* [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst()
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
Read guest last instruction from kvmppc_get_last_inst() allowing the function
to fail in order to emulate again. On bookehv architecture search for
the physical address and kmap it, instead of using Load External PID (lwepx)
instruction. This fixes an infinite loop caused by lwepx's data TLB miss
exception handled in the host and the TODO for execute-but-not-read entries
and TLB eviction.
Mihai Caraman (5):
KVM: PPC: e500mc: Revert "add load inst fixup"
KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
KVM: PPC: Book3s: Remove kvmppc_read_inst() function
KVM: PPC: Alow kvmppc_get_last_inst() to fail
KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
arch/powerpc/include/asm/kvm_book3s.h | 26 -------
arch/powerpc/include/asm/kvm_booke.h | 5 --
arch/powerpc/include/asm/kvm_ppc.h | 31 +++++++++
arch/powerpc/include/asm/mmu-book3e.h | 9 ++-
arch/powerpc/kvm/book3s.c | 17 +++++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++---
arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++----
arch/powerpc/kvm/book3s_pr.c | 114 ++++++++++++++++---------------
arch/powerpc/kvm/booke.c | 47 +++++++++++++
arch/powerpc/kvm/bookehv_interrupts.S | 55 ++-------------
arch/powerpc/kvm/e500_mmu_host.c | 98 ++++++++++++++++++++++++++
arch/powerpc/kvm/emulate.c | 18 +++--
arch/powerpc/kvm/powerpc.c | 11 ++-
13 files changed, 314 insertions(+), 172 deletions(-)
--
1.7.11.7
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst()
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: Mihai Caraman, linuxppc-dev, kvm
Read guest last instruction from kvmppc_get_last_inst() allowing the function
to fail in order to emulate again. On bookehv architecture search for
the physical address and kmap it, instead of using Load External PID (lwepx)
instruction. This fixes an infinite loop caused by lwepx's data TLB miss
exception handled in the host and the TODO for execute-but-not-read entries
and TLB eviction.
Mihai Caraman (5):
KVM: PPC: e500mc: Revert "add load inst fixup"
KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
KVM: PPC: Book3s: Remove kvmppc_read_inst() function
KVM: PPC: Alow kvmppc_get_last_inst() to fail
KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
arch/powerpc/include/asm/kvm_book3s.h | 26 -------
arch/powerpc/include/asm/kvm_booke.h | 5 --
arch/powerpc/include/asm/kvm_ppc.h | 31 +++++++++
arch/powerpc/include/asm/mmu-book3e.h | 9 ++-
arch/powerpc/kvm/book3s.c | 17 +++++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++---
arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++----
arch/powerpc/kvm/book3s_pr.c | 114 ++++++++++++++++---------------
arch/powerpc/kvm/booke.c | 47 +++++++++++++
arch/powerpc/kvm/bookehv_interrupts.S | 55 ++-------------
arch/powerpc/kvm/e500_mmu_host.c | 98 ++++++++++++++++++++++++++
arch/powerpc/kvm/emulate.c | 18 +++--
arch/powerpc/kvm/powerpc.c | 11 ++-
13 files changed, 314 insertions(+), 172 deletions(-)
--
1.7.11.7
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst()
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
Read guest last instruction from kvmppc_get_last_inst() allowing the function
to fail in order to emulate again. On bookehv architecture search for
the physical address and kmap it, instead of using Load External PID (lwepx)
instruction. This fixes an infinite loop caused by lwepx's data TLB miss
exception handled in the host and the TODO for execute-but-not-read entries
and TLB eviction.
Mihai Caraman (5):
KVM: PPC: e500mc: Revert "add load inst fixup"
KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
KVM: PPC: Book3s: Remove kvmppc_read_inst() function
KVM: PPC: Alow kvmppc_get_last_inst() to fail
KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
arch/powerpc/include/asm/kvm_book3s.h | 26 -------
arch/powerpc/include/asm/kvm_booke.h | 5 --
arch/powerpc/include/asm/kvm_ppc.h | 31 +++++++++
arch/powerpc/include/asm/mmu-book3e.h | 9 ++-
arch/powerpc/kvm/book3s.c | 17 +++++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++---
arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++----
arch/powerpc/kvm/book3s_pr.c | 114 ++++++++++++++++---------------
arch/powerpc/kvm/booke.c | 47 +++++++++++++
arch/powerpc/kvm/bookehv_interrupts.S | 55 ++-------------
arch/powerpc/kvm/e500_mmu_host.c | 98 ++++++++++++++++++++++++++
arch/powerpc/kvm/emulate.c | 18 +++--
arch/powerpc/kvm/powerpc.c | 11 ++-
13 files changed, 314 insertions(+), 172 deletions(-)
--
1.7.11.7
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH v6 1/5] KVM: PPC: e500mc: Revert "add load inst fixup"
2014-07-23 16:06 ` Mihai Caraman
(?)
@ 2014-07-23 16:06 ` Mihai Caraman
-1 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
The commit 1d628af7 "add load inst fixup" made an attempt to handle
failures generated by reading the guest current instruction. The fixup
code that was added works by chance hiding the real issue.
Load external pid (lwepx) instruction, used by KVM to read guest
instructions, is executed in a subsituted guest translation context
(EPLC[EGS] = 1). In consequence lwepx's TLB error and data storage
interrupts need to be handled by KVM, even though these interrupts
are generated from host context (MSR[GS] = 0) where lwepx is executed.
Currently, KVM hooks only interrupts generated from guest context
(MSR[GS] = 1), doing minimal checks on the fast path to avoid host
performance degradation. As a result, the host kernel handles lwepx
faults searching the faulting guest data address (loaded in DEAR) in
its own Logical Partition ID (LPID) 0 context. In case a host translation
is found the execution returns to the lwepx instruction instead of the
fixup, the host ending up in an infinite loop.
Revert the commit "add load inst fixup". lwepx issue will be addressed
in a subsequent patch without needing fixup code.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6-v2:
- no change
arch/powerpc/kvm/bookehv_interrupts.S | 26 +-------------------------
1 file changed, 1 insertion(+), 25 deletions(-)
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index a1712b8..6ff4480 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -29,7 +29,6 @@
#include <asm/asm-compat.h>
#include <asm/asm-offsets.h>
#include <asm/bitsperlong.h>
-#include <asm/thread_info.h>
#ifdef CONFIG_64BIT
#include <asm/exception-64e.h>
@@ -164,32 +163,9 @@
PPC_STL r30, VCPU_GPR(R30)(r4)
PPC_STL r31, VCPU_GPR(R31)(r4)
mtspr SPRN_EPLC, r8
-
- /* disable preemption, so we are sure we hit the fixup handler */
- CURRENT_THREAD_INFO(r8, r1)
- li r7, 1
- stw r7, TI_PREEMPT(r8)
-
isync
-
- /*
- * In case the read goes wrong, we catch it and write an invalid value
- * in LAST_INST instead.
- */
-1: lwepx r9, 0, r5
-2:
-.section .fixup, "ax"
-3: li r9, KVM_INST_FETCH_FAILED
- b 2b
-.previous
-.section __ex_table,"a"
- PPC_LONG_ALIGN
- PPC_LONG 1b,3b
-.previous
-
+ lwepx r9, 0, r5
mtspr SPRN_EPLC, r3
- li r7, 0
- stw r7, TI_PREEMPT(r8)
stw r9, VCPU_LAST_INST(r4)
.endif
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 1/5] KVM: PPC: e500mc: Revert "add load inst fixup"
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: Mihai Caraman, linuxppc-dev, kvm
The commit 1d628af7 "add load inst fixup" made an attempt to handle
failures generated by reading the guest current instruction. The fixup
code that was added works by chance hiding the real issue.
Load external pid (lwepx) instruction, used by KVM to read guest
instructions, is executed in a subsituted guest translation context
(EPLC[EGS] = 1). In consequence lwepx's TLB error and data storage
interrupts need to be handled by KVM, even though these interrupts
are generated from host context (MSR[GS] = 0) where lwepx is executed.
Currently, KVM hooks only interrupts generated from guest context
(MSR[GS] = 1), doing minimal checks on the fast path to avoid host
performance degradation. As a result, the host kernel handles lwepx
faults searching the faulting guest data address (loaded in DEAR) in
its own Logical Partition ID (LPID) 0 context. In case a host translation
is found the execution returns to the lwepx instruction instead of the
fixup, the host ending up in an infinite loop.
