are not subject to this issue.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/mmu_context.h   |  6 ----
 arch/powerpc/kvm/book3s_hv.c             | 10 ++++--
 arch/powerpc/kvm/book3s_hv_interrupt.c   | 14 ++++++--
 arch/powerpc/kvm/book3s_hv_rmhandlers.S  | 34 ------------------
 arch/powerpc/mm/book3s64/radix_pgtable.c | 27 +++++---------
 arch/powerpc/mm/book3s64/radix_tlb.c     | 46 ------------------------
 arch/powerpc/mm/mmu_context.c            |  4 +--
 7 files changed, 28 insertions(+), 113 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 652ce85f9410..bb5c7e5e142e 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -122,12 +122,6 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
 }
 #endif
 
-#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
-extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
-#else
-static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
-#endif
-
 extern void switch_cop(struct mm_struct *next);
 extern int use_cop(unsigned long acop, struct mm_struct *mm);
 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index ad16331c3370..c3064075f1d7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -806,6 +806,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
 		/* KVM does not support mflags=2 (AIL=2) */
 		if (mflags != 0 && mflags != 3)
 			return H_UNSUPPORTED_FLAG_START;
+		/* Prefetch bug */
+		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
+				kvmhv_vcpu_is_radix(vcpu) && mflags == 3)
+			return H_UNSUPPORTED_FLAG_START;
 		return H_TOO_HARD;
 	default:
 		return H_TOO_HARD;
@@ -4286,8 +4290,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (kvm->arch.threads_indep && kvm_is_radix(kvm) &&
-		    !cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		if (kvm->arch.threads_indep && kvm_is_radix(kvm))
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
@@ -4914,6 +4917,9 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 		if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) {
 			pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n");
 			kvm->arch.threads_indep = true;
+		} else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
+			pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n");
+			kvm->arch.threads_indep = true;
 		} else {
 			kvm->arch.threads_indep = indep_threads_mode;
 		}
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index b93d861d8538..9784da3f8565 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -223,6 +223,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_AMOR, ~0UL);
 
+	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+
 	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
 	/*
@@ -231,7 +234,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	__mtmsrd(0, 1); /* clear RI */
+	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		__mtmsrd(0, 1); /* clear RI */
 
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
 	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
@@ -338,8 +342,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	radix_clear_slb();
 
-	__mtmsrd(msr, 0);
-
 	accumulate_time(vcpu, &vcpu->arch.rm_exit);
 
 	/* Advance host PURR/SPURR by the amount used by guest */
@@ -406,6 +408,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
+	/*
+	 * If we are in real mode, don't switch MMU on until the MMU is
+	 * switched to host, to avoid the P9 radix prefetch bug.
+	 */
+	__mtmsrd(msr, 0);
+
 	end_timing(vcpu);
 
 	return trap;
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 6118e8a97ddd..61f71a7df238 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1710,40 +1710,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	eieio
 	tlbsync
 	ptesync
-
-BEGIN_FTR_SECTION
-	/* Radix: Handle the case where the guest used an illegal PID */
-	LOAD_REG_ADDR(r4, mmu_base_pid)
-	lwz	r3, VCPU_GUEST_PID(r9)
-	lwz	r5, 0(r4)
-	cmpw	cr0,r3,r5
-	blt	2f
-
-	/*
-	 * Illegal PID, the HW might have prefetched and cached in the TLB
-	 * some translations for the  LPID 0 / guest PID combination which
-	 * Linux doesn't know about, so we need to flush that PID out of
-	 * the TLB. First we need to set LPIDR to 0 so tlbiel applies to
-	 * the right context.
-	*/
-	li	r0,0
-	mtspr	SPRN_LPID,r0
-	isync
-
-	/* Then do a congruence class local flush */
-	ld	r6,VCPU_KVM(r9)
-	lwz	r0,KVM_TLB_SETS(r6)
-	mtctr	r0
-	li	r7,0x400		/* IS field = 0b01 */
-	ptesync
-	sldi	r0,r3,32		/* RS has PID */
-1:	PPC_TLBIEL(7,0,2,1,1)		/* RIC=2, PRS=1, R=1 */
-	addi	r7,r7,0x1000
-	bdnz	1b
-	ptesync
-END_FTR_SECTION_IFSET(CPU_FTR_P9_RADIX_PREFETCH_BUG)
-
-2:
 #endif /* CONFIG_PPC_RADIX_MMU */
 
 	/*
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 98f0b243c1ab..1ea95891a79e 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -357,30 +357,19 @@ static void __init radix_init_pgtable(void)
 	}
 
 	/* Find out how many PID bits are supported */
-	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
-		if (!mmu_pid_bits)
-			mmu_pid_bits = 20;
-		mmu_base_pid = 1;
-	} else if (cpu_has_feature(CPU_FTR_HVMODE)) {
-		if (!mmu_pid_bits)
-			mmu_pid_bits = 20;
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	if (!cpu_has_feature(CPU_FTR_HVMODE) &&
+			cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
 		/*
-		 * When KVM is possible, we only use the top half of the
-		 * PID space to avoid collisions between host and guest PIDs
-		 * which can cause problems due to prefetch when exiting the
-		 * guest with AIL=3
+		 * Older versions of KVM on these machines perfer if the
+		 * guest only uses the low 19 PID bits.
 		 */
-		mmu_base_pid = 1 << (mmu_pid_bits - 1);
-#else
-		mmu_base_pid = 1;
-#endif
-	} else {
-		/* The guest uses the bottom half of the PID space */
 		if (!mmu_pid_bits)
 			mmu_pid_bits = 19;
-		mmu_base_pid = 1;
+	} else {
+		if (!mmu_pid_bits)
+			mmu_pid_bits = 20;
 	}
+	mmu_base_pid = 1;
 
 	/*
 	 * Allocate Partition table and process table for the
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
index 409e61210789..312236a6b085 100644
--- a/arch/powerpc/mm/book3s64/radix_tlb.c
+++ b/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -1336,49 +1336,3 @@ void radix__flush_tlb_all(void)
 		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory");
 	asm volatile("eieio; tlbsync; ptesync": : :"memory");
 }
-
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-extern void radix_kvm_prefetch_workaround(struct mm_struct *mm)
-{
-	unsigned long pid = mm->context.id;
-
-	if (unlikely(pid == MMU_NO_CONTEXT))
-		return;
-
-	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-		return;
-
-	/*
-	 * If this context hasn't run on that CPU before and KVM is
-	 * around, there's a slim chance that the guest on another
-	 * CPU just brought in obsolete translation into the TLB of
-	 * this CPU due to a bad prefetch using the guest PID on
-	 * the way into the hypervisor.
-	 *
-	 * We work around this here. If KVM is possible, we check if
-	 * any sibling thread is in KVM. If it is, the window may exist
-	 * and thus we flush that PID from the core.
-	 *
-	 * A potential future improvement would be to mark which PIDs
-	 * have never been used on the system and avoid it if the PID
-	 * is new and the process has no other cpumask bit set.
-	 */
-	if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) {
-		int cpu = smp_processor_id();
-		int sib = cpu_first_thread_sibling(cpu);
-		bool flush = false;
-
-		for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) {
-			if (sib == cpu)
-				continue;
-			if (!cpu_possible(sib))
-				continue;
-			if (paca_ptrs[sib]->kvm_hstate.kvm_vcpu)
-				flush = true;
-		}
-		if (flush)
-			_tlbiel_pid(pid, RIC_FLUSH_ALL);
-	}
-}
-EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround);
-#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 18f20da0d348..7479d39976c9 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -81,9 +81,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
 		asm volatile ("dssall");
 
-	if (new_on_cpu)
-		radix_kvm_prefetch_workaround(next);
-	else
+	if (!new_on_cpu)
 		membarrier_arch_switch_mm(prev, next, tsk);
 
 	/*
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Rather than partition the guest PID space and catch and flush a rogue
guest, instead work around this issue by ensuring the MMU is always
disabled in HV mode while the guest MMU context is switched in.

This may be a bit less efficient, but it is a lot less complicated and
allows the P9 path to trivally implement the workaround too. Newer CPUs
are not subject to this issue.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/mmu_context.h   |  6 ----
 arch/powerpc/kvm/book3s_hv.c             | 10 ++++--
 arch/powerpc/kvm/book3s_hv_interrupt.c   | 14 ++++++--
 arch/powerpc/kvm/book3s_hv_rmhandlers.S  | 34 ------------------
 arch/powerpc/mm/book3s64/radix_pgtable.c | 27 +++++---------
 arch/powerpc/mm/book3s64/radix_tlb.c     | 46 ------------------------
 arch/powerpc/mm/mmu_context.c            |  4 +--
 7 files changed, 28 insertions(+), 113 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 652ce85f9410..bb5c7e5e142e 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -122,12 +122,6 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
 }
 #endif
 
-#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
-extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
-#else
-static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
-#endif
-
 extern void switch_cop(struct mm_struct *next);
 extern int use_cop(unsigned long acop, struct mm_struct *mm);
 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index ad16331c3370..c3064075f1d7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -806,6 +806,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
 		/* KVM does not support mflags=2 (AIL=2) */
 		if (mflags != 0 && mflags != 3)
 			return H_UNSUPPORTED_FLAG_START;
+		/* Prefetch bug */
+		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
+				kvmhv_vcpu_is_radix(vcpu) && mflags = 3)
+			return H_UNSUPPORTED_FLAG_START;
 		return H_TOO_HARD;
 	default:
 		return H_TOO_HARD;
@@ -4286,8 +4290,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (kvm->arch.threads_indep && kvm_is_radix(kvm) &&
-		    !cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		if (kvm->arch.threads_indep && kvm_is_radix(kvm))
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
@@ -4914,6 +4917,9 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 		if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) {
 			pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n");
 			kvm->arch.threads_indep = true;
+		} else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
+			pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n");
+			kvm->arch.threads_indep = true;
 		} else {
 			kvm->arch.threads_indep = indep_threads_mode;
 		}
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index b93d861d8538..9784da3f8565 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -223,6 +223,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_AMOR, ~0UL);
 
+	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+
 	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 
 	/*
@@ -231,7 +234,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	__mtmsrd(0, 1); /* clear RI */
+	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		__mtmsrd(0, 1); /* clear RI */
 
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
 	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
@@ -338,8 +342,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	radix_clear_slb();
 
-	__mtmsrd(msr, 0);
-
 	accumulate_time(vcpu, &vcpu->arch.rm_exit);
 
 	/* Advance host PURR/SPURR by the amount used by guest */
@@ -406,6 +408,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
+	/*
+	 * If we are in real mode, don't switch MMU on until the MMU is
+	 * switched to host, to avoid the P9 radix prefetch bug.
+	 */
+	__mtmsrd(msr, 0);
+
 	end_timing(vcpu);
 
 	return trap;
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 6118e8a97ddd..61f71a7df238 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1710,40 +1710,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	eieio
 	tlbsync
 	ptesync
-
-BEGIN_FTR_SECTION
-	/* Radix: Handle the case where the guest used an illegal PID */
-	LOAD_REG_ADDR(r4, mmu_base_pid)
-	lwz	r3, VCPU_GUEST_PID(r9)
-	lwz	r5, 0(r4)
-	cmpw	cr0,r3,r5
-	blt	2f
-
-	/*
-	 * Illegal PID, the HW might have prefetched and cached in the TLB
-	 * some translations for the  LPID 0 / guest PID combination which
-	 * Linux doesn't know about, so we need to flush that PID out of
-	 * the TLB. First we need to set LPIDR to 0 so tlbiel applies to
-	 * the right context.
-	*/
-	li	r0,0
-	mtspr	SPRN_LPID,r0
-	isync
-
-	/* Then do a congruence class local flush */
-	ld	r6,VCPU_KVM(r9)
-	lwz	r0,KVM_TLB_SETS(r6)
-	mtctr	r0
-	li	r7,0x400		/* IS field = 0b01 */
-	ptesync
-	sldi	r0,r3,32		/* RS has PID */
-1:	PPC_TLBIEL(7,0,2,1,1)		/* RIC=2, PRS=1, R=1 */
-	addi	r7,r7,0x1000
-	bdnz	1b
-	ptesync
-END_FTR_SECTION_IFSET(CPU_FTR_P9_RADIX_PREFETCH_BUG)
-
-2:
 #endif /* CONFIG_PPC_RADIX_MMU */
 
 	/*
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 98f0b243c1ab..1ea95891a79e 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -357,30 +357,19 @@ static void __init radix_init_pgtable(void)
 	}
 
 	/* Find out how many PID bits are supported */
-	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
-		if (!mmu_pid_bits)
-			mmu_pid_bits = 20;
-		mmu_base_pid = 1;
-	} else if (cpu_has_feature(CPU_FTR_HVMODE)) {
-		if (!mmu_pid_bits)
-			mmu_pid_bits = 20;
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	if (!cpu_has_feature(CPU_FTR_HVMODE) &&
+			cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
 		/*
-		 * When KVM is possible, we only use the top half of the
-		 * PID space to avoid collisions between host and guest PIDs
-		 * which can cause problems due to prefetch when exiting the
-		 * guest with AIL=3
+		 * Older versions of KVM on these machines perfer if the
+		 * guest only uses the low 19 PID bits.
 		 */
-		mmu_base_pid = 1 << (mmu_pid_bits - 1);
-#else
-		mmu_base_pid = 1;
-#endif
-	} else {
-		/* The guest uses the bottom half of the PID space */
 		if (!mmu_pid_bits)
 			mmu_pid_bits = 19;
-		mmu_base_pid = 1;
+	} else {
+		if (!mmu_pid_bits)
+			mmu_pid_bits = 20;
 	}
+	mmu_base_pid = 1;
 
 	/*
 	 * Allocate Partition table and process table for the
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
index 409e61210789..312236a6b085 100644
--- a/arch/powerpc/mm/book3s64/radix_tlb.c
+++ b/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -1336,49 +1336,3 @@ void radix__flush_tlb_all(void)
 		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory");
 	asm volatile("eieio; tlbsync; ptesync": : :"memory");
 }
-
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-extern void radix_kvm_prefetch_workaround(struct mm_struct *mm)
-{
-	unsigned long pid = mm->context.id;
-
-	if (unlikely(pid = MMU_NO_CONTEXT))
-		return;
-
-	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-		return;
-
-	/*
-	 * If this context hasn't run on that CPU before and KVM is
-	 * around, there's a slim chance that the guest on another
-	 * CPU just brought in obsolete translation into the TLB of
-	 * this CPU due to a bad prefetch using the guest PID on
-	 * the way into the hypervisor.
-	 *
-	 * We work around this here. If KVM is possible, we check if
-	 * any sibling thread is in KVM. If it is, the window may exist
-	 * and thus we flush that PID from the core.
-	 *
-	 * A potential future improvement would be to mark which PIDs
-	 * have never been used on the system and avoid it if the PID
-	 * is new and the process has no other cpumask bit set.
-	 */
-	if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) {
-		int cpu = smp_processor_id();
-		int sib = cpu_first_thread_sibling(cpu);
-		bool flush = false;
-
-		for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) {
-			if (sib = cpu)
-				continue;
-			if (!cpu_possible(sib))
-				continue;
-			if (paca_ptrs[sib]->kvm_hstate.kvm_vcpu)
-				flush = true;
-		}
-		if (flush)
-			_tlbiel_pid(pid, RIC_FLUSH_ALL);
-	}
-}
-EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround);
-#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 18f20da0d348..7479d39976c9 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -81,9 +81,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
 		asm volatile ("dssall");
 
-	if (new_on_cpu)
-		radix_kvm_prefetch_workaround(next);
-	else
+	if (!new_on_cpu)
 		membarrier_arch_switch_mm(prev, next, tsk);
 
 	/*
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 31/37] KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Radix guest support will be removed from the P7/8 path, so disallow
dependent threads mode on P9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_host.h |  1 -
 arch/powerpc/kvm/book3s_hv.c        | 27 +++++----------------------
 2 files changed, 5 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 05fb00d37609..dd017dfa4e65 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -304,7 +304,6 @@ struct kvm_arch {
 	u8 fwnmi_enabled;
 	u8 secure_guest;
 	u8 svm_enabled;
-	bool threads_indep;
 	bool nested_enable;
 	bool dawr1_enabled;
 	pgd_t *pgtable;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c3064075f1d7..1f27187ff1e7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -103,13 +103,9 @@ static int target_smt_mode;
 module_param(target_smt_mode, int, 0644);
 MODULE_PARM_DESC(target_smt_mode, "Target threads per core (0 = max)");
 
-static bool indep_threads_mode = true;
-module_param(indep_threads_mode, bool, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(indep_threads_mode, "Independent-threads mode (only on POWER9)");
-
 static bool one_vm_per_core;
 module_param(one_vm_per_core, bool, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(one_vm_per_core, "Only run vCPUs from the same VM on a core (requires indep_threads_mode=N)");
+MODULE_PARM_DESC(one_vm_per_core, "Only run vCPUs from the same VM on a core (requires POWER8 or older)");
 
 #ifdef CONFIG_KVM_XICS
 static const struct kernel_param_ops module_param_ops = {
@@ -2201,7 +2197,7 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
  */
 static int threads_per_vcore(struct kvm *kvm)
 {
-	if (kvm->arch.threads_indep)
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
 		return 1;
 	return threads_per_subcore;
 }
@@ -4290,7 +4286,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (kvm->arch.threads_indep && kvm_is_radix(kvm))
+		if (kvm_is_radix(kvm))
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
@@ -4910,21 +4906,8 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 	/*
 	 * Track that we now have a HV mode VM active. This blocks secondary
 	 * CPU threads from coming online.
-	 * On POWER9, we only need to do this if the "indep_threads_mode"
-	 * module parameter has been set to N.
 	 */
-	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
-		if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) {
-			pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n");
-			kvm->arch.threads_indep = true;
-		} else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
-			pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n");
-			kvm->arch.threads_indep = true;
-		} else {
-			kvm->arch.threads_indep = indep_threads_mode;
-		}
-	}
-	if (!kvm->arch.threads_indep)
+	if (!cpu_has_feature(CPU_FTR_ARCH_300))
 		kvm_hv_vm_activated();
 
 	/*
@@ -4965,7 +4948,7 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)
 {
 	debugfs_remove_recursive(kvm->arch.debugfs_dir);
 
-	if (!kvm->arch.threads_indep)
+	if (!cpu_has_feature(CPU_FTR_ARCH_300))
 		kvm_hv_vm_deactivated();
 
 	kvmppc_free_vcores(kvm);
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 31/37] KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Radix guest support will be removed from the P7/8 path, so disallow
dependent threads mode on P9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_host.h |  1 -
 arch/powerpc/kvm/book3s_hv.c        | 27 +++++----------------------
 2 files changed, 5 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 05fb00d37609..dd017dfa4e65 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -304,7 +304,6 @@ struct kvm_arch {
 	u8 fwnmi_enabled;
 	u8 secure_guest;
 	u8 svm_enabled;
-	bool threads_indep;
 	bool nested_enable;
 	bool dawr1_enabled;
 	pgd_t *pgtable;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c3064075f1d7..1f27187ff1e7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -103,13 +103,9 @@ static int target_smt_mode;
 module_param(target_smt_mode, int, 0644);
 MODULE_PARM_DESC(target_smt_mode, "Target threads per core (0 = max)");
 
-static bool indep_threads_mode = true;
-module_param(indep_threads_mode, bool, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(indep_threads_mode, "Independent-threads mode (only on POWER9)");
-
 static bool one_vm_per_core;
 module_param(one_vm_per_core, bool, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(one_vm_per_core, "Only run vCPUs from the same VM on a core (requires indep_threads_mode=N)");
+MODULE_PARM_DESC(one_vm_per_core, "Only run vCPUs from the same VM on a core (requires POWER8 or older)");
 
 #ifdef CONFIG_KVM_XICS
 static const struct kernel_param_ops module_param_ops = {
@@ -2201,7 +2197,7 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
  */
 static int threads_per_vcore(struct kvm *kvm)
 {
-	if (kvm->arch.threads_indep)
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
 		return 1;
 	return threads_per_subcore;
 }
@@ -4290,7 +4286,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (kvm->arch.threads_indep && kvm_is_radix(kvm))
+		if (kvm_is_radix(kvm))
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
@@ -4910,21 +4906,8 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 	/*
 	 * Track that we now have a HV mode VM active. This blocks secondary
 	 * CPU threads from coming online.
-	 * On POWER9, we only need to do this if the "indep_threads_mode"
-	 * module parameter has been set to N.
 	 */
-	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
-		if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) {
-			pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n");
-			kvm->arch.threads_indep = true;
-		} else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
-			pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n");
-			kvm->arch.threads_indep = true;
-		} else {
-			kvm->arch.threads_indep = indep_threads_mode;
-		}
-	}
-	if (!kvm->arch.threads_indep)
+	if (!cpu_has_feature(CPU_FTR_ARCH_300))
 		kvm_hv_vm_activated();
 
 	/*
@@ -4965,7 +4948,7 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)
 {
 	debugfs_remove_recursive(kvm->arch.debugfs_dir);
 
-	if (!kvm->arch.threads_indep)
+	if (!cpu_has_feature(CPU_FTR_ARCH_300))
 		kvm_hv_vm_deactivated();
 
 	kvmppc_free_vcores(kvm);
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 32/37] KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

The P9 path will run all supported radix guest combinations now, so
remove support from the old path.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 65 ++-----------------------
 1 file changed, 3 insertions(+), 62 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 61f71a7df238..a8ce68eed13e 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -899,11 +899,6 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	cmpdi	r3, 512		/* 1 microsecond */
 	blt	hdec_soon
 
-	ld	r6, VCPU_KVM(r4)
-	lbz	r0, KVM_RADIX(r6)
-	cmpwi	r0, 0
-	bne	9f
-
 	/* For hash guest, clear out and reload the SLB */
 BEGIN_MMU_FTR_SECTION
 	/* Radix host won't have populated the SLB, so no need to clear */
@@ -1389,11 +1384,7 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	patch_site 1b patch__call_kvm_flush_link_stack
 
 	/* For hash guest, read the guest SLB and save it away */
-	ld	r5, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r5)
 	li	r5, 0
-	cmpwi	r0, 0
-	bne	0f			/* for radix, save 0 entries */
 	lwz	r0,VCPU_SLB_NR(r9)	/* number of entries in SLB */
 	mtctr	r0
 	li	r6,0
@@ -1432,23 +1423,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 	slbmte	r6,r5
 1:	addi	r8,r8,16
 	.endr
-	b	guest_bypass
-
-0:	/*
-	 * Malicious or buggy radix guests may have inserted SLB entries
-	 * (only 0..3 because radix always runs with UPRT=1), so these must
-	 * be cleared here to avoid side-channels. slbmte is used rather
-	 * than slbia, as it won't clear cached translations.
-	 */
-	li	r0,0
-	stw	r0,VCPU_SLB_MAX(r9)
-	slbmte	r0,r0
-	li	r4,1
-	slbmte	r0,r4
-	li	r4,2
-	slbmte	r0,r4
-	li	r4,3
-	slbmte	r0,r4
 
 guest_bypass:
 	stw	r12, STACK_SLOT_TRAP(r1)
@@ -1694,24 +1668,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_PID, r7
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 
-#ifdef CONFIG_PPC_RADIX_MMU
-	/*
-	 * Are we running hash or radix ?
-	 */
-	ld	r5, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r5)
-	cmpwi	cr2, r0, 0
-	beq	cr2, 2f
-
-	/*
-	 * Radix: do eieio; tlbsync; ptesync sequence in case we
-	 * interrupted the guest between a tlbie and a ptesync.
-	 */
-	eieio
-	tlbsync
-	ptesync
-#endif /* CONFIG_PPC_RADIX_MMU */
-
 	/*
 	 * cp_abort is required if the processor supports local copy-paste
 	 * to clear the copy buffer that was under control of the guest.
@@ -1970,8 +1926,6 @@ kvmppc_tm_emul:
  * reflect the HDSI to the guest as a DSI.
  */
 kvmppc_hdsi:
-	ld	r3, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r3)
 	mfspr	r4, SPRN_HDAR
 	mfspr	r6, SPRN_HDSISR
 BEGIN_FTR_SECTION
@@ -1979,8 +1933,6 @@ BEGIN_FTR_SECTION
 	cmpdi	r6, 0x7fff
 	beq	6f
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-	cmpwi	r0, 0
-	bne	.Lradix_hdsi		/* on radix, just save DAR/DSISR/ASDR */
 	/* HPTE not found fault or protection fault? */
 	andis.	r0, r6, (DSISR_NOHPTE | DSISR_PROTFAULT)@h
 	beq	1f			/* if not, send it to the guest */
@@ -2057,23 +2009,11 @@ fast_interrupt_c_return:
 	stb	r0, HSTATE_IN_GUEST(r13)
 	b	guest_exit_cont
 
-.Lradix_hdsi:
-	std	r4, VCPU_FAULT_DAR(r9)
-	stw	r6, VCPU_FAULT_DSISR(r9)
-.Lradix_hisi:
-	mfspr	r5, SPRN_ASDR
-	std	r5, VCPU_FAULT_GPA(r9)
-	b	guest_exit_cont
-
 /*
  * Similarly for an HISI, reflect it to the guest as an ISI unless
  * it is an HPTE not found fault for a page that we have paged out.
  */
 kvmppc_hisi:
-	ld	r3, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r3)
-	cmpwi	r0, 0
-	bne	.Lradix_hisi		/* for radix, just save ASDR */
 	andis.	r0, r11, SRR1_ISI_NOPT@h
 	beq	1f
 	andi.	r0, r11, MSR_IR		/* instruction relocation enabled? */
@@ -3217,15 +3157,16 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWRX1, r0
 END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 
-	/* Clear hash and radix guest SLB. */
+	/* Clear guest SLB. */
 	slbmte	r0, r0
 	PPC_SLBIA(6)
+	ptesync
 
 BEGIN_MMU_FTR_SECTION
 	b	4f
 END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 
-	ptesync
+	/* load host SLB entries */
 	ld	r8, PACA_SLBSHADOWPTR(r13)
 	.rept	SLB_NUM_BOLTED
 	li	r3, SLBSHADOW_SAVEAREA
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 32/37] KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

The P9 path will run all supported radix guest combinations now, so
remove support from the old path.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 65 ++-----------------------
 1 file changed, 3 insertions(+), 62 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 61f71a7df238..a8ce68eed13e 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -899,11 +899,6 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	cmpdi	r3, 512		/* 1 microsecond */
 	blt	hdec_soon
 
-	ld	r6, VCPU_KVM(r4)
-	lbz	r0, KVM_RADIX(r6)
-	cmpwi	r0, 0
-	bne	9f
-
 	/* For hash guest, clear out and reload the SLB */
 BEGIN_MMU_FTR_SECTION
 	/* Radix host won't have populated the SLB, so no need to clear */
@@ -1389,11 +1384,7 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	patch_site 1b patch__call_kvm_flush_link_stack
 
 	/* For hash guest, read the guest SLB and save it away */
-	ld	r5, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r5)
 	li	r5, 0
-	cmpwi	r0, 0
-	bne	0f			/* for radix, save 0 entries */
 	lwz	r0,VCPU_SLB_NR(r9)	/* number of entries in SLB */
 	mtctr	r0
 	li	r6,0
@@ -1432,23 +1423,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 	slbmte	r6,r5
 1:	addi	r8,r8,16
 	.endr
-	b	guest_bypass
-
-0:	/*
-	 * Malicious or buggy radix guests may have inserted SLB entries
-	 * (only 0..3 because radix always runs with UPRT=1), so these must
-	 * be cleared here to avoid side-channels. slbmte is used rather
-	 * than slbia, as it won't clear cached translations.
-	 */
-	li	r0,0
-	stw	r0,VCPU_SLB_MAX(r9)
-	slbmte	r0,r0
-	li	r4,1
-	slbmte	r0,r4
-	li	r4,2
-	slbmte	r0,r4
-	li	r4,3
-	slbmte	r0,r4
 
 guest_bypass:
 	stw	r12, STACK_SLOT_TRAP(r1)
@@ -1694,24 +1668,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_PID, r7
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 
-#ifdef CONFIG_PPC_RADIX_MMU
-	/*
-	 * Are we running hash or radix ?
-	 */
-	ld	r5, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r5)
-	cmpwi	cr2, r0, 0
-	beq	cr2, 2f
-
-	/*
-	 * Radix: do eieio; tlbsync; ptesync sequence in case we
-	 * interrupted the guest between a tlbie and a ptesync.
-	 */
-	eieio
-	tlbsync
-	ptesync
-#endif /* CONFIG_PPC_RADIX_MMU */
-
 	/*
 	 * cp_abort is required if the processor supports local copy-paste
 	 * to clear the copy buffer that was under control of the guest.
@@ -1970,8 +1926,6 @@ kvmppc_tm_emul:
  * reflect the HDSI to the guest as a DSI.
  */
 kvmppc_hdsi:
-	ld	r3, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r3)
 	mfspr	r4, SPRN_HDAR
 	mfspr	r6, SPRN_HDSISR
 BEGIN_FTR_SECTION
@@ -1979,8 +1933,6 @@ BEGIN_FTR_SECTION
 	cmpdi	r6, 0x7fff
 	beq	6f
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-	cmpwi	r0, 0
-	bne	.Lradix_hdsi		/* on radix, just save DAR/DSISR/ASDR */
 	/* HPTE not found fault or protection fault? */
 	andis.	r0, r6, (DSISR_NOHPTE | DSISR_PROTFAULT)@h
 	beq	1f			/* if not, send it to the guest */
@@ -2057,23 +2009,11 @@ fast_interrupt_c_return:
 	stb	r0, HSTATE_IN_GUEST(r13)
 	b	guest_exit_cont
 
-.Lradix_hdsi:
-	std	r4, VCPU_FAULT_DAR(r9)
-	stw	r6, VCPU_FAULT_DSISR(r9)
-.Lradix_hisi:
-	mfspr	r5, SPRN_ASDR
-	std	r5, VCPU_FAULT_GPA(r9)
-	b	guest_exit_cont
-
 /*
  * Similarly for an HISI, reflect it to the guest as an ISI unless
  * it is an HPTE not found fault for a page that we have paged out.
  */
 kvmppc_hisi:
-	ld	r3, VCPU_KVM(r9)
-	lbz	r0, KVM_RADIX(r3)
-	cmpwi	r0, 0
-	bne	.Lradix_hisi		/* for radix, just save ASDR */
 	andis.	r0, r11, SRR1_ISI_NOPT@h
 	beq	1f
 	andi.	r0, r11, MSR_IR		/* instruction relocation enabled? */
@@ -3217,15 +3157,16 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWRX1, r0
 END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 
-	/* Clear hash and radix guest SLB. */
+	/* Clear guest SLB. */
 	slbmte	r0, r0
 	PPC_SLBIA(6)
+	ptesync
 
 BEGIN_MMU_FTR_SECTION
 	b	4f
 END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 
-	ptesync
+	/* load host SLB entries */
 	ld	r8, PACA_SLBSHADOWPTR(r13)
 	.rept	SLB_NUM_BOLTED
 	li	r3, SLBSHADOW_SAVEAREA
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 33/37] KVM: PPC: Book3S HV: small pseries_do_hcall cleanup
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Functionality should not be changed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1f27187ff1e7..9d2fa21201c1 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -923,6 +923,7 @@ static int kvmppc_get_yield_count(struct kvm_vcpu *vcpu)
 
 int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 {
+	struct kvm *kvm = vcpu->kvm;
 	unsigned long req = kvmppc_get_gpr(vcpu, 3);
 	unsigned long target, ret = H_SUCCESS;
 	int yield_count;
@@ -938,7 +939,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		break;
 	case H_PROD:
 		target = kvmppc_get_gpr(vcpu, 4);
-		tvcpu = kvmppc_find_vcpu(vcpu->kvm, target);
+		tvcpu = kvmppc_find_vcpu(kvm, target);
 		if (!tvcpu) {
 			ret = H_PARAMETER;
 			break;
@@ -952,7 +953,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		target = kvmppc_get_gpr(vcpu, 4);
 		if (target == -1)
 			break;
-		tvcpu = kvmppc_find_vcpu(vcpu->kvm, target);
+		tvcpu = kvmppc_find_vcpu(kvm, target);
 		if (!tvcpu) {
 			ret = H_PARAMETER;
 			break;
@@ -968,12 +969,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 					kvmppc_get_gpr(vcpu, 6));
 		break;
 	case H_RTAS:
-		if (list_empty(&vcpu->kvm->arch.rtas_tokens))
+		if (list_empty(&kvm->arch.rtas_tokens))
 			return RESUME_HOST;
 
-		idx = srcu_read_lock(&vcpu->kvm->srcu);
+		idx = srcu_read_lock(&kvm->srcu);
 		rc = kvmppc_rtas_hcall(vcpu);
-		srcu_read_unlock(&vcpu->kvm->srcu, idx);
+		srcu_read_unlock(&kvm->srcu, idx);
 
 		if (rc == -ENOENT)
 			return RESUME_HOST;
@@ -1060,12 +1061,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 
 	case H_SET_PARTITION_TABLE:
 		ret = H_FUNCTION;
-		if (nesting_enabled(vcpu->kvm))
+		if (nesting_enabled(kvm))
 			ret = kvmhv_set_partition_table(vcpu);
 		break;
 	case H_ENTER_NESTED:
 		ret = H_FUNCTION;
-		if (!nesting_enabled(vcpu->kvm))
+		if (!nesting_enabled(kvm))
 			break;
 		ret = kvmhv_enter_nested_guest(vcpu);
 		if (ret == H_INTERRUPT) {
@@ -1080,12 +1081,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		break;
 	case H_TLB_INVALIDATE:
 		ret = H_FUNCTION;
-		if (nesting_enabled(vcpu->kvm))
+		if (nesting_enabled(kvm))
 			ret = kvmhv_do_nested_tlbie(vcpu);
 		break;
 	case H_COPY_TOFROM_GUEST:
 		ret = H_FUNCTION;
-		if (nesting_enabled(vcpu->kvm))
+		if (nesting_enabled(kvm))
 			ret = kvmhv_copy_tofrom_guest_nested(vcpu);
 		break;
 	case H_PAGE_INIT:
@@ -1096,7 +1097,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	case H_SVM_PAGE_IN:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_page_in(vcpu->kvm,
+			ret = kvmppc_h_svm_page_in(kvm,
 						   kvmppc_get_gpr(vcpu, 4),
 						   kvmppc_get_gpr(vcpu, 5),
 						   kvmppc_get_gpr(vcpu, 6));
@@ -1104,7 +1105,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	case H_SVM_PAGE_OUT:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_page_out(vcpu->kvm,
+			ret = kvmppc_h_svm_page_out(kvm,
 						    kvmppc_get_gpr(vcpu, 4),
 						    kvmppc_get_gpr(vcpu, 5),
 						    kvmppc_get_gpr(vcpu, 6));
@@ -1112,12 +1113,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	case H_SVM_INIT_START:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_init_start(vcpu->kvm);
+			ret = kvmppc_h_svm_init_start(kvm);
 		break;
 	case H_SVM_INIT_DONE:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_init_done(vcpu->kvm);
+			ret = kvmppc_h_svm_init_done(kvm);
 		break;
 	case H_SVM_INIT_ABORT:
 		/*
@@ -1127,7 +1128,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		 * Instead the kvm->arch.secure_guest flag is checked inside
 		 * kvmppc_h_svm_init_abort().
 		 */
-		ret = kvmppc_h_svm_init_abort(vcpu->kvm);
+		ret = kvmppc_h_svm_init_abort(kvm);
 		break;
 
 	default:
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 33/37] KVM: PPC: Book3S HV: small pseries_do_hcall cleanup
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Functionality should not be changed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1f27187ff1e7..9d2fa21201c1 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -923,6 +923,7 @@ static int kvmppc_get_yield_count(struct kvm_vcpu *vcpu)
 
 int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 {
+	struct kvm *kvm = vcpu->kvm;
 	unsigned long req = kvmppc_get_gpr(vcpu, 3);
 	unsigned long target, ret = H_SUCCESS;
 	int yield_count;
@@ -938,7 +939,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		break;
 	case H_PROD:
 		target = kvmppc_get_gpr(vcpu, 4);
-		tvcpu = kvmppc_find_vcpu(vcpu->kvm, target);
+		tvcpu = kvmppc_find_vcpu(kvm, target);
 		if (!tvcpu) {
 			ret = H_PARAMETER;
 			break;
@@ -952,7 +953,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		target = kvmppc_get_gpr(vcpu, 4);
 		if (target = -1)
 			break;
-		tvcpu = kvmppc_find_vcpu(vcpu->kvm, target);
+		tvcpu = kvmppc_find_vcpu(kvm, target);
 		if (!tvcpu) {
 			ret = H_PARAMETER;
 			break;
@@ -968,12 +969,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 					kvmppc_get_gpr(vcpu, 6));
 		break;
 	case H_RTAS:
-		if (list_empty(&vcpu->kvm->arch.rtas_tokens))
+		if (list_empty(&kvm->arch.rtas_tokens))
 			return RESUME_HOST;
 
-		idx = srcu_read_lock(&vcpu->kvm->srcu);
+		idx = srcu_read_lock(&kvm->srcu);
 		rc = kvmppc_rtas_hcall(vcpu);
-		srcu_read_unlock(&vcpu->kvm->srcu, idx);
+		srcu_read_unlock(&kvm->srcu, idx);
 
 		if (rc = -ENOENT)
 			return RESUME_HOST;
@@ -1060,12 +1061,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 
 	case H_SET_PARTITION_TABLE:
 		ret = H_FUNCTION;
-		if (nesting_enabled(vcpu->kvm))
+		if (nesting_enabled(kvm))
 			ret = kvmhv_set_partition_table(vcpu);
 		break;
 	case H_ENTER_NESTED:
 		ret = H_FUNCTION;
-		if (!nesting_enabled(vcpu->kvm))
+		if (!nesting_enabled(kvm))
 			break;
 		ret = kvmhv_enter_nested_guest(vcpu);
 		if (ret = H_INTERRUPT) {
@@ -1080,12 +1081,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		break;
 	case H_TLB_INVALIDATE:
 		ret = H_FUNCTION;
-		if (nesting_enabled(vcpu->kvm))
+		if (nesting_enabled(kvm))
 			ret = kvmhv_do_nested_tlbie(vcpu);
 		break;
 	case H_COPY_TOFROM_GUEST:
 		ret = H_FUNCTION;
-		if (nesting_enabled(vcpu->kvm))
+		if (nesting_enabled(kvm))
 			ret = kvmhv_copy_tofrom_guest_nested(vcpu);
 		break;
 	case H_PAGE_INIT:
@@ -1096,7 +1097,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	case H_SVM_PAGE_IN:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_page_in(vcpu->kvm,
+			ret = kvmppc_h_svm_page_in(kvm,
 						   kvmppc_get_gpr(vcpu, 4),
 						   kvmppc_get_gpr(vcpu, 5),
 						   kvmppc_get_gpr(vcpu, 6));
@@ -1104,7 +1105,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	case H_SVM_PAGE_OUT:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_page_out(vcpu->kvm,
+			ret = kvmppc_h_svm_page_out(kvm,
 						    kvmppc_get_gpr(vcpu, 4),
 						    kvmppc_get_gpr(vcpu, 5),
 						    kvmppc_get_gpr(vcpu, 6));
@@ -1112,12 +1113,12 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	case H_SVM_INIT_START:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_init_start(vcpu->kvm);
+			ret = kvmppc_h_svm_init_start(kvm);
 		break;
 	case H_SVM_INIT_DONE:
 		ret = H_UNSUPPORTED;
 		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_init_done(vcpu->kvm);
+			ret = kvmppc_h_svm_init_done(kvm);
 		break;
 	case H_SVM_INIT_ABORT:
 		/*
@@ -1127,7 +1128,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		 * Instead the kvm->arch.secure_guest flag is checked inside
 		 * kvmppc_h_svm_init_abort().
 		 */
-		ret = kvmppc_h_svm_init_abort(vcpu->kvm);
+		ret = kvmppc_h_svm_init_abort(kvm);
 		break;
 
 	default:
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

In order to support hash guests in the P9 path (which does not do real
mode hcalls or page fault handling), these real-mode hash specific
interrupts need to be implemented in virt mode.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 118 +++++++++++++++++++++++++++++++++--
 1 file changed, 113 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 9d2fa21201c1..1bbc46f2cfbf 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -935,6 +935,52 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		return RESUME_HOST;
 
 	switch (req) {
+	case H_REMOVE:
+		ret = kvmppc_h_remove(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5),
+					kvmppc_get_gpr(vcpu, 6));
+		if (ret == H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_ENTER:
+		ret = kvmppc_h_enter(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5),
+					kvmppc_get_gpr(vcpu, 6),
+					kvmppc_get_gpr(vcpu, 7));
+		if (ret == H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_READ:
+		ret = kvmppc_h_read(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5));
+		if (ret == H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_CLEAR_MOD:
+		ret = kvmppc_h_clear_mod(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5));
+		if (ret == H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_CLEAR_REF:
+		ret = kvmppc_h_clear_ref(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5));
+		if (ret == H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_PROTECT:
+		ret = kvmppc_h_protect(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5),
+					kvmppc_get_gpr(vcpu, 6));
+		if (ret == H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_BULK_REMOVE:
+		ret = kvmppc_h_bulk_remove(vcpu);
+		if (ret == H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+
 	case H_CEDE:
 		break;
 	case H_PROD:
@@ -1134,6 +1180,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	default:
 		return RESUME_HOST;
 	}
+	WARN_ON_ONCE(ret == H_TOO_HARD);
 	kvmppc_set_gpr(vcpu, 3, ret);
 	vcpu->arch.hcall_needed = 0;
 	return RESUME_GUEST;
@@ -1420,19 +1467,80 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 	 * host page has been paged out.  Any other HDSI/HISI interrupts
 	 * have been handled already.
 	 */
-	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
-		r = RESUME_PAGE_FAULT;
-		if (vcpu->arch.fault_dsisr == HDSISR_CANARY)
+	case BOOK3S_INTERRUPT_H_DATA_STORAGE: {
+		unsigned long vsid;
+		long err;
+
+		if (vcpu->arch.fault_dsisr == HDSISR_CANARY) {
 			r = RESUME_GUEST; /* Just retry if it's the canary */
+			break;
+		}
+
+		if (kvm_is_radix(vcpu->kvm)) {
+			r = RESUME_PAGE_FAULT;
+			break;
+		}
+
+		if (!(vcpu->arch.fault_dsisr & (DSISR_NOHPTE | DSISR_PROTFAULT))) {
+			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
+			r = RESUME_GUEST;
+			break;
+		}
+		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
+			vsid = vcpu->kvm->arch.vrma_slb_v;
+		} else {
+			vsid = vcpu->arch.fault_gpa;
+		}
+		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
+				vsid, vcpu->arch.fault_dsisr, true);
+		if (err == 0) {
+			r = RESUME_GUEST;
+		} else if (err == -1 || err == -2) {
+			r = RESUME_PAGE_FAULT;
+		} else {
+			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, err);
+			r = RESUME_GUEST;
+		}
 		break;
-	case BOOK3S_INTERRUPT_H_INST_STORAGE:
+	}
+	case BOOK3S_INTERRUPT_H_INST_STORAGE: {
+		unsigned long vsid;
+		long err;
+
 		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
 		vcpu->arch.fault_dsisr = vcpu->arch.shregs.msr &
 			DSISR_SRR1_MATCH_64S;
 		if (vcpu->arch.shregs.msr & HSRR1_HISI_WRITE)
 			vcpu->arch.fault_dsisr |= DSISR_ISSTORE;
-		r = RESUME_PAGE_FAULT;
+		if (kvm_is_radix(vcpu->kvm)) {
+			r = RESUME_PAGE_FAULT;
+			break;
+		}
+
+		if (!(vcpu->arch.fault_dsisr & SRR1_ISI_NOPT)) {
+			/* XXX: clear DSISR_ISSTORE? */
+			kvmppc_core_queue_inst_storage(vcpu, vcpu->arch.fault_dsisr);
+			r = RESUME_GUEST;
+			break;
+		}
+		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
+			vsid = vcpu->kvm->arch.vrma_slb_v;
+		} else {
+			vsid = vcpu->arch.fault_gpa;
+		}
+		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
+				vsid, vcpu->arch.fault_dsisr, false);
+		if (err == 0) {
+			r = RESUME_GUEST;
+		} else if (err == -1) {
+			r = RESUME_PAGE_FAULT;
+		} else {
+			kvmppc_core_queue_inst_storage(vcpu, err);
+			r = RESUME_GUEST;
+		}
 		break;
+	}
+
 	/*
 	 * This occurs if the guest executes an illegal instruction.
 	 * If the guest debug is disabled, generate a program interrupt
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