Revert the commit "add load inst fixup". lwepx issue will be addressed
in a subsequent patch without needing fixup code.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6-v2:
- no change
arch/powerpc/kvm/bookehv_interrupts.S | 26 +-------------------------
1 file changed, 1 insertion(+), 25 deletions(-)
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index a1712b8..6ff4480 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -29,7 +29,6 @@
#include <asm/asm-compat.h>
#include <asm/asm-offsets.h>
#include <asm/bitsperlong.h>
-#include <asm/thread_info.h>
#ifdef CONFIG_64BIT
#include <asm/exception-64e.h>
@@ -164,32 +163,9 @@
PPC_STL r30, VCPU_GPR(R30)(r4)
PPC_STL r31, VCPU_GPR(R31)(r4)
mtspr SPRN_EPLC, r8
-
- /* disable preemption, so we are sure we hit the fixup handler */
- CURRENT_THREAD_INFO(r8, r1)
- li r7, 1
- stw r7, TI_PREEMPT(r8)
-
isync
-
- /*
- * In case the read goes wrong, we catch it and write an invalid value
- * in LAST_INST instead.
- */
-1: lwepx r9, 0, r5
-2:
-.section .fixup, "ax"
-3: li r9, KVM_INST_FETCH_FAILED
- b 2b
-.previous
-.section __ex_table,"a"
- PPC_LONG_ALIGN
- PPC_LONG 1b,3b
-.previous
-
+ lwepx r9, 0, r5
mtspr SPRN_EPLC, r3
- li r7, 0
- stw r7, TI_PREEMPT(r8)
stw r9, VCPU_LAST_INST(r4)
.endif
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 1/5] KVM: PPC: e500mc: Revert "add load inst fixup"
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
The commit 1d628af7 "add load inst fixup" made an attempt to handle
failures generated by reading the guest current instruction. The fixup
code that was added works by chance hiding the real issue.
Load external pid (lwepx) instruction, used by KVM to read guest
instructions, is executed in a subsituted guest translation context
(EPLC[EGS] = 1). In consequence lwepx's TLB error and data storage
interrupts need to be handled by KVM, even though these interrupts
are generated from host context (MSR[GS] = 0) where lwepx is executed.
Currently, KVM hooks only interrupts generated from guest context
(MSR[GS] = 1), doing minimal checks on the fast path to avoid host
performance degradation. As a result, the host kernel handles lwepx
faults searching the faulting guest data address (loaded in DEAR) in
its own Logical Partition ID (LPID) 0 context. In case a host translation
is found the execution returns to the lwepx instruction instead of the
fixup, the host ending up in an infinite loop.
Revert the commit "add load inst fixup". lwepx issue will be addressed
in a subsequent patch without needing fixup code.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6-v2:
- no change
arch/powerpc/kvm/bookehv_interrupts.S | 26 +-------------------------
1 file changed, 1 insertion(+), 25 deletions(-)
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index a1712b8..6ff4480 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -29,7 +29,6 @@
#include <asm/asm-compat.h>
#include <asm/asm-offsets.h>
#include <asm/bitsperlong.h>
-#include <asm/thread_info.h>
#ifdef CONFIG_64BIT
#include <asm/exception-64e.h>
@@ -164,32 +163,9 @@
PPC_STL r30, VCPU_GPR(R30)(r4)
PPC_STL r31, VCPU_GPR(R31)(r4)
mtspr SPRN_EPLC, r8
-
- /* disable preemption, so we are sure we hit the fixup handler */
- CURRENT_THREAD_INFO(r8, r1)
- li r7, 1
- stw r7, TI_PREEMPT(r8)
-
isync
-
- /*
- * In case the read goes wrong, we catch it and write an invalid value
- * in LAST_INST instead.
- */
-1: lwepx r9, 0, r5
-2:
-.section .fixup, "ax"
-3: li r9, KVM_INST_FETCH_FAILED
- b 2b
-.previous
-.section __ex_table,"a"
- PPC_LONG_ALIGN
- PPC_LONG 1b,3b
-.previous
-
+ lwepx r9, 0, r5
mtspr SPRN_EPLC, r3
- li r7, 0
- stw r7, TI_PREEMPT(r8)
stw r9, VCPU_LAST_INST(r4)
.endif
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 2/5] KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
2014-07-23 16:06 ` Mihai Caraman
(?)
@ 2014-07-23 16:06 ` Mihai Caraman
-1 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
Add mising defines MAS0_GET_TLBSEL() and MAS1_GET_TSIZE() for Book3E.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6-v2:
- no change
arch/powerpc/include/asm/mmu-book3e.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/mmu-book3e.h b/arch/powerpc/include/asm/mmu-book3e.h
index 8d24f78..cd4f04a 100644
--- a/arch/powerpc/include/asm/mmu-book3e.h
+++ b/arch/powerpc/include/asm/mmu-book3e.h
@@ -40,9 +40,11 @@
/* MAS registers bit definitions */
-#define MAS0_TLBSEL_MASK 0x30000000
-#define MAS0_TLBSEL_SHIFT 28
-#define MAS0_TLBSEL(x) (((x) << MAS0_TLBSEL_SHIFT) & MAS0_TLBSEL_MASK)
+#define MAS0_TLBSEL_MASK 0x30000000
+#define MAS0_TLBSEL_SHIFT 28
+#define MAS0_TLBSEL(x) (((x) << MAS0_TLBSEL_SHIFT) & MAS0_TLBSEL_MASK)
+#define MAS0_GET_TLBSEL(mas0) (((mas0) & MAS0_TLBSEL_MASK) >> \
+ MAS0_TLBSEL_SHIFT)
#define MAS0_ESEL_MASK 0x0FFF0000
#define MAS0_ESEL_SHIFT 16
#define MAS0_ESEL(x) (((x) << MAS0_ESEL_SHIFT) & MAS0_ESEL_MASK)
@@ -60,6 +62,7 @@
#define MAS1_TSIZE_MASK 0x00000f80
#define MAS1_TSIZE_SHIFT 7
#define MAS1_TSIZE(x) (((x) << MAS1_TSIZE_SHIFT) & MAS1_TSIZE_MASK)
+#define MAS1_GET_TSIZE(mas1) (((mas1) & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT)
#define MAS2_EPN (~0xFFFUL)
#define MAS2_X0 0x00000040
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 2/5] KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: Mihai Caraman, linuxppc-dev, kvm
Add mising defines MAS0_GET_TLBSEL() and MAS1_GET_TSIZE() for Book3E.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6-v2:
- no change
arch/powerpc/include/asm/mmu-book3e.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/mmu-book3e.h b/arch/powerpc/include/asm/mmu-book3e.h
index 8d24f78..cd4f04a 100644
--- a/arch/powerpc/include/asm/mmu-book3e.h
+++ b/arch/powerpc/include/asm/mmu-book3e.h
@@ -40,9 +40,11 @@
/* MAS registers bit definitions */
-#define MAS0_TLBSEL_MASK 0x30000000
-#define MAS0_TLBSEL_SHIFT 28
-#define MAS0_TLBSEL(x) (((x) << MAS0_TLBSEL_SHIFT) & MAS0_TLBSEL_MASK)
+#define MAS0_TLBSEL_MASK 0x30000000
+#define MAS0_TLBSEL_SHIFT 28
+#define MAS0_TLBSEL(x) (((x) << MAS0_TLBSEL_SHIFT) & MAS0_TLBSEL_MASK)
+#define MAS0_GET_TLBSEL(mas0) (((mas0) & MAS0_TLBSEL_MASK) >> \
+ MAS0_TLBSEL_SHIFT)
#define MAS0_ESEL_MASK 0x0FFF0000
#define MAS0_ESEL_SHIFT 16
#define MAS0_ESEL(x) (((x) << MAS0_ESEL_SHIFT) & MAS0_ESEL_MASK)
@@ -60,6 +62,7 @@
#define MAS1_TSIZE_MASK 0x00000f80
#define MAS1_TSIZE_SHIFT 7
#define MAS1_TSIZE(x) (((x) << MAS1_TSIZE_SHIFT) & MAS1_TSIZE_MASK)
+#define MAS1_GET_TSIZE(mas1) (((mas1) & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT)
#define MAS2_EPN (~0xFFFUL)
#define MAS2_X0 0x00000040
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 2/5] KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
Add mising defines MAS0_GET_TLBSEL() and MAS1_GET_TSIZE() for Book3E.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6-v2:
- no change
arch/powerpc/include/asm/mmu-book3e.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/mmu-book3e.h b/arch/powerpc/include/asm/mmu-book3e.h
index 8d24f78..cd4f04a 100644
--- a/arch/powerpc/include/asm/mmu-book3e.h
+++ b/arch/powerpc/include/asm/mmu-book3e.h
@@ -40,9 +40,11 @@
/* MAS registers bit definitions */
-#define MAS0_TLBSEL_MASK 0x30000000
-#define MAS0_TLBSEL_SHIFT 28
-#define MAS0_TLBSEL(x) (((x) << MAS0_TLBSEL_SHIFT) & MAS0_TLBSEL_MASK)
+#define MAS0_TLBSEL_MASK 0x30000000
+#define MAS0_TLBSEL_SHIFT 28
+#define MAS0_TLBSEL(x) (((x) << MAS0_TLBSEL_SHIFT) & MAS0_TLBSEL_MASK)
+#define MAS0_GET_TLBSEL(mas0) (((mas0) & MAS0_TLBSEL_MASK) >> \
+ MAS0_TLBSEL_SHIFT)
#define MAS0_ESEL_MASK 0x0FFF0000
#define MAS0_ESEL_SHIFT 16
#define MAS0_ESEL(x) (((x) << MAS0_ESEL_SHIFT) & MAS0_ESEL_MASK)
@@ -60,6 +62,7 @@
#define MAS1_TSIZE_MASK 0x00000f80
#define MAS1_TSIZE_SHIFT 7
#define MAS1_TSIZE(x) (((x) << MAS1_TSIZE_SHIFT) & MAS1_TSIZE_MASK)
+#define MAS1_GET_TSIZE(mas1) (((mas1) & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT)
#define MAS2_EPN (~0xFFFUL)
#define MAS2_X0 0x00000040
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 3/5] KVM: PPC: Book3s: Remove kvmppc_read_inst() function
2014-07-23 16:06 ` Mihai Caraman
(?)
@ 2014-07-23 16:06 ` Mihai Caraman
-1 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
In the context of replacing kvmppc_ld() function calls with a version of
kvmppc_get_last_inst() which allow to fail, Alex Graf suggested this:
"If we get EMULATE_AGAIN, we just have to make sure we go back into the guest.
No need to inject an ISI into the guest - it'll do that all by itself.
With an error returning kvmppc_get_last_inst we can just use completely
get rid of kvmppc_read_inst() and only use kvmppc_get_last_inst() instead."
As a intermediate step get rid of kvmppc_read_inst() and only use kvmppc_ld()
instead.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- add proper comments for VSX interrupt handling
v5:
- make paired single emulation the unusual
v4:
- new patch
arch/powerpc/kvm/book3s_pr.c | 85 ++++++++++++++++++--------------------------
1 file changed, 34 insertions(+), 51 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index e40765f..e76aec3 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -710,42 +710,6 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac)
#endif
}
-static int kvmppc_read_inst(struct kvm_vcpu *vcpu)
-{
- ulong srr0 = kvmppc_get_pc(vcpu);
- u32 last_inst = kvmppc_get_last_inst(vcpu);
- int ret;
-
- ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
- if (ret == -ENOENT) {
- ulong msr = kvmppc_get_msr(vcpu);
-
- msr = kvmppc_set_field(msr, 33, 33, 1);
- msr = kvmppc_set_field(msr, 34, 36, 0);
- msr = kvmppc_set_field(msr, 42, 47, 0);
- kvmppc_set_msr_fast(vcpu, msr);
- kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_INST_STORAGE);
- return EMULATE_AGAIN;
- }
-
- return EMULATE_DONE;
-}
-
-static int kvmppc_check_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr)
-{
-
- /* Need to do paired single emulation? */
- if (!(vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE))
- return EMULATE_DONE;
-
- /* Read out the instruction */
- if (kvmppc_read_inst(vcpu) == EMULATE_DONE)
- /* Need to emulate */
- return EMULATE_FAIL;
-
- return EMULATE_AGAIN;
-}
-
/* Handle external providers (FPU, Altivec, VSX) */
static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
ulong msr)
@@ -1149,31 +1113,49 @@ program_interrupt:
case BOOK3S_INTERRUPT_VSX:
{
int ext_msr = 0;
+ int emul;
+ ulong pc;
+ u32 last_inst;
+
+ if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
+ /* Do paired single instruction emulation */
+ pc = kvmppc_get_pc(vcpu);
+ last_inst = kvmppc_get_last_inst(vcpu);
+ emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,
+ false);
+ if (emul == EMULATE_DONE)
+ goto program_interrupt;
+ else
+ r = RESUME_GUEST;
- switch (exit_nr) {
- case BOOK3S_INTERRUPT_FP_UNAVAIL: ext_msr = MSR_FP; break;
- case BOOK3S_INTERRUPT_ALTIVEC: ext_msr = MSR_VEC; break;
- case BOOK3S_INTERRUPT_VSX: ext_msr = MSR_VSX; break;
+ break;
}
- switch (kvmppc_check_ext(vcpu, exit_nr)) {
- case EMULATE_DONE:
- /* everything ok - let's enable the ext */
- r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
+ /* Enable external provider */
+ switch (exit_nr) {
+ case BOOK3S_INTERRUPT_FP_UNAVAIL:
+ ext_msr = MSR_FP;
break;
- case EMULATE_FAIL:
- /* we need to emulate this instruction */
- goto program_interrupt;
+
+ case BOOK3S_INTERRUPT_ALTIVEC:
+ ext_msr = MSR_VEC;
break;
- default:
- /* nothing to worry about - go again */
+
+ case BOOK3S_INTERRUPT_VSX:
+ ext_msr = MSR_VSX;
break;
}
+
+ r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
break;
}
case BOOK3S_INTERRUPT_ALIGNMENT:
- if (kvmppc_read_inst(vcpu) == EMULATE_DONE) {
- u32 last_inst = kvmppc_get_last_inst(vcpu);
+ {
+ ulong pc = kvmppc_get_pc(vcpu);
+ u32 last_inst = kvmppc_get_last_inst(vcpu);
+ int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);
+
+ if (emul == EMULATE_DONE) {
u32 dsisr;
u64 dar;
@@ -1187,6 +1169,7 @@ program_interrupt:
}
r = RESUME_GUEST;
break;
+ }
#ifdef CONFIG_PPC_BOOK3S_64
case BOOK3S_INTERRUPT_FAC_UNAVAIL:
kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 3/5] KVM: PPC: Book3s: Remove kvmppc_read_inst() function
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: Mihai Caraman, linuxppc-dev, kvm
In the context of replacing kvmppc_ld() function calls with a version of
kvmppc_get_last_inst() which allow to fail, Alex Graf suggested this:
"If we get EMULATE_AGAIN, we just have to make sure we go back into the guest.
No need to inject an ISI into the guest - it'll do that all by itself.
With an error returning kvmppc_get_last_inst we can just use completely
get rid of kvmppc_read_inst() and only use kvmppc_get_last_inst() instead."