In order to support hash guests in the P9 path (which does not do real
mode hcalls or page fault handling), these real-mode hash specific
interrupts need to be implemented in virt mode.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 118 +++++++++++++++++++++++++++++++++--
 1 file changed, 113 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 9d2fa21201c1..1bbc46f2cfbf 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -935,6 +935,52 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		return RESUME_HOST;
 
 	switch (req) {
+	case H_REMOVE:
+		ret = kvmppc_h_remove(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5),
+					kvmppc_get_gpr(vcpu, 6));
+		if (ret = H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_ENTER:
+		ret = kvmppc_h_enter(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5),
+					kvmppc_get_gpr(vcpu, 6),
+					kvmppc_get_gpr(vcpu, 7));
+		if (ret = H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_READ:
+		ret = kvmppc_h_read(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5));
+		if (ret = H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_CLEAR_MOD:
+		ret = kvmppc_h_clear_mod(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5));
+		if (ret = H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_CLEAR_REF:
+		ret = kvmppc_h_clear_ref(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5));
+		if (ret = H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_PROTECT:
+		ret = kvmppc_h_protect(vcpu, kvmppc_get_gpr(vcpu, 4),
+					kvmppc_get_gpr(vcpu, 5),
+					kvmppc_get_gpr(vcpu, 6));
+		if (ret = H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+	case H_BULK_REMOVE:
+		ret = kvmppc_h_bulk_remove(vcpu);
+		if (ret = H_TOO_HARD)
+			return RESUME_HOST;
+		break;
+
 	case H_CEDE:
 		break;
 	case H_PROD:
@@ -1134,6 +1180,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 	default:
 		return RESUME_HOST;
 	}
+	WARN_ON_ONCE(ret = H_TOO_HARD);
 	kvmppc_set_gpr(vcpu, 3, ret);
 	vcpu->arch.hcall_needed = 0;
 	return RESUME_GUEST;
@@ -1420,19 +1467,80 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 	 * host page has been paged out.  Any other HDSI/HISI interrupts
 	 * have been handled already.
 	 */
-	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
-		r = RESUME_PAGE_FAULT;
-		if (vcpu->arch.fault_dsisr = HDSISR_CANARY)
+	case BOOK3S_INTERRUPT_H_DATA_STORAGE: {
+		unsigned long vsid;
+		long err;
+
+		if (vcpu->arch.fault_dsisr = HDSISR_CANARY) {
 			r = RESUME_GUEST; /* Just retry if it's the canary */
+			break;
+		}
+
+		if (kvm_is_radix(vcpu->kvm)) {
+			r = RESUME_PAGE_FAULT;
+			break;
+		}
+
+		if (!(vcpu->arch.fault_dsisr & (DSISR_NOHPTE | DSISR_PROTFAULT))) {
+			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
+			r = RESUME_GUEST;
+			break;
+		}
+		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
+			vsid = vcpu->kvm->arch.vrma_slb_v;
+		} else {
+			vsid = vcpu->arch.fault_gpa;
+		}
+		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
+				vsid, vcpu->arch.fault_dsisr, true);
+		if (err = 0) {
+			r = RESUME_GUEST;
+		} else if (err = -1 || err = -2) {
+			r = RESUME_PAGE_FAULT;
+		} else {
+			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, err);
+			r = RESUME_GUEST;
+		}
 		break;
-	case BOOK3S_INTERRUPT_H_INST_STORAGE:
+	}
+	case BOOK3S_INTERRUPT_H_INST_STORAGE: {
+		unsigned long vsid;
+		long err;
+
 		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
 		vcpu->arch.fault_dsisr = vcpu->arch.shregs.msr &
 			DSISR_SRR1_MATCH_64S;
 		if (vcpu->arch.shregs.msr & HSRR1_HISI_WRITE)
 			vcpu->arch.fault_dsisr |= DSISR_ISSTORE;
-		r = RESUME_PAGE_FAULT;
+		if (kvm_is_radix(vcpu->kvm)) {
+			r = RESUME_PAGE_FAULT;
+			break;
+		}
+
+		if (!(vcpu->arch.fault_dsisr & SRR1_ISI_NOPT)) {
+			/* XXX: clear DSISR_ISSTORE? */
+			kvmppc_core_queue_inst_storage(vcpu, vcpu->arch.fault_dsisr);
+			r = RESUME_GUEST;
+			break;
+		}
+		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
+			vsid = vcpu->kvm->arch.vrma_slb_v;
+		} else {
+			vsid = vcpu->arch.fault_gpa;
+		}
+		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
+				vsid, vcpu->arch.fault_dsisr, false);
+		if (err = 0) {
+			r = RESUME_GUEST;
+		} else if (err = -1) {
+			r = RESUME_PAGE_FAULT;
+		} else {
+			kvmppc_core_queue_inst_storage(vcpu, err);
+			r = RESUME_GUEST;
+		}
 		break;
+	}
+
 	/*
 	 * This occurs if the guest executes an illegal instruction.
 	 * If the guest debug is disabled, generate a program interrupt
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 35/37] KVM: PPC: Book3S HV P9: implement hash guest support
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c            |  20 ++--
 arch/powerpc/kvm/book3s_hv_interrupt.c  | 123 +++++++++++++++++-------
 arch/powerpc/kvm/book3s_hv_rm_mmu.c     |   4 +
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |  14 +--
 4 files changed, 109 insertions(+), 52 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1bbc46f2cfbf..97320531f37c 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3765,7 +3765,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		}
 		kvmppc_xive_pull_vcpu(vcpu);
 
-		vcpu->arch.slb_max = 0;
+		if (kvm_is_radix(vcpu->kvm))
+			vcpu->arch.slb_max = 0;
 	}
 
 	dec = mfspr(SPRN_DEC);
@@ -3998,7 +3999,6 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 /*
  * This never fails for a radix guest, as none of the operations it does
  * for a radix guest can fail or have a way to report failure.
- * kvmhv_run_single_vcpu() relies on this fact.
  */
 static int kvmhv_setup_mmu(struct kvm_vcpu *vcpu)
 {
@@ -4177,8 +4177,15 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->runner = vcpu;
 
 	/* See if the MMU is ready to go */
-	if (!kvm->arch.mmu_ready)
-		kvmhv_setup_mmu(vcpu);
+	if (!kvm->arch.mmu_ready) {
+		r = kvmhv_setup_mmu(vcpu);
+		if (r) {
+			run->exit_reason = KVM_EXIT_FAIL_ENTRY;
+			run->fail_entry.hardware_entry_failure_reason = 0;
+			vcpu->arch.ret = r;
+			return r;
+		}
+	}
 
 	if (need_resched())
 		cond_resched();
@@ -4191,7 +4198,8 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	preempt_disable();
 	pcpu = smp_processor_id();
 	vc->pcpu = pcpu;
-	kvmppc_prepare_radix_vcpu(vcpu, pcpu);
+	if (kvm_is_radix(kvm))
+		kvmppc_prepare_radix_vcpu(vcpu, pcpu);
 
 	local_irq_disable();
 	hard_irq_disable();
@@ -4395,7 +4403,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (kvm_is_radix(kvm))
+		if (radix_enabled())
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index 9784da3f8565..d79c6f4f330c 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -55,44 +55,25 @@ static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator
 #define accumulate_time(vcpu, next) do {} while (0)
 #endif
 
-static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
-{
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	struct kvm_nested_guest *nested = vcpu->arch.nested;
-	u32 lpid;
-
-	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
-
-	mtspr(SPRN_LPID, lpid);
-	mtspr(SPRN_LPCR, lpcr);
-	mtspr(SPRN_PID, vcpu->arch.pid);
-	isync();
-
-	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
-	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
-}
-
-static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
-{
-	mtspr(SPRN_PID, pid);
-	mtspr(SPRN_LPID, kvm->arch.host_lpid);
-	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
-	isync();
-}
-
 static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
 {
 	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
 	asm volatile("slbmfee  %0,%1" : "=r" (*slbee) : "r" (idx));
 }
 
+static inline void __mtslb(u64 slbee, u64 slbev)
+{
+	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+}
+
 static inline void mtslb(unsigned int idx, u64 slbee, u64 slbev)
 {
 	BUG_ON((slbee & 0xfff) != idx);
 
-	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+	__mtslb(slbee, slbev);
 }
 
+
 static inline void slb_invalidate(unsigned int ih)
 {
 	asm volatile("slbia %0" :: "i"(ih));
@@ -119,6 +100,54 @@ static void radix_clear_slb(void)
 	}
 }
 
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+
+	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+	isync();
+
+	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
+	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+}
+
+static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+	int i;
+
+	BUG_ON(nested);
+
+	lpid = kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+
+	for (i = 0; i < vcpu->arch.slb_max; i++)
+		__mtslb(vcpu->arch.slb[i].orige, vcpu->arch.slb[i].origv);
+
+	isync();
+
+	/* XXX: TLBIEL not virtualised for HPT guests */
+}
+
+
+static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+{
+	mtspr(SPRN_PID, pid);
+	mtspr(SPRN_LPID, kvm->arch.host_lpid);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+	isync();
+}
+
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -223,10 +252,17 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_AMOR, ~0UL);
 
-	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+	if (kvm_is_radix(kvm)) {
+		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+			__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+		switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+		if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+			__mtmsrd(0, 1); /* clear RI */
 
-	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+	} else {
+		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+		switch_mmu_to_guest_hpt(kvm, vcpu, lpcr);
+	}
 
 	/*
 	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
@@ -234,9 +270,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-		__mtmsrd(0, 1); /* clear RI */
-
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
 	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
 	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
@@ -340,8 +373,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 #endif
 	}
 
-	radix_clear_slb();
-
 	accumulate_time(vcpu, &vcpu->arch.rm_exit);
 
 	/* Advance host PURR/SPURR by the amount used by guest */
@@ -406,6 +437,30 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	/* HDEC must be at least as large as DEC, so decrementer_max fits */
 	mtspr(SPRN_HDEC, decrementer_max);
 
+	if (kvm_is_radix(kvm)) {
+		radix_clear_slb();
+	} else {
+		int i;
+		int nr = 0;
+
+		/*
+		 * This must run before switching to host (radix host can't
+		 * access all SLBs).
+		 */
+		for (i = 0; i < vcpu->arch.slb_nr; i++) {
+			u64 slbee, slbev;
+			mfslb(i, &slbee, &slbev);
+			if (slbee & SLB_ESID_V) {
+				vcpu->arch.slb[nr].orige = slbee | i;
+				vcpu->arch.slb[nr].origv = slbev;
+				nr++;
+			}
+		}
+		vcpu->arch.slb_max = nr;
+		mtslb(0, 0, 0);
+		slb_invalidate(6);
+	}
+
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
 	/*
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 7af7c70f1468..b5532b85c7fd 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -57,6 +57,10 @@ static int global_invalidates(struct kvm *kvm)
 	else
 		global = 1;
 
+	/* LPID has been switched to host if in virt mode so can't do local */
+	if (!global && (mfmsr() & (MSR_IR|MSR_DR)))
+		global = 1;
+
 	if (!global) {
 		/* any other core might now have stale TLB entries... */
 		smp_wmb();
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index a8ce68eed13e..be5742640780 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -899,14 +899,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	cmpdi	r3, 512		/* 1 microsecond */
 	blt	hdec_soon
 
-	/* For hash guest, clear out and reload the SLB */
-BEGIN_MMU_FTR_SECTION
-	/* Radix host won't have populated the SLB, so no need to clear */
+	/* Clear out and reload the SLB */
 	li	r6, 0
 	slbmte	r6, r6
 	PPC_SLBIA(6)
 	ptesync
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
 
 	/* Load up guest SLB entries (N.B. slb_max will be 0 for radix) */
 	lwz	r5,VCPU_SLB_MAX(r4)
@@ -1408,9 +1405,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	stw	r5,VCPU_SLB_MAX(r9)
 
 	/* load host SLB entries */
-BEGIN_MMU_FTR_SECTION
-	b	guest_bypass
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 	ld	r8,PACA_SLBSHADOWPTR(r13)
 
 	.rept	SLB_NUM_BOLTED
@@ -3162,10 +3156,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 	PPC_SLBIA(6)
 	ptesync
 
-BEGIN_MMU_FTR_SECTION
-	b	4f
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
-
 	/* load host SLB entries */
 	ld	r8, PACA_SLBSHADOWPTR(r13)
 	.rept	SLB_NUM_BOLTED
@@ -3179,7 +3169,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 3:	addi	r8, r8, 16
 	.endr
 
-4:	lwz	r7, KVM_HOST_LPID(r10)
+	lwz	r7, KVM_HOST_LPID(r10)
 	mtspr	SPRN_LPID, r7
 	mtspr	SPRN_PID, r0
 	ld	r8, KVM_HOST_LPCR(r10)
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 35/37] KVM: PPC: Book3S HV P9: implement hash guest support
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c            |  20 ++--
 arch/powerpc/kvm/book3s_hv_interrupt.c  | 123 +++++++++++++++++-------
 arch/powerpc/kvm/book3s_hv_rm_mmu.c     |   4 +
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |  14 +--
 4 files changed, 109 insertions(+), 52 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1bbc46f2cfbf..97320531f37c 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3765,7 +3765,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		}
 		kvmppc_xive_pull_vcpu(vcpu);
 
-		vcpu->arch.slb_max = 0;
+		if (kvm_is_radix(vcpu->kvm))
+			vcpu->arch.slb_max = 0;
 	}
 
 	dec = mfspr(SPRN_DEC);
@@ -3998,7 +3999,6 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 /*
  * This never fails for a radix guest, as none of the operations it does
  * for a radix guest can fail or have a way to report failure.
- * kvmhv_run_single_vcpu() relies on this fact.
  */
 static int kvmhv_setup_mmu(struct kvm_vcpu *vcpu)
 {
@@ -4177,8 +4177,15 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->runner = vcpu;
 
 	/* See if the MMU is ready to go */
-	if (!kvm->arch.mmu_ready)
-		kvmhv_setup_mmu(vcpu);
+	if (!kvm->arch.mmu_ready) {
+		r = kvmhv_setup_mmu(vcpu);
+		if (r) {
+			run->exit_reason = KVM_EXIT_FAIL_ENTRY;
+			run->fail_entry.hardware_entry_failure_reason = 0;
+			vcpu->arch.ret = r;
+			return r;
+		}
+	}
 
 	if (need_resched())
 		cond_resched();
@@ -4191,7 +4198,8 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	preempt_disable();
 	pcpu = smp_processor_id();
 	vc->pcpu = pcpu;
-	kvmppc_prepare_radix_vcpu(vcpu, pcpu);
+	if (kvm_is_radix(kvm))
+		kvmppc_prepare_radix_vcpu(vcpu, pcpu);
 
 	local_irq_disable();
 	hard_irq_disable();
@@ -4395,7 +4403,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (kvm_is_radix(kvm))
+		if (radix_enabled())
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index 9784da3f8565..d79c6f4f330c 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -55,44 +55,25 @@ static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator
 #define accumulate_time(vcpu, next) do {} while (0)
 #endif
 
-static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
-{
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	struct kvm_nested_guest *nested = vcpu->arch.nested;
-	u32 lpid;
-
-	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
-
-	mtspr(SPRN_LPID, lpid);
-	mtspr(SPRN_LPCR, lpcr);
-	mtspr(SPRN_PID, vcpu->arch.pid);
-	isync();
-
-	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
-	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
-}
-
-static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
-{
-	mtspr(SPRN_PID, pid);
-	mtspr(SPRN_LPID, kvm->arch.host_lpid);
-	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
-	isync();
-}
-
 static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
 {
 	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
 	asm volatile("slbmfee  %0,%1" : "=r" (*slbee) : "r" (idx));
 }
 
+static inline void __mtslb(u64 slbee, u64 slbev)
+{
+	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+}
+
 static inline void mtslb(unsigned int idx, u64 slbee, u64 slbev)
 {
 	BUG_ON((slbee & 0xfff) != idx);
 
-	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+	__mtslb(slbee, slbev);
 }
 
+
 static inline void slb_invalidate(unsigned int ih)
 {
 	asm volatile("slbia %0" :: "i"(ih));
@@ -119,6 +100,54 @@ static void radix_clear_slb(void)
 	}
 }
 
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+
+	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+	isync();
+
+	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
+	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+}
+
+static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	u32 lpid;
+	int i;
+
+	BUG_ON(nested);
+
+	lpid = kvm->arch.lpid;
+
+	mtspr(SPRN_LPID, lpid);
+	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_PID, vcpu->arch.pid);
+
+	for (i = 0; i < vcpu->arch.slb_max; i++)
+		__mtslb(vcpu->arch.slb[i].orige, vcpu->arch.slb[i].origv);
+
+	isync();
+
+	/* XXX: TLBIEL not virtualised for HPT guests */
+}
+
+
+static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+{
+	mtspr(SPRN_PID, pid);
+	mtspr(SPRN_LPID, kvm->arch.host_lpid);
+	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+	isync();
+}
+
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -223,10 +252,17 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_AMOR, ~0UL);
 
-	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+	if (kvm_is_radix(kvm)) {
+		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+			__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+		switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+		if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+			__mtmsrd(0, 1); /* clear RI */
 
-	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+	} else {
+		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+		switch_mmu_to_guest_hpt(kvm, vcpu, lpcr);
+	}
 
 	/*
 	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
@@ -234,9 +270,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-		__mtmsrd(0, 1); /* clear RI */
-
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
 	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
 	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
@@ -340,8 +373,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 #endif
 	}
 
-	radix_clear_slb();
-
 	accumulate_time(vcpu, &vcpu->arch.rm_exit);
 
 	/* Advance host PURR/SPURR by the amount used by guest */
@@ -406,6 +437,30 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	/* HDEC must be at least as large as DEC, so decrementer_max fits */
 	mtspr(SPRN_HDEC, decrementer_max);
 
+	if (kvm_is_radix(kvm)) {
+		radix_clear_slb();
+	} else {
+		int i;
+		int nr = 0;
+
+		/*
+		 * This must run before switching to host (radix host can't
+		 * access all SLBs).
+		 */
+		for (i = 0; i < vcpu->arch.slb_nr; i++) {
+			u64 slbee, slbev;
+			mfslb(i, &slbee, &slbev);
+			if (slbee & SLB_ESID_V) {
+				vcpu->arch.slb[nr].orige = slbee | i;
+				vcpu->arch.slb[nr].origv = slbev;
+				nr++;
+			}
+		}
+		vcpu->arch.slb_max = nr;
+		mtslb(0, 0, 0);
+		slb_invalidate(6);
+	}
+
 	switch_mmu_to_host_radix(kvm, host_pidr);
 
 	/*
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 7af7c70f1468..b5532b85c7fd 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -57,6 +57,10 @@ static int global_invalidates(struct kvm *kvm)
 	else
 		global = 1;
 
+	/* LPID has been switched to host if in virt mode so can't do local */
+	if (!global && (mfmsr() & (MSR_IR|MSR_DR)))
+		global = 1;
+
 	if (!global) {
 		/* any other core might now have stale TLB entries... */
 		smp_wmb();
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index a8ce68eed13e..be5742640780 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -899,14 +899,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	cmpdi	r3, 512		/* 1 microsecond */
 	blt	hdec_soon
 
-	/* For hash guest, clear out and reload the SLB */
-BEGIN_MMU_FTR_SECTION
-	/* Radix host won't have populated the SLB, so no need to clear */
+	/* Clear out and reload the SLB */
 	li	r6, 0
 	slbmte	r6, r6
 	PPC_SLBIA(6)
 	ptesync
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
 
 	/* Load up guest SLB entries (N.B. slb_max will be 0 for radix) */
 	lwz	r5,VCPU_SLB_MAX(r4)
@@ -1408,9 +1405,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	stw	r5,VCPU_SLB_MAX(r9)
 
 	/* load host SLB entries */
-BEGIN_MMU_FTR_SECTION
-	b	guest_bypass
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 	ld	r8,PACA_SLBSHADOWPTR(r13)
 
 	.rept	SLB_NUM_BOLTED
@@ -3162,10 +3156,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 	PPC_SLBIA(6)
 	ptesync
 
-BEGIN_MMU_FTR_SECTION
-	b	4f
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
-
 	/* load host SLB entries */
 	ld	r8, PACA_SLBSHADOWPTR(r13)
 	.rept	SLB_NUM_BOLTED
@@ -3179,7 +3169,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 3:	addi	r8, r8, 16
 	.endr
 
-4:	lwz	r7, KVM_HOST_LPID(r10)
+	lwz	r7, KVM_HOST_LPID(r10)
 	mtspr	SPRN_LPID, r7
 	mtspr	SPRN_PID, r0
 	ld	r8, KVM_HOST_LPCR(r10)
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 36/37] KVM: PPC: Book3S HV P9: implement hash host / hash guest support
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c           |  2 +-
 arch/powerpc/kvm/book3s_hv_interrupt.c | 75 ++++++++++++++++----------
 2 files changed, 47 insertions(+), 30 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 97320531f37c..10d5c7ea80ca 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4403,7 +4403,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (radix_enabled())
+		if (cpu_has_feature(CPU_FTR_ARCH_300))
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index d79c6f4f330c..af4772755e5d 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -140,12 +140,51 @@ static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64
 }
 
 
-static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+static void switch_mmu_to_host(struct kvm *kvm, u32 pid)
 {
 	mtspr(SPRN_PID, pid);
 	mtspr(SPRN_LPID, kvm->arch.host_lpid);
 	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
 	isync();
+
+	/* XXX: could save and restore host SLBs to reduce SLB faults */
+	if (!radix_enabled())
+		slb_restore_bolted_realmode();
+}
+
+static void save_host_mmu(struct kvm *kvm)
+{
+	if (!radix_enabled()) {
+		mtslb(0, 0, 0);
+		slb_invalidate(6);
+	}
+}
+
+static void save_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
+{
+	if (kvm_is_radix(kvm)) {
+		radix_clear_slb();
+	} else {
+		int i;
+		int nr = 0;
+
+		/*
+		 * This must run before switching to host (radix host can't
+		 * access all SLBs).
+		 */
+		for (i = 0; i < vcpu->arch.slb_nr; i++) {
+			u64 slbee, slbev;
+			mfslb(i, &slbee, &slbev);
+			if (slbee & SLB_ESID_V) {
+				vcpu->arch.slb[nr].orige = slbee | i;
+				vcpu->arch.slb[nr].origv = slbev;
+				nr++;
+			}
+		}
+		vcpu->arch.slb_max = nr;
+		mtslb(0, 0, 0);
+		slb_invalidate(6);
+	}
 }
 
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
@@ -252,15 +291,16 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_AMOR, ~0UL);
 
+	if (!radix_enabled() || !kvm_is_radix(kvm) || cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+
+	save_host_mmu(kvm);
 	if (kvm_is_radix(kvm)) {
-		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-			__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
 		switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 		if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
 			__mtmsrd(0, 1); /* clear RI */
 
 	} else {
-		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
 		switch_mmu_to_guest_hpt(kvm, vcpu, lpcr);
 	}
 
@@ -437,31 +477,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	/* HDEC must be at least as large as DEC, so decrementer_max fits */
 	mtspr(SPRN_HDEC, decrementer_max);
 
-	if (kvm_is_radix(kvm)) {
-		radix_clear_slb();
-	} else {
-		int i;
-		int nr = 0;
-
-		/*
-		 * This must run before switching to host (radix host can't
-		 * access all SLBs).
-		 */
-		for (i = 0; i < vcpu->arch.slb_nr; i++) {
-			u64 slbee, slbev;
-			mfslb(i, &slbee, &slbev);
-			if (slbee & SLB_ESID_V) {
-				vcpu->arch.slb[nr].orige = slbee | i;
-				vcpu->arch.slb[nr].origv = slbev;
-				nr++;
-			}
-		}
-		vcpu->arch.slb_max = nr;
-		mtslb(0, 0, 0);
-		slb_invalidate(6);
-	}
-
-	switch_mmu_to_host_radix(kvm, host_pidr);
+	save_guest_mmu(kvm, vcpu);
+	switch_mmu_to_host(kvm, host_pidr);
 
 	/*
 	 * If we are in real mode, don't switch MMU on until the MMU is
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 36/37] KVM: PPC: Book3S HV P9: implement hash host / hash guest support
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c           |  2 +-
 arch/powerpc/kvm/book3s_hv_interrupt.c | 75 ++++++++++++++++----------
 2 files changed, 47 insertions(+), 30 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 97320531f37c..10d5c7ea80ca 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4403,7 +4403,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
 		 * path, which also handles hash and dependent threads mode.
 		 */
-		if (radix_enabled())
+		if (cpu_has_feature(CPU_FTR_ARCH_300))
 			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
 						  vcpu->arch.vcore->lpcr);
 		else
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index d79c6f4f330c..af4772755e5d 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -140,12 +140,51 @@ static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64
 }
 
 
-static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+static void switch_mmu_to_host(struct kvm *kvm, u32 pid)
 {
 	mtspr(SPRN_PID, pid);
 	mtspr(SPRN_LPID, kvm->arch.host_lpid);
 	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
 	isync();
+
+	/* XXX: could save and restore host SLBs to reduce SLB faults */
+	if (!radix_enabled())
+		slb_restore_bolted_realmode();
+}
+
+static void save_host_mmu(struct kvm *kvm)
+{
+	if (!radix_enabled()) {
+		mtslb(0, 0, 0);
+		slb_invalidate(6);
+	}
+}
+
+static void save_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
+{
+	if (kvm_is_radix(kvm)) {
+		radix_clear_slb();
+	} else {
+		int i;
+		int nr = 0;
+
+		/*
+		 * This must run before switching to host (radix host can't
+		 * access all SLBs).
+		 */
+		for (i = 0; i < vcpu->arch.slb_nr; i++) {
+			u64 slbee, slbev;
+			mfslb(i, &slbee, &slbev);
+			if (slbee & SLB_ESID_V) {
+				vcpu->arch.slb[nr].orige = slbee | i;
+				vcpu->arch.slb[nr].origv = slbev;
+				nr++;
+			}
+		}
+		vcpu->arch.slb_max = nr;
+		mtslb(0, 0, 0);
+		slb_invalidate(6);
+	}
 }
 
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
@@ -252,15 +291,16 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_AMOR, ~0UL);
 
+	if (!radix_enabled() || !kvm_is_radix(kvm) || cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+
+	save_host_mmu(kvm);
 	if (kvm_is_radix(kvm)) {
-		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-			__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
 		switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
 		if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
 			__mtmsrd(0, 1); /* clear RI */
 
 	} else {
-		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
 		switch_mmu_to_guest_hpt(kvm, vcpu, lpcr);
 	}
 
@@ -437,31 +477,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	/* HDEC must be at least as large as DEC, so decrementer_max fits */
 	mtspr(SPRN_HDEC, decrementer_max);
 
-	if (kvm_is_radix(kvm)) {
-		radix_clear_slb();
-	} else {
-		int i;
-		int nr = 0;
-
-		/*
-		 * This must run before switching to host (radix host can't
-		 * access all SLBs).
-		 */
-		for (i = 0; i < vcpu->arch.slb_nr; i++) {
-			u64 slbee, slbev;
-			mfslb(i, &slbee, &slbev);
-			if (slbee & SLB_ESID_V) {
-				vcpu->arch.slb[nr].orige = slbee | i;
-				vcpu->arch.slb[nr].origv = slbev;
-				nr++;
-			}
-		}
-		vcpu->arch.slb_max = nr;
-		mtslb(0, 0, 0);
-		slb_invalidate(6);
-	}
-
-	switch_mmu_to_host_radix(kvm, host_pidr);
+	save_guest_mmu(kvm, vcpu);
+	switch_mmu_to_host(kvm, host_pidr);
 
 	/*
 	 * If we are in real mode, don't switch MMU on until the MMU is
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 37/37] KVM: PPC: Book3S HV: remove POWER9 support from P7/8 paths
  2021-02-25 13:46 ` Nicholas Piggin
@ 2021-02-25 13:46   ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is dead code now.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c            |  27 +-
 arch/powerpc/kvm/book3s_hv_interrupts.S |   9 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 404 +-----------------------
 arch/powerpc/platforms/powernv/idle.c   |  52 +--
 4 files changed, 23 insertions(+), 469 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 10d5c7ea80ca..483a1a821ea4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3040,8 +3040,7 @@ static void prepare_threads(struct kvmppc_vcore *vc)
 	for_each_runnable_thread(i, vcpu, vc) {
 		if (signal_pending(vcpu->arch.run_task))
 			vcpu->arch.ret = -EINTR;
-		else if (no_mixing_hpt_and_radix &&
-			 kvm_is_radix(vc->kvm) != radix_enabled())
+		else if (kvm_is_radix(vc->kvm))
 			vcpu->arch.ret = -EINVAL;
 		else if (vcpu->arch.vpa.update_pending ||
 			 vcpu->arch.slb_shadow.update_pending ||
@@ -3249,6 +3248,9 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	int trap;
 	bool is_power8;
 
+	if (WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)))
+		return;
+
 	/*
 	 * Remove from the list any threads that have a signal pending
 	 * or need a VPA update done
@@ -3276,9 +3278,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	 * Make sure we are running on primary threads, and that secondary
 	 * threads are offline.  Also check if the number of threads in this
 	 * guest are greater than the current system threads per guest.
-	 * On POWER9, we need to be not in independent-threads mode if
-	 * this is a HPT guest on a radix host machine where the
-	 * CPU threads may not be in different MMU modes.
 	 */
 	if ((controlled_threads > 1) &&
 	    ((vc->num_threads > threads_per_subcore) || !on_primary_thread())) {
@@ -3302,18 +3301,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	if (vc->num_threads < target_threads)
 		collect_piggybacks(&core_info, target_threads);
 
-	/*
-	 * On radix, arrange for TLB flushing if necessary.
-	 * This has to be done before disabling interrupts since
-	 * it uses smp_call_function().
-	 */
-	pcpu = smp_processor_id();
-	if (kvm_is_radix(vc->kvm)) {
-		for (sub = 0; sub < core_info.n_subcores; ++sub)
-			for_each_runnable_thread(i, vcpu, core_info.vc[sub])
-				kvmppc_prepare_radix_vcpu(vcpu, pcpu);
-	}
-
 	/*
 	 * Hard-disable interrupts, and check resched flag and signals.
 	 * If we need to reschedule or deliver a signal, clean up
@@ -3346,8 +3333,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	cmd_bit = stat_bit = 0;
 	split = core_info.n_subcores;
 	sip = NULL;
-	is_power8 = cpu_has_feature(CPU_FTR_ARCH_207S)
-		&& !cpu_has_feature(CPU_FTR_ARCH_300);
+	is_power8 = cpu_has_feature(CPU_FTR_ARCH_207S);
 
 	if (split > 1) {
 		sip = &split_info;
@@ -3630,8 +3616,7 @@ static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 }
 
 /*
- * Virtual-mode guest entry for POWER9 and later when the host and
- * guest are both using the radix MMU.  The LPIDR has already been set.
+ * Guest entry for POWER9 and later CPUs.
  */
 static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			 unsigned long lpcr)
diff --git a/arch/powerpc/kvm/book3s_hv_interrupts.S b/arch/powerpc/kvm/book3s_hv_interrupts.S
index 327417d79eac..4444f83cb133 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupts.S
+++ b/arch/powerpc/kvm/book3s_hv_interrupts.S
@@ -58,7 +58,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	/*
 	 * Put whatever is in the decrementer into the
 	 * hypervisor decrementer.
-	 * Because of a hardware deviation in P8 and P9,
+	 * Because of a hardware deviation in P8,
 	 * we need to set LPCR[HDICE] before writing HDEC.
 	 */
 	ld	r5, HSTATE_KVM_VCORE(r13)
@@ -67,15 +67,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	ori	r8, r9, LPCR_HDICE
 	mtspr	SPRN_LPCR, r8
 	isync
-	andis.	r0, r9, LPCR_LD@h
 	mfspr	r8,SPRN_DEC
 	mftb	r7
-BEGIN_FTR_SECTION
-	/* On POWER9, don't sign-extend if host LPCR[LD] bit is set */
-	bne	32f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	extsw	r8,r8
-32:	mtspr	SPRN_HDEC,r8
+	mtspr	SPRN_HDEC,r8
 	add	r8,r8,r7
 	std	r8,HSTATE_DECEXP(r13)
 
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index be5742640780..4e9808a2c3a9 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -25,7 +25,6 @@
 #include <asm/export.h>
 #include <asm/tm.h>
 #include <asm/opal.h>
-#include <asm/xive-regs.h>
 #include <asm/thread_info.h>
 #include <asm/asm-compat.h>
 #include <asm/feature-fixups.h>
@@ -34,9 +33,7 @@
 
 /* Sign-extend HDEC if not on POWER9 */
 #define EXTEND_HDEC(reg)			\
-BEGIN_FTR_SECTION;				\
-	extsw	reg, reg;			\
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
+	extsw	reg, reg
 
 /* Values in HSTATE_NAPPING(r13) */
 #define NAPPING_CEDE	1
@@ -56,8 +53,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define STACK_SLOT_HFSCR	(SFS-72)
 #define STACK_SLOT_AMR		(SFS-80)
 #define STACK_SLOT_UAMOR	(SFS-88)
-#define STACK_SLOT_DAWR1	(SFS-96)
-#define STACK_SLOT_DAWRX1	(SFS-104)
 
 /*
  * Call kvmppc_hv_entry in real mode.
@@ -347,7 +342,6 @@ kvm_secondary_got_guest:
 	LOAD_REG_ADDR(r6, decrementer_max)
 	ld	r6, 0(r6)
 	mtspr	SPRN_HDEC, r6
-BEGIN_FTR_SECTION
 	/* and set per-LPAR registers, if doing dynamic micro-threading */
 	ld	r6, HSTATE_SPLIT_MODE(r13)
 	cmpdi	r6, 0
@@ -359,7 +353,6 @@ BEGIN_FTR_SECTION
 	ld	r0, KVM_SPLIT_LDBAR(r6)
 	mtspr	SPRN_LDBAR, r0
 	isync
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 63:
 	/* Order load of vcpu after load of vcore */
 	lwsync
@@ -430,7 +423,6 @@ kvm_no_guest:
 	blr
 
 53:
-BEGIN_FTR_SECTION
 	HMT_LOW
 	ld	r5, HSTATE_KVM_VCORE(r13)
 	cmpdi	r5, 0
@@ -445,14 +437,6 @@ BEGIN_FTR_SECTION
 	b	kvm_unsplit_nap
 60:	HMT_MEDIUM
 	b	kvm_secondary_got_guest
-FTR_SECTION_ELSE
-	HMT_LOW
-	ld	r5, HSTATE_KVM_VCORE(r13)
-	cmpdi	r5, 0
-	beq	kvm_no_guest
-	HMT_MEDIUM
-	b	kvm_secondary_got_guest
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 
 54:	li	r0, KVM_HWTHREAD_IN_KVM
 	stb	r0, HSTATE_HWTHREAD_STATE(r13)
@@ -578,13 +562,11 @@ kvmppc_hv_entry:
 	bne	10f
 
 	lwz	r7,KVM_LPID(r9)
-BEGIN_FTR_SECTION
 	ld	r6,KVM_SDR1(r9)
 	li	r0,LPID_RSVD		/* switch to reserved LPID */
 	mtspr	SPRN_LPID,r0
 	ptesync
 	mtspr	SPRN_SDR1,r6		/* switch to partition page table */
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	mtspr	SPRN_LPID,r7
 	isync
 
@@ -664,16 +646,6 @@ kvmppc_got_guest:
 	mtspr	SPRN_SPURR,r8
 
 	/* Save host values of some registers */
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_TIDR
-	mfspr	r6, SPRN_PSSCR
-	mfspr	r7, SPRN_PID
-	std	r5, STACK_SLOT_TID(r1)
-	std	r6, STACK_SLOT_PSSCR(r1)
-	std	r7, STACK_SLOT_PID(r1)
-	mfspr	r5, SPRN_HFSCR
-	std	r5, STACK_SLOT_HFSCR(r1)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_CIABR
 	mfspr	r6, SPRN_DAWR0
@@ -684,12 +656,6 @@ BEGIN_FTR_SECTION
 	std	r7, STACK_SLOT_DAWRX0(r1)
 	std	r8, STACK_SLOT_IAMR(r1)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	mfspr	r6, SPRN_DAWR1
-	mfspr	r7, SPRN_DAWRX1
-	std	r6, STACK_SLOT_DAWR1(r1)
-	std	r7, STACK_SLOT_DAWRX1(r1)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S | CPU_FTR_DAWR1)
 
 	mfspr	r5, SPRN_AMR
 	std	r5, STACK_SLOT_AMR(r1)
@@ -707,13 +673,9 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -780,12 +742,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	ld	r6, VCPU_DAWRX0(r4)
 	mtspr	SPRN_DAWR0, r5
 	mtspr	SPRN_DAWRX0, r6
-BEGIN_FTR_SECTION
-	ld	r5, VCPU_DAWR1(r4)
-	ld	r6, VCPU_DAWRX1(r4)
-	mtspr	SPRN_DAWR1, r5
-	mtspr	SPRN_DAWRX1, r6
-END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 1:
 	ld	r7, VCPU_CIABR(r4)
 	ld	r8, VCPU_TAR(r4)
@@ -803,7 +759,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 	mtspr	SPRN_BESCR, r6
 	mtspr	SPRN_PID, r7
 	mtspr	SPRN_WORT, r8
-BEGIN_FTR_SECTION
 	/* POWER8-only registers */
 	ld	r5, VCPU_TCSCR(r4)
 	ld	r6, VCPU_ACOP(r4)
@@ -814,18 +769,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_CSIGR, r7
 	mtspr	SPRN_TACR, r8
 	nop
-FTR_SECTION_ELSE
-	/* POWER9-only registers */
-	ld	r5, VCPU_TID(r4)
-	ld	r6, VCPU_PSSCR(r4)
-	lbz	r8, HSTATE_FAKE_SUSPEND(r13)
-	oris	r6, r6, PSSCR_EC@h	/* This makes stop trap to HV */
-	rldimi	r6, r8, PSSCR_FAKE_SUSPEND_LG, 63 - PSSCR_FAKE_SUSPEND_LG
-	ld	r7, VCPU_HFSCR(r4)
-	mtspr	SPRN_TIDR, r5
-	mtspr	SPRN_PSSCR, r6
-	mtspr	SPRN_HFSCR, r7
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 8:
 
 	ld	r5, VCPU_SPRG0(r4)
@@ -918,93 +861,9 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	bdnz	1b
 9:
 
-#ifdef CONFIG_KVM_XICS
-	/* We are entering the guest on that thread, push VCPU to XIVE */
-	ld	r11, VCPU_XIVE_SAVED_STATE(r4)
-	li	r9, TM_QW1_OS
-	lwz	r8, VCPU_XIVE_CAM_WORD(r4)
-	cmpwi	r8, 0
-	beq	no_xive
-	li	r7, TM_QW1_OS + TM_WORD2
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
-	beq	2f
-	ld	r10, HSTATE_XIVE_TIMA_VIRT(r13)
-	cmpldi	cr1, r10, 0
-	beq     cr1, no_xive
-	eieio
-	stdx	r11,r9,r10
-	stwx	r8,r7,r10
-	b	3f
-2:	ld	r10, HSTATE_XIVE_TIMA_PHYS(r13)
-	cmpldi	cr1, r10, 0
-	beq	cr1, no_xive
-	eieio
-	stdcix	r11,r9,r10
-	stwcix	r8,r7,r10
-3:	li	r9, 1
-	stb	r9, VCPU_XIVE_PUSHED(r4)
-	eieio
-
-	/*
-	 * We clear the irq_pending flag. There is a small chance of a
-	 * race vs. the escalation interrupt happening on another
-	 * processor setting it again, but the only consequence is to
-	 * cause a spurrious wakeup on the next H_CEDE which is not an
-	 * issue.
-	 */
-	li	r0,0
-	stb	r0, VCPU_IRQ_PENDING(r4)
-
-	/*
-	 * In single escalation mode, if the escalation interrupt is
-	 * on, we mask it.
-	 */
-	lbz	r0, VCPU_XIVE_ESC_ON(r4)
-	cmpwi	cr1, r0,0
-	beq	cr1, 1f
-	li	r9, XIVE_ESB_SET_PQ_01
-	beq	4f			/* in real mode? */
-	ld	r10, VCPU_XIVE_ESC_VADDR(r4)
-	ldx	r0, r10, r9
-	b	5f
-4:	ld	r10, VCPU_XIVE_ESC_RADDR(r4)
-	ldcix	r0, r10, r9
-5:	sync
-
-	/* We have a possible subtle race here: The escalation interrupt might
-	 * have fired and be on its way to the host queue while we mask it,
-	 * and if we unmask it early enough (re-cede right away), there is
-	 * a theorical possibility that it fires again, thus landing in the
-	 * target queue more than once which is a big no-no.
-	 *
-	 * Fortunately, solving this is rather easy. If the above load setting
-	 * PQ to 01 returns a previous value where P is set, then we know the
-	 * escalation interrupt is somewhere on its way to the host. In that
-	 * case we simply don't clear the xive_esc_on flag below. It will be
-	 * eventually cleared by the handler for the escalation interrupt.
-	 *
-	 * Then, when doing a cede, we check that flag again before re-enabling
-	 * the escalation interrupt, and if set, we abort the cede.
-	 */
-	andi.	r0, r0, XIVE_ESB_VAL_P
-	bne-	1f
-
-	/* Now P is 0, we can clear the flag */
-	li	r0, 0
-	stb	r0, VCPU_XIVE_ESC_ON(r4)
-1:
-no_xive:
-#endif /* CONFIG_KVM_XICS */
-
 deliver_guest_interrupt:	/* r4 = vcpu, r13 = paca */
 	/* Check if we can deliver an external or decrementer interrupt now */
 	ld	r0, VCPU_PENDING_EXC(r4)
-BEGIN_FTR_SECTION
-	/* On POWER9, also check for emulated doorbell interrupt */
-	lbz	r3, VCPU_DBELL_REQ(r4)
-	or	r0, r0, r3
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	cmpdi	r0, 0
 	beq	71f
 	mr	r3, r4
@@ -1077,12 +936,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_PPR, r0
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 
-/* Move canary into DSISR to check for later */
-BEGIN_FTR_SECTION
-	li	r0, 0x7fff
-	mtspr	SPRN_HDSISR, r0
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-
 	ld	r6, VCPU_KVM(r4)
 	lbz	r7, KVM_SECURE_GUEST(r6)
 	cmpdi	r7, 0
@@ -1298,14 +1151,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	/* Hypervisor doorbell - exit only if host IPI flag set */
 	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
 	bne	3f
-BEGIN_FTR_SECTION
-	PPC_MSGSYNC
-	lwsync
-	/* always exit if we're running a nested guest */
-	ld	r0, VCPU_NESTED(r9)
-	cmpdi	r0, 0
-	bne	guest_exit_cont
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	lbz	r0, HSTATE_HOST_IPI(r13)
 	cmpwi	r0, 0
 	beq	maybe_reenter_guest
@@ -1335,43 +1180,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	mr	r4, r9
 	bl	kvmhv_accumulate_time
 #endif
-#ifdef CONFIG_KVM_XICS
-	/* We are exiting, pull the VP from the XIVE */
-	lbz	r0, VCPU_XIVE_PUSHED(r9)
-	cmpwi	cr0, r0, 0
-	beq	1f
-	li	r7, TM_SPC_PULL_OS_CTX
-	li	r6, TM_QW1_OS
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
-	beq	2f
-	ld	r10, HSTATE_XIVE_TIMA_VIRT(r13)
-	cmpldi	cr0, r10, 0
-	beq	1f
-	/* First load to pull the context, we ignore the value */
-	eieio
-	lwzx	r11, r7, r10
-	/* Second load to recover the context state (Words 0 and 1) */
-	ldx	r11, r6, r10
-	b	3f
-2:	ld	r10, HSTATE_XIVE_TIMA_PHYS(r13)
-	cmpldi	cr0, r10, 0
-	beq	1f
-	/* First load to pull the context, we ignore the value */
-	eieio
-	lwzcix	r11, r7, r10
-	/* Second load to recover the context state (Words 0 and 1) */
-	ldcix	r11, r6, r10
-3:	std	r11, VCPU_XIVE_SAVED_STATE(r9)
-	/* Fixup some of the state for the next load */
-	li	r10, 0
-	li	r0, 0xff
-	stb	r10, VCPU_XIVE_PUSHED(r9)
-	stb	r10, (VCPU_XIVE_SAVED_STATE+3)(r9)
-	stb	r0, (VCPU_XIVE_SAVED_STATE+4)(r9)
-	eieio
-1:
-#endif /* CONFIG_KVM_XICS */
 
 	/*
 	 * Possibly flush the link stack here, before we do a blr in
@@ -1426,12 +1234,6 @@ guest_bypass:
 	ld	r3, HSTATE_KVM_VCORE(r13)
 	mfspr	r5,SPRN_DEC
 	mftb	r6
-	/* On P9, if the guest has large decr enabled, don't sign extend */
-BEGIN_FTR_SECTION
-	ld	r4, VCORE_LPCR(r3)
-	andis.	r4, r4, LPCR_LD@h
-	bne	16f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	extsw	r5,r5
 16:	add	r5,r5,r6
 	/* r5 is a guest timebase value here, convert to host TB */
@@ -1505,7 +1307,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	std	r6, VCPU_BESCR(r9)
 	stw	r7, VCPU_GUEST_PID(r9)
 	std	r8, VCPU_WORT(r9)
-BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_TCSCR
 	mfspr	r6, SPRN_ACOP
 	mfspr	r7, SPRN_CSIGR
@@ -1514,17 +1315,6 @@ BEGIN_FTR_SECTION
 	std	r6, VCPU_ACOP(r9)
 	std	r7, VCPU_CSIGR(r9)
 	std	r8, VCPU_TACR(r9)
-FTR_SECTION_ELSE
-	mfspr	r5, SPRN_TIDR
-	mfspr	r6, SPRN_PSSCR
-	std	r5, VCPU_TID(r9)
-	rldicl	r6, r6, 4, 50		/* r6 &= PSSCR_GUEST_VIS */
-	rotldi	r6, r6, 60
-	std	r6, VCPU_PSSCR(r9)
-	/* Restore host HFSCR value */
-	ld	r7, STACK_SLOT_HFSCR(r1)
-	mtspr	SPRN_HFSCR, r7
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	/*
 	 * Restore various registers to 0, where non-zero values
 	 * set by the guest could disrupt the host.
@@ -1532,13 +1322,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	li	r0, 0
 	mtspr	SPRN_PSPB, r0
 	mtspr	SPRN_WORT, r0
-BEGIN_FTR_SECTION
 	mtspr	SPRN_TCSCR, r0
 	/* Set MMCRS to 1<<31 to freeze and disable the SPMC counters */
 	li	r0, 1
 	sldi	r0, r0, 31
 	mtspr	SPRN_MMCRS, r0
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 
 	/* Save and restore AMR, IAMR and UAMOR before turning on the MMU */
 	ld	r8, STACK_SLOT_IAMR(r1)
@@ -1595,13 +1383,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	bl	kvmppc_save_fp
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -1647,28 +1431,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWR0, r6
 	mtspr	SPRN_DAWRX0, r7
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	ld	r6, STACK_SLOT_DAWR1(r1)
-	ld	r7, STACK_SLOT_DAWRX1(r1)
-	mtspr	SPRN_DAWR1, r6
-	mtspr	SPRN_DAWRX1, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S | CPU_FTR_DAWR1)
-BEGIN_FTR_SECTION
-	ld	r5, STACK_SLOT_TID(r1)
-	ld	r6, STACK_SLOT_PSSCR(r1)
-	ld	r7, STACK_SLOT_PID(r1)
-	mtspr	SPRN_TIDR, r5
-	mtspr	SPRN_PSSCR, r6
-	mtspr	SPRN_PID, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-
-	/*
-	 * cp_abort is required if the processor supports local copy-paste
-	 * to clear the copy buffer that was under control of the guest.
-	 */
-BEGIN_FTR_SECTION
-	PPC_CP_ABORT
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 
 	/*
 	 * POWER7/POWER8 guest -> host partition switch code.
@@ -1705,13 +1467,11 @@ kvmhv_switch_to_host:
 
 	/* Primary thread switches back to host partition */
 	lwz	r7,KVM_HOST_LPID(r4)
-BEGIN_FTR_SECTION
 	ld	r6,KVM_HOST_SDR1(r4)
 	li	r8,LPID_RSVD		/* switch to reserved LPID */
 	mtspr	SPRN_LPID,r8
 	ptesync
 	mtspr	SPRN_SDR1,r6		/* switch to host page table */
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	mtspr	SPRN_LPID,r7
 	isync
 
@@ -1922,20 +1682,11 @@ kvmppc_tm_emul:
 kvmppc_hdsi:
 	mfspr	r4, SPRN_HDAR
 	mfspr	r6, SPRN_HDSISR
-BEGIN_FTR_SECTION
-	/* Look for DSISR canary. If we find it, retry instruction */
-	cmpdi	r6, 0x7fff
-	beq	6f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	/* HPTE not found fault or protection fault? */
 	andis.	r0, r6, (DSISR_NOHPTE | DSISR_PROTFAULT)@h
 	beq	1f			/* if not, send it to the guest */
 	andi.	r0, r11, MSR_DR		/* data relocation enabled? */
 	beq	3f
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_ASDR		/* on POWER9, use ASDR to get VSID */
-	b	4f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	clrrdi	r0, r4, 28
 	PPC_SLBFEE_DOT(R5, R0)		/* if so, look up SLB */
 	li	r0, BOOK3S_INTERRUPT_DATA_SEGMENT
@@ -2012,10 +1763,6 @@ kvmppc_hisi:
 	beq	1f
 	andi.	r0, r11, MSR_IR		/* instruction relocation enabled? */
 	beq	3f
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_ASDR		/* on POWER9, use ASDR to get VSID */
-	b	4f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	clrrdi	r0, r10, 28
 	PPC_SLBFEE_DOT(R5, R0)		/* if so, look up SLB */
 	li	r0, BOOK3S_INTERRUPT_INST_SEGMENT
@@ -2063,10 +1810,6 @@ hcall_try_real_mode:
 	andi.	r0,r11,MSR_PR
 	/* sc 1 from userspace - reflect to guest syscall */
 	bne	sc_1_fast_return
-	/* sc 1 from nested guest - give it to L1 to handle */
-	ld	r0, VCPU_NESTED(r9)
-	cmpdi	r0, 0
-	bne	guest_exit_cont
 	clrrdi	r3,r3,2
 	cmpldi	r3,hcall_real_table_end - hcall_real_table
 	bge	guest_exit_cont
@@ -2462,13 +2205,9 @@ _GLOBAL(kvmppc_h_cede)		/* r3 = vcpu pointer, r11 = msr, r13 = paca */
 	bl	kvmppc_save_fp
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -2488,15 +2227,8 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
 	mfspr	r3, SPRN_DEC
 	mfspr	r4, SPRN_HDEC
 	mftb	r5
-BEGIN_FTR_SECTION
-	/* On P9 check whether the guest has large decrementer mode enabled */
-	ld	r6, HSTATE_KVM_VCORE(r13)
-	ld	r6, VCORE_LPCR(r6)
-	andis.	r6, r6, LPCR_LD@h
-	bne	68f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	extsw	r3, r3
-68:	EXTEND_HDEC(r4)
+	EXTEND_HDEC(r4)
 	cmpd	r3, r4
 	ble	67f
 	mtspr	SPRN_DEC, r4
@@ -2541,28 +2273,14 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 
 kvm_nap_sequence:		/* desired LPCR value in r5 */
-BEGIN_FTR_SECTION
-	/*
-	 * PSSCR bits:	exit criterion = 1 (wakeup based on LPCR at sreset)
-	 *		enable state loss = 1 (allow SMT mode switch)
-	 *		requested level = 0 (just stop dispatching)
-	 */
-	lis	r3, (PSSCR_EC | PSSCR_ESL)@h
 	/* Set LPCR_PECE_HVEE bit to enable wakeup by HV interrupts */
 	li	r4, LPCR_PECE_HVEE@higher
 	sldi	r4, r4, 32
 	or	r5, r5, r4
-FTR_SECTION_ELSE
-	li	r3, PNV_THREAD_NAP
-ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 	mtspr	SPRN_LPCR,r5
 	isync
 
-BEGIN_FTR_SECTION
-	bl	isa300_idle_stop_mayloss
-FTR_SECTION_ELSE
 	bl	isa206_idle_insn_mayloss
-ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 
 	mfspr	r0, SPRN_CTRLF
 	ori	r0, r0, 1
@@ -2581,10 +2299,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 	beq	kvm_end_cede
 	cmpwi	r0, NAPPING_NOVCPU
 	beq	kvm_novcpu_wakeup
-BEGIN_FTR_SECTION
 	cmpwi	r0, NAPPING_UNSPLIT
 	beq	kvm_unsplit_wakeup
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	twi	31,0,0 /* Nap state must not be zero */
 
 33:	mr	r4, r3
@@ -2604,13 +2320,9 @@ kvm_end_cede:
 #endif
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -2700,47 +2412,7 @@ kvm_cede_prodded:
 	/* we've ceded but we want to give control to the host */
 kvm_cede_exit:
 	ld	r9, HSTATE_KVM_VCPU(r13)
-#ifdef CONFIG_KVM_XICS
-	/* are we using XIVE with single escalation? */
-	ld	r10, VCPU_XIVE_ESC_VADDR(r9)
-	cmpdi	r10, 0
-	beq	3f
-	li	r6, XIVE_ESB_SET_PQ_00
-	/*
-	 * If we still have a pending escalation, abort the cede,
-	 * and we must set PQ to 10 rather than 00 so that we don't
-	 * potentially end up with two entries for the escalation
-	 * interrupt in the XIVE interrupt queue.  In that case
-	 * we also don't want to set xive_esc_on to 1 here in
-	 * case we race with xive_esc_irq().
-	 */
-	lbz	r5, VCPU_XIVE_ESC_ON(r9)
-	cmpwi	r5, 0
-	beq	4f
-	li	r0, 0
-	stb	r0, VCPU_CEDED(r9)
-	/*
-	 * The escalation interrupts are special as we don't EOI them.
-	 * There is no need to use the load-after-store ordering offset
-	 * to set PQ to 10 as we won't use StoreEOI.
-	 */
-	li	r6, XIVE_ESB_SET_PQ_10
-	b	5f
-4:	li	r0, 1
-	stb	r0, VCPU_XIVE_ESC_ON(r9)
-	/* make sure store to xive_esc_on is seen before xive_esc_irq runs */
-	sync
-5:	/* Enable XIVE escalation */
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
-	beq	1f
-	ldx	r0, r10, r6
-	b	2f
-1:	ld	r10, VCPU_XIVE_ESC_RADDR(r9)
-	ldcix	r0, r10, r6
-2:	sync
-#endif /* CONFIG_KVM_XICS */
-3:	b	guest_exit_cont
+	b	guest_exit_cont
 
 	/* Try to do machine check recovery in real mode */
 machine_check_realmode:
@@ -2817,10 +2489,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	PPC_MSGCLR(6)
 	/* see if it's a host IPI */
 	li	r3, 1
-BEGIN_FTR_SECTION
-	PPC_MSGSYNC
-	lwsync
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	lbz	r0, HSTATE_HOST_IPI(r13)
 	cmpwi	r0, 0
 	bnelr
@@ -3129,70 +2797,12 @@ kvmppc_bad_host_intr:
 	std	r3, STACK_FRAME_OVERHEAD-16(r1)
 
 	/*
-	 * On POWER9 do a minimal restore of the MMU and call C code,
-	 * which will print a message and panic.
 	 * XXX On POWER7 and POWER8, we just spin here since we don't
 	 * know what the other threads are doing (and we don't want to
 	 * coordinate with them) - but at least we now have register state
 	 * in memory that we might be able to look at from another CPU.
 	 */
-BEGIN_FTR_SECTION
 	b	.
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
-	ld	r9, HSTATE_KVM_VCPU(r13)
-	ld	r10, VCPU_KVM(r9)
-
-	li	r0, 0
-	mtspr	SPRN_AMR, r0
-	mtspr	SPRN_IAMR, r0
-	mtspr	SPRN_CIABR, r0
-	mtspr	SPRN_DAWRX0, r0
-BEGIN_FTR_SECTION
-	mtspr	SPRN_DAWRX1, r0
-END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
-
-	/* Clear guest SLB. */
-	slbmte	r0, r0
-	PPC_SLBIA(6)
-	ptesync
-
-	/* load host SLB entries */
-	ld	r8, PACA_SLBSHADOWPTR(r13)
-	.rept	SLB_NUM_BOLTED
-	li	r3, SLBSHADOW_SAVEAREA
-	LDX_BE	r5, r8, r3
-	addi	r3, r3, 8
-	LDX_BE	r6, r8, r3
-	andis.	r7, r5, SLB_ESID_V@h
-	beq	3f
-	slbmte	r6, r5
-3:	addi	r8, r8, 16
-	.endr
-
-	lwz	r7, KVM_HOST_LPID(r10)
-	mtspr	SPRN_LPID, r7
-	mtspr	SPRN_PID, r0
-	ld	r8, KVM_HOST_LPCR(r10)
-	mtspr	SPRN_LPCR, r8
-	isync
-	li	r0, KVM_GUEST_MODE_NONE
-	stb	r0, HSTATE_IN_GUEST(r13)
-
-	/*
-	 * Turn on the MMU and jump to C code
-	 */
-	bcl	20, 31, .+4
-5:	mflr	r3
-	addi	r3, r3, 9f - 5b
-	li	r4, -1
-	rldimi	r3, r4, 62, 0	/* ensure 0xc000000000000000 bits are set */
-	ld	r4, PACAKMSR(r13)
-	mtspr	SPRN_SRR0, r3
-	mtspr	SPRN_SRR1, r4
-	RFI_TO_KERNEL
-9:	addi	r3, r1, STACK_FRAME_OVERHEAD
-	bl	kvmppc_bad_interrupt
-	b	9b
 
 /*
  * This mimics the MSR transition on IRQ delivery.  The new guest MSR is taken
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 999997d9e9a9..528a7e0cf83a 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -604,7 +604,7 @@ struct p9_sprs {
 	u64 uamor;
 };
 
-static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
+static unsigned long power9_idle_stop(unsigned long psscr)
 {
 	int cpu = raw_smp_processor_id();
 	int first = cpu_first_thread_sibling(cpu);
@@ -620,8 +620,6 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 	if (!(psscr & (PSSCR_EC|PSSCR_ESL))) {
 		/* EC=ESL=0 case */
 
-		BUG_ON(!mmu_on);
-
 		/*
 		 * Wake synchronously. SRESET via xscom may still cause
 		 * a 0x100 powersave wakeup with SRR1 reason!
@@ -803,8 +801,7 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 		__slb_restore_bolted_realmode();
 
 out:
-	if (mmu_on)
-		mtmsr(MSR_KERNEL);
+	mtmsr(MSR_KERNEL);
 
 	return srr1;
 }
@@ -895,7 +892,7 @@ struct p10_sprs {
 	 */
 };
 
-static unsigned long power10_idle_stop(unsigned long psscr, bool mmu_on)
+static unsigned long power10_idle_stop(unsigned long psscr)
 {
 	int cpu = raw_smp_processor_id();
 	int first = cpu_first_thread_sibling(cpu);
@@ -909,8 +906,6 @@ static unsigned long power10_idle_stop(unsigned long psscr, bool mmu_on)
 	if (!(psscr & (PSSCR_EC|PSSCR_ESL))) {
 		/* EC=ESL=0 case */
 
-		BUG_ON(!mmu_on);
-
 		/*
 		 * Wake synchronously. SRESET via xscom may still cause
 		 * a 0x100 powersave wakeup with SRR1 reason!
@@ -991,8 +986,7 @@ static unsigned long power10_idle_stop(unsigned long psscr, bool mmu_on)
 		__slb_restore_bolted_realmode();
 
 out:
-	if (mmu_on)
-		mtmsr(MSR_KERNEL);
+	mtmsr(MSR_KERNEL);
 
 	return srr1;
 }
@@ -1002,40 +996,10 @@ static unsigned long arch300_offline_stop(unsigned long psscr)
 {
 	unsigned long srr1;
 
-#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	__ppc64_runlatch_off();
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		srr1 = power10_idle_stop(psscr, true);
+		srr1 = power10_idle_stop(psscr);
 	else
-		srr1 = power9_idle_stop(psscr, true);
-	__ppc64_runlatch_on();
-#else
-	/*
-	 * Tell KVM we're entering idle.
-	 * This does not have to be done in real mode because the P9 MMU
-	 * is independent per-thread. Some steppings share radix/hash mode
-	 * between threads, but in that case KVM has a barrier sync in real
-	 * mode before and after switching between radix and hash.
-	 *
-	 * kvm_start_guest must still be called in real mode though, hence
-	 * the false argument.
-	 */
-	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE;
-
-	__ppc64_runlatch_off();
-	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		srr1 = power10_idle_stop(psscr, false);
-	else
-		srr1 = power9_idle_stop(psscr, false);
-	__ppc64_runlatch_on();
-
-	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL;
-	/* Order setting hwthread_state vs. testing hwthread_req */
-	smp_mb();
-	if (local_paca->kvm_hstate.hwthread_req)
-		srr1 = idle_kvm_start_guest(srr1);
-	mtmsr(MSR_KERNEL);
-#endif
+		srr1 = power9_idle_stop(psscr);
 
 	return srr1;
 }
@@ -1055,9 +1019,9 @@ void arch300_idle_type(unsigned long stop_psscr_val,
 
 	__ppc64_runlatch_off();
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		srr1 = power10_idle_stop(psscr, true);
+		srr1 = power10_idle_stop(psscr);
 	else
-		srr1 = power9_idle_stop(psscr, true);
+		srr1 = power9_idle_stop(psscr);
 	__ppc64_runlatch_on();
 
 	fini_irq_for_idle_irqsoff();
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 134+ messages in thread
* [PATCH v2 37/37] KVM: PPC: Book3S HV: remove POWER9 support from P7/8 paths
@ 2021-02-25 13:46   ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-25 13:46 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

This is dead code now.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c            |  27 +-
 arch/powerpc/kvm/book3s_hv_interrupts.S |   9 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 404 +-----------------------
 arch/powerpc/platforms/powernv/idle.c   |  52 +--
 4 files changed, 23 insertions(+), 469 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 10d5c7ea80ca..483a1a821ea4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3040,8 +3040,7 @@ static void prepare_threads(struct kvmppc_vcore *vc)
 	for_each_runnable_thread(i, vcpu, vc) {
 		if (signal_pending(vcpu->arch.run_task))
 			vcpu->arch.ret = -EINTR;
-		else if (no_mixing_hpt_and_radix &&
-			 kvm_is_radix(vc->kvm) != radix_enabled())
+		else if (kvm_is_radix(vc->kvm))
 			vcpu->arch.ret = -EINVAL;
 		else if (vcpu->arch.vpa.update_pending ||
 			 vcpu->arch.slb_shadow.update_pending ||
@@ -3249,6 +3248,9 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	int trap;
 	bool is_power8;
 
+	if (WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)))
+		return;
+
 	/*
 	 * Remove from the list any threads that have a signal pending
 	 * or need a VPA update done
@@ -3276,9 +3278,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	 * Make sure we are running on primary threads, and that secondary
 	 * threads are offline.  Also check if the number of threads in this
 	 * guest are greater than the current system threads per guest.
-	 * On POWER9, we need to be not in independent-threads mode if
-	 * this is a HPT guest on a radix host machine where the
-	 * CPU threads may not be in different MMU modes.
 	 */
 	if ((controlled_threads > 1) &&
 	    ((vc->num_threads > threads_per_subcore) || !on_primary_thread())) {
@@ -3302,18 +3301,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	if (vc->num_threads < target_threads)
 		collect_piggybacks(&core_info, target_threads);
 
-	/*
-	 * On radix, arrange for TLB flushing if necessary.
-	 * This has to be done before disabling interrupts since
-	 * it uses smp_call_function().
-	 */
-	pcpu = smp_processor_id();
-	if (kvm_is_radix(vc->kvm)) {
-		for (sub = 0; sub < core_info.n_subcores; ++sub)
-			for_each_runnable_thread(i, vcpu, core_info.vc[sub])
-				kvmppc_prepare_radix_vcpu(vcpu, pcpu);
-	}
-
 	/*
 	 * Hard-disable interrupts, and check resched flag and signals.
 	 * If we need to reschedule or deliver a signal, clean up
@@ -3346,8 +3333,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	cmd_bit = stat_bit = 0;
 	split = core_info.n_subcores;
 	sip = NULL;
-	is_power8 = cpu_has_feature(CPU_FTR_ARCH_207S)
-		&& !cpu_has_feature(CPU_FTR_ARCH_300);
+	is_power8 = cpu_has_feature(CPU_FTR_ARCH_207S);
 
 	if (split > 1) {
 		sip = &split_info;
@@ -3630,8 +3616,7 @@ static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 }
 
 /*
- * Virtual-mode guest entry for POWER9 and later when the host and
- * guest are both using the radix MMU.  The LPIDR has already been set.
+ * Guest entry for POWER9 and later CPUs.
  */
 static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			 unsigned long lpcr)
diff --git a/arch/powerpc/kvm/book3s_hv_interrupts.S b/arch/powerpc/kvm/book3s_hv_interrupts.S
index 327417d79eac..4444f83cb133 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupts.S
+++ b/arch/powerpc/kvm/book3s_hv_interrupts.S
@@ -58,7 +58,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	/*
 	 * Put whatever is in the decrementer into the
 	 * hypervisor decrementer.
-	 * Because of a hardware deviation in P8 and P9,
+	 * Because of a hardware deviation in P8,
 	 * we need to set LPCR[HDICE] before writing HDEC.
 	 */
 	ld	r5, HSTATE_KVM_VCORE(r13)
@@ -67,15 +67,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	ori	r8, r9, LPCR_HDICE
 	mtspr	SPRN_LPCR, r8
 	isync
-	andis.	r0, r9, LPCR_LD@h
 	mfspr	r8,SPRN_DEC
 	mftb	r7
-BEGIN_FTR_SECTION
-	/* On POWER9, don't sign-extend if host LPCR[LD] bit is set */
-	bne	32f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	extsw	r8,r8
-32:	mtspr	SPRN_HDEC,r8
+	mtspr	SPRN_HDEC,r8
 	add	r8,r8,r7
 	std	r8,HSTATE_DECEXP(r13)
 
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index be5742640780..4e9808a2c3a9 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -25,7 +25,6 @@
 #include <asm/export.h>
 #include <asm/tm.h>
 #include <asm/opal.h>
-#include <asm/xive-regs.h>
 #include <asm/thread_info.h>
 #include <asm/asm-compat.h>
 #include <asm/feature-fixups.h>
@@ -34,9 +33,7 @@
 
 /* Sign-extend HDEC if not on POWER9 */
 #define EXTEND_HDEC(reg)			\
-BEGIN_FTR_SECTION;				\
-	extsw	reg, reg;			\
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
+	extsw	reg, reg
 
 /* Values in HSTATE_NAPPING(r13) */
 #define NAPPING_CEDE	1
@@ -56,8 +53,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define STACK_SLOT_HFSCR	(SFS-72)
 #define STACK_SLOT_AMR		(SFS-80)
 #define STACK_SLOT_UAMOR	(SFS-88)
-#define STACK_SLOT_DAWR1	(SFS-96)
-#define STACK_SLOT_DAWRX1	(SFS-104)
 
 /*
  * Call kvmppc_hv_entry in real mode.
@@ -347,7 +342,6 @@ kvm_secondary_got_guest:
 	LOAD_REG_ADDR(r6, decrementer_max)
 	ld	r6, 0(r6)
 	mtspr	SPRN_HDEC, r6
-BEGIN_FTR_SECTION
 	/* and set per-LPAR registers, if doing dynamic micro-threading */
 	ld	r6, HSTATE_SPLIT_MODE(r13)
 	cmpdi	r6, 0
@@ -359,7 +353,6 @@ BEGIN_FTR_SECTION
 	ld	r0, KVM_SPLIT_LDBAR(r6)
 	mtspr	SPRN_LDBAR, r0
 	isync
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 63:
 	/* Order load of vcpu after load of vcore */
 	lwsync
@@ -430,7 +423,6 @@ kvm_no_guest:
 	blr
 
 53:
-BEGIN_FTR_SECTION
 	HMT_LOW
 	ld	r5, HSTATE_KVM_VCORE(r13)
 	cmpdi	r5, 0
@@ -445,14 +437,6 @@ BEGIN_FTR_SECTION
 	b	kvm_unsplit_nap
 60:	HMT_MEDIUM
 	b	kvm_secondary_got_guest
-FTR_SECTION_ELSE
-	HMT_LOW
-	ld	r5, HSTATE_KVM_VCORE(r13)
-	cmpdi	r5, 0
-	beq	kvm_no_guest
-	HMT_MEDIUM
-	b	kvm_secondary_got_guest
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 
 54:	li	r0, KVM_HWTHREAD_IN_KVM
 	stb	r0, HSTATE_HWTHREAD_STATE(r13)
@@ -578,13 +562,11 @@ kvmppc_hv_entry:
 	bne	10f
 
 	lwz	r7,KVM_LPID(r9)
-BEGIN_FTR_SECTION
 	ld	r6,KVM_SDR1(r9)
 	li	r0,LPID_RSVD		/* switch to reserved LPID */
 	mtspr	SPRN_LPID,r0
 	ptesync
 	mtspr	SPRN_SDR1,r6		/* switch to partition page table */
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	mtspr	SPRN_LPID,r7
 	isync
 
@@ -664,16 +646,6 @@ kvmppc_got_guest:
 	mtspr	SPRN_SPURR,r8
 
 	/* Save host values of some registers */
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_TIDR
-	mfspr	r6, SPRN_PSSCR
-	mfspr	r7, SPRN_PID
-	std	r5, STACK_SLOT_TID(r1)
-	std	r6, STACK_SLOT_PSSCR(r1)
-	std	r7, STACK_SLOT_PID(r1)
-	mfspr	r5, SPRN_HFSCR
-	std	r5, STACK_SLOT_HFSCR(r1)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_CIABR
 	mfspr	r6, SPRN_DAWR0
@@ -684,12 +656,6 @@ BEGIN_FTR_SECTION
 	std	r7, STACK_SLOT_DAWRX0(r1)
 	std	r8, STACK_SLOT_IAMR(r1)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	mfspr	r6, SPRN_DAWR1
-	mfspr	r7, SPRN_DAWRX1
-	std	r6, STACK_SLOT_DAWR1(r1)
-	std	r7, STACK_SLOT_DAWRX1(r1)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S | CPU_FTR_DAWR1)
 
 	mfspr	r5, SPRN_AMR
 	std	r5, STACK_SLOT_AMR(r1)
@@ -707,13 +673,9 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -780,12 +742,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	ld	r6, VCPU_DAWRX0(r4)
 	mtspr	SPRN_DAWR0, r5
 	mtspr	SPRN_DAWRX0, r6
-BEGIN_FTR_SECTION
-	ld	r5, VCPU_DAWR1(r4)
-	ld	r6, VCPU_DAWRX1(r4)
-	mtspr	SPRN_DAWR1, r5
-	mtspr	SPRN_DAWRX1, r6
-END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 1:
 	ld	r7, VCPU_CIABR(r4)
 	ld	r8, VCPU_TAR(r4)
@@ -803,7 +759,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 	mtspr	SPRN_BESCR, r6
 	mtspr	SPRN_PID, r7
 	mtspr	SPRN_WORT, r8
-BEGIN_FTR_SECTION
 	/* POWER8-only registers */
 	ld	r5, VCPU_TCSCR(r4)
 	ld	r6, VCPU_ACOP(r4)
@@ -814,18 +769,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_CSIGR, r7
 	mtspr	SPRN_TACR, r8
 	nop
-FTR_SECTION_ELSE
-	/* POWER9-only registers */
-	ld	r5, VCPU_TID(r4)
-	ld	r6, VCPU_PSSCR(r4)
-	lbz	r8, HSTATE_FAKE_SUSPEND(r13)
-	oris	r6, r6, PSSCR_EC@h	/* This makes stop trap to HV */
-	rldimi	r6, r8, PSSCR_FAKE_SUSPEND_LG, 63 - PSSCR_FAKE_SUSPEND_LG
-	ld	r7, VCPU_HFSCR(r4)
-	mtspr	SPRN_TIDR, r5
-	mtspr	SPRN_PSSCR, r6
-	mtspr	SPRN_HFSCR, r7
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 8:
 
 	ld	r5, VCPU_SPRG0(r4)
@@ -918,93 +861,9 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	bdnz	1b
 9:
 
-#ifdef CONFIG_KVM_XICS
-	/* We are entering the guest on that thread, push VCPU to XIVE */
-	ld	r11, VCPU_XIVE_SAVED_STATE(r4)
-	li	r9, TM_QW1_OS
-	lwz	r8, VCPU_XIVE_CAM_WORD(r4)
-	cmpwi	r8, 0
-	beq	no_xive
-	li	r7, TM_QW1_OS + TM_WORD2
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
-	beq	2f
-	ld	r10, HSTATE_XIVE_TIMA_VIRT(r13)
-	cmpldi	cr1, r10, 0
-	beq     cr1, no_xive
-	eieio
-	stdx	r11,r9,r10
-	stwx	r8,r7,r10
-	b	3f
-2:	ld	r10, HSTATE_XIVE_TIMA_PHYS(r13)
-	cmpldi	cr1, r10, 0
-	beq	cr1, no_xive
-	eieio
-	stdcix	r11,r9,r10
-	stwcix	r8,r7,r10
-3:	li	r9, 1
-	stb	r9, VCPU_XIVE_PUSHED(r4)
-	eieio
-
-	/*
-	 * We clear the irq_pending flag. There is a small chance of a
-	 * race vs. the escalation interrupt happening on another
-	 * processor setting it again, but the only consequence is to
-	 * cause a spurrious wakeup on the next H_CEDE which is not an
-	 * issue.
-	 */
-	li	r0,0
-	stb	r0, VCPU_IRQ_PENDING(r4)
-
-	/*
-	 * In single escalation mode, if the escalation interrupt is
-	 * on, we mask it.
-	 */
-	lbz	r0, VCPU_XIVE_ESC_ON(r4)
-	cmpwi	cr1, r0,0
-	beq	cr1, 1f
-	li	r9, XIVE_ESB_SET_PQ_01
-	beq	4f			/* in real mode? */
-	ld	r10, VCPU_XIVE_ESC_VADDR(r4)
-	ldx	r0, r10, r9
-	b	5f
-4:	ld	r10, VCPU_XIVE_ESC_RADDR(r4)
-	ldcix	r0, r10, r9
-5:	sync
-
-	/* We have a possible subtle race here: The escalation interrupt might
-	 * have fired and be on its way to the host queue while we mask it,
-	 * and if we unmask it early enough (re-cede right away), there is
-	 * a theorical possibility that it fires again, thus landing in the
-	 * target queue more than once which is a big no-no.
-	 *
-	 * Fortunately, solving this is rather easy. If the above load setting
-	 * PQ to 01 returns a previous value where P is set, then we know the
-	 * escalation interrupt is somewhere on its way to the host. In that
-	 * case we simply don't clear the xive_esc_on flag below. It will be
-	 * eventually cleared by the handler for the escalation interrupt.
-	 *
-	 * Then, when doing a cede, we check that flag again before re-enabling
-	 * the escalation interrupt, and if set, we abort the cede.
-	 */
-	andi.	r0, r0, XIVE_ESB_VAL_P
-	bne-	1f
-
-	/* Now P is 0, we can clear the flag */
-	li	r0, 0
-	stb	r0, VCPU_XIVE_ESC_ON(r4)
-1:
-no_xive:
-#endif /* CONFIG_KVM_XICS */
-
 deliver_guest_interrupt:	/* r4 = vcpu, r13 = paca */
 	/* Check if we can deliver an external or decrementer interrupt now */
 	ld	r0, VCPU_PENDING_EXC(r4)
-BEGIN_FTR_SECTION
-	/* On POWER9, also check for emulated doorbell interrupt */
-	lbz	r3, VCPU_DBELL_REQ(r4)
-	or	r0, r0, r3
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	cmpdi	r0, 0
 	beq	71f
 	mr	r3, r4
@@ -1077,12 +936,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_PPR, r0
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 
-/* Move canary into DSISR to check for later */
-BEGIN_FTR_SECTION
-	li	r0, 0x7fff
-	mtspr	SPRN_HDSISR, r0
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-
 	ld	r6, VCPU_KVM(r4)
 	lbz	r7, KVM_SECURE_GUEST(r6)
 	cmpdi	r7, 0
@@ -1298,14 +1151,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	/* Hypervisor doorbell - exit only if host IPI flag set */
 	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
 	bne	3f
-BEGIN_FTR_SECTION
-	PPC_MSGSYNC
-	lwsync
-	/* always exit if we're running a nested guest */
-	ld	r0, VCPU_NESTED(r9)
-	cmpdi	r0, 0
-	bne	guest_exit_cont
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	lbz	r0, HSTATE_HOST_IPI(r13)
 	cmpwi	r0, 0
 	beq	maybe_reenter_guest
@@ -1335,43 +1180,6 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	mr	r4, r9
 	bl	kvmhv_accumulate_time
 #endif
-#ifdef CONFIG_KVM_XICS
-	/* We are exiting, pull the VP from the XIVE */
-	lbz	r0, VCPU_XIVE_PUSHED(r9)
-	cmpwi	cr0, r0, 0
-	beq	1f
-	li	r7, TM_SPC_PULL_OS_CTX
-	li	r6, TM_QW1_OS
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
-	beq	2f
-	ld	r10, HSTATE_XIVE_TIMA_VIRT(r13)
-	cmpldi	cr0, r10, 0
-	beq	1f
-	/* First load to pull the context, we ignore the value */
-	eieio
-	lwzx	r11, r7, r10
-	/* Second load to recover the context state (Words 0 and 1) */
-	ldx	r11, r6, r10
-	b	3f
-2:	ld	r10, HSTATE_XIVE_TIMA_PHYS(r13)
-	cmpldi	cr0, r10, 0
-	beq	1f
-	/* First load to pull the context, we ignore the value */
-	eieio
-	lwzcix	r11, r7, r10
-	/* Second load to recover the context state (Words 0 and 1) */
-	ldcix	r11, r6, r10
-3:	std	r11, VCPU_XIVE_SAVED_STATE(r9)
-	/* Fixup some of the state for the next load */
-	li	r10, 0
-	li	r0, 0xff
-	stb	r10, VCPU_XIVE_PUSHED(r9)
-	stb	r10, (VCPU_XIVE_SAVED_STATE+3)(r9)
-	stb	r0, (VCPU_XIVE_SAVED_STATE+4)(r9)
-	eieio
-1:
-#endif /* CONFIG_KVM_XICS */
 
 	/*
 	 * Possibly flush the link stack here, before we do a blr in
@@ -1426,12 +1234,6 @@ guest_bypass:
 	ld	r3, HSTATE_KVM_VCORE(r13)
 	mfspr	r5,SPRN_DEC
 	mftb	r6
-	/* On P9, if the guest has large decr enabled, don't sign extend */
-BEGIN_FTR_SECTION
-	ld	r4, VCORE_LPCR(r3)
-	andis.	r4, r4, LPCR_LD@h
-	bne	16f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	extsw	r5,r5
 16:	add	r5,r5,r6
 	/* r5 is a guest timebase value here, convert to host TB */
@@ -1505,7 +1307,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	std	r6, VCPU_BESCR(r9)
 	stw	r7, VCPU_GUEST_PID(r9)
 	std	r8, VCPU_WORT(r9)
-BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_TCSCR
 	mfspr	r6, SPRN_ACOP
 	mfspr	r7, SPRN_CSIGR
@@ -1514,17 +1315,6 @@ BEGIN_FTR_SECTION
 	std	r6, VCPU_ACOP(r9)
 	std	r7, VCPU_CSIGR(r9)
 	std	r8, VCPU_TACR(r9)
-FTR_SECTION_ELSE
-	mfspr	r5, SPRN_TIDR
-	mfspr	r6, SPRN_PSSCR
-	std	r5, VCPU_TID(r9)
-	rldicl	r6, r6, 4, 50		/* r6 &= PSSCR_GUEST_VIS */
-	rotldi	r6, r6, 60
-	std	r6, VCPU_PSSCR(r9)
-	/* Restore host HFSCR value */
-	ld	r7, STACK_SLOT_HFSCR(r1)
-	mtspr	SPRN_HFSCR, r7
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	/*
 	 * Restore various registers to 0, where non-zero values
 	 * set by the guest could disrupt the host.
@@ -1532,13 +1322,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	li	r0, 0
 	mtspr	SPRN_PSPB, r0
 	mtspr	SPRN_WORT, r0
-BEGIN_FTR_SECTION
 	mtspr	SPRN_TCSCR, r0
 	/* Set MMCRS to 1<<31 to freeze and disable the SPMC counters */
 	li	r0, 1
 	sldi	r0, r0, 31
 	mtspr	SPRN_MMCRS, r0
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 
 	/* Save and restore AMR, IAMR and UAMOR before turning on the MMU */
 	ld	r8, STACK_SLOT_IAMR(r1)
@@ -1595,13 +1383,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	bl	kvmppc_save_fp
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -1647,28 +1431,6 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWR0, r6
 	mtspr	SPRN_DAWRX0, r7
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	ld	r6, STACK_SLOT_DAWR1(r1)
-	ld	r7, STACK_SLOT_DAWRX1(r1)
-	mtspr	SPRN_DAWR1, r6
-	mtspr	SPRN_DAWRX1, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S | CPU_FTR_DAWR1)
-BEGIN_FTR_SECTION
-	ld	r5, STACK_SLOT_TID(r1)
-	ld	r6, STACK_SLOT_PSSCR(r1)
-	ld	r7, STACK_SLOT_PID(r1)
-	mtspr	SPRN_TIDR, r5
-	mtspr	SPRN_PSSCR, r6
-	mtspr	SPRN_PID, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-
-	/*
-	 * cp_abort is required if the processor supports local copy-paste
-	 * to clear the copy buffer that was under control of the guest.
-	 */
-BEGIN_FTR_SECTION
-	PPC_CP_ABORT
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 
 	/*
 	 * POWER7/POWER8 guest -> host partition switch code.
@@ -1705,13 +1467,11 @@ kvmhv_switch_to_host:
 
 	/* Primary thread switches back to host partition */
 	lwz	r7,KVM_HOST_LPID(r4)
-BEGIN_FTR_SECTION
 	ld	r6,KVM_HOST_SDR1(r4)
 	li	r8,LPID_RSVD		/* switch to reserved LPID */
 	mtspr	SPRN_LPID,r8
 	ptesync
 	mtspr	SPRN_SDR1,r6		/* switch to host page table */
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	mtspr	SPRN_LPID,r7
 	isync
 
@@ -1922,20 +1682,11 @@ kvmppc_tm_emul:
 kvmppc_hdsi:
 	mfspr	r4, SPRN_HDAR
 	mfspr	r6, SPRN_HDSISR
-BEGIN_FTR_SECTION
-	/* Look for DSISR canary. If we find it, retry instruction */
-	cmpdi	r6, 0x7fff
-	beq	6f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	/* HPTE not found fault or protection fault? */
 	andis.	r0, r6, (DSISR_NOHPTE | DSISR_PROTFAULT)@h
 	beq	1f			/* if not, send it to the guest */
 	andi.	r0, r11, MSR_DR		/* data relocation enabled? */
 	beq	3f
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_ASDR		/* on POWER9, use ASDR to get VSID */
-	b	4f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	clrrdi	r0, r4, 28
 	PPC_SLBFEE_DOT(R5, R0)		/* if so, look up SLB */
 	li	r0, BOOK3S_INTERRUPT_DATA_SEGMENT
@@ -2012,10 +1763,6 @@ kvmppc_hisi:
 	beq	1f
 	andi.	r0, r11, MSR_IR		/* instruction relocation enabled? */
 	beq	3f
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_ASDR		/* on POWER9, use ASDR to get VSID */
-	b	4f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	clrrdi	r0, r10, 28
 	PPC_SLBFEE_DOT(R5, R0)		/* if so, look up SLB */
 	li	r0, BOOK3S_INTERRUPT_INST_SEGMENT
@@ -2063,10 +1810,6 @@ hcall_try_real_mode:
 	andi.	r0,r11,MSR_PR
 	/* sc 1 from userspace - reflect to guest syscall */
 	bne	sc_1_fast_return
-	/* sc 1 from nested guest - give it to L1 to handle */
-	ld	r0, VCPU_NESTED(r9)
-	cmpdi	r0, 0
-	bne	guest_exit_cont
 	clrrdi	r3,r3,2
 	cmpldi	r3,hcall_real_table_end - hcall_real_table
 	bge	guest_exit_cont
@@ -2462,13 +2205,9 @@ _GLOBAL(kvmppc_h_cede)		/* r3 = vcpu pointer, r11 = msr, r13 = paca */
 	bl	kvmppc_save_fp
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -2488,15 +2227,8 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
 	mfspr	r3, SPRN_DEC
 	mfspr	r4, SPRN_HDEC
 	mftb	r5
-BEGIN_FTR_SECTION
-	/* On P9 check whether the guest has large decrementer mode enabled */
-	ld	r6, HSTATE_KVM_VCORE(r13)
-	ld	r6, VCORE_LPCR(r6)
-	andis.	r6, r6, LPCR_LD@h
-	bne	68f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	extsw	r3, r3
-68:	EXTEND_HDEC(r4)
+	EXTEND_HDEC(r4)
 	cmpd	r3, r4
 	ble	67f
 	mtspr	SPRN_DEC, r4
@@ -2541,28 +2273,14 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 
 kvm_nap_sequence:		/* desired LPCR value in r5 */
-BEGIN_FTR_SECTION
-	/*
-	 * PSSCR bits:	exit criterion = 1 (wakeup based on LPCR at sreset)
-	 *		enable state loss = 1 (allow SMT mode switch)
-	 *		requested level = 0 (just stop dispatching)
-	 */
-	lis	r3, (PSSCR_EC | PSSCR_ESL)@h
 	/* Set LPCR_PECE_HVEE bit to enable wakeup by HV interrupts */
 	li	r4, LPCR_PECE_HVEE@higher
 	sldi	r4, r4, 32
 	or	r5, r5, r4
-FTR_SECTION_ELSE
-	li	r3, PNV_THREAD_NAP
-ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 	mtspr	SPRN_LPCR,r5
 	isync
 
-BEGIN_FTR_SECTION
-	bl	isa300_idle_stop_mayloss
-FTR_SECTION_ELSE
 	bl	isa206_idle_insn_mayloss
-ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 
 	mfspr	r0, SPRN_CTRLF
 	ori	r0, r0, 1
@@ -2581,10 +2299,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 	beq	kvm_end_cede
 	cmpwi	r0, NAPPING_NOVCPU
 	beq	kvm_novcpu_wakeup
-BEGIN_FTR_SECTION
 	cmpwi	r0, NAPPING_UNSPLIT
 	beq	kvm_unsplit_wakeup
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	twi	31,0,0 /* Nap state must not be zero */
 
 33:	mr	r4, r3
@@ -2604,13 +2320,9 @@ kvm_end_cede:
 #endif
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/*
- * Branch around the call if both CPU_FTR_TM and
- * CPU_FTR_P9_TM_HV_ASSIST are off.
- */
 BEGIN_FTR_SECTION
 	b	91f
-END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
+END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/*
 	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
 	 */
@@ -2700,47 +2412,7 @@ kvm_cede_prodded:
 	/* we've ceded but we want to give control to the host */
 kvm_cede_exit:
 	ld	r9, HSTATE_KVM_VCPU(r13)
-#ifdef CONFIG_KVM_XICS
-	/* are we using XIVE with single escalation? */
-	ld	r10, VCPU_XIVE_ESC_VADDR(r9)
-	cmpdi	r10, 0
-	beq	3f
-	li	r6, XIVE_ESB_SET_PQ_00
-	/*
-	 * If we still have a pending escalation, abort the cede,
-	 * and we must set PQ to 10 rather than 00 so that we don't
-	 * potentially end up with two entries for the escalation
-	 * interrupt in the XIVE interrupt queue.  In that case
-	 * we also don't want to set xive_esc_on to 1 here in
-	 * case we race with xive_esc_irq().
-	 */
-	lbz	r5, VCPU_XIVE_ESC_ON(r9)
-	cmpwi	r5, 0
-	beq	4f
-	li	r0, 0
-	stb	r0, VCPU_CEDED(r9)
-	/*
-	 * The escalation interrupts are special as we don't EOI them.
-	 * There is no need to use the load-after-store ordering offset
-	 * to set PQ to 10 as we won't use StoreEOI.
-	 */
-	li	r6, XIVE_ESB_SET_PQ_10
-	b	5f
-4:	li	r0, 1
-	stb	r0, VCPU_XIVE_ESC_ON(r9)
-	/* make sure store to xive_esc_on is seen before xive_esc_irq runs */
-	sync
-5:	/* Enable XIVE escalation */
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
-	beq	1f
-	ldx	r0, r10, r6
-	b	2f
-1:	ld	r10, VCPU_XIVE_ESC_RADDR(r9)
-	ldcix	r0, r10, r6
-2:	sync
-#endif /* CONFIG_KVM_XICS */
-3:	b	guest_exit_cont
+	b	guest_exit_cont
 
 	/* Try to do machine check recovery in real mode */
 machine_check_realmode:
@@ -2817,10 +2489,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	PPC_MSGCLR(6)
 	/* see if it's a host IPI */
 	li	r3, 1
-BEGIN_FTR_SECTION
-	PPC_MSGSYNC
-	lwsync
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	lbz	r0, HSTATE_HOST_IPI(r13)
 	cmpwi	r0, 0
 	bnelr
@@ -3129,70 +2797,12 @@ kvmppc_bad_host_intr:
 	std	r3, STACK_FRAME_OVERHEAD-16(r1)
 
 	/*
-	 * On POWER9 do a minimal restore of the MMU and call C code,
-	 * which will print a message and panic.
 	 * XXX On POWER7 and POWER8, we just spin here since we don't
 	 * know what the other threads are doing (and we don't want to
 	 * coordinate with them) - but at least we now have register state
 	 * in memory that we might be able to look at from another CPU.
 	 */
-BEGIN_FTR_SECTION
 	b	.
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
-	ld	r9, HSTATE_KVM_VCPU(r13)
-	ld	r10, VCPU_KVM(r9)
-
-	li	r0, 0
-	mtspr	SPRN_AMR, r0
-	mtspr	SPRN_IAMR, r0
-	mtspr	SPRN_CIABR, r0
-	mtspr	SPRN_DAWRX0, r0
-BEGIN_FTR_SECTION
-	mtspr	SPRN_DAWRX1, r0
-END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
-
-	/* Clear guest SLB. */
-	slbmte	r0, r0
-	PPC_SLBIA(6)
-	ptesync
-
-	/* load host SLB entries */
-	ld	r8, PACA_SLBSHADOWPTR(r13)
-	.rept	SLB_NUM_BOLTED
-	li	r3, SLBSHADOW_SAVEAREA
-	LDX_BE	r5, r8, r3
-	addi	r3, r3, 8
-	LDX_BE	r6, r8, r3
-	andis.	r7, r5, SLB_ESID_V@h
-	beq	3f
-	slbmte	r6, r5
-3:	addi	r8, r8, 16
-	.endr
-
-	lwz	r7, KVM_HOST_LPID(r10)
-	mtspr	SPRN_LPID, r7
-	mtspr	SPRN_PID, r0
-	ld	r8, KVM_HOST_LPCR(r10)
-	mtspr	SPRN_LPCR, r8
-	isync
-	li	r0, KVM_GUEST_MODE_NONE
-	stb	r0, HSTATE_IN_GUEST(r13)
-
-	/*
-	 * Turn on the MMU and jump to C code
-	 */
-	bcl	20, 31, .+4
-5:	mflr	r3
-	addi	r3, r3, 9f - 5b
-	li	r4, -1
-	rldimi	r3, r4, 62, 0	/* ensure 0xc000000000000000 bits are set */
-	ld	r4, PACAKMSR(r13)
-	mtspr	SPRN_SRR0, r3
-	mtspr	SPRN_SRR1, r4
-	RFI_TO_KERNEL
-9:	addi	r3, r1, STACK_FRAME_OVERHEAD
-	bl	kvmppc_bad_interrupt
-	b	9b
 
 /*
  * This mimics the MSR transition on IRQ delivery.  The new guest MSR is taken
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 999997d9e9a9..528a7e0cf83a 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -604,7 +604,7 @@ struct p9_sprs {
 	u64 uamor;
 };
 
-static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
+static unsigned long power9_idle_stop(unsigned long psscr)
 {
 	int cpu = raw_smp_processor_id();
 	int first = cpu_first_thread_sibling(cpu);
@@ -620,8 +620,6 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 	if (!(psscr & (PSSCR_EC|PSSCR_ESL))) {
 		/* EC=ESL=0 case */
 
-		BUG_ON(!mmu_on);
-
 		/*
 		 * Wake synchronously. SRESET via xscom may still cause
 		 * a 0x100 powersave wakeup with SRR1 reason!
@@ -803,8 +801,7 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 		__slb_restore_bolted_realmode();
 
 out:
-	if (mmu_on)
-		mtmsr(MSR_KERNEL);
+	mtmsr(MSR_KERNEL);
 
 	return srr1;
 }
@@ -895,7 +892,7 @@ struct p10_sprs {
 	 */
 };
 
-static unsigned long power10_idle_stop(unsigned long psscr, bool mmu_on)
+static unsigned long power10_idle_stop(unsigned long psscr)
 {
 	int cpu = raw_smp_processor_id();
 	int first = cpu_first_thread_sibling(cpu);
@@ -909,8 +906,6 @@ static unsigned long power10_idle_stop(unsigned long psscr, bool mmu_on)
 	if (!(psscr & (PSSCR_EC|PSSCR_ESL))) {
 		/* EC=ESL=0 case */
 
-		BUG_ON(!mmu_on);
-
 		/*
 		 * Wake synchronously. SRESET via xscom may still cause
 		 * a 0x100 powersave wakeup with SRR1 reason!
@@ -991,8 +986,7 @@ static unsigned long power10_idle_stop(unsigned long psscr, bool mmu_on)
 		__slb_restore_bolted_realmode();
 
 out:
-	if (mmu_on)
-		mtmsr(MSR_KERNEL);
+	mtmsr(MSR_KERNEL);
 
 	return srr1;
 }
@@ -1002,40 +996,10 @@ static unsigned long arch300_offline_stop(unsigned long psscr)
 {
 	unsigned long srr1;
 
-#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	__ppc64_runlatch_off();
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		srr1 = power10_idle_stop(psscr, true);
+		srr1 = power10_idle_stop(psscr);
 	else
-		srr1 = power9_idle_stop(psscr, true);
-	__ppc64_runlatch_on();
-#else
-	/*
-	 * Tell KVM we're entering idle.
-	 * This does not have to be done in real mode because the P9 MMU
-	 * is independent per-thread. Some steppings share radix/hash mode
-	 * between threads, but in that case KVM has a barrier sync in real
-	 * mode before and after switching between radix and hash.
-	 *
-	 * kvm_start_guest must still be called in real mode though, hence
-	 * the false argument.
-	 */
-	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE;
-
-	__ppc64_runlatch_off();
-	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		srr1 = power10_idle_stop(psscr, false);
-	else
-		srr1 = power9_idle_stop(psscr, false);
-	__ppc64_runlatch_on();
-
-	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL;
-	/* Order setting hwthread_state vs. testing hwthread_req */
-	smp_mb();
-	if (local_paca->kvm_hstate.hwthread_req)
-		srr1 = idle_kvm_start_guest(srr1);
-	mtmsr(MSR_KERNEL);
-#endif
+		srr1 = power9_idle_stop(psscr);
 
 	return srr1;
 }
@@ -1055,9 +1019,9 @@ void arch300_idle_type(unsigned long stop_psscr_val,
 
 	__ppc64_runlatch_off();
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		srr1 = power10_idle_stop(psscr, true);
+		srr1 = power10_idle_stop(psscr);
 	else
-		srr1 = power9_idle_stop(psscr, true);
+		srr1 = power9_idle_stop(psscr);
 	__ppc64_runlatch_on();
 
 	fini_irq_for_idle_irqsoff();
-- 
2.23.0

^ permalink raw reply related	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-25 14:51     ` Cédric Le Goater
  -1 siblings, 0 replies; 134+ messages in thread
From: Cédric Le Goater @ 2021-02-25 14:51 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev

On 2/25/21 2:46 PM, Nicholas Piggin wrote:
> In the interest of minimising the amount of code that is run in
> "real-mode", don't handle hcalls in real mode in the P9 path.
> 
> POWER8 and earlier are much more expensive to exit from HV real mode
> and switch to host mode, because on those processors HV interrupts get
> to the hypervisor with the MMU off, and the other threads in the core
> need to be pulled out of the guest, and SLBs all need to be saved,
> ERATs invalidated, and host SLB reloaded before the MMU is re-enabled
> in host mode. Hash guests also require a lot of hcalls to run. The
> XICS interrupt controller requires hcalls to run.
> 
> By contrast, POWER9 has independent thread switching, and in radix mode
> the hypervisor is already in a host virtual memory mode when the HV
> interrupt is taken. Radix + xive guests don't need hcalls to handle
> interrupts or manage translations.
> 
> So it's much less important to handle hcalls in real mode in P9.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/kvm_ppc.h      |  5 +++++
>  arch/powerpc/kvm/book3s_hv.c            | 25 ++++++++++++++++++++++---
>  arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 +++++
>  arch/powerpc/kvm/book3s_xive.c          | 25 +++++++++++++++++++++++++
>  4 files changed, 57 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index 73b1ca5a6471..db6646c2ade2 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -607,6 +607,7 @@ extern void kvmppc_free_pimap(struct kvm *kvm);
>  extern int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall);
>  extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
>  extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
> +extern int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req);
>  extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
>  extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
>  extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
> @@ -639,6 +640,8 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
>  static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
>  static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
>  	{ return 0; }
> +static inline int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
> +	{ return 0; }
>  #endif
>  
>  #ifdef CONFIG_KVM_XIVE
> @@ -673,6 +676,7 @@ extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
>  			       int level, bool line_status);
>  extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
>  extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
> +extern void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu);

I can not find this routine. Is it missing or coming later in the patchset ? 