As a intermediate step get rid of kvmppc_read_inst() and only use kvmppc_ld()
instead.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- add proper comments for VSX interrupt handling
v5:
- make paired single emulation the unusual
v4:
- new patch
arch/powerpc/kvm/book3s_pr.c | 85 ++++++++++++++++++--------------------------
1 file changed, 34 insertions(+), 51 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index e40765f..e76aec3 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -710,42 +710,6 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac)
#endif
}
-static int kvmppc_read_inst(struct kvm_vcpu *vcpu)
-{
- ulong srr0 = kvmppc_get_pc(vcpu);
- u32 last_inst = kvmppc_get_last_inst(vcpu);
- int ret;
-
- ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
- if (ret == -ENOENT) {
- ulong msr = kvmppc_get_msr(vcpu);
-
- msr = kvmppc_set_field(msr, 33, 33, 1);
- msr = kvmppc_set_field(msr, 34, 36, 0);
- msr = kvmppc_set_field(msr, 42, 47, 0);
- kvmppc_set_msr_fast(vcpu, msr);
- kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_INST_STORAGE);
- return EMULATE_AGAIN;
- }
-
- return EMULATE_DONE;
-}
-
-static int kvmppc_check_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr)
-{
-
- /* Need to do paired single emulation? */
- if (!(vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE))
- return EMULATE_DONE;
-
- /* Read out the instruction */
- if (kvmppc_read_inst(vcpu) == EMULATE_DONE)
- /* Need to emulate */
- return EMULATE_FAIL;
-
- return EMULATE_AGAIN;
-}
-
/* Handle external providers (FPU, Altivec, VSX) */
static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
ulong msr)
@@ -1149,31 +1113,49 @@ program_interrupt:
case BOOK3S_INTERRUPT_VSX:
{
int ext_msr = 0;
+ int emul;
+ ulong pc;
+ u32 last_inst;
+
+ if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
+ /* Do paired single instruction emulation */
+ pc = kvmppc_get_pc(vcpu);
+ last_inst = kvmppc_get_last_inst(vcpu);
+ emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,
+ false);
+ if (emul == EMULATE_DONE)
+ goto program_interrupt;
+ else
+ r = RESUME_GUEST;
- switch (exit_nr) {
- case BOOK3S_INTERRUPT_FP_UNAVAIL: ext_msr = MSR_FP; break;
- case BOOK3S_INTERRUPT_ALTIVEC: ext_msr = MSR_VEC; break;
- case BOOK3S_INTERRUPT_VSX: ext_msr = MSR_VSX; break;
+ break;
}
- switch (kvmppc_check_ext(vcpu, exit_nr)) {
- case EMULATE_DONE:
- /* everything ok - let's enable the ext */
- r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
+ /* Enable external provider */
+ switch (exit_nr) {
+ case BOOK3S_INTERRUPT_FP_UNAVAIL:
+ ext_msr = MSR_FP;
break;
- case EMULATE_FAIL:
- /* we need to emulate this instruction */
- goto program_interrupt;
+
+ case BOOK3S_INTERRUPT_ALTIVEC:
+ ext_msr = MSR_VEC;
break;
- default:
- /* nothing to worry about - go again */
+
+ case BOOK3S_INTERRUPT_VSX:
+ ext_msr = MSR_VSX;
break;
}
+
+ r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
break;
}
case BOOK3S_INTERRUPT_ALIGNMENT:
- if (kvmppc_read_inst(vcpu) == EMULATE_DONE) {
- u32 last_inst = kvmppc_get_last_inst(vcpu);
+ {
+ ulong pc = kvmppc_get_pc(vcpu);
+ u32 last_inst = kvmppc_get_last_inst(vcpu);
+ int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);
+
+ if (emul == EMULATE_DONE) {
u32 dsisr;
u64 dar;
@@ -1187,6 +1169,7 @@ program_interrupt:
}
r = RESUME_GUEST;
break;
+ }
#ifdef CONFIG_PPC_BOOK3S_64
case BOOK3S_INTERRUPT_FAC_UNAVAIL:
kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 3/5] KVM: PPC: Book3s: Remove kvmppc_read_inst() function
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
In the context of replacing kvmppc_ld() function calls with a version of
kvmppc_get_last_inst() which allow to fail, Alex Graf suggested this:
"If we get EMULATE_AGAIN, we just have to make sure we go back into the guest.
No need to inject an ISI into the guest - it'll do that all by itself.
With an error returning kvmppc_get_last_inst we can just use completely
get rid of kvmppc_read_inst() and only use kvmppc_get_last_inst() instead."
As a intermediate step get rid of kvmppc_read_inst() and only use kvmppc_ld()
instead.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- add proper comments for VSX interrupt handling
v5:
- make paired single emulation the unusual
v4:
- new patch
arch/powerpc/kvm/book3s_pr.c | 85 ++++++++++++++++++--------------------------
1 file changed, 34 insertions(+), 51 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index e40765f..e76aec3 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -710,42 +710,6 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac)
#endif
}
-static int kvmppc_read_inst(struct kvm_vcpu *vcpu)
-{
- ulong srr0 = kvmppc_get_pc(vcpu);
- u32 last_inst = kvmppc_get_last_inst(vcpu);
- int ret;
-
- ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
- if (ret = -ENOENT) {
- ulong msr = kvmppc_get_msr(vcpu);
-
- msr = kvmppc_set_field(msr, 33, 33, 1);
- msr = kvmppc_set_field(msr, 34, 36, 0);
- msr = kvmppc_set_field(msr, 42, 47, 0);
- kvmppc_set_msr_fast(vcpu, msr);
- kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_INST_STORAGE);
- return EMULATE_AGAIN;
- }
-
- return EMULATE_DONE;
-}
-
-static int kvmppc_check_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr)
-{
-
- /* Need to do paired single emulation? */
- if (!(vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE))
- return EMULATE_DONE;
-
- /* Read out the instruction */
- if (kvmppc_read_inst(vcpu) = EMULATE_DONE)
- /* Need to emulate */
- return EMULATE_FAIL;
-
- return EMULATE_AGAIN;
-}
-
/* Handle external providers (FPU, Altivec, VSX) */
static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
ulong msr)
@@ -1149,31 +1113,49 @@ program_interrupt:
case BOOK3S_INTERRUPT_VSX:
{
int ext_msr = 0;
+ int emul;
+ ulong pc;
+ u32 last_inst;
+
+ if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
+ /* Do paired single instruction emulation */
+ pc = kvmppc_get_pc(vcpu);
+ last_inst = kvmppc_get_last_inst(vcpu);
+ emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,
+ false);
+ if (emul = EMULATE_DONE)
+ goto program_interrupt;
+ else
+ r = RESUME_GUEST;
- switch (exit_nr) {
- case BOOK3S_INTERRUPT_FP_UNAVAIL: ext_msr = MSR_FP; break;
- case BOOK3S_INTERRUPT_ALTIVEC: ext_msr = MSR_VEC; break;
- case BOOK3S_INTERRUPT_VSX: ext_msr = MSR_VSX; break;
+ break;
}
- switch (kvmppc_check_ext(vcpu, exit_nr)) {
- case EMULATE_DONE:
- /* everything ok - let's enable the ext */
- r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
+ /* Enable external provider */
+ switch (exit_nr) {
+ case BOOK3S_INTERRUPT_FP_UNAVAIL:
+ ext_msr = MSR_FP;
break;
- case EMULATE_FAIL:
- /* we need to emulate this instruction */
- goto program_interrupt;
+
+ case BOOK3S_INTERRUPT_ALTIVEC:
+ ext_msr = MSR_VEC;
break;
- default:
- /* nothing to worry about - go again */
+
+ case BOOK3S_INTERRUPT_VSX:
+ ext_msr = MSR_VSX;
break;
}
+
+ r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
break;
}
case BOOK3S_INTERRUPT_ALIGNMENT:
- if (kvmppc_read_inst(vcpu) = EMULATE_DONE) {
- u32 last_inst = kvmppc_get_last_inst(vcpu);
+ {
+ ulong pc = kvmppc_get_pc(vcpu);
+ u32 last_inst = kvmppc_get_last_inst(vcpu);
+ int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);
+
+ if (emul = EMULATE_DONE) {
u32 dsisr;
u64 dar;
@@ -1187,6 +1169,7 @@ program_interrupt:
}
r = RESUME_GUEST;
break;
+ }
#ifdef CONFIG_PPC_BOOK3S_64
case BOOK3S_INTERRUPT_FAC_UNAVAIL:
kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 4/5] KVM: PPC: Alow kvmppc_get_last_inst() to fail
2014-07-23 16:06 ` Mihai Caraman
(?)
@ 2014-07-23 16:06 ` Mihai Caraman
-1 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
On book3e, guest last instruction is read on the exit path using load
external pid (lwepx) dedicated instruction. This load operation may fail
due to TLB eviction and execute-but-not-read entries.
This patch lay down the path for an alternative solution to read the guest
last instruction, by allowing kvmppc_get_lat_inst() function to fail.
Architecture specific implmentations of kvmppc_load_last_inst() may read
last guest instruction and instruct the emulation layer to re-execute the
guest in case of failure.