C. 
 
>  
>  static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
>  {
> @@ -714,6 +718,7 @@ static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 ir
>  				      int level, bool line_status) { return -ENODEV; }
>  static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
>  static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
> +static inline void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu) { }
>  
>  static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
>  	{ return 0; }
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 7e23838b7f9b..d4770b222d7e 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1144,7 +1144,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>   * This has to be done early, not in kvmppc_pseries_do_hcall(), so
>   * that the cede logic in kvmppc_run_single_vcpu() works properly.
>   */
> -static void kvmppc_nested_cede(struct kvm_vcpu *vcpu)
> +static void kvmppc_cede(struct kvm_vcpu *vcpu)
>  {
>  	vcpu->arch.shregs.msr |= MSR_EE;
>  	vcpu->arch.ceded = 1;
> @@ -3731,15 +3731,34 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  		/* H_CEDE has to be handled now, not later */
>  		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
>  		    kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
> -			kvmppc_nested_cede(vcpu);
> +			kvmppc_cede(vcpu);
>  			kvmppc_set_gpr(vcpu, 3, 0);
>  			trap = 0;
>  		}
>  	} else {
>  		kvmppc_xive_push_vcpu(vcpu);
>  		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
> -		kvmppc_xive_pull_vcpu(vcpu);
> +		/* H_CEDE has to be handled now, not later */
> +		/* XICS hcalls must be handled before xive is pulled */
> +		if (trap == BOOK3S_INTERRUPT_SYSCALL &&
> +		    !(vcpu->arch.shregs.msr & MSR_PR)) {
> +			unsigned long req = kvmppc_get_gpr(vcpu, 3);
>  
> +			if (req == H_CEDE) {
> +				kvmppc_cede(vcpu);
> +				kvmppc_xive_cede_vcpu(vcpu); /* may un-cede */
> +				kvmppc_set_gpr(vcpu, 3, 0);
> +				trap = 0;
> +			}
> +			if (req == H_EOI || req == H_CPPR || req == H_IPI ||
> +			    req == H_IPOLL || req == H_XIRR || req == H_XIRR_X) {
> +				unsigned long ret;
> +				ret = kvmppc_xive_xics_hcall(vcpu, req);
> +				kvmppc_set_gpr(vcpu, 3, ret);
> +				trap = 0;
> +			}
> +		}
> +		kvmppc_xive_pull_vcpu(vcpu);
>  	}
>  
>  	vcpu->arch.slb_max = 0;
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index c11597f815e4..2d0d14ed1d92 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -1397,9 +1397,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>  	mr	r4,r9
>  	bge	fast_guest_return
>  2:
> +	/* If we came in through the P9 short path, no real mode hcalls */
> +	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
> +	cmpwi	r0, 0
> +	bne	no_try_real
>  	/* See if this is an hcall we can handle in real mode */
>  	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
>  	beq	hcall_try_real_mode
> +no_try_real:
>  
>  	/* Hypervisor doorbell - exit only if host IPI flag set */
>  	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
> diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
> index 8632fb998a55..d2266d36a7c7 100644
> --- a/arch/powerpc/kvm/book3s_xive.c
> +++ b/arch/powerpc/kvm/book3s_xive.c
> @@ -2109,6 +2109,31 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
>  	return 0;
>  }
>  
> +int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +
> +	switch (req) {
> +	case H_XIRR:
> +		return xive_vm_h_xirr(vcpu);
> +	case H_CPPR:
> +		return xive_vm_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
> +	case H_EOI:
> +		return xive_vm_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
> +	case H_IPI:
> +		return xive_vm_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					  kvmppc_get_gpr(vcpu, 5));
> +	case H_IPOLL:
> +		return xive_vm_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
> +	case H_XIRR_X:
> +		xive_vm_h_xirr(vcpu);
> +		kvmppc_set_gpr(vcpu, 5, get_tb() + vc->tb_offset);
> +		return H_SUCCESS;
> +	}
> +
> +	return H_UNSUPPORTED;
> +}
> +
>  int kvmppc_xive_debug_show_queues(struct seq_file *m, struct kvm_vcpu *vcpu)
>  {
>  	struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> 


^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
@ 2021-02-25 14:51     ` Cédric Le Goater
  0 siblings, 0 replies; 134+ messages in thread
From: Cédric Le Goater @ 2021-02-25 14:51 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev

On 2/25/21 2:46 PM, Nicholas Piggin wrote:
> In the interest of minimising the amount of code that is run in
> "real-mode", don't handle hcalls in real mode in the P9 path.
> 
> POWER8 and earlier are much more expensive to exit from HV real mode
> and switch to host mode, because on those processors HV interrupts get
> to the hypervisor with the MMU off, and the other threads in the core
> need to be pulled out of the guest, and SLBs all need to be saved,
> ERATs invalidated, and host SLB reloaded before the MMU is re-enabled
> in host mode. Hash guests also require a lot of hcalls to run. The
> XICS interrupt controller requires hcalls to run.
> 
> By contrast, POWER9 has independent thread switching, and in radix mode
> the hypervisor is already in a host virtual memory mode when the HV
> interrupt is taken. Radix + xive guests don't need hcalls to handle
> interrupts or manage translations.
> 
> So it's much less important to handle hcalls in real mode in P9.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/kvm_ppc.h      |  5 +++++
>  arch/powerpc/kvm/book3s_hv.c            | 25 ++++++++++++++++++++++---
>  arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 +++++
>  arch/powerpc/kvm/book3s_xive.c          | 25 +++++++++++++++++++++++++
>  4 files changed, 57 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index 73b1ca5a6471..db6646c2ade2 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -607,6 +607,7 @@ extern void kvmppc_free_pimap(struct kvm *kvm);
>  extern int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall);
>  extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
>  extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
> +extern int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req);
>  extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
>  extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
>  extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
> @@ -639,6 +640,8 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
>  static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
>  static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
>  	{ return 0; }
> +static inline int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
> +	{ return 0; }
>  #endif
>  
>  #ifdef CONFIG_KVM_XIVE
> @@ -673,6 +676,7 @@ extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
>  			       int level, bool line_status);
>  extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
>  extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
> +extern void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu);

I can not find this routine. Is it missing or coming later in the patchset ? 

C. 
 
>  
>  static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
>  {
> @@ -714,6 +718,7 @@ static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 ir
>  				      int level, bool line_status) { return -ENODEV; }
>  static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
>  static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
> +static inline void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu) { }
>  
>  static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
>  	{ return 0; }
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 7e23838b7f9b..d4770b222d7e 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1144,7 +1144,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>   * This has to be done early, not in kvmppc_pseries_do_hcall(), so
>   * that the cede logic in kvmppc_run_single_vcpu() works properly.
>   */
> -static void kvmppc_nested_cede(struct kvm_vcpu *vcpu)
> +static void kvmppc_cede(struct kvm_vcpu *vcpu)
>  {
>  	vcpu->arch.shregs.msr |= MSR_EE;
>  	vcpu->arch.ceded = 1;
> @@ -3731,15 +3731,34 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  		/* H_CEDE has to be handled now, not later */
>  		if (trap = BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
>  		    kvmppc_get_gpr(vcpu, 3) = H_CEDE) {
> -			kvmppc_nested_cede(vcpu);
> +			kvmppc_cede(vcpu);
>  			kvmppc_set_gpr(vcpu, 3, 0);
>  			trap = 0;
>  		}
>  	} else {
>  		kvmppc_xive_push_vcpu(vcpu);
>  		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
> -		kvmppc_xive_pull_vcpu(vcpu);
> +		/* H_CEDE has to be handled now, not later */
> +		/* XICS hcalls must be handled before xive is pulled */
> +		if (trap = BOOK3S_INTERRUPT_SYSCALL &&
> +		    !(vcpu->arch.shregs.msr & MSR_PR)) {
> +			unsigned long req = kvmppc_get_gpr(vcpu, 3);
>  
> +			if (req = H_CEDE) {
> +				kvmppc_cede(vcpu);
> +				kvmppc_xive_cede_vcpu(vcpu); /* may un-cede */
> +				kvmppc_set_gpr(vcpu, 3, 0);
> +				trap = 0;
> +			}
> +			if (req = H_EOI || req = H_CPPR || req = H_IPI ||
> +			    req = H_IPOLL || req = H_XIRR || req = H_XIRR_X) {
> +				unsigned long ret;
> +				ret = kvmppc_xive_xics_hcall(vcpu, req);
> +				kvmppc_set_gpr(vcpu, 3, ret);
> +				trap = 0;
> +			}
> +		}
> +		kvmppc_xive_pull_vcpu(vcpu);
>  	}
>  
>  	vcpu->arch.slb_max = 0;
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index c11597f815e4..2d0d14ed1d92 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -1397,9 +1397,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>  	mr	r4,r9
>  	bge	fast_guest_return
>  2:
> +	/* If we came in through the P9 short path, no real mode hcalls */
> +	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
> +	cmpwi	r0, 0
> +	bne	no_try_real
>  	/* See if this is an hcall we can handle in real mode */
>  	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
>  	beq	hcall_try_real_mode
> +no_try_real:
>  
>  	/* Hypervisor doorbell - exit only if host IPI flag set */
>  	cmpwi	r12, BOOK3S_INTERRUPT_H_DOORBELL
> diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
> index 8632fb998a55..d2266d36a7c7 100644
> --- a/arch/powerpc/kvm/book3s_xive.c
> +++ b/arch/powerpc/kvm/book3s_xive.c
> @@ -2109,6 +2109,31 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
>  	return 0;
>  }
>  
> +int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +
> +	switch (req) {
> +	case H_XIRR:
> +		return xive_vm_h_xirr(vcpu);
> +	case H_CPPR:
> +		return xive_vm_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
> +	case H_EOI:
> +		return xive_vm_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
> +	case H_IPI:
> +		return xive_vm_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					  kvmppc_get_gpr(vcpu, 5));
> +	case H_IPOLL:
> +		return xive_vm_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
> +	case H_XIRR_X:
> +		xive_vm_h_xirr(vcpu);
> +		kvmppc_set_gpr(vcpu, 5, get_tb() + vc->tb_offset);
> +		return H_SUCCESS;
> +	}
> +
> +	return H_UNSUPPORTED;
> +}
> +
>  int kvmppc_xive_debug_show_queues(struct seq_file *m, struct kvm_vcpu *vcpu)
>  {
>  	struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-26  5:01     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  5:01 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Hi Nick,

> The va argument is not used in the function or set by its asm caller,
> so remove it to be safe.

Huh, so it isn't. I tracked the original implementation down to commit
a8606e20e41a ("KVM: PPC: Handle some PAPR hcalls in the kernel") where
paulus first added the ability to handle it in the kernel - there it
takes a va argument but even then doesn't do anything with it.

ajd also pointed out that we don't pass a va when linux is running as a
guest, and LoPAR does not mention va as an argument.

One small nit: checkpatch is complaining about spaces vs tabs:
ERROR: code indent should use tabs where possible
#25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
+                      unsigned long pte_index, unsigned long avpn);$

WARNING: please, no spaces at the start of a line
#25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
+                      unsigned long pte_index, unsigned long avpn);$

Once that is resolved,
  Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel Axtens

> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/kvm_ppc.h  | 3 +--
>  arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
>  2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index 8aacd76bb702..9531b1c1b190 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
>                       unsigned long pte_index, unsigned long avpn);
>  long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
> -                      unsigned long pte_index, unsigned long avpn,
> -                      unsigned long va);
> +                      unsigned long pte_index, unsigned long avpn);
>  long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
>                     unsigned long pte_index);
>  long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
> diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> index 88da2764c1bb..7af7c70f1468 100644
> --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> @@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
>  }
>  
>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
> -		      unsigned long pte_index, unsigned long avpn,
> -		      unsigned long va)
> +		      unsigned long pte_index, unsigned long avpn)
>  {
>  	struct kvm *kvm = vcpu->kvm;
>  	__be64 *hpte;
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
@ 2021-02-26  5:01     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  5:01 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Hi Nick,

> The va argument is not used in the function or set by its asm caller,
> so remove it to be safe.

Huh, so it isn't. I tracked the original implementation down to commit
a8606e20e41a ("KVM: PPC: Handle some PAPR hcalls in the kernel") where
paulus first added the ability to handle it in the kernel - there it
takes a va argument but even then doesn't do anything with it.

ajd also pointed out that we don't pass a va when linux is running as a
guest, and LoPAR does not mention va as an argument.

One small nit: checkpatch is complaining about spaces vs tabs:
ERROR: code indent should use tabs where possible
#25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
+                      unsigned long pte_index, unsigned long avpn);$

WARNING: please, no spaces at the start of a line
#25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
+                      unsigned long pte_index, unsigned long avpn);$

Once that is resolved,
  Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel Axtens

> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/kvm_ppc.h  | 3 +--
>  arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
>  2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index 8aacd76bb702..9531b1c1b190 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
>                       unsigned long pte_index, unsigned long avpn);
>  long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
> -                      unsigned long pte_index, unsigned long avpn,
> -                      unsigned long va);
> +                      unsigned long pte_index, unsigned long avpn);
>  long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
>                     unsigned long pte_index);
>  long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
> diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> index 88da2764c1bb..7af7c70f1468 100644
> --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> @@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
>  }
>  
>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
> -		      unsigned long pte_index, unsigned long avpn,
> -		      unsigned long va)
> +		      unsigned long pte_index, unsigned long avpn)
>  {
>  	struct kvm *kvm = vcpu->kvm;
>  	__be64 *hpte;
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 02/37] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-26  5:21     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  5:21 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Hi Nick,

> This config option causes the warning in init_default_hcalls to fire
> because the TCE handlers are in the default hcall list but not
> implemented.

I checked that the TCE handlers are indeed not defined unless
CONFIG_SPAPR_TCE_IOMMU=y, and so I can see how you would hit the
warning.

This seems like the right solution to me.

Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 13bad6bf4c95..895090636295 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -5369,8 +5369,10 @@ static unsigned int default_hcall_list[] = {
>  	H_READ,
>  	H_PROTECT,
>  	H_BULK_REMOVE,
> +#ifdef CONFIG_SPAPR_TCE_IOMMU
>  	H_GET_TCE,
>  	H_PUT_TCE,
> +#endif
>  	H_SET_DABR,
>  	H_SET_XDABR,
>  	H_CEDE,
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 02/37] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls
@ 2021-02-26  5:21     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  5:21 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Hi Nick,

> This config option causes the warning in init_default_hcalls to fire
> because the TCE handlers are in the default hcall list but not
> implemented.

I checked that the TCE handlers are indeed not defined unless
CONFIG_SPAPR_TCE_IOMMU=y, and so I can see how you would hit the
warning.

This seems like the right solution to me.

Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 13bad6bf4c95..895090636295 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -5369,8 +5369,10 @@ static unsigned int default_hcall_list[] = {
>  	H_READ,
>  	H_PROTECT,
>  	H_BULK_REMOVE,
> +#ifdef CONFIG_SPAPR_TCE_IOMMU
>  	H_GET_TCE,
>  	H_PUT_TCE,
> +#endif
>  	H_SET_DABR,
>  	H_SET_XDABR,
>  	H_CEDE,
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-26  5:44     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  5:44 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Nicholas Piggin <npiggin@gmail.com> writes:

> The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
> MSR[IR]=0, so the faults of concern are the d-side ones caused by access
> to guest context by the hypervisor.
>
> Instruction breakpoint interrupts are not a concern here. It's unlikely
> any good would come of causing breaks in this code, but skipping the
> instruction that caused it won't help matters (e.g., skip the mtmsr that
> sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).

I'm not entirely clear on the example here, but the patch makes sense
and I can follow your logic for removing the IKVM_SKIP handler from the
instruction breakpoint exception.

On that basis:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

>
> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index a027600beeb1..0097e0676ed7 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
>  INT_DEFINE_BEGIN(instruction_breakpoint)
>  	IVEC=0x1300
>  #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> -	IKVM_SKIP=1
>  	IKVM_REAL=1
>  #endif
>  INT_DEFINE_END(instruction_breakpoint)
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
@ 2021-02-26  5:44     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  5:44 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Nicholas Piggin <npiggin@gmail.com> writes:

> The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
> MSR[IR]=0, so the faults of concern are the d-side ones caused by access
> to guest context by the hypervisor.
>
> Instruction breakpoint interrupts are not a concern here. It's unlikely
> any good would come of causing breaks in this code, but skipping the
> instruction that caused it won't help matters (e.g., skip the mtmsr that
> sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).

I'm not entirely clear on the example here, but the patch makes sense
and I can follow your logic for removing the IKVM_SKIP handler from the
instruction breakpoint exception.

On that basis:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

>
> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index a027600beeb1..0097e0676ed7 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
>  INT_DEFINE_BEGIN(instruction_breakpoint)
>  	IVEC=0x1300
>  #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> -	IKVM_SKIP=1
>  	IKVM_REAL=1
>  #endif
>  INT_DEFINE_END(instruction_breakpoint)
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-26  6:06     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  6:06 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

>  void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
>  {
> +	/*
> +	 * Guest must always run with machine check interrupt
> +	 * enabled.
> +	 */
> +	if (!(msr & MSR_ME))
> +		msr |= MSR_ME;

This 'if' is technically redundant but you mention a future patch warning
on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
I get to that patch :)

The patch seems sane to me, I agree that we don't want guests running with
MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
sane so this is another sanity-enforcement in the same sort of vein.

All up:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

> +
>  	/*
>  	 * Check for illegal transactional state bit combination
>  	 * and if we find it, force the TS field to a safe state.
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
@ 2021-02-26  6:06     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-02-26  6:06 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

>  void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
>  {
> +	/*
> +	 * Guest must always run with machine check interrupt
> +	 * enabled.
> +	 */
> +	if (!(msr & MSR_ME))
> +		msr |= MSR_ME;

This 'if' is technically redundant but you mention a future patch warning
on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
I get to that patch :)

The patch seems sane to me, I agree that we don't want guests running with
MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
sane so this is another sanity-enforcement in the same sort of vein.

All up:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

> +
>  	/*
>  	 * Check for illegal transactional state bit combination
>  	 * and if we find it, force the TS field to a safe state.
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-26 15:56     ` Fabiano Rosas
  -1 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-02-26 15:56 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> Switching the MMU from radix<->radix mode is tricky particularly as the
> MMU can remain enabled and requires a certain sequence of SPR updates.
> Move these together into their own functions.
>
> This also includes the radix TLB check / flush because it's tied in to
> MMU switching due to tlbiel getting LPID from LPIDR.
>
> (XXX: isync / hwsync synchronisation TBD)

I see bot mtlpidr and mtlpcr requiring a CSI in the ISA. Do you say we
might need more than an isync?

Regardless, I'd expect that to be separate from the refactoring here,
so:

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 55 +++++++++++++++++++++---------------
>  1 file changed, 32 insertions(+), 23 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 895090636295..23d6dc04b0e9 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -3440,12 +3440,38 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
>  	trace_kvmppc_run_core(vc, 1);
>  }
>
> +static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	struct kvm_nested_guest *nested = vcpu->arch.nested;
> +	u32 lpid;
> +
> +	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> +
> +	mtspr(SPRN_LPID, lpid);
> +	mtspr(SPRN_LPCR, lpcr);
> +	mtspr(SPRN_PID, vcpu->arch.pid);
> +	isync();
> +
> +	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
> +	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
> +}
> +
> +static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
> +{
> +	mtspr(SPRN_PID, pid);
> +	mtspr(SPRN_LPID, kvm->arch.host_lpid);
> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> +	isync();
> +}
> +
>  /*
>   * Load up hypervisor-mode registers on P9.
>   */
>  static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  				     unsigned long lpcr)
>  {
> +	struct kvm *kvm = vcpu->kvm;
>  	struct kvmppc_vcore *vc = vcpu->arch.vcore;
>  	s64 hdec;
>  	u64 tb, purr, spurr;
> @@ -3468,12 +3494,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
>  	 * so set HDICE before writing HDEC.
>  	 */
> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr | LPCR_HDICE);
> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
>  	isync();
>
>  	hdec = time_limit - mftb();
>  	if (hdec < 0) {
> -		mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
> +		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
>  		isync();
>  		return BOOK3S_INTERRUPT_HV_DECREMENTER;
>  	}
> @@ -3508,7 +3534,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	}
>  	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
>  	mtspr(SPRN_IC, vcpu->arch.ic);
> -	mtspr(SPRN_PID, vcpu->arch.pid);
>
>  	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
>  	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> @@ -3522,8 +3547,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	mtspr(SPRN_AMOR, ~0UL);
>
> -	mtspr(SPRN_LPCR, lpcr);
> -	isync();
> +	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>
>  	kvmppc_xive_push_vcpu(vcpu);
>
> @@ -3562,7 +3586,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  		mtspr(SPRN_DAWR1, host_dawr1);
>  		mtspr(SPRN_DAWRX1, host_dawrx1);
>  	}
> -	mtspr(SPRN_PID, host_pidr);
>
>  	/*
>  	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
> @@ -3577,9 +3600,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	if (cpu_has_feature(CPU_FTR_ARCH_31))
>  		asm volatile(PPC_CP_ABORT);
>
> -	mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid);	/* restore host LPID */
> -	isync();
> -
>  	vc->dpdes = mfspr(SPRN_DPDES);
>  	vc->vtb = mfspr(SPRN_VTB);
>  	mtspr(SPRN_DPDES, 0);
> @@ -3596,7 +3616,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	}
>
>  	mtspr(SPRN_HDEC, 0x7fffffff);
> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
> +
> +	switch_mmu_to_host_radix(kvm, host_pidr);
>
>  	return trap;
>  }
> @@ -4130,7 +4151,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>  {
>  	struct kvm_run *run = vcpu->run;
>  	int trap, r, pcpu;
> -	int srcu_idx, lpid;
> +	int srcu_idx;
>  	struct kvmppc_vcore *vc;
>  	struct kvm *kvm = vcpu->kvm;
>  	struct kvm_nested_guest *nested = vcpu->arch.nested;
> @@ -4204,13 +4225,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>  	vc->vcore_state = VCORE_RUNNING;
>  	trace_kvmppc_run_core(vc, 0);
>
> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
> -		lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> -		mtspr(SPRN_LPID, lpid);
> -		isync();
> -		kvmppc_check_need_tlb_flush(kvm, pcpu, nested);
> -	}
> -
>  	guest_enter_irqoff();
>
>  	srcu_idx = srcu_read_lock(&kvm->srcu);
> @@ -4229,11 +4243,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	srcu_read_unlock(&kvm->srcu, srcu_idx);
>
> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
> -		mtspr(SPRN_LPID, kvm->arch.host_lpid);
> -		isync();
> -	}
> -
>  	set_irq_happened(trap);
>
>  	kvmppc_set_host_core(pcpu);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
@ 2021-02-26 15:56     ` Fabiano Rosas
  0 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-02-26 15:56 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> Switching the MMU from radix<->radix mode is tricky particularly as the
> MMU can remain enabled and requires a certain sequence of SPR updates.
> Move these together into their own functions.
>
> This also includes the radix TLB check / flush because it's tied in to
> MMU switching due to tlbiel getting LPID from LPIDR.
>
> (XXX: isync / hwsync synchronisation TBD)

I see bot mtlpidr and mtlpcr requiring a CSI in the ISA. Do you say we
might need more than an isync?

Regardless, I'd expect that to be separate from the refactoring here,
so:

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 55 +++++++++++++++++++++---------------
>  1 file changed, 32 insertions(+), 23 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 895090636295..23d6dc04b0e9 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -3440,12 +3440,38 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
>  	trace_kvmppc_run_core(vc, 1);
>  }
>
> +static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	struct kvm_nested_guest *nested = vcpu->arch.nested;
> +	u32 lpid;
> +
> +	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> +
> +	mtspr(SPRN_LPID, lpid);
> +	mtspr(SPRN_LPCR, lpcr);
> +	mtspr(SPRN_PID, vcpu->arch.pid);
> +	isync();
> +
> +	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
> +	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
> +}
> +
> +static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
> +{
> +	mtspr(SPRN_PID, pid);
> +	mtspr(SPRN_LPID, kvm->arch.host_lpid);
> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> +	isync();
> +}
> +
>  /*
>   * Load up hypervisor-mode registers on P9.
>   */
>  static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  				     unsigned long lpcr)
>  {
> +	struct kvm *kvm = vcpu->kvm;
>  	struct kvmppc_vcore *vc = vcpu->arch.vcore;
>  	s64 hdec;
>  	u64 tb, purr, spurr;
> @@ -3468,12 +3494,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
>  	 * so set HDICE before writing HDEC.
>  	 */
> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr | LPCR_HDICE);
> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
>  	isync();
>
>  	hdec = time_limit - mftb();
>  	if (hdec < 0) {
> -		mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
> +		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
>  		isync();
>  		return BOOK3S_INTERRUPT_HV_DECREMENTER;
>  	}
> @@ -3508,7 +3534,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	}
>  	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
>  	mtspr(SPRN_IC, vcpu->arch.ic);
> -	mtspr(SPRN_PID, vcpu->arch.pid);
>
>  	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
>  	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> @@ -3522,8 +3547,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	mtspr(SPRN_AMOR, ~0UL);
>
> -	mtspr(SPRN_LPCR, lpcr);
> -	isync();
> +	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>
>  	kvmppc_xive_push_vcpu(vcpu);
>
> @@ -3562,7 +3586,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  		mtspr(SPRN_DAWR1, host_dawr1);
>  		mtspr(SPRN_DAWRX1, host_dawrx1);
>  	}
> -	mtspr(SPRN_PID, host_pidr);
>
>  	/*
>  	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
> @@ -3577,9 +3600,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	if (cpu_has_feature(CPU_FTR_ARCH_31))
>  		asm volatile(PPC_CP_ABORT);
>
> -	mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid);	/* restore host LPID */
> -	isync();
> -
>  	vc->dpdes = mfspr(SPRN_DPDES);
>  	vc->vtb = mfspr(SPRN_VTB);
>  	mtspr(SPRN_DPDES, 0);
> @@ -3596,7 +3616,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  	}
>
>  	mtspr(SPRN_HDEC, 0x7fffffff);
> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
> +
> +	switch_mmu_to_host_radix(kvm, host_pidr);
>
>  	return trap;
>  }
> @@ -4130,7 +4151,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>  {
>  	struct kvm_run *run = vcpu->run;
>  	int trap, r, pcpu;
> -	int srcu_idx, lpid;
> +	int srcu_idx;
>  	struct kvmppc_vcore *vc;
>  	struct kvm *kvm = vcpu->kvm;
>  	struct kvm_nested_guest *nested = vcpu->arch.nested;
> @@ -4204,13 +4225,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>  	vc->vcore_state = VCORE_RUNNING;
>  	trace_kvmppc_run_core(vc, 0);
>
> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
> -		lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> -		mtspr(SPRN_LPID, lpid);
> -		isync();
> -		kvmppc_check_need_tlb_flush(kvm, pcpu, nested);
> -	}
> -
>  	guest_enter_irqoff();
>
>  	srcu_idx = srcu_read_lock(&kvm->srcu);
> @@ -4229,11 +4243,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	srcu_read_unlock(&kvm->srcu, srcu_idx);
>
> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
> -		mtspr(SPRN_LPID, kvm->arch.host_lpid);
> -		isync();
> -	}
> -
>  	set_irq_happened(trap);
>
>  	kvmppc_set_host_core(pcpu);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-26 16:38     ` Fabiano Rosas
  -1 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-02-26 16:38 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
> processors, so it must be enabled before HDEC is set.
>
> Rather than set it in the host LPCR then setting HDEC, move the HDEC
> update to after the guest MMU context (including LPCR) is loaded.
> There shouldn't be much concern with delaying HDEC by some 10s or 100s
> of nanoseconds by setting it a bit later.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++--------------
>  1 file changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index d4770b222d7e..63cc92c45c5d 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -3490,23 +3490,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  		host_dawrx1 = mfspr(SPRN_DAWRX1);
>  	}
>
> -	/*
> -	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
> -	 * so set HDICE before writing HDEC.
> -	 */
> -	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
> -	isync();
> -
> -	hdec = time_limit - mftb();

Would it be possible to leave the mftb() in this patch and then replace
them all at once in patch 20/37 - "KVM: PPC: Book3S HV P9: Reduce mftb
per guest entry/exit"?

> -	if (hdec < 0) {
> -		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> -		isync();
> +	tb = mftb();
> +	hdec = time_limit - tb;
> +	if (hdec < 0)
>  		return BOOK3S_INTERRUPT_HV_DECREMENTER;
> -	}
> -	mtspr(SPRN_HDEC, hdec);
>
>  	if (vc->tb_offset) {
> -		u64 new_tb = mftb() + vc->tb_offset;
> +		u64 new_tb = tb + vc->tb_offset;
>  		mtspr(SPRN_TBU40, new_tb);
>  		tb = mftb();
>  		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> @@ -3549,6 +3539,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>
> +	/*
> +	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
> +	 * so set guest LPCR (with HDICE) before writing HDEC.
> +	 */
> +	mtspr(SPRN_HDEC, hdec);
> +
>  	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
>  	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR
@ 2021-02-26 16:38     ` Fabiano Rosas
  0 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-02-26 16:38 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
> processors, so it must be enabled before HDEC is set.
>
> Rather than set it in the host LPCR then setting HDEC, move the HDEC
> update to after the guest MMU context (including LPCR) is loaded.
> There shouldn't be much concern with delaying HDEC by some 10s or 100s
> of nanoseconds by setting it a bit later.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++--------------
>  1 file changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index d4770b222d7e..63cc92c45c5d 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -3490,23 +3490,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>  		host_dawrx1 = mfspr(SPRN_DAWRX1);
>  	}
>
> -	/*
> -	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
> -	 * so set HDICE before writing HDEC.
> -	 */
> -	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
> -	isync();
> -
> -	hdec = time_limit - mftb();

Would it be possible to leave the mftb() in this patch and then replace
them all at once in patch 20/37 - "KVM: PPC: Book3S HV P9: Reduce mftb
per guest entry/exit"?

> -	if (hdec < 0) {
> -		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> -		isync();
> +	tb = mftb();
> +	hdec = time_limit - tb;
> +	if (hdec < 0)
>  		return BOOK3S_INTERRUPT_HV_DECREMENTER;
> -	}
> -	mtspr(SPRN_HDEC, hdec);
>
>  	if (vc->tb_offset) {
> -		u64 new_tb = mftb() + vc->tb_offset;
> +		u64 new_tb = tb + vc->tb_offset;
>  		mtspr(SPRN_TBU40, new_tb);
>  		tb = mftb();
>  		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> @@ -3549,6 +3539,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>
> +	/*
> +	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
> +	 * so set guest LPCR (with HDICE) before writing HDEC.
> +	 */
> +	mtspr(SPRN_HDEC, hdec);
> +
>  	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
>  	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-02-26 22:37     ` Fabiano Rosas
  -1 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-02-26 22:37 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

Hi, thanks for this. It helped me clarify a bunch of details that I
haven't understood while reading the asm code.

Some comments below:

> Almost all logic is moved to C, by introducing a new in_guest mode that
> selects and branches very early in the interrupt handler to the P9 exit
> code.
>
> The remaining assembly is only about 160 lines of low level stack setup,
> with VCPU vs host register save and restore, plus a small shim to the
> legacy paths in the interrupt handler.
>
> There are two motivations for this, the first is just make the code more
> maintainable being in C. The second is to reduce the amount of code
> running in a special KVM mode, "realmode". I put that in quotes because
> with radix it is no longer necessarily real-mode in the MMU, but it
> still has to be treated specially because it may be in real-mode, and
> has various important registers like PID, DEC, TB, etc set to guest.
> This is hostile to the rest of Linux and can't use arbitrary kernel
> functionality or be instrumented well.
>
> This initial patch is a reasonably faithful conversion of the asm code.
> It does lack any loop to return quickly back into the guest without
> switching out of realmode in the case of unimportant or easily handled
> interrupts, as explained in the previous change, handling HV interrupts
> in real mode is not so important for P9.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---

<snip>

> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index f826c8dc2e19..cc7b76865a16 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -1,10 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
>  #include <asm/asm-offsets.h>
>  #include <asm/cache.h>
> +#include <asm/code-patching-asm.h>
>  #include <asm/exception-64s.h>
> +#include <asm/export.h>
>  #include <asm/kvm_asm.h>
>  #include <asm/kvm_book3s_asm.h>
>  #include <asm/ppc_asm.h>
>  #include <asm/reg.h>
> +#include <asm/ultravisor-api.h>
>
>  /*
>   * These are branched to from interrupt handlers in exception-64s.S which set
> @@ -13,13 +17,24 @@
>  .global	kvmppc_hcall
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_hcall:
> +	lbz	r10,HSTATE_IN_GUEST(r13)
> +	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
> +	beq	kvmppc_p9_exit_hcall
>  	ld	r10,PACA_EXGEN+EX_R13(r13)
>  	SET_SCRATCH0(r10)
>  	li	r10,0xc00
> +	li	r11,PACA_EXGEN
> +	b	1f
>
>  .global	kvmppc_interrupt
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_interrupt:
> +	std	r10,HSTATE_SCRATCH0(r13)
> +	lbz	r10,HSTATE_IN_GUEST(r13)
> +	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
> +	beq	kvmppc_p9_exit_interrupt
> +	ld	r10,HSTATE_SCRATCH0(r13)
> +	lbz	r11,HSTATE_IN_GUEST(r13)
>  	li	r11,PACA_EXGEN
>  	cmpdi	r10,0x200
>  	bgt+	1f
> @@ -114,3 +129,169 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>  	GET_SCRATCH0(r13)
>  	HRFI_TO_KERNEL
>  #endif
> +
> +/* Stack frame offsets for kvmppc_hv_entry */
> +#define SFS			208
> +#define STACK_SLOT_VCPU		(SFS-8)
> +#define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
> +
> +/*
> + * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
> + *
> + * Enter the guest on a ISAv3.0 or later system where we have exactly
> + * one vcpu per vcore, and both the host and guest are radix, and threads
> + * are set to "indepdent mode".
> + */
> +.balign	IFETCH_ALIGN_BYTES
> +_GLOBAL(kvmppc_p9_enter_guest)
> +EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
> +	mflr	r0
> +	std	r0,PPC_LR_STKOFF(r1)
> +	stdu	r1,-SFS(r1)
> +
> +	std	r1,HSTATE_HOST_R1(r13)
> +	std	r3,STACK_SLOT_VCPU(r1)

The vcpu was stored on the paca previously. I don't get the change,
could you explain?

> +
> +	mfcr	r4
> +	stw	r4,SFS+8(r1)
> +
> +	reg = 14
> +	.rept	18
> +	std	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
> +	reg = reg + 1
> +	.endr
> +
> +	ld	r4,VCPU_LR(r3)
> +	mtlr	r4
> +	ld	r4,VCPU_CTR(r3)
> +	mtctr	r4
> +	ld	r4,VCPU_XER(r3)
> +	mtspr	SPRN_XER,r4
> +
> +	ld	r1,VCPU_CR(r3)
> +
> +BEGIN_FTR_SECTION
> +	ld	r4,VCPU_CFAR(r3)
> +	mtspr	SPRN_CFAR,r4
> +END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
> +BEGIN_FTR_SECTION
> +	ld	r4,VCPU_PPR(r3)
> +	mtspr	SPRN_PPR,r4
> +END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> +
> +	reg = 4
> +	.rept	28
> +	ld	reg,__VCPU_GPR(reg)(r3)
> +	reg = reg + 1
> +	.endr
> +
> +	ld	r4,VCPU_KVM(r3)
> +	lbz	r4,KVM_SECURE_GUEST(r4)
> +	cmpdi	r4,0
> +	ld	r4,VCPU_GPR(R4)(r3)
> +	bne	.Lret_to_ultra
> +
> +	mtcr	r1
> +
> +	ld	r0,VCPU_GPR(R0)(r3)
> +	ld	r1,VCPU_GPR(R1)(r3)
> +	ld	r2,VCPU_GPR(R2)(r3)
> +	ld	r3,VCPU_GPR(R3)(r3)
> +
> +	HRFI_TO_GUEST
> +	b	.
> +
> +	/*
> +	 * Use UV_RETURN ultracall to return control back to the Ultravisor
> +	 * after processing an hypercall or interrupt that was forwarded
> +	 * (a.k.a. reflected) to the Hypervisor.
> +	 *
> +	 * All registers have already been reloaded except the ucall requires:
> +	 *   R0 = hcall result
> +	 *   R2 = SRR1, so UV can detect a synthesized interrupt (if any)
> +	 *   R3 = UV_RETURN
> +	 */
> +.Lret_to_ultra:
> +	mtcr	r1
> +	ld	r1,VCPU_GPR(R1)(r3)
> +
> +	ld	r0,VCPU_GPR(R3)(r3)
> +	mfspr	r2,SPRN_SRR1
> +	LOAD_REG_IMMEDIATE(r3, UV_RETURN)
> +	sc	2
> +
> +/*
> + * kvmppc_p9_exit_hcall and kvmppc_p9_exit_interrupt are branched to from
> + * above if the interrupt was taken for a guest that was entered via
> + * kvmppc_p9_enter_guest().
> + *
> + * This code recovers the host stack and vcpu pointer, saves all GPRs and
> + * CR, LR, CTR, XER as well as guest MSR and NIA into the VCPU, then re-
> + * establishes the host stack and registers to return from  the
> + * kvmppc_p9_enter_guest() function.
> + */
> +.balign	IFETCH_ALIGN_BYTES
> +kvmppc_p9_exit_hcall:
> +	mfspr	r11,SPRN_SRR0
> +	mfspr	r12,SPRN_SRR1
> +	li	r10,0xc00
> +	std	r10,HSTATE_SCRATCH0(r13)
> +
> +.balign	IFETCH_ALIGN_BYTES
> +kvmppc_p9_exit_interrupt:
> +	std     r1,HSTATE_SCRATCH1(r13)
> +	std     r3,HSTATE_SCRATCH2(r13)
> +	ld	r1,HSTATE_HOST_R1(r13)
> +	ld	r3,STACK_SLOT_VCPU(r1)
> +
> +	std	r9,VCPU_CR(r3)
> +
> +1:
> +	std	r11,VCPU_PC(r3)
> +	std	r12,VCPU_MSR(r3)
> +
> +	reg = 14
> +	.rept	18
> +	std	reg,__VCPU_GPR(reg)(r3)
> +	reg = reg + 1
> +	.endr
> +
> +	/* r1, r3, r9-r13 are saved to vcpu by C code */

If we just saved r1 and r3, why don't we put them in the vcpu right now?
That would avoid having the C code knowing about scratch areas.

> +	std	r0,VCPU_GPR(R0)(r3)
> +	std	r2,VCPU_GPR(R2)(r3)
> +	reg = 4
> +	.rept	5
> +	std	reg,__VCPU_GPR(reg)(r3)
> +	reg = reg + 1
> +	.endr
> +
> +	ld	r2,PACATOC(r13)
> +
> +	mflr	r4
> +	std	r4,VCPU_LR(r3)
> +	mfspr	r4,SPRN_XER
> +	std	r4,VCPU_XER(r3)
> +
> +	reg = 14
> +	.rept	18
> +	ld	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
> +	reg = reg + 1
> +	.endr
> +
> +	lwz	r4,SFS+8(r1)
> +	mtcr	r4
> +
> +	/*
> +	 * Flush the link stack here, before executing the first blr on the
> +	 * way out of the guest.
> +	 *
> +	 * The link stack won't match coming out of the guest anyway so the
> +	 * only cost is the flush itself. The call clobbers r0.
> +	 */
> +1:	nop
> +	patch_site 1b patch__call_kvm_flush_link_stack_2
> +
> +	addi	r1,r1,SFS
> +	ld	r0,PPC_LR_STKOFF(r1)
> +	mtlr	r0
> +	blr
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 1997cf347d3e..28a2761515e3 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1421,6 +1421,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
>  	 */
>  	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
>  		r = RESUME_PAGE_FAULT;
> +		if (vcpu->arch.fault_dsisr == HDSISR_CANARY)
> +			r = RESUME_GUEST; /* Just retry if it's the canary */
>  		break;
>  	case BOOK3S_INTERRUPT_H_INST_STORAGE:
>  		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
> @@ -3736,14 +3738,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  		vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
>  		vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
>  		mtspr(SPRN_PSSCR_PR, host_psscr);
> -
>  		/* H_CEDE has to be handled now, not later */
> -		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
> +		if (trap == BOOK3S_INTERRUPT_SYSCALL &&
>  		    kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
>  			kvmppc_cede(vcpu);
>  			kvmppc_set_gpr(vcpu, 3, 0);
>  			trap = 0;
>  		}
> +
>  	} else {
>  		kvmppc_xive_push_vcpu(vcpu);
>  		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
> @@ -3768,9 +3770,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  			}
>  		}
>  		kvmppc_xive_pull_vcpu(vcpu);
> +
> +		vcpu->arch.slb_max = 0;
>  	}
>
> -	vcpu->arch.slb_max = 0;
>  	dec = mfspr(SPRN_DEC);
>  	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
>  		dec = (s32) dec;
> @@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>  		else
>  			r = kvmppc_run_vcpu(vcpu);
>
> -		if (run->exit_reason == KVM_EXIT_PAPR_HCALL &&
> -		    !(vcpu->arch.shregs.msr & MSR_PR)) {
> -			trace_kvm_hcall_enter(vcpu);
> -			r = kvmppc_pseries_do_hcall(vcpu);
> -			trace_kvm_hcall_exit(vcpu, r);
> +		if (run->exit_reason == KVM_EXIT_PAPR_HCALL) {
> +			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
> +				/*
> +				 * Guest userspace executed sc 1, reflect it
> +				 * back as a privileged program check interrupt.
> +				 */
> +				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
> +				r = RESUME_GUEST;

This is in conflict with this snippet in kvmppc_handle_exit_hv:

	case BOOK3S_INTERRUPT_SYSCALL:
	{
		/* hcall - punt to userspace */
		int i;

		/* hypercall with MSR_PR has already been handled in rmode,
		 * and never reaches here.
		 */

That function already queues some 0x700s so maybe we could move this one
in there as well.

> +			} else {
> +				trace_kvm_hcall_enter(vcpu);
> +				r = kvmppc_pseries_do_hcall(vcpu);
> +				trace_kvm_hcall_exit(vcpu, r);
> +			}
>  			kvmppc_core_prepare_to_enter(vcpu);
>  		} else if (r == RESUME_PAGE_FAULT) {
>  			srcu_idx = srcu_read_lock(&kvm->srcu);
> diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
> new file mode 100644
> index 000000000000..5a7b036c447f
> --- /dev/null
> +++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
> @@ -0,0 +1,221 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include <linux/kernel.h>
> +#include <linux/kvm_host.h>
> +#include <asm/asm-prototypes.h>
> +#include <asm/dbell.h>
> +#include <asm/kvm_ppc.h>
> +
> +#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
> +static void __start_timing(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	u64 tb = mftb() - vc->tb_offset_applied;
> +
> +	vcpu->arch.cur_activity = next;
> +	vcpu->arch.cur_tb_start = tb;
> +}
> +
> +static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	struct kvmhv_tb_accumulator *curr;
> +	u64 tb = mftb() - vc->tb_offset_applied;
> +	u64 prev_tb;
> +	u64 delta;
> +	u64 seq;
> +
> +	curr = vcpu->arch.cur_activity;
> +	vcpu->arch.cur_activity = next;
> +	prev_tb = vcpu->arch.cur_tb_start;
> +	vcpu->arch.cur_tb_start = tb;
> +
> +	if (!curr)
> +		return;
> +
> +	delta = tb - prev_tb;
> +
> +	seq = curr->seqcount;
> +	curr->seqcount = seq + 1;
> +	smp_wmb();
> +	curr->tb_total += delta;
> +	if (seq == 0 || delta < curr->tb_min)
> +		curr->tb_min = delta;
> +	if (delta > curr->tb_max)
> +		curr->tb_max = delta;
> +	smp_wmb();
> +	curr->seqcount = seq + 2;
> +}
> +
> +#define start_timing(vcpu, next) __start_timing(vcpu, next)
> +#define end_timing(vcpu) __start_timing(vcpu, NULL)
> +#define accumulate_time(vcpu, next) __accumulate_time(vcpu, next)
> +#else
> +#define start_timing(vcpu, next) do {} while (0)
> +#define end_timing(vcpu) do {} while (0)
> +#define accumulate_time(vcpu, next) do {} while (0)
> +#endif
> +
> +static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
> +{
> +	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
> +	asm volatile("slbmfee  %0,%1" : "=r" (*slbee) : "r" (idx));
> +}
> +
> +static inline void mtslb(unsigned int idx, u64 slbee, u64 slbev)
> +{
> +	BUG_ON((slbee & 0xfff) != idx);
> +
> +	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
> +}
> +
> +static inline void slb_invalidate(unsigned int ih)
> +{
> +	asm volatile("slbia %0" :: "i"(ih));
> +}
> +
> +/*
> + * Malicious or buggy radix guests may have inserted SLB entries
> + * (only 0..3 because radix always runs with UPRT=1), so these must
> + * be cleared here to avoid side-channels. slbmte is used rather
> + * than slbia, as it won't clear cached translations.
> + */
> +static void radix_clear_slb(void)
> +{
> +	u64 slbee, slbev;
> +	int i;
> +
> +	for (i = 0; i < 4; i++) {
> +		mfslb(i, &slbee, &slbev);
> +		if (unlikely(slbee || slbev)) {
> +			slbee = i;
> +			slbev = 0;
> +			mtslb(i, slbee, slbev);
> +		}
> +	}
> +}
> +
> +int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
> +{
> +	u64 *exsave;
> +	unsigned long msr = mfmsr();
> +	int trap;
> +
> +	start_timing(vcpu, &vcpu->arch.rm_entry);
> +
> +	vcpu->arch.ceded = 0;
> +
> +	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
> +	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
> +
> +	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
> +	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
> +
> +	/*
> +	 * On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage
> +	 * Interrupt (HDSI) the HDSISR is not be updated at all.

s/be //

> +	 *
> +	 * To work around this we put a canary value into the HDSISR before
> +	 * returning to a guest and then check for this canary when we take a
> +	 * HDSI. If we find the canary on a HDSI, we know the hardware didn't
> +	 * update the HDSISR. In this case we return to the guest to retake the
> +	 * HDSI which should correctly update the HDSISR the second time HDSI
> +	 * entry.
> +	 *
> +	 * Just do this on all p9 processors for now.
> +	 */
> +	mtspr(SPRN_HDSISR, HDSISR_CANARY);
> +
> +	accumulate_time(vcpu, &vcpu->arch.guest_time);
> +
> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
> +	kvmppc_p9_enter_guest(vcpu);
> +	// Radix host and guest means host never runs with guest MMU state
> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
> +
> +	accumulate_time(vcpu, &vcpu->arch.rm_intr);
> +
> +	/* Get these from r11/12 and paca exsave */
> +	vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
> +	vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
> +	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
> +	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
> +
> +	trap = local_paca->kvm_hstate.scratch0 & ~0x2;

Couldn't we return the trap from kvmppc_p9_enter_guest? Seems like a
nice pattern to have and avoids exposing the IVEC+0x2 magic which is hidden
in asm already.