Make kvmppc_get_last_inst() definition common between architectures.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- rewrite kvmppc_get_last_inst() swap code to be understood at a glimpse :)
- use inst in kvmppc_load_last_inst
- these changes compile on book3s, please validate the functionality and
do the necessary changes!
v5:
- don't swap when load fail
- convert the return value space of kvmppc_ld()
v4:
- common declaration and enum for kvmppc_load_last_inst()
- remove kvmppc_read_inst() in a preceding patch
v3:
- rework patch description
- add common definition for kvmppc_get_last_inst()
- check return values in book3s code
v2:
- integrated kvmppc_get_last_inst() in book3s code and checked build
- addressed cosmetic feedback
arch/powerpc/include/asm/kvm_book3s.h | 26 ------------------
arch/powerpc/include/asm/kvm_booke.h | 5 ----
arch/powerpc/include/asm/kvm_ppc.h | 31 ++++++++++++++++++++++
arch/powerpc/kvm/book3s.c | 17 ++++++++++++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++++--------
arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++++++++++++----------
arch/powerpc/kvm/book3s_pr.c | 45 +++++++++++++++++++++++---------
arch/powerpc/kvm/booke.c | 3 +++
arch/powerpc/kvm/e500_mmu_host.c | 6 +++++
arch/powerpc/kvm/emulate.c | 18 ++++++++-----
arch/powerpc/kvm/powerpc.c | 11 ++++++--
11 files changed, 140 insertions(+), 77 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 20fb6f2..a86ca65 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -276,32 +276,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu)
return (kvmppc_get_msr(vcpu) & MSR_LE) != (MSR_KERNEL & MSR_LE);
}
-static inline u32 kvmppc_get_last_inst_internal(struct kvm_vcpu *vcpu, ulong pc)
-{
- /* Load the instruction manually if it failed to do so in the
- * exit path */
- if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED)
- kvmppc_ld(vcpu, &pc, sizeof(u32), &vcpu->arch.last_inst, false);
-
- return kvmppc_need_byteswap(vcpu) ? swab32(vcpu->arch.last_inst) :
- vcpu->arch.last_inst;
-}
-
-static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu)
-{
- return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu));
-}
-
-/*
- * Like kvmppc_get_last_inst(), but for fetching a sc instruction.
- * Because the sc instruction sets SRR0 to point to the following
- * instruction, we have to fetch from pc - 4.
- */
-static inline u32 kvmppc_get_last_sc(struct kvm_vcpu *vcpu)
-{
- return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu) - 4);
-}
-
static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault_dar;
diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h
index c7aed61..cbb1990 100644
--- a/arch/powerpc/include/asm/kvm_booke.h
+++ b/arch/powerpc/include/asm/kvm_booke.h
@@ -69,11 +69,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu)
return false;
}
-static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.last_inst;
-}
-
static inline void kvmppc_set_ctr(struct kvm_vcpu *vcpu, ulong val)
{
vcpu->arch.ctr = val;
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index e2fd5a1..2da5f547 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -47,6 +47,11 @@ enum emulation_result {
EMULATE_EXIT_USER, /* emulation requires exit to user-space */
};
+enum instruction_type {
+ INST_GENERIC,
+ INST_SC, /* system call */
+};
+
extern int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
extern int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
extern void kvmppc_handler_highmem(void);
@@ -62,6 +67,9 @@ extern int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
u64 val, unsigned int bytes,
int is_default_endian);
+extern int kvmppc_load_last_inst(struct kvm_vcpu *vcpu,
+ enum instruction_type type, u32 *inst);
+
extern int kvmppc_emulate_instruction(struct kvm_run *run,
struct kvm_vcpu *vcpu);
extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu);
@@ -234,6 +242,29 @@ struct kvmppc_ops {
extern struct kvmppc_ops *kvmppc_hv_ops;
extern struct kvmppc_ops *kvmppc_pr_ops;
+static inline int kvmppc_get_last_inst(struct kvm_vcpu *vcpu,
+ enum instruction_type type, u32 *inst)
+{
+ int ret = EMULATE_DONE;
+ u32 fetched_inst;
+
+ /* Load the instruction manually if it failed to do so in the
+ * exit path */
+ if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED)
+ ret = kvmppc_load_last_inst(vcpu, type, &vcpu->arch.last_inst);
+
+ /* Write fetch_failed unswapped if the fetch failed */
+ if (ret == EMULATE_DONE)
+ fetched_inst = kvmppc_need_byteswap(vcpu) ?
+ swab32(vcpu->arch.last_inst) :
+ vcpu->arch.last_inst;
+ else
+ fetched_inst = vcpu->arch.last_inst;
+
+ *inst = fetched_inst;
+ return ret;
+}
+
static inline bool is_kvmppc_hv_enabled(struct kvm *kvm)
{
return kvm->arch.kvm_ops == kvmppc_hv_ops;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 31facfc..37ca8a0 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -488,6 +488,23 @@ mmio:
}
EXPORT_SYMBOL_GPL(kvmppc_ld);
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *inst)
+{
+ ulong pc = kvmppc_get_pc(vcpu);
+ int r;
+
+ if (type == INST_SC)
+ pc -= 4;
+
+ r = kvmppc_ld(vcpu, &pc, sizeof(u32), inst, false);
+ if (r == EMULATE_DONE)
+ return r;
+ else
+ return EMULATE_AGAIN;
+}
+EXPORT_SYMBOL_GPL(kvmppc_load_last_inst);
+
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
return 0;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 2d154d9..fa944a3 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -530,21 +530,14 @@ static int instruction_is_store(unsigned int instr)
static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long gpa, gva_t ea, int is_store)
{
- int ret;
u32 last_inst;
- unsigned long srr0 = kvmppc_get_pc(vcpu);
- /* We try to load the last instruction. We don't let
- * emulate_instruction do it as it doesn't check what
- * kvmppc_ld returns.
+ /*
* If we fail, we just return to the guest and try executing it again.
*/
- if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) {
- ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
- if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED)
- return RESUME_GUEST;
- vcpu->arch.last_inst = last_inst;
- }
+ if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
+ EMULATE_DONE)
+ return RESUME_GUEST;
/*
* WARNING: We do not know for sure whether the instruction we just
@@ -558,7 +551,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
* we just return and retry the instruction.
*/
- if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store)
+ if (instruction_is_store(last_inst) != !!is_store)
return RESUME_GUEST;
/*
diff --git a/arch/powerpc/kvm/book3s_paired_singles.c b/arch/powerpc/kvm/book3s_paired_singles.c
index 6c8011f..bfb8035 100644
--- a/arch/powerpc/kvm/book3s_paired_singles.c
+++ b/arch/powerpc/kvm/book3s_paired_singles.c
@@ -639,26 +639,36 @@ static int kvmppc_ps_one_in(struct kvm_vcpu *vcpu, bool rc,
int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
- u32 inst = kvmppc_get_last_inst(vcpu);
+ u32 inst;
enum emulation_result emulated = EMULATE_DONE;
+ int ax_rd, ax_ra, ax_rb, ax_rc;
+ short full_d;
+ u64 *fpr_d, *fpr_a, *fpr_b, *fpr_c;
- int ax_rd = inst_get_field(inst, 6, 10);
- int ax_ra = inst_get_field(inst, 11, 15);
- int ax_rb = inst_get_field(inst, 16, 20);
- int ax_rc = inst_get_field(inst, 21, 25);
- short full_d = inst_get_field(inst, 16, 31);
-
- u64 *fpr_d = &VCPU_FPR(vcpu, ax_rd);
- u64 *fpr_a = &VCPU_FPR(vcpu, ax_ra);
- u64 *fpr_b = &VCPU_FPR(vcpu, ax_rb);
- u64 *fpr_c = &VCPU_FPR(vcpu, ax_rc);
-
- bool rcomp = (inst & 1) ? true : false;
- u32 cr = kvmppc_get_cr(vcpu);
+ bool rcomp;
+ u32 cr;
#ifdef DEBUG
int i;
#endif
+ emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
+ if (emulated != EMULATE_DONE)
+ return emulated;
+
+ ax_rd = inst_get_field(inst, 6, 10);
+ ax_ra = inst_get_field(inst, 11, 15);
+ ax_rb = inst_get_field(inst, 16, 20);
+ ax_rc = inst_get_field(inst, 21, 25);
+ full_d = inst_get_field(inst, 16, 31);
+
+ fpr_d = &VCPU_FPR(vcpu, ax_rd);
+ fpr_a = &VCPU_FPR(vcpu, ax_ra);
+ fpr_b = &VCPU_FPR(vcpu, ax_rb);
+ fpr_c = &VCPU_FPR(vcpu, ax_rc);
+
+ rcomp = (inst & 1) ? true : false;
+ cr = kvmppc_get_cr(vcpu);
+
if (!kvmppc_inst_is_paired_single(vcpu, inst))
return EMULATE_FAIL;
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index e76aec3..b18f2d4 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -1018,15 +1018,24 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
{
enum emulation_result er;
ulong flags;
+ u32 last_inst;
+ int emul;
program_interrupt:
flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
+ emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
+ if (emul != EMULATE_DONE) {
+ r = RESUME_GUEST;
+ break;
+ }
+
if (kvmppc_get_msr(vcpu) & MSR_PR) {
#ifdef EXIT_DEBUG
- printk(KERN_INFO "Userspace triggered 0x700 exception at 0x%lx (0x%x)\n", kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu));
+ pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",
+ kvmppc_get_pc(vcpu), last_inst);
#endif
- if ((kvmppc_get_last_inst(vcpu) & 0xff0007ff) !=
+ if ((last_inst & 0xff0007ff) !=
(INS_DCBZ & 0xfffffff7)) {
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
@@ -1045,7 +1054,7 @@ program_interrupt:
break;
case EMULATE_FAIL:
printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",
- __func__, kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu));
+ __func__, kvmppc_get_pc(vcpu), last_inst);
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
break;
@@ -1062,8 +1071,23 @@ program_interrupt:
break;
}
case BOOK3S_INTERRUPT_SYSCALL:
+ {
+ u32 last_sc;
+ int emul;
+
+ /* Get last sc for papr */
+ if (vcpu->arch.papr_enabled) {
+ /* The sc instuction points SRR0 to the next inst */
+ emul = kvmppc_get_last_inst(vcpu, INST_SC, &last_sc);
+ if (emul != EMULATE_DONE) {
+ kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) - 4);
+ r = RESUME_GUEST;
+ break;
+ }
+ }
+
if (vcpu->arch.papr_enabled &&
- (kvmppc_get_last_sc(vcpu) == 0x44000022) &&
+ (last_sc == 0x44000022) &&
!(kvmppc_get_msr(vcpu) & MSR_PR)) {
/* SC 1 papr hypercalls */
ulong cmd = kvmppc_get_gpr(vcpu, 3);
@@ -1108,21 +1132,19 @@ program_interrupt:
r = RESUME_GUEST;
}
break;
+ }
case BOOK3S_INTERRUPT_FP_UNAVAIL:
case BOOK3S_INTERRUPT_ALTIVEC:
case BOOK3S_INTERRUPT_VSX:
{
int ext_msr = 0;
int emul;
- ulong pc;
u32 last_inst;
if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
/* Do paired single instruction emulation */
- pc = kvmppc_get_pc(vcpu);
- last_inst = kvmppc_get_last_inst(vcpu);
- emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,
- false);
+ emul = kvmppc_get_last_inst(vcpu, INST_GENERIC,
+ &last_inst);
if (emul == EMULATE_DONE)
goto program_interrupt;
else
@@ -1151,9 +1173,8 @@ program_interrupt:
}
case BOOK3S_INTERRUPT_ALIGNMENT:
{
- ulong pc = kvmppc_get_pc(vcpu);
- u32 last_inst = kvmppc_get_last_inst(vcpu);
- int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);
+ u32 last_inst;
+ int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul == EMULATE_DONE) {
u32 dsisr;
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index ab62109..34a42b9 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -752,6 +752,9 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
* they were actually modified by emulation. */
return RESUME_GUEST_NV;
+ case EMULATE_AGAIN:
+ return RESUME_GUEST;
+
case EMULATE_DO_DCR:
run->exit_reason = KVM_EXIT_DCR;
return RESUME_HOST;
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 79677d7..4385c14 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -610,6 +610,12 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
}
}
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *instr)
+{
+ return EMULATE_AGAIN;
+}
+
/************* MMU Notifiers *************/
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index da86d9b..c5c64b6 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -224,19 +224,25 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
* from opcode tables in the future. */
int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
- u32 inst = kvmppc_get_last_inst(vcpu);
- int ra = get_ra(inst);
- int rs = get_rs(inst);
- int rt = get_rt(inst);
- int sprn = get_sprn(inst);
- enum emulation_result emulated = EMULATE_DONE;
+ u32 inst;
+ int ra, rs, rt, sprn;
+ enum emulation_result emulated;
int advance = 1;
/* this default type might be overwritten by subcategories */
kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
+ emulated = kvmppc_get_last_inst(vcpu, false, &inst);
+ if (emulated != EMULATE_DONE)
+ return emulated;
+
pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
+ ra = get_ra(inst);
+ rs = get_rs(inst);
+ rt = get_rt(inst);
+ sprn = get_sprn(inst);
+
switch (get_op(inst)) {
case OP_TRAP:
#ifdef CONFIG_PPC_BOOK3S
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index fe0257a..cfa6cfa 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -280,6 +280,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
* actually modified. */
r = RESUME_GUEST_NV;
break;
+ case EMULATE_AGAIN:
+ r = RESUME_GUEST;
+ break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
/* We must reload nonvolatiles because "update" load/store
@@ -289,11 +292,15 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
r = RESUME_HOST_NV;
break;
case EMULATE_FAIL:
+ {
+ u32 last_inst;
+
+ kvmppc_get_last_inst(vcpu, false, &last_inst);
/* XXX Deliver Program interrupt to guest. */
- printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
- kvmppc_get_last_inst(vcpu));
+ pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst);
r = RESUME_HOST;
break;
+ }
default:
WARN_ON(1);
r = RESUME_GUEST;
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 4/5] KVM: PPC: Alow kvmppc_get_last_inst() to fail
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: Mihai Caraman, linuxppc-dev, kvm
On book3e, guest last instruction is read on the exit path using load
external pid (lwepx) dedicated instruction. This load operation may fail
due to TLB eviction and execute-but-not-read entries.
This patch lay down the path for an alternative solution to read the guest
last instruction, by allowing kvmppc_get_lat_inst() function to fail.
Architecture specific implmentations of kvmppc_load_last_inst() may read
last guest instruction and instruct the emulation layer to re-execute the
guest in case of failure.
Make kvmppc_get_last_inst() definition common between architectures.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- rewrite kvmppc_get_last_inst() swap code to be understood at a glimpse :)
- use inst in kvmppc_load_last_inst
- these changes compile on book3s, please validate the functionality and
do the necessary changes!
v5:
- don't swap when load fail
- convert the return value space of kvmppc_ld()
v4:
- common declaration and enum for kvmppc_load_last_inst()
- remove kvmppc_read_inst() in a preceding patch
v3:
- rework patch description
- add common definition for kvmppc_get_last_inst()
- check return values in book3s code
v2:
- integrated kvmppc_get_last_inst() in book3s code and checked build
- addressed cosmetic feedback
arch/powerpc/include/asm/kvm_book3s.h | 26 ------------------
arch/powerpc/include/asm/kvm_booke.h | 5 ----
arch/powerpc/include/asm/kvm_ppc.h | 31 ++++++++++++++++++++++
arch/powerpc/kvm/book3s.c | 17 ++++++++++++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++++--------
arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++++++++++++----------
arch/powerpc/kvm/book3s_pr.c | 45 +++++++++++++++++++++++---------
arch/powerpc/kvm/booke.c | 3 +++
arch/powerpc/kvm/e500_mmu_host.c | 6 +++++
arch/powerpc/kvm/emulate.c | 18 ++++++++-----
arch/powerpc/kvm/powerpc.c | 11 ++++++--
11 files changed, 140 insertions(+), 77 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 20fb6f2..a86ca65 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -276,32 +276,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu)
return (kvmppc_get_msr(vcpu) & MSR_LE) != (MSR_KERNEL & MSR_LE);
}
-static inline u32 kvmppc_get_last_inst_internal(struct kvm_vcpu *vcpu, ulong pc)
-{
- /* Load the instruction manually if it failed to do so in the
- * exit path */
- if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED)
- kvmppc_ld(vcpu, &pc, sizeof(u32), &vcpu->arch.last_inst, false);
-
- return kvmppc_need_byteswap(vcpu) ? swab32(vcpu->arch.last_inst) :
- vcpu->arch.last_inst;
-}
-
-static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu)
-{
- return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu));
-}
-
-/*
- * Like kvmppc_get_last_inst(), but for fetching a sc instruction.