> +	if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
> +		exsave = local_paca->exgen;
> +	} else if (trap == BOOK3S_INTERRUPT_SYSTEM_RESET) {
> +		exsave = local_paca->exnmi;
> +	} else { /* trap == 0x200 */
> +		exsave = local_paca->exmc;
> +	}
> +
> +	vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
> +	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
> +	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
> +	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
> +	vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
> +	vcpu->arch.regs.gpr[12] = exsave[EX_R12/sizeof(u64)];
> +	vcpu->arch.regs.gpr[13] = exsave[EX_R13/sizeof(u64)];
> +	vcpu->arch.ppr = exsave[EX_PPR/sizeof(u64)];
> +	vcpu->arch.cfar = exsave[EX_CFAR/sizeof(u64)];
> +	vcpu->arch.regs.ctr = exsave[EX_CTR/sizeof(u64)];
> +
> +	vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
> +
> +	if (unlikely(trap == BOOK3S_INTERRUPT_MACHINE_CHECK)) {
> +		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
> +		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
> +		kvmppc_realmode_machine_check(vcpu);
> +
> +	} else if (unlikely(trap == BOOK3S_INTERRUPT_HMI)) {
> +		kvmppc_realmode_hmi_handler();
> +
> +	} else if (trap == BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
> +		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
> +
> +	} else if (trap == BOOK3S_INTERRUPT_H_DATA_STORAGE) {
> +		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
> +		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
> +		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
> +
> +	} else if (trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
> +		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
> +
> +	} else if (trap == BOOK3S_INTERRUPT_H_FAC_UNAVAIL) {
> +		vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
> +
> +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> +	/*
> +	 * Softpatch interrupt for transactional memory emulation cases
> +	 * on POWER9 DD2.2.  This is early in the guest exit path - we
> +	 * haven't saved registers or done a treclaim yet.
> +	 */
> +	} else if (trap == BOOK3S_INTERRUPT_HV_SOFTPATCH) {
> +		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
> +
> +		/*
> +		 * The cases we want to handle here are those where the guest
> +		 * is in real suspend mode and is trying to transition to
> +		 * transactional mode.
> +		 */
> +		if (local_paca->kvm_hstate.fake_suspend &&
> +				(vcpu->arch.shregs.msr & MSR_TS_S)) {
> +			if (kvmhv_p9_tm_emulation_early(vcpu)) {
> +				/* Prevent it being handled again. */
> +				trap = 0;
> +			}
> +		}
> +#endif
> +	}
> +
> +	radix_clear_slb();
> +
> +	__mtmsrd(msr, 0);

Isn't this the same as mtmsr(msr) ?

> +
> +	accumulate_time(vcpu, &vcpu->arch.rm_exit);
> +
> +	end_timing(vcpu);
> +
> +	return trap;
> +}
> +EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);

<snip>

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
@ 2021-02-26 22:37     ` Fabiano Rosas
  0 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-02-26 22:37 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

Hi, thanks for this. It helped me clarify a bunch of details that I
haven't understood while reading the asm code.

Some comments below:

> Almost all logic is moved to C, by introducing a new in_guest mode that
> selects and branches very early in the interrupt handler to the P9 exit
> code.
>
> The remaining assembly is only about 160 lines of low level stack setup,
> with VCPU vs host register save and restore, plus a small shim to the
> legacy paths in the interrupt handler.
>
> There are two motivations for this, the first is just make the code more
> maintainable being in C. The second is to reduce the amount of code
> running in a special KVM mode, "realmode". I put that in quotes because
> with radix it is no longer necessarily real-mode in the MMU, but it
> still has to be treated specially because it may be in real-mode, and
> has various important registers like PID, DEC, TB, etc set to guest.
> This is hostile to the rest of Linux and can't use arbitrary kernel
> functionality or be instrumented well.
>
> This initial patch is a reasonably faithful conversion of the asm code.
> It does lack any loop to return quickly back into the guest without
> switching out of realmode in the case of unimportant or easily handled
> interrupts, as explained in the previous change, handling HV interrupts
> in real mode is not so important for P9.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---

<snip>

> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index f826c8dc2e19..cc7b76865a16 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -1,10 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
>  #include <asm/asm-offsets.h>
>  #include <asm/cache.h>
> +#include <asm/code-patching-asm.h>
>  #include <asm/exception-64s.h>
> +#include <asm/export.h>
>  #include <asm/kvm_asm.h>
>  #include <asm/kvm_book3s_asm.h>
>  #include <asm/ppc_asm.h>
>  #include <asm/reg.h>
> +#include <asm/ultravisor-api.h>
>
>  /*
>   * These are branched to from interrupt handlers in exception-64s.S which set
> @@ -13,13 +17,24 @@
>  .global	kvmppc_hcall
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_hcall:
> +	lbz	r10,HSTATE_IN_GUEST(r13)
> +	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
> +	beq	kvmppc_p9_exit_hcall
>  	ld	r10,PACA_EXGEN+EX_R13(r13)
>  	SET_SCRATCH0(r10)
>  	li	r10,0xc00
> +	li	r11,PACA_EXGEN
> +	b	1f
>
>  .global	kvmppc_interrupt
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_interrupt:
> +	std	r10,HSTATE_SCRATCH0(r13)
> +	lbz	r10,HSTATE_IN_GUEST(r13)
> +	cmpwi	r10,KVM_GUEST_MODE_GUEST_HV_FAST
> +	beq	kvmppc_p9_exit_interrupt
> +	ld	r10,HSTATE_SCRATCH0(r13)
> +	lbz	r11,HSTATE_IN_GUEST(r13)
>  	li	r11,PACA_EXGEN
>  	cmpdi	r10,0x200
>  	bgt+	1f
> @@ -114,3 +129,169 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>  	GET_SCRATCH0(r13)
>  	HRFI_TO_KERNEL
>  #endif
> +
> +/* Stack frame offsets for kvmppc_hv_entry */
> +#define SFS			208
> +#define STACK_SLOT_VCPU		(SFS-8)
> +#define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
> +
> +/*
> + * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
> + *
> + * Enter the guest on a ISAv3.0 or later system where we have exactly
> + * one vcpu per vcore, and both the host and guest are radix, and threads
> + * are set to "indepdent mode".
> + */
> +.balign	IFETCH_ALIGN_BYTES
> +_GLOBAL(kvmppc_p9_enter_guest)
> +EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
> +	mflr	r0
> +	std	r0,PPC_LR_STKOFF(r1)
> +	stdu	r1,-SFS(r1)
> +
> +	std	r1,HSTATE_HOST_R1(r13)
> +	std	r3,STACK_SLOT_VCPU(r1)

The vcpu was stored on the paca previously. I don't get the change,
could you explain?

> +
> +	mfcr	r4
> +	stw	r4,SFS+8(r1)
> +
> +	reg = 14
> +	.rept	18
> +	std	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
> +	reg = reg + 1
> +	.endr
> +
> +	ld	r4,VCPU_LR(r3)
> +	mtlr	r4
> +	ld	r4,VCPU_CTR(r3)
> +	mtctr	r4
> +	ld	r4,VCPU_XER(r3)
> +	mtspr	SPRN_XER,r4
> +
> +	ld	r1,VCPU_CR(r3)
> +
> +BEGIN_FTR_SECTION
> +	ld	r4,VCPU_CFAR(r3)
> +	mtspr	SPRN_CFAR,r4
> +END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
> +BEGIN_FTR_SECTION
> +	ld	r4,VCPU_PPR(r3)
> +	mtspr	SPRN_PPR,r4
> +END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> +
> +	reg = 4
> +	.rept	28
> +	ld	reg,__VCPU_GPR(reg)(r3)
> +	reg = reg + 1
> +	.endr
> +
> +	ld	r4,VCPU_KVM(r3)
> +	lbz	r4,KVM_SECURE_GUEST(r4)
> +	cmpdi	r4,0
> +	ld	r4,VCPU_GPR(R4)(r3)
> +	bne	.Lret_to_ultra
> +
> +	mtcr	r1
> +
> +	ld	r0,VCPU_GPR(R0)(r3)
> +	ld	r1,VCPU_GPR(R1)(r3)
> +	ld	r2,VCPU_GPR(R2)(r3)
> +	ld	r3,VCPU_GPR(R3)(r3)
> +
> +	HRFI_TO_GUEST
> +	b	.
> +
> +	/*
> +	 * Use UV_RETURN ultracall to return control back to the Ultravisor
> +	 * after processing an hypercall or interrupt that was forwarded
> +	 * (a.k.a. reflected) to the Hypervisor.
> +	 *
> +	 * All registers have already been reloaded except the ucall requires:
> +	 *   R0 = hcall result
> +	 *   R2 = SRR1, so UV can detect a synthesized interrupt (if any)
> +	 *   R3 = UV_RETURN
> +	 */
> +.Lret_to_ultra:
> +	mtcr	r1
> +	ld	r1,VCPU_GPR(R1)(r3)
> +
> +	ld	r0,VCPU_GPR(R3)(r3)
> +	mfspr	r2,SPRN_SRR1
> +	LOAD_REG_IMMEDIATE(r3, UV_RETURN)
> +	sc	2
> +
> +/*
> + * kvmppc_p9_exit_hcall and kvmppc_p9_exit_interrupt are branched to from
> + * above if the interrupt was taken for a guest that was entered via
> + * kvmppc_p9_enter_guest().
> + *
> + * This code recovers the host stack and vcpu pointer, saves all GPRs and
> + * CR, LR, CTR, XER as well as guest MSR and NIA into the VCPU, then re-
> + * establishes the host stack and registers to return from  the
> + * kvmppc_p9_enter_guest() function.
> + */
> +.balign	IFETCH_ALIGN_BYTES
> +kvmppc_p9_exit_hcall:
> +	mfspr	r11,SPRN_SRR0
> +	mfspr	r12,SPRN_SRR1
> +	li	r10,0xc00
> +	std	r10,HSTATE_SCRATCH0(r13)
> +
> +.balign	IFETCH_ALIGN_BYTES
> +kvmppc_p9_exit_interrupt:
> +	std     r1,HSTATE_SCRATCH1(r13)
> +	std     r3,HSTATE_SCRATCH2(r13)
> +	ld	r1,HSTATE_HOST_R1(r13)
> +	ld	r3,STACK_SLOT_VCPU(r1)
> +
> +	std	r9,VCPU_CR(r3)
> +
> +1:
> +	std	r11,VCPU_PC(r3)
> +	std	r12,VCPU_MSR(r3)
> +
> +	reg = 14
> +	.rept	18
> +	std	reg,__VCPU_GPR(reg)(r3)
> +	reg = reg + 1
> +	.endr
> +
> +	/* r1, r3, r9-r13 are saved to vcpu by C code */

If we just saved r1 and r3, why don't we put them in the vcpu right now?
That would avoid having the C code knowing about scratch areas.

> +	std	r0,VCPU_GPR(R0)(r3)
> +	std	r2,VCPU_GPR(R2)(r3)
> +	reg = 4
> +	.rept	5
> +	std	reg,__VCPU_GPR(reg)(r3)
> +	reg = reg + 1
> +	.endr
> +
> +	ld	r2,PACATOC(r13)
> +
> +	mflr	r4
> +	std	r4,VCPU_LR(r3)
> +	mfspr	r4,SPRN_XER
> +	std	r4,VCPU_XER(r3)
> +
> +	reg = 14
> +	.rept	18
> +	ld	reg,STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
> +	reg = reg + 1
> +	.endr
> +
> +	lwz	r4,SFS+8(r1)
> +	mtcr	r4
> +
> +	/*
> +	 * Flush the link stack here, before executing the first blr on the
> +	 * way out of the guest.
> +	 *
> +	 * The link stack won't match coming out of the guest anyway so the
> +	 * only cost is the flush itself. The call clobbers r0.
> +	 */
> +1:	nop
> +	patch_site 1b patch__call_kvm_flush_link_stack_2
> +
> +	addi	r1,r1,SFS
> +	ld	r0,PPC_LR_STKOFF(r1)
> +	mtlr	r0
> +	blr
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 1997cf347d3e..28a2761515e3 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1421,6 +1421,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
>  	 */
>  	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
>  		r = RESUME_PAGE_FAULT;
> +		if (vcpu->arch.fault_dsisr = HDSISR_CANARY)
> +			r = RESUME_GUEST; /* Just retry if it's the canary */
>  		break;
>  	case BOOK3S_INTERRUPT_H_INST_STORAGE:
>  		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
> @@ -3736,14 +3738,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  		vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
>  		vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
>  		mtspr(SPRN_PSSCR_PR, host_psscr);
> -
>  		/* H_CEDE has to be handled now, not later */
> -		if (trap = BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
> +		if (trap = BOOK3S_INTERRUPT_SYSCALL &&
>  		    kvmppc_get_gpr(vcpu, 3) = H_CEDE) {
>  			kvmppc_cede(vcpu);
>  			kvmppc_set_gpr(vcpu, 3, 0);
>  			trap = 0;
>  		}
> +
>  	} else {
>  		kvmppc_xive_push_vcpu(vcpu);
>  		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
> @@ -3768,9 +3770,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  			}
>  		}
>  		kvmppc_xive_pull_vcpu(vcpu);
> +
> +		vcpu->arch.slb_max = 0;
>  	}
>
> -	vcpu->arch.slb_max = 0;
>  	dec = mfspr(SPRN_DEC);
>  	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
>  		dec = (s32) dec;
> @@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>  		else
>  			r = kvmppc_run_vcpu(vcpu);
>
> -		if (run->exit_reason = KVM_EXIT_PAPR_HCALL &&
> -		    !(vcpu->arch.shregs.msr & MSR_PR)) {
> -			trace_kvm_hcall_enter(vcpu);
> -			r = kvmppc_pseries_do_hcall(vcpu);
> -			trace_kvm_hcall_exit(vcpu, r);
> +		if (run->exit_reason = KVM_EXIT_PAPR_HCALL) {
> +			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
> +				/*
> +				 * Guest userspace executed sc 1, reflect it
> +				 * back as a privileged program check interrupt.
> +				 */
> +				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
> +				r = RESUME_GUEST;

This is in conflict with this snippet in kvmppc_handle_exit_hv:

	case BOOK3S_INTERRUPT_SYSCALL:
	{
		/* hcall - punt to userspace */
		int i;

		/* hypercall with MSR_PR has already been handled in rmode,
		 * and never reaches here.
		 */

That function already queues some 0x700s so maybe we could move this one
in there as well.

> +			} else {
> +				trace_kvm_hcall_enter(vcpu);
> +				r = kvmppc_pseries_do_hcall(vcpu);
> +				trace_kvm_hcall_exit(vcpu, r);
> +			}
>  			kvmppc_core_prepare_to_enter(vcpu);
>  		} else if (r = RESUME_PAGE_FAULT) {
>  			srcu_idx = srcu_read_lock(&kvm->srcu);
> diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
> new file mode 100644
> index 000000000000..5a7b036c447f
> --- /dev/null
> +++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
> @@ -0,0 +1,221 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include <linux/kernel.h>
> +#include <linux/kvm_host.h>
> +#include <asm/asm-prototypes.h>
> +#include <asm/dbell.h>
> +#include <asm/kvm_ppc.h>
> +
> +#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
> +static void __start_timing(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	u64 tb = mftb() - vc->tb_offset_applied;
> +
> +	vcpu->arch.cur_activity = next;
> +	vcpu->arch.cur_tb_start = tb;
> +}
> +
> +static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	struct kvmhv_tb_accumulator *curr;
> +	u64 tb = mftb() - vc->tb_offset_applied;
> +	u64 prev_tb;
> +	u64 delta;
> +	u64 seq;
> +
> +	curr = vcpu->arch.cur_activity;
> +	vcpu->arch.cur_activity = next;
> +	prev_tb = vcpu->arch.cur_tb_start;
> +	vcpu->arch.cur_tb_start = tb;
> +
> +	if (!curr)
> +		return;
> +
> +	delta = tb - prev_tb;
> +
> +	seq = curr->seqcount;
> +	curr->seqcount = seq + 1;
> +	smp_wmb();
> +	curr->tb_total += delta;
> +	if (seq = 0 || delta < curr->tb_min)
> +		curr->tb_min = delta;
> +	if (delta > curr->tb_max)
> +		curr->tb_max = delta;
> +	smp_wmb();
> +	curr->seqcount = seq + 2;
> +}
> +
> +#define start_timing(vcpu, next) __start_timing(vcpu, next)
> +#define end_timing(vcpu) __start_timing(vcpu, NULL)
> +#define accumulate_time(vcpu, next) __accumulate_time(vcpu, next)
> +#else
> +#define start_timing(vcpu, next) do {} while (0)
> +#define end_timing(vcpu) do {} while (0)
> +#define accumulate_time(vcpu, next) do {} while (0)
> +#endif
> +
> +static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
> +{
> +	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
> +	asm volatile("slbmfee  %0,%1" : "=r" (*slbee) : "r" (idx));
> +}
> +
> +static inline void mtslb(unsigned int idx, u64 slbee, u64 slbev)
> +{
> +	BUG_ON((slbee & 0xfff) != idx);
> +
> +	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
> +}
> +
> +static inline void slb_invalidate(unsigned int ih)
> +{
> +	asm volatile("slbia %0" :: "i"(ih));
> +}
> +
> +/*
> + * Malicious or buggy radix guests may have inserted SLB entries
> + * (only 0..3 because radix always runs with UPRT=1), so these must
> + * be cleared here to avoid side-channels. slbmte is used rather
> + * than slbia, as it won't clear cached translations.
> + */
> +static void radix_clear_slb(void)
> +{
> +	u64 slbee, slbev;
> +	int i;
> +
> +	for (i = 0; i < 4; i++) {
> +		mfslb(i, &slbee, &slbev);
> +		if (unlikely(slbee || slbev)) {
> +			slbee = i;
> +			slbev = 0;
> +			mtslb(i, slbee, slbev);
> +		}
> +	}
> +}
> +
> +int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
> +{
> +	u64 *exsave;
> +	unsigned long msr = mfmsr();
> +	int trap;
> +
> +	start_timing(vcpu, &vcpu->arch.rm_entry);
> +
> +	vcpu->arch.ceded = 0;
> +
> +	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
> +	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
> +
> +	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
> +	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
> +
> +	/*
> +	 * On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage
> +	 * Interrupt (HDSI) the HDSISR is not be updated at all.

s/be //

> +	 *
> +	 * To work around this we put a canary value into the HDSISR before
> +	 * returning to a guest and then check for this canary when we take a
> +	 * HDSI. If we find the canary on a HDSI, we know the hardware didn't
> +	 * update the HDSISR. In this case we return to the guest to retake the
> +	 * HDSI which should correctly update the HDSISR the second time HDSI
> +	 * entry.
> +	 *
> +	 * Just do this on all p9 processors for now.
> +	 */
> +	mtspr(SPRN_HDSISR, HDSISR_CANARY);
> +
> +	accumulate_time(vcpu, &vcpu->arch.guest_time);
> +
> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
> +	kvmppc_p9_enter_guest(vcpu);
> +	// Radix host and guest means host never runs with guest MMU state
> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
> +
> +	accumulate_time(vcpu, &vcpu->arch.rm_intr);
> +
> +	/* Get these from r11/12 and paca exsave */
> +	vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
> +	vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
> +	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
> +	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
> +
> +	trap = local_paca->kvm_hstate.scratch0 & ~0x2;

Couldn't we return the trap from kvmppc_p9_enter_guest? Seems like a
nice pattern to have and avoids exposing the IVEC+0x2 magic which is hidden
in asm already.

> +	if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
> +		exsave = local_paca->exgen;
> +	} else if (trap = BOOK3S_INTERRUPT_SYSTEM_RESET) {
> +		exsave = local_paca->exnmi;
> +	} else { /* trap = 0x200 */
> +		exsave = local_paca->exmc;
> +	}
> +
> +	vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
> +	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
> +	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
> +	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
> +	vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
> +	vcpu->arch.regs.gpr[12] = exsave[EX_R12/sizeof(u64)];
> +	vcpu->arch.regs.gpr[13] = exsave[EX_R13/sizeof(u64)];
> +	vcpu->arch.ppr = exsave[EX_PPR/sizeof(u64)];
> +	vcpu->arch.cfar = exsave[EX_CFAR/sizeof(u64)];
> +	vcpu->arch.regs.ctr = exsave[EX_CTR/sizeof(u64)];
> +
> +	vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
> +
> +	if (unlikely(trap = BOOK3S_INTERRUPT_MACHINE_CHECK)) {
> +		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
> +		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
> +		kvmppc_realmode_machine_check(vcpu);
> +
> +	} else if (unlikely(trap = BOOK3S_INTERRUPT_HMI)) {
> +		kvmppc_realmode_hmi_handler();
> +
> +	} else if (trap = BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
> +		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
> +
> +	} else if (trap = BOOK3S_INTERRUPT_H_DATA_STORAGE) {
> +		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
> +		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
> +		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
> +
> +	} else if (trap = BOOK3S_INTERRUPT_H_INST_STORAGE) {
> +		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
> +
> +	} else if (trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL) {
> +		vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
> +
> +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> +	/*
> +	 * Softpatch interrupt for transactional memory emulation cases
> +	 * on POWER9 DD2.2.  This is early in the guest exit path - we
> +	 * haven't saved registers or done a treclaim yet.
> +	 */
> +	} else if (trap = BOOK3S_INTERRUPT_HV_SOFTPATCH) {
> +		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
> +
> +		/*
> +		 * The cases we want to handle here are those where the guest
> +		 * is in real suspend mode and is trying to transition to
> +		 * transactional mode.
> +		 */
> +		if (local_paca->kvm_hstate.fake_suspend &&
> +				(vcpu->arch.shregs.msr & MSR_TS_S)) {
> +			if (kvmhv_p9_tm_emulation_early(vcpu)) {
> +				/* Prevent it being handled again. */
> +				trap = 0;
> +			}
> +		}
> +#endif
> +	}
> +
> +	radix_clear_slb();
> +
> +	__mtmsrd(msr, 0);

Isn't this the same as mtmsr(msr) ?

> +
> +	accumulate_time(vcpu, &vcpu->arch.rm_exit);
> +
> +	end_timing(vcpu);
> +
> +	return trap;
> +}
> +EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);

<snip>

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
  2021-02-26  5:01     ` Daniel Axtens
@ 2021-02-26 23:50       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:50 UTC (permalink / raw)
  To: Daniel Axtens, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Daniel Axtens's message of February 26, 2021 3:01 pm:
> Hi Nick,
> 
>> The va argument is not used in the function or set by its asm caller,
>> so remove it to be safe.
> 
> Huh, so it isn't. I tracked the original implementation down to commit
> a8606e20e41a ("KVM: PPC: Handle some PAPR hcalls in the kernel") where
> paulus first added the ability to handle it in the kernel - there it
> takes a va argument but even then doesn't do anything with it.
> 
> ajd also pointed out that we don't pass a va when linux is running as a
> guest, and LoPAR does not mention va as an argument.

Yeah interesting, maybe it was from a pre-release version of PAPR? Who
knows.

> One small nit: checkpatch is complaining about spaces vs tabs:
> ERROR: code indent should use tabs where possible
> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
> +                      unsigned long pte_index, unsigned long avpn);$
> 
> WARNING: please, no spaces at the start of a line
> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
> +                      unsigned long pte_index, unsigned long avpn);$

All the declarations are using the same style in this file so I think
I'll leave it for someone to do a cleanup patch on. Okay?

> 
> Once that is resolved,
>   Reviewed-by: Daniel Axtens <dja@axtens.net>

Thanks,
Nick

> 
> Kind regards,
> Daniel Axtens
> 
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/include/asm/kvm_ppc.h  | 3 +--
>>  arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
>>  2 files changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
>> index 8aacd76bb702..9531b1c1b190 100644
>> --- a/arch/powerpc/include/asm/kvm_ppc.h
>> +++ b/arch/powerpc/include/asm/kvm_ppc.h
>> @@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
>>                       unsigned long pte_index, unsigned long avpn);
>>  long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
>>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
>> -                      unsigned long pte_index, unsigned long avpn,
>> -                      unsigned long va);
>> +                      unsigned long pte_index, unsigned long avpn);
>>  long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
>>                     unsigned long pte_index);
>>  long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
>> diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
>> index 88da2764c1bb..7af7c70f1468 100644
>> --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
>> +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
>> @@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
>>  }
>>  
>>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
>> -		      unsigned long pte_index, unsigned long avpn,
>> -		      unsigned long va)
>> +		      unsigned long pte_index, unsigned long avpn)
>>  {
>>  	struct kvm *kvm = vcpu->kvm;
>>  	__be64 *hpte;
>> -- 
>> 2.23.0
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
@ 2021-02-26 23:50       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:50 UTC (permalink / raw)
  To: Daniel Axtens, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Daniel Axtens's message of February 26, 2021 3:01 pm:
> Hi Nick,
> 
>> The va argument is not used in the function or set by its asm caller,
>> so remove it to be safe.
> 
> Huh, so it isn't. I tracked the original implementation down to commit
> a8606e20e41a ("KVM: PPC: Handle some PAPR hcalls in the kernel") where
> paulus first added the ability to handle it in the kernel - there it
> takes a va argument but even then doesn't do anything with it.
> 
> ajd also pointed out that we don't pass a va when linux is running as a
> guest, and LoPAR does not mention va as an argument.

Yeah interesting, maybe it was from a pre-release version of PAPR? Who
knows.

> One small nit: checkpatch is complaining about spaces vs tabs:
> ERROR: code indent should use tabs where possible
> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
> +                      unsigned long pte_index, unsigned long avpn);$
> 
> WARNING: please, no spaces at the start of a line
> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
> +                      unsigned long pte_index, unsigned long avpn);$

All the declarations are using the same style in this file so I think
I'll leave it for someone to do a cleanup patch on. Okay?

> 
> Once that is resolved,
>   Reviewed-by: Daniel Axtens <dja@axtens.net>

Thanks,
Nick

> 
> Kind regards,
> Daniel Axtens
> 
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/include/asm/kvm_ppc.h  | 3 +--
>>  arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
>>  2 files changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
>> index 8aacd76bb702..9531b1c1b190 100644
>> --- a/arch/powerpc/include/asm/kvm_ppc.h
>> +++ b/arch/powerpc/include/asm/kvm_ppc.h
>> @@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
>>                       unsigned long pte_index, unsigned long avpn);
>>  long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
>>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
>> -                      unsigned long pte_index, unsigned long avpn,
>> -                      unsigned long va);
>> +                      unsigned long pte_index, unsigned long avpn);
>>  long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
>>                     unsigned long pte_index);
>>  long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
>> diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
>> index 88da2764c1bb..7af7c70f1468 100644
>> --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
>> +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
>> @@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
>>  }
>>  
>>  long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
>> -		      unsigned long pte_index, unsigned long avpn,
>> -		      unsigned long va)
>> +		      unsigned long pte_index, unsigned long avpn)
>>  {
>>  	struct kvm *kvm = vcpu->kvm;
>>  	__be64 *hpte;
>> -- 
>> 2.23.0
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
  2021-02-26  5:44     ` Daniel Axtens
@ 2021-02-26 23:51       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:51 UTC (permalink / raw)
  To: Daniel Axtens, kvm-ppc; +Cc: linuxppc-dev, Fabiano Rosas

Excerpts from Daniel Axtens's message of February 26, 2021 3:44 pm:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
>> MSR[IR]=0, so the faults of concern are the d-side ones caused by access
>> to guest context by the hypervisor.
>>
>> Instruction breakpoint interrupts are not a concern here. It's unlikely
>> any good would come of causing breaks in this code, but skipping the
>> instruction that caused it won't help matters (e.g., skip the mtmsr that
>> sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).
> 
> I'm not entirely clear on the example here, but the patch makes sense
> and I can follow your logic for removing the IKVM_SKIP handler from the
> instruction breakpoint exception.

The example just means that a breakpoint interrupt on any instruction 
inside the guest mode skip region would be skipped, and skipping one of 
those (mtmsrd or store that gets us out of guest mode skip) would cause 
a crash.

Thanks,
Nick

> 
> On that basis:
> Reviewed-by: Daniel Axtens <dja@axtens.net>
> 
> Kind regards,
> Daniel
> 
>>
>> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kernel/exceptions-64s.S | 1 -
>>  1 file changed, 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
>> index a027600beeb1..0097e0676ed7 100644
>> --- a/arch/powerpc/kernel/exceptions-64s.S
>> +++ b/arch/powerpc/kernel/exceptions-64s.S
>> @@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
>>  INT_DEFINE_BEGIN(instruction_breakpoint)
>>  	IVEC=0x1300
>>  #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
>> -	IKVM_SKIP=1
>>  	IKVM_REAL=1
>>  #endif
>>  INT_DEFINE_END(instruction_breakpoint)
>> -- 
>> 2.23.0
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
@ 2021-02-26 23:51       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:51 UTC (permalink / raw)
  To: Daniel Axtens, kvm-ppc; +Cc: linuxppc-dev, Fabiano Rosas

Excerpts from Daniel Axtens's message of February 26, 2021 3:44 pm:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
>> MSR[IR]=0, so the faults of concern are the d-side ones caused by access
>> to guest context by the hypervisor.
>>
>> Instruction breakpoint interrupts are not a concern here. It's unlikely
>> any good would come of causing breaks in this code, but skipping the
>> instruction that caused it won't help matters (e.g., skip the mtmsr that
>> sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).
> 
> I'm not entirely clear on the example here, but the patch makes sense
> and I can follow your logic for removing the IKVM_SKIP handler from the
> instruction breakpoint exception.

The example just means that a breakpoint interrupt on any instruction 
inside the guest mode skip region would be skipped, and skipping one of 
those (mtmsrd or store that gets us out of guest mode skip) would cause 
a crash.

Thanks,
Nick

> 
> On that basis:
> Reviewed-by: Daniel Axtens <dja@axtens.net>
> 
> Kind regards,
> Daniel
> 
>>
>> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kernel/exceptions-64s.S | 1 -
>>  1 file changed, 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
>> index a027600beeb1..0097e0676ed7 100644
>> --- a/arch/powerpc/kernel/exceptions-64s.S
>> +++ b/arch/powerpc/kernel/exceptions-64s.S
>> @@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
>>  INT_DEFINE_BEGIN(instruction_breakpoint)
>>  	IVEC=0x1300
>>  #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
>> -	IKVM_SKIP=1
>>  	IKVM_REAL=1
>>  #endif
>>  INT_DEFINE_END(instruction_breakpoint)
>> -- 
>> 2.23.0
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
  2021-02-26  6:06     ` Daniel Axtens
@ 2021-02-26 23:55       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:55 UTC (permalink / raw)
  To: Daniel Axtens, kvm-ppc; +Cc: linuxppc-dev, Fabiano Rosas

Excerpts from Daniel Axtens's message of February 26, 2021 4:06 pm:
> Hi Nick,
> 
>>  void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
>>  {
>> +	/*
>> +	 * Guest must always run with machine check interrupt
>> +	 * enabled.
>> +	 */
>> +	if (!(msr & MSR_ME))
>> +		msr |= MSR_ME;
> 
> This 'if' is technically redundant but you mention a future patch warning
> on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
> I get to that patch :)

That's true. The warning is actually further down when we're setting up 
the msr to run in guest mode. At this point the MSR I think comes from
qemu (and arguably the guest setup code shouldn't need to know about HV
specific MSR bits) so a warning here wouldn't be appropriate.

I could remove the if, although the compiler might already do that.

> 
> The patch seems sane to me, I agree that we don't want guests running with
> MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
> sane so this is another sanity-enforcement in the same sort of vein.
> 
> All up:
> Reviewed-by: Daniel Axtens <dja@axtens.net>

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
@ 2021-02-26 23:55       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:55 UTC (permalink / raw)
  To: Daniel Axtens, kvm-ppc; +Cc: linuxppc-dev, Fabiano Rosas

Excerpts from Daniel Axtens's message of February 26, 2021 4:06 pm:
> Hi Nick,
> 
>>  void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
>>  {
>> +	/*
>> +	 * Guest must always run with machine check interrupt
>> +	 * enabled.
>> +	 */
>> +	if (!(msr & MSR_ME))
>> +		msr |= MSR_ME;
> 
> This 'if' is technically redundant but you mention a future patch warning
> on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
> I get to that patch :)

That's true. The warning is actually further down when we're setting up 
the msr to run in guest mode. At this point the MSR I think comes from
qemu (and arguably the guest setup code shouldn't need to know about HV
specific MSR bits) so a warning here wouldn't be appropriate.

I could remove the if, although the compiler might already do that.

> 
> The patch seems sane to me, I agree that we don't want guests running with
> MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
> sane so this is another sanity-enforcement in the same sort of vein.
> 
> All up:
> Reviewed-by: Daniel Axtens <dja@axtens.net>

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
  2021-02-26 15:56     ` Fabiano Rosas
@ 2021-02-26 23:57       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:57 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of February 27, 2021 1:56 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> Switching the MMU from radix<->radix mode is tricky particularly as the
>> MMU can remain enabled and requires a certain sequence of SPR updates.
>> Move these together into their own functions.
>>
>> This also includes the radix TLB check / flush because it's tied in to
>> MMU switching due to tlbiel getting LPID from LPIDR.
>>
>> (XXX: isync / hwsync synchronisation TBD)
> 
> I see bot mtlpidr and mtlpcr requiring a CSI in the ISA. Do you say we
> might need more than an isync?

We might need a CSI before it, we might also need a hwsync before it. I
don't know whether we need isyncs between any of them (I don't think we
should because they're all mtsprs).


> 
> Regardless, I'd expect that to be separate from the refactoring here,
> so:
> 
> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

Thanks,
Nick
> 
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kvm/book3s_hv.c | 55 +++++++++++++++++++++---------------
>>  1 file changed, 32 insertions(+), 23 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index 895090636295..23d6dc04b0e9 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -3440,12 +3440,38 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
>>  	trace_kvmppc_run_core(vc, 1);
>>  }
>>
>> +static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
>> +{
>> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
>> +	struct kvm_nested_guest *nested = vcpu->arch.nested;
>> +	u32 lpid;
>> +
>> +	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
>> +
>> +	mtspr(SPRN_LPID, lpid);
>> +	mtspr(SPRN_LPCR, lpcr);
>> +	mtspr(SPRN_PID, vcpu->arch.pid);
>> +	isync();
>> +
>> +	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
>> +	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
>> +}
>> +
>> +static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
>> +{
>> +	mtspr(SPRN_PID, pid);
>> +	mtspr(SPRN_LPID, kvm->arch.host_lpid);
>> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
>> +	isync();
>> +}
>> +
>>  /*
>>   * Load up hypervisor-mode registers on P9.
>>   */
>>  static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  				     unsigned long lpcr)
>>  {
>> +	struct kvm *kvm = vcpu->kvm;
>>  	struct kvmppc_vcore *vc = vcpu->arch.vcore;
>>  	s64 hdec;
>>  	u64 tb, purr, spurr;
>> @@ -3468,12 +3494,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
>>  	 * so set HDICE before writing HDEC.
>>  	 */
>> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr | LPCR_HDICE);
>> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
>>  	isync();
>>
>>  	hdec = time_limit - mftb();
>>  	if (hdec < 0) {
>> -		mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
>> +		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
>>  		isync();
>>  		return BOOK3S_INTERRUPT_HV_DECREMENTER;
>>  	}
>> @@ -3508,7 +3534,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	}
>>  	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
>>  	mtspr(SPRN_IC, vcpu->arch.ic);
>> -	mtspr(SPRN_PID, vcpu->arch.pid);
>>
>>  	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
>>  	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
>> @@ -3522,8 +3547,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>
>>  	mtspr(SPRN_AMOR, ~0UL);
>>
>> -	mtspr(SPRN_LPCR, lpcr);
>> -	isync();
>> +	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>>
>>  	kvmppc_xive_push_vcpu(vcpu);
>>
>> @@ -3562,7 +3586,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  		mtspr(SPRN_DAWR1, host_dawr1);
>>  		mtspr(SPRN_DAWRX1, host_dawrx1);
>>  	}
>> -	mtspr(SPRN_PID, host_pidr);
>>
>>  	/*
>>  	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
>> @@ -3577,9 +3600,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	if (cpu_has_feature(CPU_FTR_ARCH_31))
>>  		asm volatile(PPC_CP_ABORT);
>>
>> -	mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid);	/* restore host LPID */
>> -	isync();
>> -
>>  	vc->dpdes = mfspr(SPRN_DPDES);
>>  	vc->vtb = mfspr(SPRN_VTB);
>>  	mtspr(SPRN_DPDES, 0);
>> @@ -3596,7 +3616,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	}
>>
>>  	mtspr(SPRN_HDEC, 0x7fffffff);
>> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
>> +
>> +	switch_mmu_to_host_radix(kvm, host_pidr);
>>
>>  	return trap;
>>  }
>> @@ -4130,7 +4151,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>>  {
>>  	struct kvm_run *run = vcpu->run;
>>  	int trap, r, pcpu;
>> -	int srcu_idx, lpid;
>> +	int srcu_idx;
>>  	struct kvmppc_vcore *vc;
>>  	struct kvm *kvm = vcpu->kvm;
>>  	struct kvm_nested_guest *nested = vcpu->arch.nested;
>> @@ -4204,13 +4225,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	vc->vcore_state = VCORE_RUNNING;
>>  	trace_kvmppc_run_core(vc, 0);
>>
>> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
>> -		lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
>> -		mtspr(SPRN_LPID, lpid);
>> -		isync();
>> -		kvmppc_check_need_tlb_flush(kvm, pcpu, nested);
>> -	}
>> -
>>  	guest_enter_irqoff();
>>
>>  	srcu_idx = srcu_read_lock(&kvm->srcu);
>> @@ -4229,11 +4243,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>>
>>  	srcu_read_unlock(&kvm->srcu, srcu_idx);
>>
>> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
>> -		mtspr(SPRN_LPID, kvm->arch.host_lpid);
>> -		isync();
>> -	}
>> -
>>  	set_irq_happened(trap);
>>
>>  	kvmppc_set_host_core(pcpu);
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
@ 2021-02-26 23:57       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:57 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of February 27, 2021 1:56 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> Switching the MMU from radix<->radix mode is tricky particularly as the
>> MMU can remain enabled and requires a certain sequence of SPR updates.
>> Move these together into their own functions.
>>
>> This also includes the radix TLB check / flush because it's tied in to
>> MMU switching due to tlbiel getting LPID from LPIDR.
>>
>> (XXX: isync / hwsync synchronisation TBD)
> 
> I see bot mtlpidr and mtlpcr requiring a CSI in the ISA. Do you say we
> might need more than an isync?

We might need a CSI before it, we might also need a hwsync before it. I
don't know whether we need isyncs between any of them (I don't think we
should because they're all mtsprs).


> 
> Regardless, I'd expect that to be separate from the refactoring here,
> so:
> 
> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

Thanks,
Nick
> 
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kvm/book3s_hv.c | 55 +++++++++++++++++++++---------------
>>  1 file changed, 32 insertions(+), 23 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index 895090636295..23d6dc04b0e9 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -3440,12 +3440,38 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
>>  	trace_kvmppc_run_core(vc, 1);
>>  }
>>
>> +static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
>> +{
>> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
>> +	struct kvm_nested_guest *nested = vcpu->arch.nested;
>> +	u32 lpid;
>> +
>> +	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
>> +
>> +	mtspr(SPRN_LPID, lpid);
>> +	mtspr(SPRN_LPCR, lpcr);
>> +	mtspr(SPRN_PID, vcpu->arch.pid);
>> +	isync();
>> +
>> +	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
>> +	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
>> +}
>> +
>> +static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
>> +{
>> +	mtspr(SPRN_PID, pid);
>> +	mtspr(SPRN_LPID, kvm->arch.host_lpid);
>> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
>> +	isync();
>> +}
>> +
>>  /*
>>   * Load up hypervisor-mode registers on P9.
>>   */
>>  static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  				     unsigned long lpcr)
>>  {
>> +	struct kvm *kvm = vcpu->kvm;
>>  	struct kvmppc_vcore *vc = vcpu->arch.vcore;
>>  	s64 hdec;
>>  	u64 tb, purr, spurr;
>> @@ -3468,12 +3494,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
>>  	 * so set HDICE before writing HDEC.
>>  	 */
>> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr | LPCR_HDICE);
>> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
>>  	isync();
>>
>>  	hdec = time_limit - mftb();
>>  	if (hdec < 0) {
>> -		mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
>> +		mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
>>  		isync();
>>  		return BOOK3S_INTERRUPT_HV_DECREMENTER;
>>  	}
>> @@ -3508,7 +3534,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	}
>>  	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
>>  	mtspr(SPRN_IC, vcpu->arch.ic);
>> -	mtspr(SPRN_PID, vcpu->arch.pid);
>>
>>  	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
>>  	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
>> @@ -3522,8 +3547,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>
>>  	mtspr(SPRN_AMOR, ~0UL);
>>
>> -	mtspr(SPRN_LPCR, lpcr);
>> -	isync();
>> +	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>>
>>  	kvmppc_xive_push_vcpu(vcpu);
>>
>> @@ -3562,7 +3586,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  		mtspr(SPRN_DAWR1, host_dawr1);
>>  		mtspr(SPRN_DAWRX1, host_dawrx1);
>>  	}
>> -	mtspr(SPRN_PID, host_pidr);
>>
>>  	/*
>>  	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
>> @@ -3577,9 +3600,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	if (cpu_has_feature(CPU_FTR_ARCH_31))
>>  		asm volatile(PPC_CP_ABORT);
>>
>> -	mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid);	/* restore host LPID */
>> -	isync();
>> -
>>  	vc->dpdes = mfspr(SPRN_DPDES);
>>  	vc->vtb = mfspr(SPRN_VTB);
>>  	mtspr(SPRN_DPDES, 0);
>> @@ -3596,7 +3616,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	}
>>
>>  	mtspr(SPRN_HDEC, 0x7fffffff);
>> -	mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
>> +
>> +	switch_mmu_to_host_radix(kvm, host_pidr);
>>
>>  	return trap;
>>  }
>> @@ -4130,7 +4151,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>>  {
>>  	struct kvm_run *run = vcpu->run;
>>  	int trap, r, pcpu;
>> -	int srcu_idx, lpid;
>> +	int srcu_idx;
>>  	struct kvmppc_vcore *vc;
>>  	struct kvm *kvm = vcpu->kvm;
>>  	struct kvm_nested_guest *nested = vcpu->arch.nested;
>> @@ -4204,13 +4225,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	vc->vcore_state = VCORE_RUNNING;
>>  	trace_kvmppc_run_core(vc, 0);
>>
>> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
>> -		lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
>> -		mtspr(SPRN_LPID, lpid);
>> -		isync();
>> -		kvmppc_check_need_tlb_flush(kvm, pcpu, nested);
>> -	}
>> -
>>  	guest_enter_irqoff();
>>
>>  	srcu_idx = srcu_read_lock(&kvm->srcu);
>> @@ -4229,11 +4243,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
>>
>>  	srcu_read_unlock(&kvm->srcu, srcu_idx);
>>
>> -	if (cpu_has_feature(CPU_FTR_HVMODE)) {
>> -		mtspr(SPRN_LPID, kvm->arch.host_lpid);
>> -		isync();
>> -	}
>> -
>>  	set_irq_happened(trap);
>>
>>  	kvmppc_set_host_core(pcpu);
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
  2021-02-25 14:51     ` Cédric Le Goater
@ 2021-02-26 23:59       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:59 UTC (permalink / raw)
  To: Cédric Le Goater, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Cédric Le Goater's message of February 26, 2021 12:51 am:
> On 2/25/21 2:46 PM, Nicholas Piggin wrote:
>> In the interest of minimising the amount of code that is run in
>> "real-mode", don't handle hcalls in real mode in the P9 path.
>> 
>> POWER8 and earlier are much more expensive to exit from HV real mode
>> and switch to host mode, because on those processors HV interrupts get
>> to the hypervisor with the MMU off, and the other threads in the core
>> need to be pulled out of the guest, and SLBs all need to be saved,
>> ERATs invalidated, and host SLB reloaded before the MMU is re-enabled
>> in host mode. Hash guests also require a lot of hcalls to run. The
>> XICS interrupt controller requires hcalls to run.
>> 
>> By contrast, POWER9 has independent thread switching, and in radix mode
>> the hypervisor is already in a host virtual memory mode when the HV
>> interrupt is taken. Radix + xive guests don't need hcalls to handle
>> interrupts or manage translations.
>> 
>> So it's much less important to handle hcalls in real mode in P9.
>> 
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/include/asm/kvm_ppc.h      |  5 +++++
>>  arch/powerpc/kvm/book3s_hv.c            | 25 ++++++++++++++++++++++---
>>  arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 +++++
>>  arch/powerpc/kvm/book3s_xive.c          | 25 +++++++++++++++++++++++++
>>  4 files changed, 57 insertions(+), 3 deletions(-)
>> 
>> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
>> index 73b1ca5a6471..db6646c2ade2 100644
>> --- a/arch/powerpc/include/asm/kvm_ppc.h
>> +++ b/arch/powerpc/include/asm/kvm_ppc.h
>> @@ -607,6 +607,7 @@ extern void kvmppc_free_pimap(struct kvm *kvm);
>>  extern int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall);
>>  extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
>>  extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
>> +extern int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req);
>>  extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
>>  extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
>>  extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
>> @@ -639,6 +640,8 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
>>  static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
>>  static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
>>  	{ return 0; }
>> +static inline int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
>> +	{ return 0; }
>>  #endif
>>  
>>  #ifdef CONFIG_KVM_XIVE
>> @@ -673,6 +676,7 @@ extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
>>  			       int level, bool line_status);
>>  extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
>>  extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
>> +extern void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu);
> 
> I can not find this routine. Is it missing or coming later in the patchset ? 