- * Because the sc instruction sets SRR0 to point to the following
- * instruction, we have to fetch from pc - 4.
- */
-static inline u32 kvmppc_get_last_sc(struct kvm_vcpu *vcpu)
-{
- return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu) - 4);
-}
-
static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault_dar;
diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h
index c7aed61..cbb1990 100644
--- a/arch/powerpc/include/asm/kvm_booke.h
+++ b/arch/powerpc/include/asm/kvm_booke.h
@@ -69,11 +69,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu)
return false;
}
-static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.last_inst;
-}
-
static inline void kvmppc_set_ctr(struct kvm_vcpu *vcpu, ulong val)
{
vcpu->arch.ctr = val;
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index e2fd5a1..2da5f547 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -47,6 +47,11 @@ enum emulation_result {
EMULATE_EXIT_USER, /* emulation requires exit to user-space */
};
+enum instruction_type {
+ INST_GENERIC,
+ INST_SC, /* system call */
+};
+
extern int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
extern int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
extern void kvmppc_handler_highmem(void);
@@ -62,6 +67,9 @@ extern int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
u64 val, unsigned int bytes,
int is_default_endian);
+extern int kvmppc_load_last_inst(struct kvm_vcpu *vcpu,
+ enum instruction_type type, u32 *inst);
+
extern int kvmppc_emulate_instruction(struct kvm_run *run,
struct kvm_vcpu *vcpu);
extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu);
@@ -234,6 +242,29 @@ struct kvmppc_ops {
extern struct kvmppc_ops *kvmppc_hv_ops;
extern struct kvmppc_ops *kvmppc_pr_ops;
+static inline int kvmppc_get_last_inst(struct kvm_vcpu *vcpu,
+ enum instruction_type type, u32 *inst)
+{
+ int ret = EMULATE_DONE;
+ u32 fetched_inst;
+
+ /* Load the instruction manually if it failed to do so in the
+ * exit path */
+ if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED)
+ ret = kvmppc_load_last_inst(vcpu, type, &vcpu->arch.last_inst);
+
+ /* Write fetch_failed unswapped if the fetch failed */
+ if (ret == EMULATE_DONE)
+ fetched_inst = kvmppc_need_byteswap(vcpu) ?
+ swab32(vcpu->arch.last_inst) :
+ vcpu->arch.last_inst;
+ else
+ fetched_inst = vcpu->arch.last_inst;
+
+ *inst = fetched_inst;
+ return ret;
+}
+
static inline bool is_kvmppc_hv_enabled(struct kvm *kvm)
{
return kvm->arch.kvm_ops == kvmppc_hv_ops;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 31facfc..37ca8a0 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -488,6 +488,23 @@ mmio:
}
EXPORT_SYMBOL_GPL(kvmppc_ld);
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *inst)
+{
+ ulong pc = kvmppc_get_pc(vcpu);
+ int r;
+
+ if (type == INST_SC)
+ pc -= 4;
+
+ r = kvmppc_ld(vcpu, &pc, sizeof(u32), inst, false);
+ if (r == EMULATE_DONE)
+ return r;
+ else
+ return EMULATE_AGAIN;
+}
+EXPORT_SYMBOL_GPL(kvmppc_load_last_inst);
+
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
return 0;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 2d154d9..fa944a3 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -530,21 +530,14 @@ static int instruction_is_store(unsigned int instr)
static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long gpa, gva_t ea, int is_store)
{
- int ret;
u32 last_inst;
- unsigned long srr0 = kvmppc_get_pc(vcpu);
- /* We try to load the last instruction. We don't let
- * emulate_instruction do it as it doesn't check what
- * kvmppc_ld returns.
+ /*
* If we fail, we just return to the guest and try executing it again.
*/
- if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) {
- ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
- if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED)
- return RESUME_GUEST;
- vcpu->arch.last_inst = last_inst;
- }
+ if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
+ EMULATE_DONE)
+ return RESUME_GUEST;
/*
* WARNING: We do not know for sure whether the instruction we just
@@ -558,7 +551,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
* we just return and retry the instruction.
*/
- if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store)
+ if (instruction_is_store(last_inst) != !!is_store)
return RESUME_GUEST;
/*
diff --git a/arch/powerpc/kvm/book3s_paired_singles.c b/arch/powerpc/kvm/book3s_paired_singles.c
index 6c8011f..bfb8035 100644
--- a/arch/powerpc/kvm/book3s_paired_singles.c
+++ b/arch/powerpc/kvm/book3s_paired_singles.c
@@ -639,26 +639,36 @@ static int kvmppc_ps_one_in(struct kvm_vcpu *vcpu, bool rc,
int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
- u32 inst = kvmppc_get_last_inst(vcpu);
+ u32 inst;
enum emulation_result emulated = EMULATE_DONE;
+ int ax_rd, ax_ra, ax_rb, ax_rc;
+ short full_d;
+ u64 *fpr_d, *fpr_a, *fpr_b, *fpr_c;
- int ax_rd = inst_get_field(inst, 6, 10);
- int ax_ra = inst_get_field(inst, 11, 15);
- int ax_rb = inst_get_field(inst, 16, 20);
- int ax_rc = inst_get_field(inst, 21, 25);
- short full_d = inst_get_field(inst, 16, 31);
-
- u64 *fpr_d = &VCPU_FPR(vcpu, ax_rd);
- u64 *fpr_a = &VCPU_FPR(vcpu, ax_ra);
- u64 *fpr_b = &VCPU_FPR(vcpu, ax_rb);
- u64 *fpr_c = &VCPU_FPR(vcpu, ax_rc);
-
- bool rcomp = (inst & 1) ? true : false;
- u32 cr = kvmppc_get_cr(vcpu);
+ bool rcomp;
+ u32 cr;
#ifdef DEBUG
int i;
#endif
+ emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
+ if (emulated != EMULATE_DONE)
+ return emulated;
+
+ ax_rd = inst_get_field(inst, 6, 10);
+ ax_ra = inst_get_field(inst, 11, 15);
+ ax_rb = inst_get_field(inst, 16, 20);
+ ax_rc = inst_get_field(inst, 21, 25);
+ full_d = inst_get_field(inst, 16, 31);
+
+ fpr_d = &VCPU_FPR(vcpu, ax_rd);
+ fpr_a = &VCPU_FPR(vcpu, ax_ra);
+ fpr_b = &VCPU_FPR(vcpu, ax_rb);
+ fpr_c = &VCPU_FPR(vcpu, ax_rc);
+
+ rcomp = (inst & 1) ? true : false;
+ cr = kvmppc_get_cr(vcpu);
+
if (!kvmppc_inst_is_paired_single(vcpu, inst))
return EMULATE_FAIL;
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index e76aec3..b18f2d4 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -1018,15 +1018,24 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
{
enum emulation_result er;
ulong flags;
+ u32 last_inst;
+ int emul;
program_interrupt:
flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
+ emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
+ if (emul != EMULATE_DONE) {
+ r = RESUME_GUEST;
+ break;
+ }
+
if (kvmppc_get_msr(vcpu) & MSR_PR) {
#ifdef EXIT_DEBUG
- printk(KERN_INFO "Userspace triggered 0x700 exception at 0x%lx (0x%x)\n", kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu));
+ pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",
+ kvmppc_get_pc(vcpu), last_inst);
#endif
- if ((kvmppc_get_last_inst(vcpu) & 0xff0007ff) !=
+ if ((last_inst & 0xff0007ff) !=
(INS_DCBZ & 0xfffffff7)) {
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
@@ -1045,7 +1054,7 @@ program_interrupt:
break;
case EMULATE_FAIL:
printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",
- __func__, kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu));
+ __func__, kvmppc_get_pc(vcpu), last_inst);
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
break;
@@ -1062,8 +1071,23 @@ program_interrupt:
break;
}
case BOOK3S_INTERRUPT_SYSCALL:
+ {
+ u32 last_sc;
+ int emul;
+
+ /* Get last sc for papr */
+ if (vcpu->arch.papr_enabled) {
+ /* The sc instuction points SRR0 to the next inst */
+ emul = kvmppc_get_last_inst(vcpu, INST_SC, &last_sc);
+ if (emul != EMULATE_DONE) {
+ kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) - 4);
+ r = RESUME_GUEST;
+ break;
+ }
+ }
+
if (vcpu->arch.papr_enabled &&
- (kvmppc_get_last_sc(vcpu) == 0x44000022) &&
+ (last_sc == 0x44000022) &&
!(kvmppc_get_msr(vcpu) & MSR_PR)) {
/* SC 1 papr hypercalls */
ulong cmd = kvmppc_get_gpr(vcpu, 3);