Yeah it leaked into a later patch but it belongs here. I'll fix it.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
@ 2021-02-26 23:59       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:59 UTC (permalink / raw)
  To: Cédric Le Goater, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Cédric Le Goater's message of February 26, 2021 12:51 am:
> On 2/25/21 2:46 PM, Nicholas Piggin wrote:
>> In the interest of minimising the amount of code that is run in
>> "real-mode", don't handle hcalls in real mode in the P9 path.
>> 
>> POWER8 and earlier are much more expensive to exit from HV real mode
>> and switch to host mode, because on those processors HV interrupts get
>> to the hypervisor with the MMU off, and the other threads in the core
>> need to be pulled out of the guest, and SLBs all need to be saved,
>> ERATs invalidated, and host SLB reloaded before the MMU is re-enabled
>> in host mode. Hash guests also require a lot of hcalls to run. The
>> XICS interrupt controller requires hcalls to run.
>> 
>> By contrast, POWER9 has independent thread switching, and in radix mode
>> the hypervisor is already in a host virtual memory mode when the HV
>> interrupt is taken. Radix + xive guests don't need hcalls to handle
>> interrupts or manage translations.
>> 
>> So it's much less important to handle hcalls in real mode in P9.
>> 
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/include/asm/kvm_ppc.h      |  5 +++++
>>  arch/powerpc/kvm/book3s_hv.c            | 25 ++++++++++++++++++++++---
>>  arch/powerpc/kvm/book3s_hv_rmhandlers.S |  5 +++++
>>  arch/powerpc/kvm/book3s_xive.c          | 25 +++++++++++++++++++++++++
>>  4 files changed, 57 insertions(+), 3 deletions(-)
>> 
>> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
>> index 73b1ca5a6471..db6646c2ade2 100644
>> --- a/arch/powerpc/include/asm/kvm_ppc.h
>> +++ b/arch/powerpc/include/asm/kvm_ppc.h
>> @@ -607,6 +607,7 @@ extern void kvmppc_free_pimap(struct kvm *kvm);
>>  extern int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall);
>>  extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
>>  extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
>> +extern int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req);
>>  extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
>>  extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
>>  extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
>> @@ -639,6 +640,8 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
>>  static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
>>  static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
>>  	{ return 0; }
>> +static inline int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
>> +	{ return 0; }
>>  #endif
>>  
>>  #ifdef CONFIG_KVM_XIVE
>> @@ -673,6 +676,7 @@ extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
>>  			       int level, bool line_status);
>>  extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
>>  extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
>> +extern void kvmppc_xive_cede_vcpu(struct kvm_vcpu *vcpu);
> 
> I can not find this routine. Is it missing or coming later in the patchset ? 

Yeah it leaked into a later patch but it belongs here. I'll fix it.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR
  2021-02-26 16:38     ` Fabiano Rosas
@ 2021-02-26 23:59       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:59 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of February 27, 2021 2:38 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
>> processors, so it must be enabled before HDEC is set.
>>
>> Rather than set it in the host LPCR then setting HDEC, move the HDEC
>> update to after the guest MMU context (including LPCR) is loaded.
>> There shouldn't be much concern with delaying HDEC by some 10s or 100s
>> of nanoseconds by setting it a bit later.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++--------------
>>  1 file changed, 10 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index d4770b222d7e..63cc92c45c5d 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -3490,23 +3490,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  		host_dawrx1 = mfspr(SPRN_DAWRX1);
>>  	}
>>
>> -	/*
>> -	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
>> -	 * so set HDICE before writing HDEC.
>> -	 */
>> -	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
>> -	isync();
>> -
>> -	hdec = time_limit - mftb();
> 
> Would it be possible to leave the mftb() in this patch and then replace
> them all at once in patch 20/37 - "KVM: PPC: Book3S HV P9: Reduce mftb
> per guest entry/exit"?

I suppose that makes sense. I'll see how that looks.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR
@ 2021-02-26 23:59       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-26 23:59 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of February 27, 2021 2:38 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
>> processors, so it must be enabled before HDEC is set.
>>
>> Rather than set it in the host LPCR then setting HDEC, move the HDEC
>> update to after the guest MMU context (including LPCR) is loaded.
>> There shouldn't be much concern with delaying HDEC by some 10s or 100s
>> of nanoseconds by setting it a bit later.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++--------------
>>  1 file changed, 10 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index d4770b222d7e..63cc92c45c5d 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -3490,23 +3490,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
>>  		host_dawrx1 = mfspr(SPRN_DAWRX1);
>>  	}
>>
>> -	/*
>> -	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
>> -	 * so set HDICE before writing HDEC.
>> -	 */
>> -	mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
>> -	isync();
>> -
>> -	hdec = time_limit - mftb();
> 
> Would it be possible to leave the mftb() in this patch and then replace
> them all at once in patch 20/37 - "KVM: PPC: Book3S HV P9: Reduce mftb
> per guest entry/exit"?

I suppose that makes sense. I'll see how that looks.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
  2021-02-26 22:37     ` Fabiano Rosas
@ 2021-02-27  0:21       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-27  0:21 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of February 27, 2021 8:37 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
> Hi, thanks for this. It helped me clarify a bunch of details that I
> haven't understood while reading the asm code.

Yes, me too :)

>> +/*
>> + * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
>> + *
>> + * Enter the guest on a ISAv3.0 or later system where we have exactly
>> + * one vcpu per vcore, and both the host and guest are radix, and threads
>> + * are set to "indepdent mode".
>> + */
>> +.balign	IFETCH_ALIGN_BYTES
>> +_GLOBAL(kvmppc_p9_enter_guest)
>> +EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
>> +	mflr	r0
>> +	std	r0,PPC_LR_STKOFF(r1)
>> +	stdu	r1,-SFS(r1)
>> +
>> +	std	r1,HSTATE_HOST_R1(r13)
>> +	std	r3,STACK_SLOT_VCPU(r1)
> 
> The vcpu was stored on the paca previously. I don't get the change,
> could you explain?

The stack is a nicer place to keep things. We only need one place to 
save the stack, then most things can come from there. There's actually 
more paca stuff we could move into local variables or onto the stack
too.

It was probably done like this because PR KVM which probably can't 
access the stack in real mode when running in an LPAR, and came across 
to the HV code that way. New path doesn't require it.

>> +kvmppc_p9_exit_interrupt:
>> +	std     r1,HSTATE_SCRATCH1(r13)
>> +	std     r3,HSTATE_SCRATCH2(r13)
>> +	ld	r1,HSTATE_HOST_R1(r13)
>> +	ld	r3,STACK_SLOT_VCPU(r1)
>> +
>> +	std	r9,VCPU_CR(r3)
>> +
>> +1:
>> +	std	r11,VCPU_PC(r3)
>> +	std	r12,VCPU_MSR(r3)
>> +
>> +	reg = 14
>> +	.rept	18
>> +	std	reg,__VCPU_GPR(reg)(r3)
>> +	reg = reg + 1
>> +	.endr
>> +
>> +	/* r1, r3, r9-r13 are saved to vcpu by C code */
> 
> If we just saved r1 and r3, why don't we put them in the vcpu right now?
> That would avoid having the C code knowing about scratch areas.

Putting it in C avoids having the asm code know about scratch areas.

>> @@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>>  		else
>>  			r = kvmppc_run_vcpu(vcpu);
>>
>> -		if (run->exit_reason == KVM_EXIT_PAPR_HCALL &&
>> -		    !(vcpu->arch.shregs.msr & MSR_PR)) {
>> -			trace_kvm_hcall_enter(vcpu);
>> -			r = kvmppc_pseries_do_hcall(vcpu);
>> -			trace_kvm_hcall_exit(vcpu, r);
>> +		if (run->exit_reason == KVM_EXIT_PAPR_HCALL) {
>> +			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
>> +				/*
>> +				 * Guest userspace executed sc 1, reflect it
>> +				 * back as a privileged program check interrupt.
>> +				 */
>> +				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
>> +				r = RESUME_GUEST;
> 
> This is in conflict with this snippet in kvmppc_handle_exit_hv:
> 
> 	case BOOK3S_INTERRUPT_SYSCALL:
> 	{
> 		/* hcall - punt to userspace */
> 		int i;
> 
> 		/* hypercall with MSR_PR has already been handled in rmode,
> 		 * and never reaches here.
> 		 */
> 
> That function already queues some 0x700s so maybe we could move this one
> in there as well.

I don't think it conflicts, but I think perhaps it should go in the 
patch which removed the real mode handlers.

kvmppc_handle_exit_hv is used by both HV paths so for now it's a bit 
neater to try get things into the same state, but we could do this in a 
later patch perhaps.

>> +	 *
>> +	 * To work around this we put a canary value into the HDSISR before
>> +	 * returning to a guest and then check for this canary when we take a
>> +	 * HDSI. If we find the canary on a HDSI, we know the hardware didn't
>> +	 * update the HDSISR. In this case we return to the guest to retake the
>> +	 * HDSI which should correctly update the HDSISR the second time HDSI
>> +	 * entry.
>> +	 *
>> +	 * Just do this on all p9 processors for now.
>> +	 */
>> +	mtspr(SPRN_HDSISR, HDSISR_CANARY);
>> +
>> +	accumulate_time(vcpu, &vcpu->arch.guest_time);
>> +
>> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
>> +	kvmppc_p9_enter_guest(vcpu);
>> +	// Radix host and guest means host never runs with guest MMU state
>> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
>> +
>> +	accumulate_time(vcpu, &vcpu->arch.rm_intr);
>> +
>> +	/* Get these from r11/12 and paca exsave */
>> +	vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
>> +	vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
>> +	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
>> +	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
>> +
>> +	trap = local_paca->kvm_hstate.scratch0 & ~0x2;
> 
> Couldn't we return the trap from kvmppc_p9_enter_guest? Seems like a
> nice pattern to have and avoids exposing the IVEC+0x2 magic which is hidden
> in asm already.

I use the 0x2 test in C in a later patch.

The IVEC+0x2 thing might just go away entirely though for new HV path, 
but we'd still clear it in C on the principle of minimal asm code.

>> +	radix_clear_slb();
>> +
>> +	__mtmsrd(msr, 0);
> 
> Isn't this the same as mtmsr(msr) ?

Yes. For 64s you can use the __ variant though. We use it in other 
places in this function with L=1 so it doesn't make sense to mix 
variants.

Thanks,
Nick

> 
>> +
>> +	accumulate_time(vcpu, &vcpu->arch.rm_exit);
>> +
>> +	end_timing(vcpu);
>> +
>> +	return trap;
>> +}
>> +EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
> 
> <snip>
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
@ 2021-02-27  0:21       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-27  0:21 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of February 27, 2021 8:37 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
> Hi, thanks for this. It helped me clarify a bunch of details that I
> haven't understood while reading the asm code.

Yes, me too :)

>> +/*
>> + * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
>> + *
>> + * Enter the guest on a ISAv3.0 or later system where we have exactly
>> + * one vcpu per vcore, and both the host and guest are radix, and threads
>> + * are set to "indepdent mode".
>> + */
>> +.balign	IFETCH_ALIGN_BYTES
>> +_GLOBAL(kvmppc_p9_enter_guest)
>> +EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
>> +	mflr	r0
>> +	std	r0,PPC_LR_STKOFF(r1)
>> +	stdu	r1,-SFS(r1)
>> +
>> +	std	r1,HSTATE_HOST_R1(r13)
>> +	std	r3,STACK_SLOT_VCPU(r1)
> 
> The vcpu was stored on the paca previously. I don't get the change,
> could you explain?

The stack is a nicer place to keep things. We only need one place to 
save the stack, then most things can come from there. There's actually 
more paca stuff we could move into local variables or onto the stack
too.

It was probably done like this because PR KVM which probably can't 
access the stack in real mode when running in an LPAR, and came across 
to the HV code that way. New path doesn't require it.

>> +kvmppc_p9_exit_interrupt:
>> +	std     r1,HSTATE_SCRATCH1(r13)
>> +	std     r3,HSTATE_SCRATCH2(r13)
>> +	ld	r1,HSTATE_HOST_R1(r13)
>> +	ld	r3,STACK_SLOT_VCPU(r1)
>> +
>> +	std	r9,VCPU_CR(r3)
>> +
>> +1:
>> +	std	r11,VCPU_PC(r3)
>> +	std	r12,VCPU_MSR(r3)
>> +
>> +	reg = 14
>> +	.rept	18
>> +	std	reg,__VCPU_GPR(reg)(r3)
>> +	reg = reg + 1
>> +	.endr
>> +
>> +	/* r1, r3, r9-r13 are saved to vcpu by C code */
> 
> If we just saved r1 and r3, why don't we put them in the vcpu right now?
> That would avoid having the C code knowing about scratch areas.

Putting it in C avoids having the asm code know about scratch areas.

>> @@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>>  		else
>>  			r = kvmppc_run_vcpu(vcpu);
>>
>> -		if (run->exit_reason == KVM_EXIT_PAPR_HCALL &&
>> -		    !(vcpu->arch.shregs.msr & MSR_PR)) {
>> -			trace_kvm_hcall_enter(vcpu);
>> -			r = kvmppc_pseries_do_hcall(vcpu);
>> -			trace_kvm_hcall_exit(vcpu, r);
>> +		if (run->exit_reason == KVM_EXIT_PAPR_HCALL) {
>> +			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
>> +				/*
>> +				 * Guest userspace executed sc 1, reflect it
>> +				 * back as a privileged program check interrupt.
>> +				 */
>> +				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
>> +				r = RESUME_GUEST;
> 
> This is in conflict with this snippet in kvmppc_handle_exit_hv:
> 
> 	case BOOK3S_INTERRUPT_SYSCALL:
> 	{
> 		/* hcall - punt to userspace */
> 		int i;
> 
> 		/* hypercall with MSR_PR has already been handled in rmode,
> 		 * and never reaches here.
> 		 */
> 
> That function already queues some 0x700s so maybe we could move this one
> in there as well.

I don't think it conflicts, but I think perhaps it should go in the 
patch which removed the real mode handlers.

kvmppc_handle_exit_hv is used by both HV paths so for now it's a bit 
neater to try get things into the same state, but we could do this in a 
later patch perhaps.

>> +	 *
>> +	 * To work around this we put a canary value into the HDSISR before
>> +	 * returning to a guest and then check for this canary when we take a
>> +	 * HDSI. If we find the canary on a HDSI, we know the hardware didn't
>> +	 * update the HDSISR. In this case we return to the guest to retake the
>> +	 * HDSI which should correctly update the HDSISR the second time HDSI
>> +	 * entry.
>> +	 *
>> +	 * Just do this on all p9 processors for now.
>> +	 */
>> +	mtspr(SPRN_HDSISR, HDSISR_CANARY);
>> +
>> +	accumulate_time(vcpu, &vcpu->arch.guest_time);
>> +
>> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
>> +	kvmppc_p9_enter_guest(vcpu);
>> +	// Radix host and guest means host never runs with guest MMU state
>> +	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
>> +
>> +	accumulate_time(vcpu, &vcpu->arch.rm_intr);
>> +
>> +	/* Get these from r11/12 and paca exsave */
>> +	vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
>> +	vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
>> +	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
>> +	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
>> +
>> +	trap = local_paca->kvm_hstate.scratch0 & ~0x2;
> 
> Couldn't we return the trap from kvmppc_p9_enter_guest? Seems like a
> nice pattern to have and avoids exposing the IVEC+0x2 magic which is hidden
> in asm already.

I use the 0x2 test in C in a later patch.

The IVEC+0x2 thing might just go away entirely though for new HV path, 
but we'd still clear it in C on the principle of minimal asm code.

>> +	radix_clear_slb();
>> +
>> +	__mtmsrd(msr, 0);
> 
> Isn't this the same as mtmsr(msr) ?

Yes. For 64s you can use the __ variant though. We use it in other 
places in this function with L=1 so it doesn't make sense to mix 
variants.

Thanks,
Nick

> 
>> +
>> +	accumulate_time(vcpu, &vcpu->arch.rm_exit);
>> +
>> +	end_timing(vcpu);
>> +
>> +	return trap;
>> +}
>> +EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
> 
> <snip>
> 

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
  2021-02-27  0:21       ` Nicholas Piggin
@ 2021-02-27  0:55         ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-27  0:55 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Nicholas Piggin's message of February 27, 2021 10:21 am:
> Excerpts from Fabiano Rosas's message of February 27, 2021 8:37 am:
>> Nicholas Piggin <npiggin@gmail.com> writes:
>> 
>> Hi, thanks for this. It helped me clarify a bunch of details that I
>> haven't understood while reading the asm code.
> 
> Yes, me too :)
> 
>>> +/*
>>> + * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
>>> + *
>>> + * Enter the guest on a ISAv3.0 or later system where we have exactly
>>> + * one vcpu per vcore, and both the host and guest are radix, and threads
>>> + * are set to "indepdent mode".
>>> + */
>>> +.balign	IFETCH_ALIGN_BYTES
>>> +_GLOBAL(kvmppc_p9_enter_guest)
>>> +EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
>>> +	mflr	r0
>>> +	std	r0,PPC_LR_STKOFF(r1)
>>> +	stdu	r1,-SFS(r1)
>>> +
>>> +	std	r1,HSTATE_HOST_R1(r13)
>>> +	std	r3,STACK_SLOT_VCPU(r1)
>> 
>> The vcpu was stored on the paca previously. I don't get the change,
>> could you explain?
> 
> The stack is a nicer place to keep things. We only need one place to 
> save the stack, then most things can come from there. There's actually 
> more paca stuff we could move into local variables or onto the stack
> too.
> 
> It was probably done like this because PR KVM which probably can't 
> access the stack in real mode when running in an LPAR, and came across 
> to the HV code that way. New path doesn't require it.
> 
>>> +kvmppc_p9_exit_interrupt:
>>> +	std     r1,HSTATE_SCRATCH1(r13)
>>> +	std     r3,HSTATE_SCRATCH2(r13)
>>> +	ld	r1,HSTATE_HOST_R1(r13)
>>> +	ld	r3,STACK_SLOT_VCPU(r1)
>>> +
>>> +	std	r9,VCPU_CR(r3)
>>> +
>>> +1:
>>> +	std	r11,VCPU_PC(r3)
>>> +	std	r12,VCPU_MSR(r3)
>>> +
>>> +	reg = 14
>>> +	.rept	18
>>> +	std	reg,__VCPU_GPR(reg)(r3)
>>> +	reg = reg + 1
>>> +	.endr
>>> +
>>> +	/* r1, r3, r9-r13 are saved to vcpu by C code */
>> 
>> If we just saved r1 and r3, why don't we put them in the vcpu right now?
>> That would avoid having the C code knowing about scratch areas.
> 
> Putting it in C avoids having the asm code know about scratch areas.
> 
>>> @@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>>>  		else
>>>  			r = kvmppc_run_vcpu(vcpu);
>>>
>>> -		if (run->exit_reason == KVM_EXIT_PAPR_HCALL &&
>>> -		    !(vcpu->arch.shregs.msr & MSR_PR)) {
>>> -			trace_kvm_hcall_enter(vcpu);
>>> -			r = kvmppc_pseries_do_hcall(vcpu);
>>> -			trace_kvm_hcall_exit(vcpu, r);
>>> +		if (run->exit_reason == KVM_EXIT_PAPR_HCALL) {
>>> +			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
>>> +				/*
>>> +				 * Guest userspace executed sc 1, reflect it
>>> +				 * back as a privileged program check interrupt.
>>> +				 */
>>> +				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
>>> +				r = RESUME_GUEST;
>> 
>> This is in conflict with this snippet in kvmppc_handle_exit_hv:
>> 
>> 	case BOOK3S_INTERRUPT_SYSCALL:
>> 	{
>> 		/* hcall - punt to userspace */
>> 		int i;
>> 
>> 		/* hypercall with MSR_PR has already been handled in rmode,
>> 		 * and never reaches here.
>> 		 */
>> 
>> That function already queues some 0x700s so maybe we could move this one
>> in there as well.
> 
> I don't think it conflicts, but I think perhaps it should go in the 
> patch which removed the real mode handlers.

Oh I'm wrong, it's actually the other way around by the looks.

Okay I'll fix this up.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
@ 2021-02-27  0:55         ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-02-27  0:55 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Nicholas Piggin's message of February 27, 2021 10:21 am:
> Excerpts from Fabiano Rosas's message of February 27, 2021 8:37 am:
>> Nicholas Piggin <npiggin@gmail.com> writes:
>> 
>> Hi, thanks for this. It helped me clarify a bunch of details that I
>> haven't understood while reading the asm code.
> 
> Yes, me too :)
> 
>>> +/*
>>> + * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
>>> + *
>>> + * Enter the guest on a ISAv3.0 or later system where we have exactly
>>> + * one vcpu per vcore, and both the host and guest are radix, and threads
>>> + * are set to "indepdent mode".
>>> + */
>>> +.balign	IFETCH_ALIGN_BYTES
>>> +_GLOBAL(kvmppc_p9_enter_guest)
>>> +EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
>>> +	mflr	r0
>>> +	std	r0,PPC_LR_STKOFF(r1)
>>> +	stdu	r1,-SFS(r1)
>>> +
>>> +	std	r1,HSTATE_HOST_R1(r13)
>>> +	std	r3,STACK_SLOT_VCPU(r1)
>> 
>> The vcpu was stored on the paca previously. I don't get the change,
>> could you explain?
> 
> The stack is a nicer place to keep things. We only need one place to 
> save the stack, then most things can come from there. There's actually 
> more paca stuff we could move into local variables or onto the stack
> too.
> 
> It was probably done like this because PR KVM which probably can't 
> access the stack in real mode when running in an LPAR, and came across 
> to the HV code that way. New path doesn't require it.
> 
>>> +kvmppc_p9_exit_interrupt:
>>> +	std     r1,HSTATE_SCRATCH1(r13)
>>> +	std     r3,HSTATE_SCRATCH2(r13)
>>> +	ld	r1,HSTATE_HOST_R1(r13)
>>> +	ld	r3,STACK_SLOT_VCPU(r1)
>>> +
>>> +	std	r9,VCPU_CR(r3)
>>> +
>>> +1:
>>> +	std	r11,VCPU_PC(r3)
>>> +	std	r12,VCPU_MSR(r3)
>>> +
>>> +	reg = 14
>>> +	.rept	18
>>> +	std	reg,__VCPU_GPR(reg)(r3)
>>> +	reg = reg + 1
>>> +	.endr
>>> +
>>> +	/* r1, r3, r9-r13 are saved to vcpu by C code */
>> 
>> If we just saved r1 and r3, why don't we put them in the vcpu right now?
>> That would avoid having the C code knowing about scratch areas.
> 
> Putting it in C avoids having the asm code know about scratch areas.
> 
>>> @@ -4429,11 +4432,19 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>>>  		else
>>>  			r = kvmppc_run_vcpu(vcpu);
>>>
>>> -		if (run->exit_reason == KVM_EXIT_PAPR_HCALL &&
>>> -		    !(vcpu->arch.shregs.msr & MSR_PR)) {
>>> -			trace_kvm_hcall_enter(vcpu);
>>> -			r = kvmppc_pseries_do_hcall(vcpu);
>>> -			trace_kvm_hcall_exit(vcpu, r);
>>> +		if (run->exit_reason == KVM_EXIT_PAPR_HCALL) {
>>> +			if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
>>> +				/*
>>> +				 * Guest userspace executed sc 1, reflect it
>>> +				 * back as a privileged program check interrupt.
>>> +				 */
>>> +				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
>>> +				r = RESUME_GUEST;
>> 
>> This is in conflict with this snippet in kvmppc_handle_exit_hv:
>> 
>> 	case BOOK3S_INTERRUPT_SYSCALL:
>> 	{
>> 		/* hcall - punt to userspace */
>> 		int i;
>> 
>> 		/* hypercall with MSR_PR has already been handled in rmode,
>> 		 * and never reaches here.
>> 		 */
>> 
>> That function already queues some 0x700s so maybe we could move this one
>> in there as well.
> 
> I don't think it conflicts, but I think perhaps it should go in the 
> patch which removed the real mode handlers.

Oh I'm wrong, it's actually the other way around by the looks.

Okay I'll fix this up.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entry_p9
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-02 13:48     ` Fabiano Rosas
  -1 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-02 13:48 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> Now the initial C implementation is done, inline more HV code to make
> rearranging things easier.
>
> And rename __kvmhv_vcpu_entry_p9 to drop the leading underscores as it's
> now C, and is now a more complete vcpu entry.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

> ---
>  arch/powerpc/include/asm/kvm_book3s_64.h |   2 +-
>  arch/powerpc/kvm/book3s_hv.c             | 181 +----------------------
>  arch/powerpc/kvm/book3s_hv_interrupt.c   | 168 ++++++++++++++++++++-
>  3 files changed, 169 insertions(+), 182 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
> index c214bcffb441..eaf3a562bf1e 100644
> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
> @@ -153,7 +153,7 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
>  	return radix;
>  }
>
> -int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
> +int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr);
>
>  #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
>  #endif
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 28a2761515e3..f99503acdda5 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -3442,183 +3442,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
>  	trace_kvmppc_run_core(vc, 1);
>  }
>
> -static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
> -{
> -	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> -	struct kvm_nested_guest *nested = vcpu->arch.nested;
> -	u32 lpid;
> -
> -	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> -
> -	mtspr(SPRN_LPID, lpid);
> -	mtspr(SPRN_LPCR, lpcr);
> -	mtspr(SPRN_PID, vcpu->arch.pid);
> -	isync();
> -
> -	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
> -	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
> -}
> -
> -static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
> -{
> -	mtspr(SPRN_PID, pid);
> -	mtspr(SPRN_LPID, kvm->arch.host_lpid);
> -	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> -	isync();
> -}
> -
> -/*
> - * Load up hypervisor-mode registers on P9.
> - */
> -static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
> -				     unsigned long lpcr)
> -{
> -	struct kvm *kvm = vcpu->kvm;
> -	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> -	s64 hdec;
> -	u64 tb, purr, spurr;
> -	int trap;
> -	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
> -	unsigned long host_ciabr = mfspr(SPRN_CIABR);
> -	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
> -	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
> -	unsigned long host_psscr = mfspr(SPRN_PSSCR);
> -	unsigned long host_pidr = mfspr(SPRN_PID);
> -	unsigned long host_dawr1 = 0;
> -	unsigned long host_dawrx1 = 0;
> -
> -	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> -		host_dawr1 = mfspr(SPRN_DAWR1);
> -		host_dawrx1 = mfspr(SPRN_DAWRX1);
> -	}
> -
> -	tb = mftb();
> -	hdec = time_limit - tb;
> -	if (hdec < 0)
> -		return BOOK3S_INTERRUPT_HV_DECREMENTER;
> -
> -	if (vc->tb_offset) {
> -		u64 new_tb = tb + vc->tb_offset;
> -		mtspr(SPRN_TBU40, new_tb);
> -		tb = mftb();
> -		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> -			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> -		vc->tb_offset_applied = vc->tb_offset;
> -	}
> -
> -	if (vc->pcr)
> -		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
> -	mtspr(SPRN_DPDES, vc->dpdes);
> -	mtspr(SPRN_VTB, vc->vtb);
> -
> -	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
> -	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
> -	mtspr(SPRN_PURR, vcpu->arch.purr);
> -	mtspr(SPRN_SPURR, vcpu->arch.spurr);
> -
> -	if (dawr_enabled()) {
> -		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
> -		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
> -		if (cpu_has_feature(CPU_FTR_DAWR1)) {
> -			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
> -			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
> -		}
> -	}
> -	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
> -	mtspr(SPRN_IC, vcpu->arch.ic);
> -
> -	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
> -	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> -
> -	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
> -
> -	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
> -	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
> -	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
> -	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
> -
> -	mtspr(SPRN_AMOR, ~0UL);
> -
> -	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
> -
> -	/*
> -	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
> -	 * so set guest LPCR (with HDICE) before writing HDEC.
> -	 */
> -	mtspr(SPRN_HDEC, hdec);
> -
> -	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
> -	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
> -
> -	trap = __kvmhv_vcpu_entry_p9(vcpu);
> -
> -	/* Advance host PURR/SPURR by the amount used by guest */
> -	purr = mfspr(SPRN_PURR);
> -	spurr = mfspr(SPRN_SPURR);
> -	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
> -	      purr - vcpu->arch.purr);
> -	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
> -	      spurr - vcpu->arch.spurr);
> -	vcpu->arch.purr = purr;
> -	vcpu->arch.spurr = spurr;
> -
> -	vcpu->arch.ic = mfspr(SPRN_IC);
> -	vcpu->arch.pid = mfspr(SPRN_PID);
> -	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
> -
> -	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
> -	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
> -	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
> -	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
> -
> -	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
> -	mtspr(SPRN_PSSCR, host_psscr |
> -	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> -	mtspr(SPRN_HFSCR, host_hfscr);
> -	mtspr(SPRN_CIABR, host_ciabr);
> -	mtspr(SPRN_DAWR0, host_dawr0);
> -	mtspr(SPRN_DAWRX0, host_dawrx0);
> -	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> -		mtspr(SPRN_DAWR1, host_dawr1);
> -		mtspr(SPRN_DAWRX1, host_dawrx1);
> -	}
> -
> -	/*
> -	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
> -	 * case we interrupted the guest between a tlbie and a ptesync.
> -	 */
> -	asm volatile("eieio; tlbsync; ptesync");
> -
> -	/*
> -	 * cp_abort is required if the processor supports local copy-paste
> -	 * to clear the copy buffer that was under control of the guest.
> -	 */
> -	if (cpu_has_feature(CPU_FTR_ARCH_31))
> -		asm volatile(PPC_CP_ABORT);
> -
> -	vc->dpdes = mfspr(SPRN_DPDES);
> -	vc->vtb = mfspr(SPRN_VTB);
> -	mtspr(SPRN_DPDES, 0);
> -	if (vc->pcr)
> -		mtspr(SPRN_PCR, PCR_MASK);
> -
> -	if (vc->tb_offset_applied) {
> -		u64 new_tb = mftb() - vc->tb_offset_applied;
> -		mtspr(SPRN_TBU40, new_tb);
> -		tb = mftb();
> -		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> -			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> -		vc->tb_offset_applied = 0;
> -	}
> -
> -	/* HDEC must be at least as large as DEC, so decrementer_max fits */
> -	mtspr(SPRN_HDEC, decrementer_max);
> -
> -	switch_mmu_to_host_radix(kvm, host_pidr);
> -
> -	return trap;
> -}
> -
>  /*
>   * Virtual-mode guest entry for POWER9 and later when the host and
>   * guest are both using the radix MMU.  The LPIDR has already been set.
> @@ -3710,7 +3533,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  		 * We need to save and restore the guest visible part of the
>  		 * psscr (i.e. using SPRN_PSSCR_PR) since the hypervisor
>  		 * doesn't do this for us. Note only required if pseries since
> -		 * this is done in kvmhv_load_hv_regs_and_go() below otherwise.
> +		 * this is done in kvmhv_vcpu_entry_p9() below otherwise.
>  		 */
>  		unsigned long host_psscr;
>  		/* call our hypervisor to load up HV regs and go */
> @@ -3748,7 +3571,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	} else {
>  		kvmppc_xive_push_vcpu(vcpu);
> -		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
> +		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr);
>  		/* H_CEDE has to be handled now, not later */
>  		/* XICS hcalls must be handled before xive is pulled */
>  		if (trap == BOOK3S_INTERRUPT_SYSCALL &&
> diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
> index 5a7b036c447f..dea3eca3648a 100644
> --- a/arch/powerpc/kvm/book3s_hv_interrupt.c
> +++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
> @@ -55,6 +55,31 @@ static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator
>  #define accumulate_time(vcpu, next) do {} while (0)
>  #endif
>
> +static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	struct kvm_nested_guest *nested = vcpu->arch.nested;
> +	u32 lpid;
> +
> +	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> +
> +	mtspr(SPRN_LPID, lpid);
> +	mtspr(SPRN_LPCR, lpcr);
> +	mtspr(SPRN_PID, vcpu->arch.pid);
> +	isync();
> +
> +	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
> +	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
> +}
> +
> +static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
> +{
> +	mtspr(SPRN_PID, pid);
> +	mtspr(SPRN_LPID, kvm->arch.host_lpid);
> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> +	isync();
> +}
> +
>  static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
>  {
>  	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
> @@ -94,11 +119,86 @@ static void radix_clear_slb(void)
>  	}
>  }
>
> -int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
> +int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
>  {
> +	struct kvm *kvm = vcpu->kvm;
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	s64 hdec;
> +	u64 tb, purr, spurr;
>  	u64 *exsave;
>  	unsigned long msr = mfmsr();
>  	int trap;
> +	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
> +	unsigned long host_ciabr = mfspr(SPRN_CIABR);
> +	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
> +	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
> +	unsigned long host_psscr = mfspr(SPRN_PSSCR);
> +	unsigned long host_pidr = mfspr(SPRN_PID);
> +	unsigned long host_dawr1 = 0;
> +	unsigned long host_dawrx1 = 0;
> +
> +	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> +		host_dawr1 = mfspr(SPRN_DAWR1);
> +		host_dawrx1 = mfspr(SPRN_DAWRX1);
> +	}
> +
> +	tb = mftb();
> +	hdec = time_limit - tb;
> +	if (hdec < 0)
> +		return BOOK3S_INTERRUPT_HV_DECREMENTER;
> +
> +	if (vc->tb_offset) {
> +		u64 new_tb = tb + vc->tb_offset;
> +		mtspr(SPRN_TBU40, new_tb);
> +		tb = mftb();
> +		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> +			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> +		vc->tb_offset_applied = vc->tb_offset;
> +	}
> +
> +	if (vc->pcr)
> +		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
> +	mtspr(SPRN_DPDES, vc->dpdes);
> +	mtspr(SPRN_VTB, vc->vtb);
> +
> +	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
> +	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
> +	mtspr(SPRN_PURR, vcpu->arch.purr);
> +	mtspr(SPRN_SPURR, vcpu->arch.spurr);
> +
> +	if (dawr_enabled()) {
> +		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
> +		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
> +		if (cpu_has_feature(CPU_FTR_DAWR1)) {
> +			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
> +			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
> +		}
> +	}
> +	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
> +	mtspr(SPRN_IC, vcpu->arch.ic);
> +
> +	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
> +	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> +
> +	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
> +
> +	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
> +	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
> +	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
> +	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
> +
> +	mtspr(SPRN_AMOR, ~0UL);
> +
> +	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
> +
> +	/*
> +	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
> +	 * so set guest LPCR (with HDICE) before writing HDEC.
> +	 */
> +	mtspr(SPRN_HDEC, hdec);
> +
> +	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
> +	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
>
>  	start_timing(vcpu, &vcpu->arch.rm_entry);
>
> @@ -216,6 +316,70 @@ int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
>
>  	end_timing(vcpu);
>
> +	/* Advance host PURR/SPURR by the amount used by guest */
> +	purr = mfspr(SPRN_PURR);
> +	spurr = mfspr(SPRN_SPURR);
> +	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
> +	      purr - vcpu->arch.purr);
> +	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
> +	      spurr - vcpu->arch.spurr);
> +	vcpu->arch.purr = purr;
> +	vcpu->arch.spurr = spurr;
> +
> +	vcpu->arch.ic = mfspr(SPRN_IC);
> +	vcpu->arch.pid = mfspr(SPRN_PID);
> +	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
> +
> +	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
> +	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
> +	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
> +	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
> +
> +	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
> +	mtspr(SPRN_PSSCR, host_psscr |
> +	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> +	mtspr(SPRN_HFSCR, host_hfscr);
> +	mtspr(SPRN_CIABR, host_ciabr);
> +	mtspr(SPRN_DAWR0, host_dawr0);
> +	mtspr(SPRN_DAWRX0, host_dawrx0);
> +	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> +		mtspr(SPRN_DAWR1, host_dawr1);
> +		mtspr(SPRN_DAWRX1, host_dawrx1);
> +	}
> +
> +	/*
> +	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
> +	 * case we interrupted the guest between a tlbie and a ptesync.
> +	 */
> +	asm volatile("eieio; tlbsync; ptesync");
> +
> +	/*
> +	 * cp_abort is required if the processor supports local copy-paste
> +	 * to clear the copy buffer that was under control of the guest.
> +	 */
> +	if (cpu_has_feature(CPU_FTR_ARCH_31))
> +		asm volatile(PPC_CP_ABORT);
> +
> +	vc->dpdes = mfspr(SPRN_DPDES);
> +	vc->vtb = mfspr(SPRN_VTB);
> +	mtspr(SPRN_DPDES, 0);
> +	if (vc->pcr)
> +		mtspr(SPRN_PCR, PCR_MASK);
> +
> +	if (vc->tb_offset_applied) {
> +		u64 new_tb = mftb() - vc->tb_offset_applied;
> +		mtspr(SPRN_TBU40, new_tb);
> +		tb = mftb();
> +		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> +			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> +		vc->tb_offset_applied = 0;
> +	}
> +
> +	/* HDEC must be at least as large as DEC, so decrementer_max fits */
> +	mtspr(SPRN_HDEC, decrementer_max);
> +
> +	switch_mmu_to_host_radix(kvm, host_pidr);
> +
>  	return trap;
>  }
> -EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
> +EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entr
@ 2021-03-02 13:48     ` Fabiano Rosas
  0 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-02 13:48 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> Now the initial C implementation is done, inline more HV code to make
> rearranging things easier.
>
> And rename __kvmhv_vcpu_entry_p9 to drop the leading underscores as it's
> now C, and is now a more complete vcpu entry.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

> ---
>  arch/powerpc/include/asm/kvm_book3s_64.h |   2 +-
>  arch/powerpc/kvm/book3s_hv.c             | 181 +----------------------
>  arch/powerpc/kvm/book3s_hv_interrupt.c   | 168 ++++++++++++++++++++-
>  3 files changed, 169 insertions(+), 182 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
> index c214bcffb441..eaf3a562bf1e 100644
> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
> @@ -153,7 +153,7 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
>  	return radix;
>  }
>
> -int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
> +int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr);
>
>  #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
>  #endif
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 28a2761515e3..f99503acdda5 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -3442,183 +3442,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
>  	trace_kvmppc_run_core(vc, 1);
>  }
>
> -static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
> -{
> -	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> -	struct kvm_nested_guest *nested = vcpu->arch.nested;
> -	u32 lpid;
> -
> -	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> -
> -	mtspr(SPRN_LPID, lpid);
> -	mtspr(SPRN_LPCR, lpcr);
> -	mtspr(SPRN_PID, vcpu->arch.pid);
> -	isync();
> -
> -	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
> -	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
> -}
> -
> -static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
> -{
> -	mtspr(SPRN_PID, pid);
> -	mtspr(SPRN_LPID, kvm->arch.host_lpid);
> -	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> -	isync();
> -}
> -
> -/*
> - * Load up hypervisor-mode registers on P9.
> - */
> -static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
> -				     unsigned long lpcr)
> -{
> -	struct kvm *kvm = vcpu->kvm;
> -	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> -	s64 hdec;
> -	u64 tb, purr, spurr;
> -	int trap;
> -	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
> -	unsigned long host_ciabr = mfspr(SPRN_CIABR);
> -	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
> -	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
> -	unsigned long host_psscr = mfspr(SPRN_PSSCR);
> -	unsigned long host_pidr = mfspr(SPRN_PID);
> -	unsigned long host_dawr1 = 0;
> -	unsigned long host_dawrx1 = 0;
> -
> -	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> -		host_dawr1 = mfspr(SPRN_DAWR1);
> -		host_dawrx1 = mfspr(SPRN_DAWRX1);
> -	}
> -
> -	tb = mftb();
> -	hdec = time_limit - tb;
> -	if (hdec < 0)
> -		return BOOK3S_INTERRUPT_HV_DECREMENTER;
> -
> -	if (vc->tb_offset) {
> -		u64 new_tb = tb + vc->tb_offset;
> -		mtspr(SPRN_TBU40, new_tb);
> -		tb = mftb();
> -		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> -			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> -		vc->tb_offset_applied = vc->tb_offset;
> -	}
> -
> -	if (vc->pcr)
> -		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
> -	mtspr(SPRN_DPDES, vc->dpdes);
> -	mtspr(SPRN_VTB, vc->vtb);
> -
> -	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
> -	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
> -	mtspr(SPRN_PURR, vcpu->arch.purr);
> -	mtspr(SPRN_SPURR, vcpu->arch.spurr);
> -
> -	if (dawr_enabled()) {
> -		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
> -		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
> -		if (cpu_has_feature(CPU_FTR_DAWR1)) {
> -			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
> -			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
> -		}
> -	}
> -	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
> -	mtspr(SPRN_IC, vcpu->arch.ic);
> -
> -	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
> -	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> -
> -	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
> -
> -	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
> -	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
> -	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
> -	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
> -
> -	mtspr(SPRN_AMOR, ~0UL);
> -
> -	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
> -
> -	/*
> -	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
> -	 * so set guest LPCR (with HDICE) before writing HDEC.
> -	 */
> -	mtspr(SPRN_HDEC, hdec);
> -
> -	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
> -	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
> -
> -	trap = __kvmhv_vcpu_entry_p9(vcpu);
> -
> -	/* Advance host PURR/SPURR by the amount used by guest */
> -	purr = mfspr(SPRN_PURR);
> -	spurr = mfspr(SPRN_SPURR);
> -	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
> -	      purr - vcpu->arch.purr);
> -	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
> -	      spurr - vcpu->arch.spurr);
> -	vcpu->arch.purr = purr;
> -	vcpu->arch.spurr = spurr;
> -
> -	vcpu->arch.ic = mfspr(SPRN_IC);
> -	vcpu->arch.pid = mfspr(SPRN_PID);
> -	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
> -
> -	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
> -	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
> -	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
> -	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
> -
> -	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
> -	mtspr(SPRN_PSSCR, host_psscr |
> -	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> -	mtspr(SPRN_HFSCR, host_hfscr);
> -	mtspr(SPRN_CIABR, host_ciabr);
> -	mtspr(SPRN_DAWR0, host_dawr0);
> -	mtspr(SPRN_DAWRX0, host_dawrx0);
> -	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> -		mtspr(SPRN_DAWR1, host_dawr1);
> -		mtspr(SPRN_DAWRX1, host_dawrx1);
> -	}
> -
> -	/*
> -	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
> -	 * case we interrupted the guest between a tlbie and a ptesync.
> -	 */
> -	asm volatile("eieio; tlbsync; ptesync");
> -
> -	/*
> -	 * cp_abort is required if the processor supports local copy-paste
> -	 * to clear the copy buffer that was under control of the guest.
> -	 */
> -	if (cpu_has_feature(CPU_FTR_ARCH_31))
> -		asm volatile(PPC_CP_ABORT);
> -
> -	vc->dpdes = mfspr(SPRN_DPDES);
> -	vc->vtb = mfspr(SPRN_VTB);
> -	mtspr(SPRN_DPDES, 0);
> -	if (vc->pcr)
> -		mtspr(SPRN_PCR, PCR_MASK);
> -
> -	if (vc->tb_offset_applied) {
> -		u64 new_tb = mftb() - vc->tb_offset_applied;
> -		mtspr(SPRN_TBU40, new_tb);
> -		tb = mftb();
> -		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> -			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> -		vc->tb_offset_applied = 0;
> -	}
> -
> -	/* HDEC must be at least as large as DEC, so decrementer_max fits */
> -	mtspr(SPRN_HDEC, decrementer_max);
> -
> -	switch_mmu_to_host_radix(kvm, host_pidr);
> -
> -	return trap;
> -}
> -
>  /*
>   * Virtual-mode guest entry for POWER9 and later when the host and
>   * guest are both using the radix MMU.  The LPIDR has already been set.
> @@ -3710,7 +3533,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  		 * We need to save and restore the guest visible part of the
>  		 * psscr (i.e. using SPRN_PSSCR_PR) since the hypervisor
>  		 * doesn't do this for us. Note only required if pseries since
> -		 * this is done in kvmhv_load_hv_regs_and_go() below otherwise.
> +		 * this is done in kvmhv_vcpu_entry_p9() below otherwise.
>  		 */
>  		unsigned long host_psscr;
>  		/* call our hypervisor to load up HV regs and go */
> @@ -3748,7 +3571,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>
>  	} else {
>  		kvmppc_xive_push_vcpu(vcpu);
> -		trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
> +		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr);
>  		/* H_CEDE has to be handled now, not later */
>  		/* XICS hcalls must be handled before xive is pulled */
>  		if (trap = BOOK3S_INTERRUPT_SYSCALL &&
> diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
> index 5a7b036c447f..dea3eca3648a 100644
> --- a/arch/powerpc/kvm/book3s_hv_interrupt.c
> +++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
> @@ -55,6 +55,31 @@ static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator
>  #define accumulate_time(vcpu, next) do {} while (0)
>  #endif
>
> +static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
> +{
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	struct kvm_nested_guest *nested = vcpu->arch.nested;
> +	u32 lpid;
> +
> +	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
> +
> +	mtspr(SPRN_LPID, lpid);
> +	mtspr(SPRN_LPCR, lpcr);
> +	mtspr(SPRN_PID, vcpu->arch.pid);
> +	isync();
> +
> +	/* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
> +	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
> +}
> +
> +static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
> +{
> +	mtspr(SPRN_PID, pid);
> +	mtspr(SPRN_LPID, kvm->arch.host_lpid);
> +	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
> +	isync();
> +}
> +
>  static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
>  {
>  	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
> @@ -94,11 +119,86 @@ static void radix_clear_slb(void)
>  	}
>  }
>
> -int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
> +int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
>  {
> +	struct kvm *kvm = vcpu->kvm;
> +	struct kvmppc_vcore *vc = vcpu->arch.vcore;
> +	s64 hdec;
> +	u64 tb, purr, spurr;
>  	u64 *exsave;
>  	unsigned long msr = mfmsr();
>  	int trap;
> +	unsigned long host_hfscr = mfspr(SPRN_HFSCR);
> +	unsigned long host_ciabr = mfspr(SPRN_CIABR);
> +	unsigned long host_dawr0 = mfspr(SPRN_DAWR0);
> +	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
> +	unsigned long host_psscr = mfspr(SPRN_PSSCR);
> +	unsigned long host_pidr = mfspr(SPRN_PID);
> +	unsigned long host_dawr1 = 0;
> +	unsigned long host_dawrx1 = 0;
> +
> +	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> +		host_dawr1 = mfspr(SPRN_DAWR1);
> +		host_dawrx1 = mfspr(SPRN_DAWRX1);
> +	}
> +
> +	tb = mftb();
> +	hdec = time_limit - tb;
> +	if (hdec < 0)
> +		return BOOK3S_INTERRUPT_HV_DECREMENTER;
> +
> +	if (vc->tb_offset) {
> +		u64 new_tb = tb + vc->tb_offset;
> +		mtspr(SPRN_TBU40, new_tb);
> +		tb = mftb();
> +		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> +			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> +		vc->tb_offset_applied = vc->tb_offset;
> +	}
> +
> +	if (vc->pcr)
> +		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
> +	mtspr(SPRN_DPDES, vc->dpdes);
> +	mtspr(SPRN_VTB, vc->vtb);
> +
> +	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
> +	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
> +	mtspr(SPRN_PURR, vcpu->arch.purr);
> +	mtspr(SPRN_SPURR, vcpu->arch.spurr);
> +
> +	if (dawr_enabled()) {
> +		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
> +		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
> +		if (cpu_has_feature(CPU_FTR_DAWR1)) {
> +			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
> +			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
> +		}
> +	}
> +	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
> +	mtspr(SPRN_IC, vcpu->arch.ic);
> +
> +	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
> +	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> +
> +	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
> +
> +	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
> +	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
> +	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
> +	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
> +
> +	mtspr(SPRN_AMOR, ~0UL);
> +
> +	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
> +
> +	/*
> +	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
> +	 * so set guest LPCR (with HDICE) before writing HDEC.
> +	 */
> +	mtspr(SPRN_HDEC, hdec);
> +
> +	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
> +	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
>
>  	start_timing(vcpu, &vcpu->arch.rm_entry);
>
> @@ -216,6 +316,70 @@ int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
>
>  	end_timing(vcpu);
>
> +	/* Advance host PURR/SPURR by the amount used by guest */
> +	purr = mfspr(SPRN_PURR);
> +	spurr = mfspr(SPRN_SPURR);
> +	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
> +	      purr - vcpu->arch.purr);
> +	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
> +	      spurr - vcpu->arch.spurr);
> +	vcpu->arch.purr = purr;
> +	vcpu->arch.spurr = spurr;
> +
> +	vcpu->arch.ic = mfspr(SPRN_IC);
> +	vcpu->arch.pid = mfspr(SPRN_PID);
> +	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
> +
> +	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
> +	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
> +	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
> +	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
> +
> +	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
> +	mtspr(SPRN_PSSCR, host_psscr |
> +	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
> +	mtspr(SPRN_HFSCR, host_hfscr);
> +	mtspr(SPRN_CIABR, host_ciabr);
> +	mtspr(SPRN_DAWR0, host_dawr0);
> +	mtspr(SPRN_DAWRX0, host_dawrx0);
> +	if (cpu_has_feature(CPU_FTR_DAWR1)) {
> +		mtspr(SPRN_DAWR1, host_dawr1);
> +		mtspr(SPRN_DAWRX1, host_dawrx1);
> +	}
> +
> +	/*
> +	 * Since this is radix, do a eieio; tlbsync; ptesync sequence in
> +	 * case we interrupted the guest between a tlbie and a ptesync.
> +	 */
> +	asm volatile("eieio; tlbsync; ptesync");
> +
> +	/*
> +	 * cp_abort is required if the processor supports local copy-paste
> +	 * to clear the copy buffer that was under control of the guest.
> +	 */
> +	if (cpu_has_feature(CPU_FTR_ARCH_31))
> +		asm volatile(PPC_CP_ABORT);
> +
> +	vc->dpdes = mfspr(SPRN_DPDES);
> +	vc->vtb = mfspr(SPRN_VTB);
> +	mtspr(SPRN_DPDES, 0);
> +	if (vc->pcr)
> +		mtspr(SPRN_PCR, PCR_MASK);
> +
> +	if (vc->tb_offset_applied) {
> +		u64 new_tb = mftb() - vc->tb_offset_applied;
> +		mtspr(SPRN_TBU40, new_tb);
> +		tb = mftb();
> +		if ((tb & 0xffffff) < (new_tb & 0xffffff))
> +			mtspr(SPRN_TBU40, new_tb + 0x1000000);
> +		vc->tb_offset_applied = 0;
> +	}
> +
> +	/* HDEC must be at least as large as DEC, so decrementer_max fits */
> +	mtspr(SPRN_HDEC, decrementer_max);
> +
> +	switch_mmu_to_host_radix(kvm, host_pidr);
> +
>  	return trap;
>  }
> -EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9);
> +EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-02 15:04     ` Fabiano Rosas
  -1 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-02 15:04 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> This is a first step to wrapping supervisor and user SPR saving and
> loading up into helpers, which will then be called independently in
> bare metal and nested HV cases in order to optimise SPR access.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---

<snip>

> +/* vcpu guest regs must already be saved */
> +static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
> +				    struct p9_host_os_sprs *host_os_sprs)
> +{
> +	mtspr(SPRN_PSPB, 0);
> +	mtspr(SPRN_WORT, 0);
> +	mtspr(SPRN_UAMOR, 0);
> +	mtspr(SPRN_PSPB, 0);

Not your fault, but PSPB is set twice here.

> +
> +	mtspr(SPRN_DSCR, host_os_sprs->dscr);
> +	mtspr(SPRN_TIDR, host_os_sprs->tidr);
> +	mtspr(SPRN_IAMR, host_os_sprs->iamr);
> +
> +	if (host_os_sprs->amr != vcpu->arch.amr)
> +		mtspr(SPRN_AMR, host_os_sprs->amr);
> +
> +	if (host_os_sprs->fscr != vcpu->arch.fscr)
> +		mtspr(SPRN_FSCR, host_os_sprs->fscr);
> +}
> +

<snip>

> @@ -3605,34 +3666,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  	vcpu->arch.dec_expires = dec + tb;
>  	vcpu->cpu = -1;
>  	vcpu->arch.thread_cpu = -1;
> -	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
> -
> -	vcpu->arch.iamr = mfspr(SPRN_IAMR);
> -	vcpu->arch.pspb = mfspr(SPRN_PSPB);
> -	vcpu->arch.fscr = mfspr(SPRN_FSCR);
> -	vcpu->arch.tar = mfspr(SPRN_TAR);
> -	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
> -	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
> -	vcpu->arch.bescr = mfspr(SPRN_BESCR);
> -	vcpu->arch.wort = mfspr(SPRN_WORT);
> -	vcpu->arch.tid = mfspr(SPRN_TIDR);
> -	vcpu->arch.amr = mfspr(SPRN_AMR);
> -	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
> -	vcpu->arch.dscr = mfspr(SPRN_DSCR);
> -
> -	mtspr(SPRN_PSPB, 0);
> -	mtspr(SPRN_WORT, 0);
> -	mtspr(SPRN_UAMOR, 0);
> -	mtspr(SPRN_DSCR, host_dscr);
> -	mtspr(SPRN_TIDR, host_tidr);
> -	mtspr(SPRN_IAMR, host_iamr);
> -	mtspr(SPRN_PSPB, 0);
>
> -	if (host_amr != vcpu->arch.amr)
> -		mtspr(SPRN_AMR, host_amr);
> +	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
>
> -	if (host_fscr != vcpu->arch.fscr)
> -		mtspr(SPRN_FSCR, host_fscr);
> +	store_spr_state(vcpu);

store_spr_state should come first, right? We want to save the guest
state before restoring the host state.

>
>  	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
>  	store_fp_state(&vcpu->arch.fp);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
@ 2021-03-02 15:04     ` Fabiano Rosas
  0 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-02 15:04 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> This is a first step to wrapping supervisor and user SPR saving and
> loading up into helpers, which will then be called independently in
> bare metal and nested HV cases in order to optimise SPR access.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---

<snip>

> +/* vcpu guest regs must already be saved */
> +static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
> +				    struct p9_host_os_sprs *host_os_sprs)
> +{
> +	mtspr(SPRN_PSPB, 0);
> +	mtspr(SPRN_WORT, 0);
> +	mtspr(SPRN_UAMOR, 0);
> +	mtspr(SPRN_PSPB, 0);

Not your fault, but PSPB is set twice here.

> +
> +	mtspr(SPRN_DSCR, host_os_sprs->dscr);
> +	mtspr(SPRN_TIDR, host_os_sprs->tidr);
> +	mtspr(SPRN_IAMR, host_os_sprs->iamr);
> +
> +	if (host_os_sprs->amr != vcpu->arch.amr)
> +		mtspr(SPRN_AMR, host_os_sprs->amr);
> +
> +	if (host_os_sprs->fscr != vcpu->arch.fscr)
> +		mtspr(SPRN_FSCR, host_os_sprs->fscr);
> +}
> +

<snip>

> @@ -3605,34 +3666,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>  	vcpu->arch.dec_expires = dec + tb;
>  	vcpu->cpu = -1;
>  	vcpu->arch.thread_cpu = -1;
> -	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
> -
> -	vcpu->arch.iamr = mfspr(SPRN_IAMR);
> -	vcpu->arch.pspb = mfspr(SPRN_PSPB);
> -	vcpu->arch.fscr = mfspr(SPRN_FSCR);
> -	vcpu->arch.tar = mfspr(SPRN_TAR);
> -	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
> -	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
> -	vcpu->arch.bescr = mfspr(SPRN_BESCR);
> -	vcpu->arch.wort = mfspr(SPRN_WORT);
> -	vcpu->arch.tid = mfspr(SPRN_TIDR);
> -	vcpu->arch.amr = mfspr(SPRN_AMR);
> -	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
> -	vcpu->arch.dscr = mfspr(SPRN_DSCR);
> -
> -	mtspr(SPRN_PSPB, 0);
> -	mtspr(SPRN_WORT, 0);
> -	mtspr(SPRN_UAMOR, 0);
> -	mtspr(SPRN_DSCR, host_dscr);
> -	mtspr(SPRN_TIDR, host_tidr);
> -	mtspr(SPRN_IAMR, host_iamr);
> -	mtspr(SPRN_PSPB, 0);
>
> -	if (host_amr != vcpu->arch.amr)
> -		mtspr(SPRN_AMR, host_amr);
> +	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
>
> -	if (host_fscr != vcpu->arch.fscr)
> -		mtspr(SPRN_FSCR, host_fscr);
> +	store_spr_state(vcpu);

store_spr_state should come first, right? We want to save the guest
state before restoring the host state.

>
>  	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
>  	store_fp_state(&vcpu->arch.fp);

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-02 21:21     ` Fabiano Rosas
  -1 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-02 21:21 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> Rather than partition the guest PID space and catch and flush a rogue
> guest, instead work around this issue by ensuring the MMU is always
> disabled in HV mode while the guest MMU context is switched in.
>
> This may be a bit less efficient, but it is a lot less complicated and
> allows the P9 path to trivally implement the workaround too. Newer CPUs
> are not subject to this issue.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/mmu_context.h   |  6 ----
>  arch/powerpc/kvm/book3s_hv.c             | 10 ++++--
>  arch/powerpc/kvm/book3s_hv_interrupt.c   | 14 ++++++--
>  arch/powerpc/kvm/book3s_hv_rmhandlers.S  | 34 ------------------
>  arch/powerpc/mm/book3s64/radix_pgtable.c | 27 +++++---------
>  arch/powerpc/mm/book3s64/radix_tlb.c     | 46 ------------------------
>  arch/powerpc/mm/mmu_context.c            |  4 +--
>  7 files changed, 28 insertions(+), 113 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
> index 652ce85f9410..bb5c7e5e142e 100644
> --- a/arch/powerpc/include/asm/mmu_context.h
> +++ b/arch/powerpc/include/asm/mmu_context.h
> @@ -122,12 +122,6 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
>  }
>  #endif
>
> -#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
> -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
> -#else
> -static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
> -#endif
> -
>  extern void switch_cop(struct mm_struct *next);
>  extern int use_cop(unsigned long acop, struct mm_struct *mm);
>  extern void drop_cop(unsigned long acop, struct mm_struct *mm);
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index ad16331c3370..c3064075f1d7 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -806,6 +806,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
>  		/* KVM does not support mflags=2 (AIL=2) */
>  		if (mflags != 0 && mflags != 3)
>  			return H_UNSUPPORTED_FLAG_START;
> +		/* Prefetch bug */
> +		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
> +				kvmhv_vcpu_is_radix(vcpu) && mflags == 3)
> +			return H_UNSUPPORTED_FLAG_START;

So does this mean that if the host has the prefetch bug, all of its
guests will run with AIL=0 all the time? And what we're avoiding here is
a guest setting AIL=3 which would (since there's no HAIL) cause
hypervisor interrupts to be taken with MMU on, is that it?

Do we need to add this verification to kvmppc_set_lpcr as well? QEMU
could in theory call the KVM_SET_ONE_REG ioctl and set AIL to any value.

>  		return H_TOO_HARD;
>  	default:
>  		return H_TOO_HARD;
> @@ -4286,8 +4290,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>  		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
>  		 * path, which also handles hash and dependent threads mode.
>  		 */
> -		if (kvm->arch.threads_indep && kvm_is_radix(kvm) &&
> -		    !cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> +		if (kvm->arch.threads_indep && kvm_is_radix(kvm))
>  			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
>  						  vcpu->arch.vcore->lpcr);
>  		else
> @@ -4914,6 +4917,9 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
>  		if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) {
>  			pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n");
>  			kvm->arch.threads_indep = true;
> +		} else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
> +			pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n");
> +			kvm->arch.threads_indep = true;
>  		} else {
>  			kvm->arch.threads_indep = indep_threads_mode;
>  		}
> diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
> index b93d861d8538..9784da3f8565 100644
> --- a/arch/powerpc/kvm/book3s_hv_interrupt.c
> +++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
> @@ -223,6 +223,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>
>  	mtspr(SPRN_AMOR, ~0UL);
>
> +	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> +		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
> +
>  	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>
>  	/*
> @@ -231,7 +234,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>  	 */
>  	mtspr(SPRN_HDEC, hdec);
>
> -	__mtmsrd(0, 1); /* clear RI */
> +	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> +		__mtmsrd(0, 1); /* clear RI */
>
>  	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
>  	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
> @@ -338,8 +342,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>
>  	radix_clear_slb();
>
> -	__mtmsrd(msr, 0);
> -
>  	accumulate_time(vcpu, &vcpu->arch.rm_exit);
>
>  	/* Advance host PURR/SPURR by the amount used by guest */
> @@ -406,6 +408,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>
>  	switch_mmu_to_host_radix(kvm, host_pidr);
>
> +	/*
> +	 * If we are in real mode, don't switch MMU on until the MMU is
> +	 * switched to host, to avoid the P9 radix prefetch bug.
> +	 */
> +	__mtmsrd(msr, 0);
> +
>  	end_timing(vcpu);
>
>  	return trap;
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 6118e8a97ddd..61f71a7df238 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -1710,40 +1710,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
>  	eieio
>  	tlbsync
>  	ptesync
> -
> -BEGIN_FTR_SECTION
> -	/* Radix: Handle the case where the guest used an illegal PID */
> -	LOAD_REG_ADDR(r4, mmu_base_pid)
> -	lwz	r3, VCPU_GUEST_PID(r9)
> -	lwz	r5, 0(r4)
> -	cmpw	cr0,r3,r5
> -	blt	2f
> -
> -	/*
> -	 * Illegal PID, the HW might have prefetched and cached in the TLB
> -	 * some translations for the  LPID 0 / guest PID combination which
> -	 * Linux doesn't know about, so we need to flush that PID out of
> -	 * the TLB. First we need to set LPIDR to 0 so tlbiel applies to
> -	 * the right context.
> -	*/
> -	li	r0,0
> -	mtspr	SPRN_LPID,r0
> -	isync
> -
> -	/* Then do a congruence class local flush */
> -	ld	r6,VCPU_KVM(r9)
> -	lwz	r0,KVM_TLB_SETS(r6)
> -	mtctr	r0
> -	li	r7,0x400		/* IS field = 0b01 */
> -	ptesync
> -	sldi	r0,r3,32		/* RS has PID */
> -1:	PPC_TLBIEL(7,0,2,1,1)		/* RIC=2, PRS=1, R=1 */
> -	addi	r7,r7,0x1000
> -	bdnz	1b
> -	ptesync
> -END_FTR_SECTION_IFSET(CPU_FTR_P9_RADIX_PREFETCH_BUG)
> -
> -2:
>  #endif /* CONFIG_PPC_RADIX_MMU */
>
>  	/*
> diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
> index 98f0b243c1ab..1ea95891a79e 100644
> --- a/arch/powerpc/mm/book3s64/radix_pgtable.c
> +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
> @@ -357,30 +357,19 @@ static void __init radix_init_pgtable(void)
>  	}
>
>  	/* Find out how many PID bits are supported */
> -	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
> -		if (!mmu_pid_bits)
> -			mmu_pid_bits = 20;
> -		mmu_base_pid = 1;
> -	} else if (cpu_has_feature(CPU_FTR_HVMODE)) {
> -		if (!mmu_pid_bits)
> -			mmu_pid_bits = 20;
> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +	if (!cpu_has_feature(CPU_FTR_HVMODE) &&
> +			cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
>  		/*
> -		 * When KVM is possible, we only use the top half of the
> -		 * PID space to avoid collisions between host and guest PIDs
> -		 * which can cause problems due to prefetch when exiting the
> -		 * guest with AIL=3
> +		 * Older versions of KVM on these machines perfer if the
> +		 * guest only uses the low 19 PID bits.
>  		 */
> -		mmu_base_pid = 1 << (mmu_pid_bits - 1);
> -#else
> -		mmu_base_pid = 1;
> -#endif
> -	} else {
> -		/* The guest uses the bottom half of the PID space */
>  		if (!mmu_pid_bits)
>  			mmu_pid_bits = 19;
> -		mmu_base_pid = 1;
> +	} else {
> +		if (!mmu_pid_bits)
> +			mmu_pid_bits = 20;
>  	}
> +	mmu_base_pid = 1;
>
>  	/*
>  	 * Allocate Partition table and process table for the
> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
> index 409e61210789..312236a6b085 100644
> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
> @@ -1336,49 +1336,3 @@ void radix__flush_tlb_all(void)
>  		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory");
>  	asm volatile("eieio; tlbsync; ptesync": : :"memory");
>  }
> -
> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm)
> -{
> -	unsigned long pid = mm->context.id;
> -
> -	if (unlikely(pid == MMU_NO_CONTEXT))
> -		return;
> -
> -	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> -		return;
> -
> -	/*
> -	 * If this context hasn't run on that CPU before and KVM is
> -	 * around, there's a slim chance that the guest on another
> -	 * CPU just brought in obsolete translation into the TLB of
> -	 * this CPU due to a bad prefetch using the guest PID on
> -	 * the way into the hypervisor.
> -	 *
> -	 * We work around this here. If KVM is possible, we check if
> -	 * any sibling thread is in KVM. If it is, the window may exist
> -	 * and thus we flush that PID from the core.
> -	 *
> -	 * A potential future improvement would be to mark which PIDs
> -	 * have never been used on the system and avoid it if the PID
> -	 * is new and the process has no other cpumask bit set.
> -	 */
> -	if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) {
> -		int cpu = smp_processor_id();
> -		int sib = cpu_first_thread_sibling(cpu);
> -		bool flush = false;
> -
> -		for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) {
> -			if (sib == cpu)
> -				continue;
> -			if (!cpu_possible(sib))
> -				continue;
> -			if (paca_ptrs[sib]->kvm_hstate.kvm_vcpu)
> -				flush = true;
> -		}
> -		if (flush)
> -			_tlbiel_pid(pid, RIC_FLUSH_ALL);
> -	}
> -}
> -EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround);
> -#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
> diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
> index 18f20da0d348..7479d39976c9 100644
> --- a/arch/powerpc/mm/mmu_context.c
> +++ b/arch/powerpc/mm/mmu_context.c
> @@ -81,9 +81,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
>  	if (cpu_has_feature(CPU_FTR_ALTIVEC))
>  		asm volatile ("dssall");
>
> -	if (new_on_cpu)
> -		radix_kvm_prefetch_workaround(next);
> -	else
> +	if (!new_on_cpu)
>  		membarrier_arch_switch_mm(prev, next, tsk);
>
>  	/*

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU
@ 2021-03-02 21:21     ` Fabiano Rosas
  0 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-02 21:21 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> Rather than partition the guest PID space and catch and flush a rogue
> guest, instead work around this issue by ensuring the MMU is always
> disabled in HV mode while the guest MMU context is switched in.
>
> This may be a bit less efficient, but it is a lot less complicated and
> allows the P9 path to trivally implement the workaround too. Newer CPUs
> are not subject to this issue.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/mmu_context.h   |  6 ----
>  arch/powerpc/kvm/book3s_hv.c             | 10 ++++--
>  arch/powerpc/kvm/book3s_hv_interrupt.c   | 14 ++++++--
>  arch/powerpc/kvm/book3s_hv_rmhandlers.S  | 34 ------------------
>  arch/powerpc/mm/book3s64/radix_pgtable.c | 27 +++++---------
>  arch/powerpc/mm/book3s64/radix_tlb.c     | 46 ------------------------
>  arch/powerpc/mm/mmu_context.c            |  4 +--
>  7 files changed, 28 insertions(+), 113 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
> index 652ce85f9410..bb5c7e5e142e 100644
> --- a/arch/powerpc/include/asm/mmu_context.h
> +++ b/arch/powerpc/include/asm/mmu_context.h
> @@ -122,12 +122,6 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
>  }
>  #endif
>
> -#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
> -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
> -#else
> -static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
> -#endif
> -
>  extern void switch_cop(struct mm_struct *next);
>  extern int use_cop(unsigned long acop, struct mm_struct *mm);
>  extern void drop_cop(unsigned long acop, struct mm_struct *mm);
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index ad16331c3370..c3064075f1d7 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -806,6 +806,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
>  		/* KVM does not support mflags=2 (AIL=2) */
>  		if (mflags != 0 && mflags != 3)
>  			return H_UNSUPPORTED_FLAG_START;
> +		/* Prefetch bug */
> +		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
> +				kvmhv_vcpu_is_radix(vcpu) && mflags = 3)
> +			return H_UNSUPPORTED_FLAG_START;

So does this mean that if the host has the prefetch bug, all of its
guests will run with AIL=0 all the time? And what we're avoiding here is
a guest setting AIL=3 which would (since there's no HAIL) cause
hypervisor interrupts to be taken with MMU on, is that it?

Do we need to add this verification to kvmppc_set_lpcr as well? QEMU
could in theory call the KVM_SET_ONE_REG ioctl and set AIL to any value.

>  		return H_TOO_HARD;
>  	default:
>  		return H_TOO_HARD;
> @@ -4286,8 +4290,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
>  		 * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
>  		 * path, which also handles hash and dependent threads mode.
>  		 */
> -		if (kvm->arch.threads_indep && kvm_is_radix(kvm) &&
> -		    !cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> +		if (kvm->arch.threads_indep && kvm_is_radix(kvm))
>  			r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
>  						  vcpu->arch.vcore->lpcr);
>  		else
> @@ -4914,6 +4917,9 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
>  		if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) {
>  			pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n");
>  			kvm->arch.threads_indep = true;
> +		} else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
> +			pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n");
> +			kvm->arch.threads_indep = true;
>  		} else {
>  			kvm->arch.threads_indep = indep_threads_mode;
>  		}
> diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
> index b93d861d8538..9784da3f8565 100644
> --- a/arch/powerpc/kvm/book3s_hv_interrupt.c
> +++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
> @@ -223,6 +223,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>
>  	mtspr(SPRN_AMOR, ~0UL);
>
> +	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> +		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
> +
>  	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
>
>  	/*
> @@ -231,7 +234,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>  	 */
>  	mtspr(SPRN_HDEC, hdec);
>
> -	__mtmsrd(0, 1); /* clear RI */
> +	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> +		__mtmsrd(0, 1); /* clear RI */
>
>  	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
>  	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
> @@ -338,8 +342,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>
>  	radix_clear_slb();
>
> -	__mtmsrd(msr, 0);
> -
>  	accumulate_time(vcpu, &vcpu->arch.rm_exit);
>
>  	/* Advance host PURR/SPURR by the amount used by guest */
> @@ -406,6 +408,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
>
>  	switch_mmu_to_host_radix(kvm, host_pidr);
>
> +	/*
> +	 * If we are in real mode, don't switch MMU on until the MMU is
> +	 * switched to host, to avoid the P9 radix prefetch bug.
> +	 */
> +	__mtmsrd(msr, 0);
> +
>  	end_timing(vcpu);
>
>  	return trap;
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 6118e8a97ddd..61f71a7df238 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -1710,40 +1710,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
>  	eieio
>  	tlbsync
>  	ptesync
> -
> -BEGIN_FTR_SECTION
> -	/* Radix: Handle the case where the guest used an illegal PID */
> -	LOAD_REG_ADDR(r4, mmu_base_pid)
> -	lwz	r3, VCPU_GUEST_PID(r9)
> -	lwz	r5, 0(r4)
> -	cmpw	cr0,r3,r5
> -	blt	2f
> -
> -	/*
> -	 * Illegal PID, the HW might have prefetched and cached in the TLB
> -	 * some translations for the  LPID 0 / guest PID combination which
> -	 * Linux doesn't know about, so we need to flush that PID out of
> -	 * the TLB. First we need to set LPIDR to 0 so tlbiel applies to
> -	 * the right context.
> -	*/
> -	li	r0,0
> -	mtspr	SPRN_LPID,r0
> -	isync
> -
> -	/* Then do a congruence class local flush */
> -	ld	r6,VCPU_KVM(r9)
> -	lwz	r0,KVM_TLB_SETS(r6)
> -	mtctr	r0
> -	li	r7,0x400		/* IS field = 0b01 */
> -	ptesync
> -	sldi	r0,r3,32		/* RS has PID */
> -1:	PPC_TLBIEL(7,0,2,1,1)		/* RIC=2, PRS=1, R=1 */
> -	addi	r7,r7,0x1000
> -	bdnz	1b
> -	ptesync
> -END_FTR_SECTION_IFSET(CPU_FTR_P9_RADIX_PREFETCH_BUG)
> -
> -2:
>  #endif /* CONFIG_PPC_RADIX_MMU */
>
>  	/*
> diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
> index 98f0b243c1ab..1ea95891a79e 100644
> --- a/arch/powerpc/mm/book3s64/radix_pgtable.c
> +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
> @@ -357,30 +357,19 @@ static void __init radix_init_pgtable(void)
>  	}
>
>  	/* Find out how many PID bits are supported */
> -	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
> -		if (!mmu_pid_bits)
> -			mmu_pid_bits = 20;
> -		mmu_base_pid = 1;
> -	} else if (cpu_has_feature(CPU_FTR_HVMODE)) {
> -		if (!mmu_pid_bits)
> -			mmu_pid_bits = 20;
> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +	if (!cpu_has_feature(CPU_FTR_HVMODE) &&
> +			cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
>  		/*
> -		 * When KVM is possible, we only use the top half of the
> -		 * PID space to avoid collisions between host and guest PIDs
> -		 * which can cause problems due to prefetch when exiting the
> -		 * guest with AIL=3
> +		 * Older versions of KVM on these machines perfer if the
> +		 * guest only uses the low 19 PID bits.
>  		 */
> -		mmu_base_pid = 1 << (mmu_pid_bits - 1);
> -#else
> -		mmu_base_pid = 1;
> -#endif
> -	} else {
> -		/* The guest uses the bottom half of the PID space */
>  		if (!mmu_pid_bits)
>  			mmu_pid_bits = 19;
> -		mmu_base_pid = 1;
> +	} else {
> +		if (!mmu_pid_bits)
> +			mmu_pid_bits = 20;
>  	}
> +	mmu_base_pid = 1;
>
>  	/*
>  	 * Allocate Partition table and process table for the
> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
> index 409e61210789..312236a6b085 100644
> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
> @@ -1336,49 +1336,3 @@ void radix__flush_tlb_all(void)
>  		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory");
>  	asm volatile("eieio; tlbsync; ptesync": : :"memory");
>  }
> -
> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm)
> -{
> -	unsigned long pid = mm->context.id;
> -
> -	if (unlikely(pid = MMU_NO_CONTEXT))
> -		return;
> -
> -	if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
> -		return;
> -
> -	/*
> -	 * If this context hasn't run on that CPU before and KVM is
> -	 * around, there's a slim chance that the guest on another
> -	 * CPU just brought in obsolete translation into the TLB of
> -	 * this CPU due to a bad prefetch using the guest PID on
> -	 * the way into the hypervisor.
> -	 *
> -	 * We work around this here. If KVM is possible, we check if
> -	 * any sibling thread is in KVM. If it is, the window may exist
> -	 * and thus we flush that PID from the core.
> -	 *
> -	 * A potential future improvement would be to mark which PIDs
> -	 * have never been used on the system and avoid it if the PID
> -	 * is new and the process has no other cpumask bit set.
> -	 */
> -	if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) {
> -		int cpu = smp_processor_id();
> -		int sib = cpu_first_thread_sibling(cpu);
> -		bool flush = false;
> -
> -		for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) {
> -			if (sib = cpu)
> -				continue;
> -			if (!cpu_possible(sib))
> -				continue;
> -			if (paca_ptrs[sib]->kvm_hstate.kvm_vcpu)
> -				flush = true;
> -		}
> -		if (flush)
> -			_tlbiel_pid(pid, RIC_FLUSH_ALL);
> -	}
> -}
> -EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround);
> -#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
> diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
> index 18f20da0d348..7479d39976c9 100644
> --- a/arch/powerpc/mm/mmu_context.c
> +++ b/arch/powerpc/mm/mmu_context.c
> @@ -81,9 +81,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
>  	if (cpu_has_feature(CPU_FTR_ALTIVEC))
>  		asm volatile ("dssall");
>
> -	if (new_on_cpu)
> -		radix_kvm_prefetch_workaround(next);
> -	else
> +	if (!new_on_cpu)
>  		membarrier_arch_switch_mm(prev, next, tsk);
>
>  	/*

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-03 20:09     ` Fabiano Rosas
  -1 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-03 20:09 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> In order to support hash guests in the P9 path (which does not do real
> mode hcalls or page fault handling), these real-mode hash specific
> interrupts need to be implemented in virt mode.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 118 +++++++++++++++++++++++++++++++++--
>  1 file changed, 113 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 9d2fa21201c1..1bbc46f2cfbf 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -935,6 +935,52 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>  		return RESUME_HOST;
>
>  	switch (req) {
> +	case H_REMOVE:
> +		ret = kvmppc_h_remove(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5),
> +					kvmppc_get_gpr(vcpu, 6));
> +		if (ret == H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_ENTER:
> +		ret = kvmppc_h_enter(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5),
> +					kvmppc_get_gpr(vcpu, 6),
> +					kvmppc_get_gpr(vcpu, 7));
> +		if (ret == H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_READ:
> +		ret = kvmppc_h_read(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5));
> +		if (ret == H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_CLEAR_MOD:
> +		ret = kvmppc_h_clear_mod(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5));
> +		if (ret == H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_CLEAR_REF:
> +		ret = kvmppc_h_clear_ref(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5));
> +		if (ret == H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_PROTECT:
> +		ret = kvmppc_h_protect(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5),
> +					kvmppc_get_gpr(vcpu, 6));
> +		if (ret == H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_BULK_REMOVE:
> +		ret = kvmppc_h_bulk_remove(vcpu);
> +		if (ret == H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +

Some of these symbols need to be exported.

ERROR: modpost: "kvmppc_h_bulk_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_clear_mod" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_xive_xics_hcall" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "decrementers_next_tb" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_hpte_hv_fault" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_protect" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_enter" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_clear_ref" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_read" [arch/powerpc/kvm/kvm-hv.ko] undefined!

>  	case H_CEDE:
>  		break;
>  	case H_PROD:
> @@ -1134,6 +1180,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>  	default:
>  		return RESUME_HOST;
>  	}
> +	WARN_ON_ONCE(ret == H_TOO_HARD);
>  	kvmppc_set_gpr(vcpu, 3, ret);
>  	vcpu->arch.hcall_needed = 0;
>  	return RESUME_GUEST;
> @@ -1420,19 +1467,80 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
>  	 * host page has been paged out.  Any other HDSI/HISI interrupts
>  	 * have been handled already.
>  	 */
> -	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
> -		r = RESUME_PAGE_FAULT;
> -		if (vcpu->arch.fault_dsisr == HDSISR_CANARY)
> +	case BOOK3S_INTERRUPT_H_DATA_STORAGE: {
> +		unsigned long vsid;
> +		long err;
> +
> +		if (vcpu->arch.fault_dsisr == HDSISR_CANARY) {
>  			r = RESUME_GUEST; /* Just retry if it's the canary */
> +			break;
> +		}
> +
> +		if (kvm_is_radix(vcpu->kvm)) {
> +			r = RESUME_PAGE_FAULT;
> +			break;
> +		}
> +
> +		if (!(vcpu->arch.fault_dsisr & (DSISR_NOHPTE | DSISR_PROTFAULT))) {
> +			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
> +			r = RESUME_GUEST;
> +			break;
> +		}
> +		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
> +			vsid = vcpu->kvm->arch.vrma_slb_v;
> +		} else {
> +			vsid = vcpu->arch.fault_gpa;
> +		}
> +		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
> +				vsid, vcpu->arch.fault_dsisr, true);
> +		if (err == 0) {
> +			r = RESUME_GUEST;
> +		} else if (err == -1 || err == -2) {
> +			r = RESUME_PAGE_FAULT;
> +		} else {
> +			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, err);
> +			r = RESUME_GUEST;
> +		}
>  		break;
> -	case BOOK3S_INTERRUPT_H_INST_STORAGE:
> +	}
> +	case BOOK3S_INTERRUPT_H_INST_STORAGE: {
> +		unsigned long vsid;
> +		long err;
> +
>  		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
>  		vcpu->arch.fault_dsisr = vcpu->arch.shregs.msr &
>  			DSISR_SRR1_MATCH_64S;
>  		if (vcpu->arch.shregs.msr & HSRR1_HISI_WRITE)
>  			vcpu->arch.fault_dsisr |= DSISR_ISSTORE;
> -		r = RESUME_PAGE_FAULT;
> +		if (kvm_is_radix(vcpu->kvm)) {
> +			r = RESUME_PAGE_FAULT;
> +			break;
> +		}
> +
> +		if (!(vcpu->arch.fault_dsisr & SRR1_ISI_NOPT)) {
> +			/* XXX: clear DSISR_ISSTORE? */
> +			kvmppc_core_queue_inst_storage(vcpu, vcpu->arch.fault_dsisr);
> +			r = RESUME_GUEST;
> +			break;
> +		}
> +		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
> +			vsid = vcpu->kvm->arch.vrma_slb_v;
> +		} else {
> +			vsid = vcpu->arch.fault_gpa;
> +		}
> +		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
> +				vsid, vcpu->arch.fault_dsisr, false);
> +		if (err == 0) {
> +			r = RESUME_GUEST;
> +		} else if (err == -1) {
> +			r = RESUME_PAGE_FAULT;
> +		} else {
> +			kvmppc_core_queue_inst_storage(vcpu, err);
> +			r = RESUME_GUEST;
> +		}
>  		break;
> +	}
> +
>  	/*
>  	 * This occurs if the guest executes an illegal instruction.
>  	 * If the guest debug is disabled, generate a program interrupt

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults
@ 2021-03-03 20:09     ` Fabiano Rosas
  0 siblings, 0 replies; 134+ messages in thread
From: Fabiano Rosas @ 2021-03-03 20:09 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> In order to support hash guests in the P9 path (which does not do real
> mode hcalls or page fault handling), these real-mode hash specific
> interrupts need to be implemented in virt mode.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 118 +++++++++++++++++++++++++++++++++--
>  1 file changed, 113 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 9d2fa21201c1..1bbc46f2cfbf 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -935,6 +935,52 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>  		return RESUME_HOST;
>
>  	switch (req) {
> +	case H_REMOVE:
> +		ret = kvmppc_h_remove(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5),
> +					kvmppc_get_gpr(vcpu, 6));
> +		if (ret = H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_ENTER:
> +		ret = kvmppc_h_enter(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5),
> +					kvmppc_get_gpr(vcpu, 6),
> +					kvmppc_get_gpr(vcpu, 7));
> +		if (ret = H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_READ:
> +		ret = kvmppc_h_read(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5));
> +		if (ret = H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_CLEAR_MOD:
> +		ret = kvmppc_h_clear_mod(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5));
> +		if (ret = H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_CLEAR_REF:
> +		ret = kvmppc_h_clear_ref(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5));
> +		if (ret = H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_PROTECT:
> +		ret = kvmppc_h_protect(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					kvmppc_get_gpr(vcpu, 5),
> +					kvmppc_get_gpr(vcpu, 6));
> +		if (ret = H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +	case H_BULK_REMOVE:
> +		ret = kvmppc_h_bulk_remove(vcpu);
> +		if (ret = H_TOO_HARD)
> +			return RESUME_HOST;
> +		break;
> +

Some of these symbols need to be exported.

ERROR: modpost: "kvmppc_h_bulk_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_clear_mod" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_xive_xics_hcall" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "decrementers_next_tb" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_hpte_hv_fault" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_protect" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_enter" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_clear_ref" [arch/powerpc/kvm/kvm-hv.ko] undefined!
ERROR: modpost: "kvmppc_h_read" [arch/powerpc/kvm/kvm-hv.ko] undefined!

>  	case H_CEDE:
>  		break;
>  	case H_PROD:
> @@ -1134,6 +1180,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>  	default:
>  		return RESUME_HOST;
>  	}
> +	WARN_ON_ONCE(ret = H_TOO_HARD);
>  	kvmppc_set_gpr(vcpu, 3, ret);
>  	vcpu->arch.hcall_needed = 0;
>  	return RESUME_GUEST;
> @@ -1420,19 +1467,80 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
>  	 * host page has been paged out.  Any other HDSI/HISI interrupts
>  	 * have been handled already.
>  	 */
> -	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
> -		r = RESUME_PAGE_FAULT;
> -		if (vcpu->arch.fault_dsisr = HDSISR_CANARY)
> +	case BOOK3S_INTERRUPT_H_DATA_STORAGE: {
> +		unsigned long vsid;
> +		long err;
> +
> +		if (vcpu->arch.fault_dsisr = HDSISR_CANARY) {
>  			r = RESUME_GUEST; /* Just retry if it's the canary */
> +			break;
> +		}
> +
> +		if (kvm_is_radix(vcpu->kvm)) {
> +			r = RESUME_PAGE_FAULT;
> +			break;
> +		}
> +
> +		if (!(vcpu->arch.fault_dsisr & (DSISR_NOHPTE | DSISR_PROTFAULT))) {
> +			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
> +			r = RESUME_GUEST;
> +			break;
> +		}
> +		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
> +			vsid = vcpu->kvm->arch.vrma_slb_v;
> +		} else {
> +			vsid = vcpu->arch.fault_gpa;
> +		}
> +		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
> +				vsid, vcpu->arch.fault_dsisr, true);
> +		if (err = 0) {
> +			r = RESUME_GUEST;
> +		} else if (err = -1 || err = -2) {
> +			r = RESUME_PAGE_FAULT;
> +		} else {
> +			kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dar, err);
> +			r = RESUME_GUEST;
> +		}
>  		break;
> -	case BOOK3S_INTERRUPT_H_INST_STORAGE:
> +	}
> +	case BOOK3S_INTERRUPT_H_INST_STORAGE: {
> +		unsigned long vsid;
> +		long err;
> +
>  		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
>  		vcpu->arch.fault_dsisr = vcpu->arch.shregs.msr &
>  			DSISR_SRR1_MATCH_64S;
>  		if (vcpu->arch.shregs.msr & HSRR1_HISI_WRITE)
>  			vcpu->arch.fault_dsisr |= DSISR_ISSTORE;
> -		r = RESUME_PAGE_FAULT;
> +		if (kvm_is_radix(vcpu->kvm)) {
> +			r = RESUME_PAGE_FAULT;
> +			break;
> +		}
> +
> +		if (!(vcpu->arch.fault_dsisr & SRR1_ISI_NOPT)) {
> +			/* XXX: clear DSISR_ISSTORE? */
> +			kvmppc_core_queue_inst_storage(vcpu, vcpu->arch.fault_dsisr);
> +			r = RESUME_GUEST;
> +			break;
> +		}
> +		if (!(vcpu->arch.shregs.msr & MSR_DR)) {
> +			vsid = vcpu->kvm->arch.vrma_slb_v;
> +		} else {
> +			vsid = vcpu->arch.fault_gpa;
> +		}
> +		err = kvmppc_hpte_hv_fault(vcpu, vcpu->arch.fault_dar,
> +				vsid, vcpu->arch.fault_dsisr, false);
> +		if (err = 0) {
> +			r = RESUME_GUEST;
> +		} else if (err = -1) {
> +			r = RESUME_PAGE_FAULT;
> +		} else {
> +			kvmppc_core_queue_inst_storage(vcpu, err);
> +			r = RESUME_GUEST;
> +		}
>  		break;
> +	}
> +
>  	/*
>  	 * This occurs if the guest executes an illegal instruction.
>  	 * If the guest debug is disabled, generate a program interrupt

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
  2021-03-02 15:04     ` Fabiano Rosas
@ 2021-03-04 11:02       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-03-04 11:02 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of March 3, 2021 1:04 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> This is a first step to wrapping supervisor and user SPR saving and
>> loading up into helpers, which will then be called independently in
>> bare metal and nested HV cases in order to optimise SPR access.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
> 
> <snip>
> 
>> +/* vcpu guest regs must already be saved */
>> +static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
>> +				    struct p9_host_os_sprs *host_os_sprs)
>> +{
>> +	mtspr(SPRN_PSPB, 0);
>> +	mtspr(SPRN_WORT, 0);
>> +	mtspr(SPRN_UAMOR, 0);
>> +	mtspr(SPRN_PSPB, 0);
> 
> Not your fault, but PSPB is set twice here.

Yeah you're right.

>> +
>> +	mtspr(SPRN_DSCR, host_os_sprs->dscr);
>> +	mtspr(SPRN_TIDR, host_os_sprs->tidr);
>> +	mtspr(SPRN_IAMR, host_os_sprs->iamr);
>> +
>> +	if (host_os_sprs->amr != vcpu->arch.amr)
>> +		mtspr(SPRN_AMR, host_os_sprs->amr);
>> +
>> +	if (host_os_sprs->fscr != vcpu->arch.fscr)
>> +		mtspr(SPRN_FSCR, host_os_sprs->fscr);
>> +}
>> +
> 
> <snip>
> 
>> @@ -3605,34 +3666,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	vcpu->arch.dec_expires = dec + tb;
>>  	vcpu->cpu = -1;
>>  	vcpu->arch.thread_cpu = -1;
>> -	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
>> -
>> -	vcpu->arch.iamr = mfspr(SPRN_IAMR);
>> -	vcpu->arch.pspb = mfspr(SPRN_PSPB);
>> -	vcpu->arch.fscr = mfspr(SPRN_FSCR);
>> -	vcpu->arch.tar = mfspr(SPRN_TAR);
>> -	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
>> -	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
>> -	vcpu->arch.bescr = mfspr(SPRN_BESCR);
>> -	vcpu->arch.wort = mfspr(SPRN_WORT);
>> -	vcpu->arch.tid = mfspr(SPRN_TIDR);
>> -	vcpu->arch.amr = mfspr(SPRN_AMR);
>> -	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
>> -	vcpu->arch.dscr = mfspr(SPRN_DSCR);
>> -
>> -	mtspr(SPRN_PSPB, 0);
>> -	mtspr(SPRN_WORT, 0);
>> -	mtspr(SPRN_UAMOR, 0);
>> -	mtspr(SPRN_DSCR, host_dscr);
>> -	mtspr(SPRN_TIDR, host_tidr);
>> -	mtspr(SPRN_IAMR, host_iamr);
>> -	mtspr(SPRN_PSPB, 0);
>>
>> -	if (host_amr != vcpu->arch.amr)
>> -		mtspr(SPRN_AMR, host_amr);
>> +	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
>>
>> -	if (host_fscr != vcpu->arch.fscr)
>> -		mtspr(SPRN_FSCR, host_fscr);
>> +	store_spr_state(vcpu);
> 
> store_spr_state should come first, right? We want to save the guest
> state before restoring the host state.

Yes good catch. I switched that back around later but looks like I
never brought the fix back to the right patch. Interestingly, things 
pretty much work like this if the guest or host doesn't do anything
much with the SPRs!

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
@ 2021-03-04 11:02       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-03-04 11:02 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of March 3, 2021 1:04 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> This is a first step to wrapping supervisor and user SPR saving and
>> loading up into helpers, which will then be called independently in
>> bare metal and nested HV cases in order to optimise SPR access.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
> 
> <snip>
> 
>> +/* vcpu guest regs must already be saved */
>> +static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
>> +				    struct p9_host_os_sprs *host_os_sprs)
>> +{
>> +	mtspr(SPRN_PSPB, 0);
>> +	mtspr(SPRN_WORT, 0);
>> +	mtspr(SPRN_UAMOR, 0);
>> +	mtspr(SPRN_PSPB, 0);
> 
> Not your fault, but PSPB is set twice here.

Yeah you're right.

>> +
>> +	mtspr(SPRN_DSCR, host_os_sprs->dscr);
>> +	mtspr(SPRN_TIDR, host_os_sprs->tidr);
>> +	mtspr(SPRN_IAMR, host_os_sprs->iamr);
>> +
>> +	if (host_os_sprs->amr != vcpu->arch.amr)
>> +		mtspr(SPRN_AMR, host_os_sprs->amr);
>> +
>> +	if (host_os_sprs->fscr != vcpu->arch.fscr)
>> +		mtspr(SPRN_FSCR, host_os_sprs->fscr);
>> +}
>> +
> 
> <snip>
> 
>> @@ -3605,34 +3666,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
>>  	vcpu->arch.dec_expires = dec + tb;
>>  	vcpu->cpu = -1;
>>  	vcpu->arch.thread_cpu = -1;
>> -	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
>> -
>> -	vcpu->arch.iamr = mfspr(SPRN_IAMR);
>> -	vcpu->arch.pspb = mfspr(SPRN_PSPB);
>> -	vcpu->arch.fscr = mfspr(SPRN_FSCR);
>> -	vcpu->arch.tar = mfspr(SPRN_TAR);
>> -	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
>> -	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
>> -	vcpu->arch.bescr = mfspr(SPRN_BESCR);
>> -	vcpu->arch.wort = mfspr(SPRN_WORT);
>> -	vcpu->arch.tid = mfspr(SPRN_TIDR);
>> -	vcpu->arch.amr = mfspr(SPRN_AMR);
>> -	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
>> -	vcpu->arch.dscr = mfspr(SPRN_DSCR);
>> -
>> -	mtspr(SPRN_PSPB, 0);
>> -	mtspr(SPRN_WORT, 0);
>> -	mtspr(SPRN_UAMOR, 0);
>> -	mtspr(SPRN_DSCR, host_dscr);
>> -	mtspr(SPRN_TIDR, host_tidr);
>> -	mtspr(SPRN_IAMR, host_iamr);
>> -	mtspr(SPRN_PSPB, 0);
>>
>> -	if (host_amr != vcpu->arch.amr)
>> -		mtspr(SPRN_AMR, host_amr);
>> +	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
>>
>> -	if (host_fscr != vcpu->arch.fscr)
>> -		mtspr(SPRN_FSCR, host_fscr);
>> +	store_spr_state(vcpu);
> 
> store_spr_state should come first, right? We want to save the guest
> state before restoring the host state.

Yes good catch. I switched that back around later but looks like I
never brought the fix back to the right patch. Interestingly, things 
pretty much work like this if the guest or host doesn't do anything
much with the SPRs!

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU
  2021-03-02 21:21     ` Fabiano Rosas
@ 2021-03-04 11:04       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-03-04 11:04 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of March 3, 2021 7:21 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> Rather than partition the guest PID space and catch and flush a rogue
>> guest, instead work around this issue by ensuring the MMU is always
>> disabled in HV mode while the guest MMU context is switched in.
>>
>> This may be a bit less efficient, but it is a lot less complicated and
>> allows the P9 path to trivally implement the workaround too. Newer CPUs
>> are not subject to this issue.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/include/asm/mmu_context.h   |  6 ----
>>  arch/powerpc/kvm/book3s_hv.c             | 10 ++++--
>>  arch/powerpc/kvm/book3s_hv_interrupt.c   | 14 ++++++--
>>  arch/powerpc/kvm/book3s_hv_rmhandlers.S  | 34 ------------------
>>  arch/powerpc/mm/book3s64/radix_pgtable.c | 27 +++++---------
>>  arch/powerpc/mm/book3s64/radix_tlb.c     | 46 ------------------------
>>  arch/powerpc/mm/mmu_context.c            |  4 +--
>>  7 files changed, 28 insertions(+), 113 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
>> index 652ce85f9410..bb5c7e5e142e 100644
>> --- a/arch/powerpc/include/asm/mmu_context.h
>> +++ b/arch/powerpc/include/asm/mmu_context.h
>> @@ -122,12 +122,6 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
>>  }
>>  #endif
>>
>> -#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
>> -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
>> -#else
>> -static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
>> -#endif
>> -
>>  extern void switch_cop(struct mm_struct *next);
>>  extern int use_cop(unsigned long acop, struct mm_struct *mm);
>>  extern void drop_cop(unsigned long acop, struct mm_struct *mm);
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index ad16331c3370..c3064075f1d7 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -806,6 +806,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
>>  		/* KVM does not support mflags=2 (AIL=2) */
>>  		if (mflags != 0 && mflags != 3)
>>  			return H_UNSUPPORTED_FLAG_START;
>> +		/* Prefetch bug */
>> +		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
>> +				kvmhv_vcpu_is_radix(vcpu) && mflags == 3)
>> +			return H_UNSUPPORTED_FLAG_START;
> 
> So does this mean that if the host has the prefetch bug, all of its
> guests will run with AIL=0 all the time?

All radix guests will, yes.

> And what we're avoiding here is
> a guest setting AIL=3 which would (since there's no HAIL) cause
> hypervisor interrupts to be taken with MMU on, is that it?

Yes that's right.

> Do we need to add this verification to kvmppc_set_lpcr as well? QEMU
> could in theory call the KVM_SET_ONE_REG ioctl and set AIL to any value.

Yeah I guess so. We don't restrict other AIL values there by the looks
but maybe we should.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU
@ 2021-03-04 11:04       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-03-04 11:04 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of March 3, 2021 7:21 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> Rather than partition the guest PID space and catch and flush a rogue
>> guest, instead work around this issue by ensuring the MMU is always
>> disabled in HV mode while the guest MMU context is switched in.
>>
>> This may be a bit less efficient, but it is a lot less complicated and
>> allows the P9 path to trivally implement the workaround too. Newer CPUs
>> are not subject to this issue.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/include/asm/mmu_context.h   |  6 ----
>>  arch/powerpc/kvm/book3s_hv.c             | 10 ++++--
>>  arch/powerpc/kvm/book3s_hv_interrupt.c   | 14 ++++++--
>>  arch/powerpc/kvm/book3s_hv_rmhandlers.S  | 34 ------------------
>>  arch/powerpc/mm/book3s64/radix_pgtable.c | 27 +++++---------
>>  arch/powerpc/mm/book3s64/radix_tlb.c     | 46 ------------------------
>>  arch/powerpc/mm/mmu_context.c            |  4 +--
>>  7 files changed, 28 insertions(+), 113 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
>> index 652ce85f9410..bb5c7e5e142e 100644
>> --- a/arch/powerpc/include/asm/mmu_context.h
>> +++ b/arch/powerpc/include/asm/mmu_context.h
>> @@ -122,12 +122,6 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
>>  }
>>  #endif
>>
>> -#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
>> -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
>> -#else
>> -static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
>> -#endif
>> -
>>  extern void switch_cop(struct mm_struct *next);
>>  extern int use_cop(unsigned long acop, struct mm_struct *mm);
>>  extern void drop_cop(unsigned long acop, struct mm_struct *mm);
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index ad16331c3370..c3064075f1d7 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -806,6 +806,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
>>  		/* KVM does not support mflags=2 (AIL=2) */
>>  		if (mflags != 0 && mflags != 3)
>>  			return H_UNSUPPORTED_FLAG_START;
>> +		/* Prefetch bug */
>> +		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
>> +				kvmhv_vcpu_is_radix(vcpu) && mflags == 3)
>> +			return H_UNSUPPORTED_FLAG_START;
> 
> So does this mean that if the host has the prefetch bug, all of its
> guests will run with AIL=0 all the time?

All radix guests will, yes.

> And what we're avoiding here is
> a guest setting AIL=3 which would (since there's no HAIL) cause
> hypervisor interrupts to be taken with MMU on, is that it?

Yes that's right.

> Do we need to add this verification to kvmppc_set_lpcr as well? QEMU
> could in theory call the KVM_SET_ONE_REG ioctl and set AIL to any value.

Yeah I guess so. We don't restrict other AIL values there by the looks
but maybe we should.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults
  2021-03-03 20:09     ` Fabiano Rosas
@ 2021-03-04 11:05       ` Nicholas Piggin
  -1 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-03-04 11:05 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of March 4, 2021 6:09 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> In order to support hash guests in the P9 path (which does not do real
>> mode hcalls or page fault handling), these real-mode hash specific
>> interrupts need to be implemented in virt mode.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kvm/book3s_hv.c | 118 +++++++++++++++++++++++++++++++++--
>>  1 file changed, 113 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index 9d2fa21201c1..1bbc46f2cfbf 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -935,6 +935,52 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>>  		return RESUME_HOST;
>>
>>  	switch (req) {
>> +	case H_REMOVE:
>> +		ret = kvmppc_h_remove(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5),
>> +					kvmppc_get_gpr(vcpu, 6));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_ENTER:
>> +		ret = kvmppc_h_enter(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5),
>> +					kvmppc_get_gpr(vcpu, 6),
>> +					kvmppc_get_gpr(vcpu, 7));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_READ:
>> +		ret = kvmppc_h_read(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_CLEAR_MOD:
>> +		ret = kvmppc_h_clear_mod(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_CLEAR_REF:
>> +		ret = kvmppc_h_clear_ref(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_PROTECT:
>> +		ret = kvmppc_h_protect(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5),
>> +					kvmppc_get_gpr(vcpu, 6));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_BULK_REMOVE:
>> +		ret = kvmppc_h_bulk_remove(vcpu);
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +
> 
> Some of these symbols need to be exported.
> 
> ERROR: modpost: "kvmppc_h_bulk_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_clear_mod" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_xive_xics_hcall" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "decrementers_next_tb" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_hpte_hv_fault" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_protect" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_enter" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_clear_ref" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_read" [arch/powerpc/kvm/kvm-hv.ko] undefined!

Yeah sorry about that there's a few issues there, I'll try polish that 
up a bit before the next post.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults
@ 2021-03-04 11:05       ` Nicholas Piggin
  0 siblings, 0 replies; 134+ messages in thread
From: Nicholas Piggin @ 2021-03-04 11:05 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: linuxppc-dev

Excerpts from Fabiano Rosas's message of March 4, 2021 6:09 am:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
>> In order to support hash guests in the P9 path (which does not do real
>> mode hcalls or page fault handling), these real-mode hash specific
>> interrupts need to be implemented in virt mode.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>  arch/powerpc/kvm/book3s_hv.c | 118 +++++++++++++++++++++++++++++++++--
>>  1 file changed, 113 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index 9d2fa21201c1..1bbc46f2cfbf 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -935,6 +935,52 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>>  		return RESUME_HOST;
>>
>>  	switch (req) {
>> +	case H_REMOVE:
>> +		ret = kvmppc_h_remove(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5),
>> +					kvmppc_get_gpr(vcpu, 6));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_ENTER:
>> +		ret = kvmppc_h_enter(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5),
>> +					kvmppc_get_gpr(vcpu, 6),
>> +					kvmppc_get_gpr(vcpu, 7));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_READ:
>> +		ret = kvmppc_h_read(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_CLEAR_MOD:
>> +		ret = kvmppc_h_clear_mod(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_CLEAR_REF:
>> +		ret = kvmppc_h_clear_ref(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_PROTECT:
>> +		ret = kvmppc_h_protect(vcpu, kvmppc_get_gpr(vcpu, 4),
>> +					kvmppc_get_gpr(vcpu, 5),
>> +					kvmppc_get_gpr(vcpu, 6));
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +	case H_BULK_REMOVE:
>> +		ret = kvmppc_h_bulk_remove(vcpu);
>> +		if (ret == H_TOO_HARD)
>> +			return RESUME_HOST;
>> +		break;
>> +
> 
> Some of these symbols need to be exported.
> 
> ERROR: modpost: "kvmppc_h_bulk_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_clear_mod" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_xive_xics_hcall" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_remove" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "decrementers_next_tb" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_hpte_hv_fault" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_protect" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_enter" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_clear_ref" [arch/powerpc/kvm/kvm-hv.ko] undefined!
> ERROR: modpost: "kvmppc_h_read" [arch/powerpc/kvm/kvm-hv.ko] undefined!

Yeah sorry about that there's a few issues there, I'll try polish that 
up a bit before the next post.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
  2021-02-26 23:50       ` Nicholas Piggin
@ 2021-03-05  4:45         ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  4:45 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev

Hi Nick,

>> ERROR: code indent should use tabs where possible
>> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
>> +                      unsigned long pte_index, unsigned long avpn);$
>> 
>> WARNING: please, no spaces at the start of a line
>> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
>> +                      unsigned long pte_index, unsigned long avpn);$
>
> All the declarations are using the same style in this file so I think
> I'll leave it for someone to do a cleanup patch on. Okay?

Huh, right you are. In that case:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument
@ 2021-03-05  4:45         ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  4:45 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev

Hi Nick,

>> ERROR: code indent should use tabs where possible
>> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
>> +                      unsigned long pte_index, unsigned long avpn);$
>> 
>> WARNING: please, no spaces at the start of a line
>> #25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
>> +                      unsigned long pte_index, unsigned long avpn);$
>
> All the declarations are using the same style in this file so I think
> I'll leave it for someone to do a cleanup patch on. Okay?

Huh, right you are. In that case:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
  2021-02-26 23:55       ` Nicholas Piggin
@ 2021-03-05  4:50         ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  4:50 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Fabiano Rosas

>> This 'if' is technically redundant but you mention a future patch warning
>> on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
>> I get to that patch :)
>
> That's true. The warning is actually further down when we're setting up 
> the msr to run in guest mode. At this point the MSR I think comes from
> qemu (and arguably the guest setup code shouldn't need to know about HV
> specific MSR bits) so a warning here wouldn't be appropriate.
>
> I could remove the if, although the compiler might already do that.

Yes, I think the compiler is almost certainly going to remove that.

I'd probably not include the 'if' statement even though it probably gets
removed by the compiler but I think that's more a matter of taste than
anything else.

Kind regards,
Daniel

>
>> 
>> The patch seems sane to me, I agree that we don't want guests running with
>> MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
>> sane so this is another sanity-enforcement in the same sort of vein.
>> 
>> All up:
>> Reviewed-by: Daniel Axtens <dja@axtens.net>
>
> Thanks,
> Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
@ 2021-03-05  4:50         ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  4:50 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Fabiano Rosas

>> This 'if' is technically redundant but you mention a future patch warning
>> on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
>> I get to that patch :)
>
> That's true. The warning is actually further down when we're setting up 
> the msr to run in guest mode. At this point the MSR I think comes from
> qemu (and arguably the guest setup code shouldn't need to know about HV
> specific MSR bits) so a warning here wouldn't be appropriate.
>
> I could remove the if, although the compiler might already do that.

Yes, I think the compiler is almost certainly going to remove that.

I'd probably not include the 'if' statement even though it probably gets
removed by the compiler but I think that's more a matter of taste than
anything else.

Kind regards,
Daniel

>
>> 
>> The patch seems sane to me, I agree that we don't want guests running with
>> MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
>> sane so this is another sanity-enforcement in the same sort of vein.
>> 
>> All up:
>> Reviewed-by: Daniel Axtens <dja@axtens.net>
>
> Thanks,
> Nick

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 06/37] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-05  5:03     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  5:03 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

> Rather than bifurcate the call depending on whether or not HV is
> possible, and have the HV entry test for PR, just make a single
> common point which does the demultiplexing. This makes it simpler
> to add another type of exit handler.
>
> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

I checked this against the RFC which I was happy with and there are no
changes that I am concerned about. The expanded comment is also nice.

As such:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S    |  8 +-----
>  arch/powerpc/kvm/Makefile               |  3 +++
>  arch/powerpc/kvm/book3s_64_entry.S      | 35 +++++++++++++++++++++++++
>  arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 ++------
>  4 files changed, 41 insertions(+), 16 deletions(-)
>  create mode 100644 arch/powerpc/kvm/book3s_64_entry.S
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 0097e0676ed7..ba13d749d203 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -208,7 +208,6 @@ do_define_int n
>  .endm
>  
>  #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
>  /*
>   * All interrupts which set HSRR registers, as well as SRESET and MCE and
>   * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
> @@ -238,13 +237,8 @@ do_define_int n
>  
>  /*
>   * If an interrupt is taken while a guest is running, it is immediately routed
> - * to KVM to handle. If both HV and PR KVM arepossible, KVM interrupts go first
> - * to kvmppc_interrupt_hv, which handles the PR guest case.
> + * to KVM to handle.
>   */
> -#define kvmppc_interrupt kvmppc_interrupt_hv
> -#else
> -#define kvmppc_interrupt kvmppc_interrupt_pr
> -#endif
>  
>  .macro KVMTEST name
>  	lbz	r10,HSTATE_IN_GUEST(r13)
> diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
> index 2bfeaa13befb..cdd119028f64 100644
> --- a/arch/powerpc/kvm/Makefile
> +++ b/arch/powerpc/kvm/Makefile
> @@ -59,6 +59,9 @@ kvm-pr-y := \
>  kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
>  	tm.o
>  
> +kvm-book3s_64-builtin-objs-y += \
> +	book3s_64_entry.o
> +
>  ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
>  kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
>  	book3s_rmhandlers.o
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> new file mode 100644
> index 000000000000..e9a6a8fbb164
> --- /dev/null
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -0,0 +1,35 @@
> +#include <asm/asm-offsets.h>
> +#include <asm/cache.h>
> +#include <asm/kvm_asm.h>
> +#include <asm/kvm_book3s_asm.h>
> +#include <asm/ppc_asm.h>
> +#include <asm/reg.h>
> +
> +/*
> + * This is branched to from interrupt handlers in exception-64s.S which set
> + * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
> + */
> +.global	kvmppc_interrupt
> +.balign IFETCH_ALIGN_BYTES
> +kvmppc_interrupt:
> +	/*
> +	 * Register contents:
> +	 * R12		= (guest CR << 32) | interrupt vector
> +	 * R13		= PACA
> +	 * guest R12 saved in shadow VCPU SCRATCH0
> +	 * guest R13 saved in SPRN_SCRATCH0
> +	 */
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +	std	r9,HSTATE_SCRATCH2(r13)
> +	lbz	r9,HSTATE_IN_GUEST(r13)
> +	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
> +	beq	kvmppc_bad_host_intr
> +#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> +	cmpwi	r9,KVM_GUEST_MODE_GUEST
> +	ld	r9,HSTATE_SCRATCH2(r13)
> +	beq	kvmppc_interrupt_pr
> +#endif
> +	b	kvmppc_interrupt_hv
> +#else
> +	b	kvmppc_interrupt_pr
> +#endif
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 5e634db4809b..f976efb7e4a9 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -1269,16 +1269,8 @@ kvmppc_interrupt_hv:
>  	 * R13		= PACA
>  	 * guest R12 saved in shadow VCPU SCRATCH0
>  	 * guest R13 saved in SPRN_SCRATCH0
> +	 * guest R9 saved in HSTATE_SCRATCH2
>  	 */
> -	std	r9, HSTATE_SCRATCH2(r13)
> -	lbz	r9, HSTATE_IN_GUEST(r13)
> -	cmpwi	r9, KVM_GUEST_MODE_HOST_HV
> -	beq	kvmppc_bad_host_intr
> -#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> -	cmpwi	r9, KVM_GUEST_MODE_GUEST
> -	ld	r9, HSTATE_SCRATCH2(r13)
> -	beq	kvmppc_interrupt_pr
> -#endif
>  	/* We're now back in the host but in guest MMU context */
>  	li	r9, KVM_GUEST_MODE_HOST_HV
>  	stb	r9, HSTATE_IN_GUEST(r13)
> @@ -3280,6 +3272,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
>   * cfar is saved in HSTATE_CFAR(r13)
>   * ppr is saved in HSTATE_PPR(r13)
>   */
> +.global kvmppc_bad_host_intr
>  kvmppc_bad_host_intr:
>  	/*
>  	 * Switch to the emergency stack, but start half-way down in
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 06/37] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
@ 2021-03-05  5:03     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  5:03 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

> Rather than bifurcate the call depending on whether or not HV is
> possible, and have the HV entry test for PR, just make a single
> common point which does the demultiplexing. This makes it simpler
> to add another type of exit handler.
>
> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

I checked this against the RFC which I was happy with and there are no
changes that I am concerned about. The expanded comment is also nice.

As such:
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S    |  8 +-----
>  arch/powerpc/kvm/Makefile               |  3 +++
>  arch/powerpc/kvm/book3s_64_entry.S      | 35 +++++++++++++++++++++++++
>  arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 ++------
>  4 files changed, 41 insertions(+), 16 deletions(-)
>  create mode 100644 arch/powerpc/kvm/book3s_64_entry.S
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 0097e0676ed7..ba13d749d203 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -208,7 +208,6 @@ do_define_int n
>  .endm
>  
>  #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
>  /*
>   * All interrupts which set HSRR registers, as well as SRESET and MCE and
>   * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
> @@ -238,13 +237,8 @@ do_define_int n
>  
>  /*
>   * If an interrupt is taken while a guest is running, it is immediately routed
> - * to KVM to handle. If both HV and PR KVM arepossible, KVM interrupts go first
> - * to kvmppc_interrupt_hv, which handles the PR guest case.
> + * to KVM to handle.
>   */
> -#define kvmppc_interrupt kvmppc_interrupt_hv
> -#else
> -#define kvmppc_interrupt kvmppc_interrupt_pr
> -#endif
>  
>  .macro KVMTEST name
>  	lbz	r10,HSTATE_IN_GUEST(r13)
> diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
> index 2bfeaa13befb..cdd119028f64 100644
> --- a/arch/powerpc/kvm/Makefile
> +++ b/arch/powerpc/kvm/Makefile
> @@ -59,6 +59,9 @@ kvm-pr-y := \
>  kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
>  	tm.o
>  
> +kvm-book3s_64-builtin-objs-y += \
> +	book3s_64_entry.o
> +
>  ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
>  kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
>  	book3s_rmhandlers.o
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> new file mode 100644
> index 000000000000..e9a6a8fbb164
> --- /dev/null
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -0,0 +1,35 @@
> +#include <asm/asm-offsets.h>
> +#include <asm/cache.h>
> +#include <asm/kvm_asm.h>
> +#include <asm/kvm_book3s_asm.h>
> +#include <asm/ppc_asm.h>
> +#include <asm/reg.h>
> +
> +/*
> + * This is branched to from interrupt handlers in exception-64s.S which set
> + * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
> + */
> +.global	kvmppc_interrupt
> +.balign IFETCH_ALIGN_BYTES
> +kvmppc_interrupt:
> +	/*
> +	 * Register contents:
> +	 * R12		= (guest CR << 32) | interrupt vector
> +	 * R13		= PACA
> +	 * guest R12 saved in shadow VCPU SCRATCH0
> +	 * guest R13 saved in SPRN_SCRATCH0
> +	 */
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +	std	r9,HSTATE_SCRATCH2(r13)
> +	lbz	r9,HSTATE_IN_GUEST(r13)
> +	cmpwi	r9,KVM_GUEST_MODE_HOST_HV
> +	beq	kvmppc_bad_host_intr
> +#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> +	cmpwi	r9,KVM_GUEST_MODE_GUEST
> +	ld	r9,HSTATE_SCRATCH2(r13)
> +	beq	kvmppc_interrupt_pr
> +#endif
> +	b	kvmppc_interrupt_hv
> +#else
> +	b	kvmppc_interrupt_pr
> +#endif
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 5e634db4809b..f976efb7e4a9 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -1269,16 +1269,8 @@ kvmppc_interrupt_hv:
>  	 * R13		= PACA
>  	 * guest R12 saved in shadow VCPU SCRATCH0
>  	 * guest R13 saved in SPRN_SCRATCH0
> +	 * guest R9 saved in HSTATE_SCRATCH2
>  	 */
> -	std	r9, HSTATE_SCRATCH2(r13)
> -	lbz	r9, HSTATE_IN_GUEST(r13)
> -	cmpwi	r9, KVM_GUEST_MODE_HOST_HV
> -	beq	kvmppc_bad_host_intr
> -#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> -	cmpwi	r9, KVM_GUEST_MODE_GUEST
> -	ld	r9, HSTATE_SCRATCH2(r13)
> -	beq	kvmppc_interrupt_pr
> -#endif
>  	/* We're now back in the host but in guest MMU context */
>  	li	r9, KVM_GUEST_MODE_HOST_HV
>  	stb	r9, HSTATE_IN_GUEST(r13)
> @@ -3280,6 +3272,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
>   * cfar is saved in HSTATE_CFAR(r13)
>   * ppr is saved in HSTATE_PPR(r13)
>   */
> +.global kvmppc_bad_host_intr
>  kvmppc_bad_host_intr:
>  	/*
>  	 * Switch to the emergency stack, but start half-way down in
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 07/37] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-05  5:54     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  5:54 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

> -	.if IKVM_SKIP
> -89:	mtocrf	0x80,r9
> -	ld	r10,IAREA+EX_CTR(r13)
> -	mtctr	r10
> -	ld	r9,IAREA+EX_R9(r13)
> -	ld	r10,IAREA+EX_R10(r13)
> -	ld	r11,IAREA+EX_R11(r13)
> -	ld	r12,IAREA+EX_R12(r13)
> -	.if IHSRR_IF_HVMODE
> -	BEGIN_FTR_SECTION
> -	b	kvmppc_skip_Hinterrupt
> -	FTR_SECTION_ELSE
> -	b	kvmppc_skip_interrupt
> -	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)

I was initially concerned that you were pulling out the complexities
around IHSRR_IF_HVMODE, but I checked exceptions-64s.S and the only
exception handler that sets IHSRR_IF_HVMODE is hardware_interrupt and
that does not set IKVM_SKIP, so we are indeed fine to not keep this
complex little asm section.

> -	.elseif IHSRR
> -	b	kvmppc_skip_Hinterrupt
> -	.else
> -	b	kvmppc_skip_interrupt
> -	.endif
> -	.endif
>  .endm

> +/*
> + * KVM uses a trick where it is running in MSR[HV]=1 mode in real-mode with the
> + * guest MMU context loaded, and it sets KVM_GUEST_MODE_SKIP and enables
> + * MSR[DR]=1 while leaving MSR[IR]=0, so it continues to fetch HV instructions
> + * but loads and stores will access the guest context. This is used to load
> + * the faulting instruction without walking page tables.
> + *
> + * However the guest context may not be able to translate, or it may cause a
> + * machine check or other issue, which will result in a fault in the host
> + * (even with KVM-HV).
> + *
> + * These faults are caught here and if the fault was (or was likely) due to
> + * that load, then we just return with the PC advanced +4 and skip the load,
> + * which then goes via the slow path.
> + */

This is a really helpful comment! Thanks!

> +.Lmaybe_skip:
> +	cmpwi	r12,BOOK3S_INTERRUPT_MACHINE_CHECK
> +	beq	1f
> +	cmpwi	r12,BOOK3S_INTERRUPT_DATA_STORAGE
> +	beq	1f
> +	cmpwi	r12,BOOK3S_INTERRUPT_DATA_SEGMENT
> +	beq	1f
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +	/* HSRR interrupts have 2 added to trap vector */
> +	cmpwi	r12,BOOK3S_INTERRUPT_H_DATA_STORAGE | 0x2

This took me by surprise for a while, but I checked how it works in
exceptions-64s.S and indeed the GEN_KVM macro will add 0x2 to the IVEC
if IHSRR is set, and it is set for h_data_storage.

So this checks out to me.

I have checked, to the best of my limited assembler capabilities that
the logic before and after matches. It seems good to me.

On that limited basis,
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel


> +	beq	2f
> +#endif
> +	b	.Lno_skip
> +1:	mfspr	r9,SPRN_SRR0
> +	addi	r9,r9,4
> +	mtspr	SPRN_SRR0,r9
> +	ld	r12,HSTATE_SCRATCH0(r13)
> +	ld	r9,HSTATE_SCRATCH2(r13)
> +	GET_SCRATCH0(r13)
> +	RFI_TO_KERNEL
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +2:	mfspr	r9,SPRN_HSRR0
> +	addi	r9,r9,4
> +	mtspr	SPRN_HSRR0,r9
> +	ld	r12,HSTATE_SCRATCH0(r13)
> +	ld	r9,HSTATE_SCRATCH2(r13)
> +	GET_SCRATCH0(r13)
> +	HRFI_TO_KERNEL
> +#endif
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 07/37] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
@ 2021-03-05  5:54     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  5:54 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

> -	.if IKVM_SKIP
> -89:	mtocrf	0x80,r9
> -	ld	r10,IAREA+EX_CTR(r13)
> -	mtctr	r10
> -	ld	r9,IAREA+EX_R9(r13)
> -	ld	r10,IAREA+EX_R10(r13)
> -	ld	r11,IAREA+EX_R11(r13)
> -	ld	r12,IAREA+EX_R12(r13)
> -	.if IHSRR_IF_HVMODE
> -	BEGIN_FTR_SECTION
> -	b	kvmppc_skip_Hinterrupt
> -	FTR_SECTION_ELSE
> -	b	kvmppc_skip_interrupt
> -	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)

I was initially concerned that you were pulling out the complexities
around IHSRR_IF_HVMODE, but I checked exceptions-64s.S and the only
exception handler that sets IHSRR_IF_HVMODE is hardware_interrupt and
that does not set IKVM_SKIP, so we are indeed fine to not keep this
complex little asm section.

> -	.elseif IHSRR
> -	b	kvmppc_skip_Hinterrupt
> -	.else
> -	b	kvmppc_skip_interrupt
> -	.endif
> -	.endif
>  .endm

> +/*
> + * KVM uses a trick where it is running in MSR[HV]=1 mode in real-mode with the
> + * guest MMU context loaded, and it sets KVM_GUEST_MODE_SKIP and enables
> + * MSR[DR]=1 while leaving MSR[IR]=0, so it continues to fetch HV instructions
> + * but loads and stores will access the guest context. This is used to load
> + * the faulting instruction without walking page tables.
> + *
> + * However the guest context may not be able to translate, or it may cause a
> + * machine check or other issue, which will result in a fault in the host
> + * (even with KVM-HV).
> + *
> + * These faults are caught here and if the fault was (or was likely) due to
> + * that load, then we just return with the PC advanced +4 and skip the load,
> + * which then goes via the slow path.
> + */

This is a really helpful comment! Thanks!

> +.Lmaybe_skip:
> +	cmpwi	r12,BOOK3S_INTERRUPT_MACHINE_CHECK
> +	beq	1f
> +	cmpwi	r12,BOOK3S_INTERRUPT_DATA_STORAGE
> +	beq	1f
> +	cmpwi	r12,BOOK3S_INTERRUPT_DATA_SEGMENT
> +	beq	1f
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +	/* HSRR interrupts have 2 added to trap vector */
> +	cmpwi	r12,BOOK3S_INTERRUPT_H_DATA_STORAGE | 0x2

This took me by surprise for a while, but I checked how it works in
exceptions-64s.S and indeed the GEN_KVM macro will add 0x2 to the IVEC
if IHSRR is set, and it is set for h_data_storage.

So this checks out to me.

I have checked, to the best of my limited assembler capabilities that
the logic before and after matches. It seems good to me.

On that limited basis,
Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel


> +	beq	2f
> +#endif
> +	b	.Lno_skip
> +1:	mfspr	r9,SPRN_SRR0
> +	addi	r9,r9,4
> +	mtspr	SPRN_SRR0,r9
> +	ld	r12,HSTATE_SCRATCH0(r13)
> +	ld	r9,HSTATE_SCRATCH2(r13)
> +	GET_SCRATCH0(r13)
> +	RFI_TO_KERNEL
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +2:	mfspr	r9,SPRN_HSRR0
> +	addi	r9,r9,4
> +	mtspr	SPRN_HSRR0,r9
> +	ld	r12,HSTATE_SCRATCH0(r13)
> +	ld	r9,HSTATE_SCRATCH2(r13)
> +	GET_SCRATCH0(r13)
> +	HRFI_TO_KERNEL
> +#endif
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 08/37] KVM: PPC: Book3S 64: add hcall interrupt handler
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-05  6:03     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  6:03 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

> Add a separate hcall entry point. This can be used to deal with the
> different calling convention.

Looks good to me, makes sense, passes checkpatch.

Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel


> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S | 4 ++--
>  arch/powerpc/kvm/book3s_64_entry.S   | 6 +++++-
>  2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index d956dd9ed61f..9ae463e8522b 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -1992,13 +1992,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>  	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
>  	 * outside the head section.
>  	 */
> -	__LOAD_FAR_HANDLER(r10, kvmppc_interrupt)
> +	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
>  	mtctr   r10
>  	ld	r10,PACA_EXGEN+EX_R10(r13)
>  	bctr
>  #else
>  	ld	r10,PACA_EXGEN+EX_R10(r13)
> -	b       kvmppc_interrupt
> +	b       kvmppc_hcall
>  #endif
>  #endif
>  
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index c1276f616af4..9572f759255c 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -7,9 +7,13 @@
>  #include <asm/reg.h>
>  
>  /*
> - * This is branched to from interrupt handlers in exception-64s.S which set
> + * These are branched to from interrupt handlers in exception-64s.S which set
>   * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
>   */
> +.global	kvmppc_hcall
> +.balign IFETCH_ALIGN_BYTES
> +kvmppc_hcall:
> +
>  .global	kvmppc_interrupt
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_interrupt:
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 08/37] KVM: PPC: Book3S 64: add hcall interrupt handler
@ 2021-03-05  6:03     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  6:03 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas

Hi Nick,

> Add a separate hcall entry point. This can be used to deal with the
> different calling convention.

Looks good to me, makes sense, passes checkpatch.

Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel


> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S | 4 ++--
>  arch/powerpc/kvm/book3s_64_entry.S   | 6 +++++-
>  2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index d956dd9ed61f..9ae463e8522b 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -1992,13 +1992,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>  	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
>  	 * outside the head section.
>  	 */
> -	__LOAD_FAR_HANDLER(r10, kvmppc_interrupt)
> +	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
>  	mtctr   r10
>  	ld	r10,PACA_EXGEN+EX_R10(r13)
>  	bctr
>  #else
>  	ld	r10,PACA_EXGEN+EX_R10(r13)
> -	b       kvmppc_interrupt
> +	b       kvmppc_hcall
>  #endif
>  #endif
>  
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index c1276f616af4..9572f759255c 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -7,9 +7,13 @@
>  #include <asm/reg.h>
>  
>  /*
> - * This is branched to from interrupt handlers in exception-64s.S which set
> + * These are branched to from interrupt handlers in exception-64s.S which set
>   * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
>   */
> +.global	kvmppc_hcall
> +.balign IFETCH_ALIGN_BYTES
> +kvmppc_hcall:
> +
>  .global	kvmppc_interrupt
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_interrupt:
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 09/37] KVM: PPC: Book3S 64: Move hcall early register setup to KVM
  2021-02-25 13:46   ` Nicholas Piggin
@ 2021-03-05  6:48     ` Daniel Axtens
  -1 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  6:48 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> System calls / hcalls have a different calling convention than
> other interrupts, so there is code in the KVMTEST to massage these
> into the same form as other interrupt handlers.
>
> Move this work into the KVM hcall handler. This means teaching KVM
> a little more about the low level interrupt handler setup, PACA save
> areas, etc., although that's not obviously worse than the current
> approach of coming up with an entirely different interrupt register
> / save convention.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/exception-64s.h | 13 +++++++
>  arch/powerpc/kernel/exceptions-64s.S     | 44 ++----------------------
>  arch/powerpc/kvm/book3s_64_entry.S       | 17 +++++++++
>  3 files changed, 32 insertions(+), 42 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
> index c1a8aac01cf9..bb6f78fcf981 100644
> --- a/arch/powerpc/include/asm/exception-64s.h
> +++ b/arch/powerpc/include/asm/exception-64s.h
> @@ -35,6 +35,19 @@
>  /* PACA save area size in u64 units (exgen, exmc, etc) */
>  #define EX_SIZE		10
>  
> +/* PACA save area offsets */
> +#define EX_R9		0
> +#define EX_R10		8
> +#define EX_R11		16
> +#define EX_R12		24
> +#define EX_R13		32
> +#define EX_DAR		40
> +#define EX_DSISR	48
> +#define EX_CCR		52
> +#define EX_CFAR		56
> +#define EX_PPR		64
> +#define EX_CTR		72

I wonder - now that EX_blah and EX_SIZE both live in the one header
file, if we could calculate EX_SIZE based on the last offset... or have
a BUILD_BUG_ON or something? ... just trying not to lose the sanity
checking afforded to us by the .if macro we lose when moving these out
of exceptions-64s.S...

> +
>  /*
>   * maximum recursive depth of MCE exceptions
>   */
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 9ae463e8522b..b7092ba87da8 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -21,22 +21,6 @@
>  #include <asm/feature-fixups.h>
>  #include <asm/kup.h>
>  
> -/* PACA save area offsets (exgen, exmc, etc) */
> -#define EX_R9		0
> -#define EX_R10		8
> -#define EX_R11		16
> -#define EX_R12		24
> -#define EX_R13		32
> -#define EX_DAR		40
> -#define EX_DSISR	48
> -#define EX_CCR		52
> -#define EX_CFAR		56
> -#define EX_PPR		64
> -#define EX_CTR		72
> -.if EX_SIZE != 10
> -	.error "EX_SIZE is wrong"
> -.endif
> -
>  /*
>   * Following are fixed section helper macros.
>   *
> @@ -1964,45 +1948,21 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
>  
>  #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
>  TRAMP_REAL_BEGIN(system_call_kvm)
> -	/*
> -	 * This is a hcall, so register convention is as above, with these
> -	 * differences:
> -	 * r13 = PACA
> -	 * ctr = orig r13
> -	 * orig r10 saved in PACA
> -	 */
> -	 /*
> -	  * Save the PPR (on systems that support it) before changing to
> -	  * HMT_MEDIUM. That allows the KVM code to save that value into the
> -	  * guest state (it is the guest's PPR value).
> -	  */
> -BEGIN_FTR_SECTION
> -	mfspr	r10,SPRN_PPR
> -	std	r10,HSTATE_PPR(r13)
> -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> -	HMT_MEDIUM
>  	mfctr	r10
> -	SET_SCRATCH0(r10)
> -	mfcr	r10
> -	std	r12,HSTATE_SCRATCH0(r13)
> -	sldi	r12,r10,32
> -	ori	r12,r12,0xc00
> +	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
>  #ifdef CONFIG_RELOCATABLE
>  	/*
> -	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
> +	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives

That change probably belongs in the previous patch :)

Beyond that, I'm still wrapping my head around the deep magic going on
here! Hopefully I'll get a bit a bit further next time I look.

Kind regards,
Daniel

>  	 * outside the head section.
>  	 */
>  	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
>  	mtctr   r10
> -	ld	r10,PACA_EXGEN+EX_R10(r13)
>  	bctr
>  #else
> -	ld	r10,PACA_EXGEN+EX_R10(r13)
>  	b       kvmppc_hcall
>  #endif
>  #endif
>  
> -
>  /**
>   * Interrupt 0xd00 - Trace Interrupt.
>   * This is a synchronous interrupt in response to instruction step or
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index 9572f759255c..1c9518ab7d96 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -13,6 +13,23 @@
>  .global	kvmppc_hcall
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_hcall:
> +	/*
> +	 * This is a hcall, so register convention is as
> +	 * Documentation/powerpc/papr_hcalls.rst, with these additions:
> +	 * R13		= PACA
> +	 * guest R13 saved in SPRN_SCRATCH0
> +	 * R10		= free
> +	 */
> +BEGIN_FTR_SECTION
> +	mfspr	r10,SPRN_PPR
> +	std	r10,HSTATE_PPR(r13)
> +END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> +	HMT_MEDIUM
> +	mfcr	r10
> +	std	r12,HSTATE_SCRATCH0(r13)
> +	sldi	r12,r10,32
> +	ori	r12,r12,0xc00
> +	ld	r10,PACA_EXGEN+EX_R10(r13)
>  
>  .global	kvmppc_interrupt
>  .balign IFETCH_ALIGN_BYTES
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
* Re: [PATCH v2 09/37] KVM: PPC: Book3S 64: Move hcall early register setup to KVM
@ 2021-03-05  6:48     ` Daniel Axtens
  0 siblings, 0 replies; 134+ messages in thread
From: Daniel Axtens @ 2021-03-05  6:48 UTC (permalink / raw)
  To: Nicholas Piggin, kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin

Nicholas Piggin <npiggin@gmail.com> writes:

> System calls / hcalls have a different calling convention than
> other interrupts, so there is code in the KVMTEST to massage these
> into the same form as other interrupt handlers.
>
> Move this work into the KVM hcall handler. This means teaching KVM
> a little more about the low level interrupt handler setup, PACA save
> areas, etc., although that's not obviously worse than the current
> approach of coming up with an entirely different interrupt register
> / save convention.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/include/asm/exception-64s.h | 13 +++++++
>  arch/powerpc/kernel/exceptions-64s.S     | 44 ++----------------------
>  arch/powerpc/kvm/book3s_64_entry.S       | 17 +++++++++
>  3 files changed, 32 insertions(+), 42 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
> index c1a8aac01cf9..bb6f78fcf981 100644
> --- a/arch/powerpc/include/asm/exception-64s.h
> +++ b/arch/powerpc/include/asm/exception-64s.h
> @@ -35,6 +35,19 @@
>  /* PACA save area size in u64 units (exgen, exmc, etc) */
>  #define EX_SIZE		10
>  
> +/* PACA save area offsets */
> +#define EX_R9		0
> +#define EX_R10		8
> +#define EX_R11		16
> +#define EX_R12		24
> +#define EX_R13		32
> +#define EX_DAR		40
> +#define EX_DSISR	48
> +#define EX_CCR		52
> +#define EX_CFAR		56
> +#define EX_PPR		64
> +#define EX_CTR		72

I wonder - now that EX_blah and EX_SIZE both live in the one header
file, if we could calculate EX_SIZE based on the last offset... or have
a BUILD_BUG_ON or something? ... just trying not to lose the sanity
checking afforded to us by the .if macro we lose when moving these out
of exceptions-64s.S...

> +
>  /*
>   * maximum recursive depth of MCE exceptions
>   */
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 9ae463e8522b..b7092ba87da8 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -21,22 +21,6 @@
>  #include <asm/feature-fixups.h>
>  #include <asm/kup.h>
>  
> -/* PACA save area offsets (exgen, exmc, etc) */
> -#define EX_R9		0
> -#define EX_R10		8
> -#define EX_R11		16
> -#define EX_R12		24
> -#define EX_R13		32
> -#define EX_DAR		40
> -#define EX_DSISR	48
> -#define EX_CCR		52
> -#define EX_CFAR		56
> -#define EX_PPR		64
> -#define EX_CTR		72
> -.if EX_SIZE != 10
> -	.error "EX_SIZE is wrong"
> -.endif
> -
>  /*
>   * Following are fixed section helper macros.
>   *
> @@ -1964,45 +1948,21 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
>  
>  #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
>  TRAMP_REAL_BEGIN(system_call_kvm)
> -	/*
> -	 * This is a hcall, so register convention is as above, with these
> -	 * differences:
> -	 * r13 = PACA
> -	 * ctr = orig r13
> -	 * orig r10 saved in PACA
> -	 */
> -	 /*
> -	  * Save the PPR (on systems that support it) before changing to
> -	  * HMT_MEDIUM. That allows the KVM code to save that value into the
> -	  * guest state (it is the guest's PPR value).
> -	  */
> -BEGIN_FTR_SECTION
> -	mfspr	r10,SPRN_PPR
> -	std	r10,HSTATE_PPR(r13)
> -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> -	HMT_MEDIUM
>  	mfctr	r10
> -	SET_SCRATCH0(r10)
> -	mfcr	r10
> -	std	r12,HSTATE_SCRATCH0(r13)
> -	sldi	r12,r10,32
> -	ori	r12,r12,0xc00
> +	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
>  #ifdef CONFIG_RELOCATABLE
>  	/*
> -	 * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
> +	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives

That change probably belongs in the previous patch :)

Beyond that, I'm still wrapping my head around the deep magic going on
here! Hopefully I'll get a bit a bit further next time I look.

Kind regards,
Daniel

>  	 * outside the head section.
>  	 */
>  	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
>  	mtctr   r10
> -	ld	r10,PACA_EXGEN+EX_R10(r13)
>  	bctr
>  #else
> -	ld	r10,PACA_EXGEN+EX_R10(r13)
>  	b       kvmppc_hcall
>  #endif
>  #endif
>  
> -
>  /**
>   * Interrupt 0xd00 - Trace Interrupt.
>   * This is a synchronous interrupt in response to instruction step or
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index 9572f759255c..1c9518ab7d96 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -13,6 +13,23 @@
>  .global	kvmppc_hcall
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_hcall:
> +	/*
> +	 * This is a hcall, so register convention is as
> +	 * Documentation/powerpc/papr_hcalls.rst, with these additions:
> +	 * R13		= PACA
> +	 * guest R13 saved in SPRN_SCRATCH0
> +	 * R10		= free
> +	 */
> +BEGIN_FTR_SECTION
> +	mfspr	r10,SPRN_PPR
> +	std	r10,HSTATE_PPR(r13)
> +END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> +	HMT_MEDIUM
> +	mfcr	r10
> +	std	r12,HSTATE_SCRATCH0(r13)
> +	sldi	r12,r10,32
> +	ori	r12,r12,0xc00
> +	ld	r10,PACA_EXGEN+EX_R10(r13)
>  
>  .global	kvmppc_interrupt
>  .balign IFETCH_ALIGN_BYTES
> -- 
> 2.23.0

^ permalink raw reply	[flat|nested] 134+ messages in thread
end of thread, other threads:[~2021-03-05  6:48 UTC | newest]

Thread overview: 134+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-25 13:46 [PATCH v2 00/37] KVM: PPC: Book3S: C-ify the P9 entry/exit code Nicholas Piggin
2021-02-25 13:46 ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  5:01   ` Daniel Axtens
2021-02-26  5:01     ` Daniel Axtens
2021-02-26 23:50     ` Nicholas Piggin
2021-02-26 23:50       ` Nicholas Piggin
2021-03-05  4:45       ` Daniel Axtens
2021-03-05  4:45         ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 02/37] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  5:21   ` Daniel Axtens
2021-02-26  5:21     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 03/37] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  5:44   ` Daniel Axtens
2021-02-26  5:44     ` Daniel Axtens
2021-02-26 23:51     ` Nicholas Piggin
2021-02-26 23:51       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  6:06   ` Daniel Axtens
2021-02-26  6:06     ` Daniel Axtens
2021-02-26 23:55     ` Nicholas Piggin
2021-02-26 23:55       ` Nicholas Piggin
2021-03-05  4:50       ` Daniel Axtens
2021-03-05  4:50         ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 06/37] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  5:03   ` Daniel Axtens
2021-03-05  5:03     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 07/37] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  5:54   ` Daniel Axtens
2021-03-05  5:54     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 08/37] KVM: PPC: Book3S 64: add hcall interrupt handler Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  6:03   ` Daniel Axtens
2021-03-05  6:03     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 09/37] KVM: PPC: Book3S 64: Move hcall early register setup to KVM Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  6:48   ` Daniel Axtens
2021-03-05  6:48     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 10/37] KVM: PPC: Book3S 64: Move interrupt " Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 11/37] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 12/37] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26 15:56   ` Fabiano Rosas
2021-02-26 15:56     ` Fabiano Rosas
2021-02-26 23:57     ` Nicholas Piggin
2021-02-26 23:57       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 14/37] KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 15/37] KVM: PPC: Book3S HV P9: Move xive vcpu context management into kvmhv_p9_guest_entry Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 14:51   ` Cédric Le Goater
2021-02-25 14:51     ` Cédric Le Goater
2021-02-26 23:59     ` Nicholas Piggin
2021-02-26 23:59       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26 16:38   ` Fabiano Rosas
2021-02-26 16:38     ` Fabiano Rosas
2021-02-26 23:59     ` Nicholas Piggin
2021-02-26 23:59       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 18/37] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 19/37] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 20/37] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 21/37] powerpc: add set_dec_or_work API for safely updating decrementer Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 22/37] KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26 22:37   ` Fabiano Rosas
2021-02-26 22:37     ` Fabiano Rosas
2021-02-27  0:21     ` Nicholas Piggin
2021-02-27  0:21       ` Nicholas Piggin
2021-02-27  0:55       ` Nicholas Piggin
2021-02-27  0:55         ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entry_p9 Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-02 13:48   ` Fabiano Rosas
2021-03-02 13:48     ` [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entr Fabiano Rosas
2021-02-25 13:46 ` [PATCH v2 25/37] KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0 Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 26/37] KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 27/37] KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-02 15:04   ` Fabiano Rosas
2021-03-02 15:04     ` Fabiano Rosas
2021-03-04 11:02     ` Nicholas Piggin
2021-03-04 11:02       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 29/37] KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as possible Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-02 21:21   ` Fabiano Rosas
2021-03-02 21:21     ` Fabiano Rosas
2021-03-04 11:04     ` Nicholas Piggin
2021-03-04 11:04       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 31/37] KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9 Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 32/37] KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 33/37] KVM: PPC: Book3S HV: small pseries_do_hcall cleanup Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-03 20:09   ` Fabiano Rosas
2021-03-03 20:09     ` Fabiano Rosas
2021-03-04 11:05     ` Nicholas Piggin
2021-03-04 11:05       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 35/37] KVM: PPC: Book3S HV P9: implement hash guest support Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 36/37] KVM: PPC: Book3S HV P9: implement hash host / " Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 37/37] KVM: PPC: Book3S HV: remove POWER9 support from P7/8 paths Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin

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