@@ -1108,21 +1132,19 @@ program_interrupt:
r = RESUME_GUEST;
}
break;
+ }
case BOOK3S_INTERRUPT_FP_UNAVAIL:
case BOOK3S_INTERRUPT_ALTIVEC:
case BOOK3S_INTERRUPT_VSX:
{
int ext_msr = 0;
int emul;
- ulong pc;
u32 last_inst;
if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
/* Do paired single instruction emulation */
- pc = kvmppc_get_pc(vcpu);
- last_inst = kvmppc_get_last_inst(vcpu);
- emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,
- false);
+ emul = kvmppc_get_last_inst(vcpu, INST_GENERIC,
+ &last_inst);
if (emul == EMULATE_DONE)
goto program_interrupt;
else
@@ -1151,9 +1173,8 @@ program_interrupt:
}
case BOOK3S_INTERRUPT_ALIGNMENT:
{
- ulong pc = kvmppc_get_pc(vcpu);
- u32 last_inst = kvmppc_get_last_inst(vcpu);
- int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);
+ u32 last_inst;
+ int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul == EMULATE_DONE) {
u32 dsisr;
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index ab62109..34a42b9 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -752,6 +752,9 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
* they were actually modified by emulation. */
return RESUME_GUEST_NV;
+ case EMULATE_AGAIN:
+ return RESUME_GUEST;
+
case EMULATE_DO_DCR:
run->exit_reason = KVM_EXIT_DCR;
return RESUME_HOST;
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 79677d7..4385c14 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -610,6 +610,12 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
}
}
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *instr)
+{
+ return EMULATE_AGAIN;
+}
+
/************* MMU Notifiers *************/
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index da86d9b..c5c64b6 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -224,19 +224,25 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
* from opcode tables in the future. */
int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
- u32 inst = kvmppc_get_last_inst(vcpu);
- int ra = get_ra(inst);
- int rs = get_rs(inst);
- int rt = get_rt(inst);
- int sprn = get_sprn(inst);
- enum emulation_result emulated = EMULATE_DONE;
+ u32 inst;
+ int ra, rs, rt, sprn;
+ enum emulation_result emulated;
int advance = 1;
/* this default type might be overwritten by subcategories */
kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
+ emulated = kvmppc_get_last_inst(vcpu, false, &inst);
+ if (emulated != EMULATE_DONE)
+ return emulated;
+
pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
+ ra = get_ra(inst);
+ rs = get_rs(inst);
+ rt = get_rt(inst);
+ sprn = get_sprn(inst);
+
switch (get_op(inst)) {
case OP_TRAP:
#ifdef CONFIG_PPC_BOOK3S
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index fe0257a..cfa6cfa 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -280,6 +280,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
* actually modified. */
r = RESUME_GUEST_NV;
break;
+ case EMULATE_AGAIN:
+ r = RESUME_GUEST;
+ break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
/* We must reload nonvolatiles because "update" load/store
@@ -289,11 +292,15 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
r = RESUME_HOST_NV;
break;
case EMULATE_FAIL:
+ {
+ u32 last_inst;
+
+ kvmppc_get_last_inst(vcpu, false, &last_inst);
/* XXX Deliver Program interrupt to guest. */
- printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
- kvmppc_get_last_inst(vcpu));
+ pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst);
r = RESUME_HOST;
break;
+ }
default:
WARN_ON(1);
r = RESUME_GUEST;
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 4/5] KVM: PPC: Alow kvmppc_get_last_inst() to fail
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
On book3e, guest last instruction is read on the exit path using load
external pid (lwepx) dedicated instruction. This load operation may fail
due to TLB eviction and execute-but-not-read entries.
This patch lay down the path for an alternative solution to read the guest
last instruction, by allowing kvmppc_get_lat_inst() function to fail.
Architecture specific implmentations of kvmppc_load_last_inst() may read
last guest instruction and instruct the emulation layer to re-execute the
guest in case of failure.
Make kvmppc_get_last_inst() definition common between architectures.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- rewrite kvmppc_get_last_inst() swap code to be understood at a glimpse :)
- use inst in kvmppc_load_last_inst
- these changes compile on book3s, please validate the functionality and
do the necessary changes!
v5:
- don't swap when load fail
- convert the return value space of kvmppc_ld()
v4:
- common declaration and enum for kvmppc_load_last_inst()
- remove kvmppc_read_inst() in a preceding patch
v3:
- rework patch description
- add common definition for kvmppc_get_last_inst()
- check return values in book3s code
v2:
- integrated kvmppc_get_last_inst() in book3s code and checked build
- addressed cosmetic feedback
arch/powerpc/include/asm/kvm_book3s.h | 26 ------------------
arch/powerpc/include/asm/kvm_booke.h | 5 ----
arch/powerpc/include/asm/kvm_ppc.h | 31 ++++++++++++++++++++++
arch/powerpc/kvm/book3s.c | 17 ++++++++++++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++++--------
arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++++++++++++----------
arch/powerpc/kvm/book3s_pr.c | 45 +++++++++++++++++++++++---------
arch/powerpc/kvm/booke.c | 3 +++
arch/powerpc/kvm/e500_mmu_host.c | 6 +++++
arch/powerpc/kvm/emulate.c | 18 ++++++++-----
arch/powerpc/kvm/powerpc.c | 11 ++++++--
11 files changed, 140 insertions(+), 77 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 20fb6f2..a86ca65 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -276,32 +276,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu)
return (kvmppc_get_msr(vcpu) & MSR_LE) != (MSR_KERNEL & MSR_LE);
}
-static inline u32 kvmppc_get_last_inst_internal(struct kvm_vcpu *vcpu, ulong pc)
-{
- /* Load the instruction manually if it failed to do so in the
- * exit path */
- if (vcpu->arch.last_inst = KVM_INST_FETCH_FAILED)
- kvmppc_ld(vcpu, &pc, sizeof(u32), &vcpu->arch.last_inst, false);
-
- return kvmppc_need_byteswap(vcpu) ? swab32(vcpu->arch.last_inst) :
- vcpu->arch.last_inst;
-}
-
-static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu)
-{
- return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu));
-}
-
-/*
- * Like kvmppc_get_last_inst(), but for fetching a sc instruction.
- * Because the sc instruction sets SRR0 to point to the following
- * instruction, we have to fetch from pc - 4.
- */
-static inline u32 kvmppc_get_last_sc(struct kvm_vcpu *vcpu)
-{
- return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu) - 4);
-}
-
static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault_dar;
diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h
index c7aed61..cbb1990 100644
--- a/arch/powerpc/include/asm/kvm_booke.h
+++ b/arch/powerpc/include/asm/kvm_booke.h
@@ -69,11 +69,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu)
return false;
}
-static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.last_inst;
-}
-
static inline void kvmppc_set_ctr(struct kvm_vcpu *vcpu, ulong val)
{
vcpu->arch.ctr = val;
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index e2fd5a1..2da5f547 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -47,6 +47,11 @@ enum emulation_result {
EMULATE_EXIT_USER, /* emulation requires exit to user-space */
};
+enum instruction_type {
+ INST_GENERIC,
+ INST_SC, /* system call */
+};
+
extern int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
extern int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
extern void kvmppc_handler_highmem(void);
@@ -62,6 +67,9 @@ extern int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
u64 val, unsigned int bytes,
int is_default_endian);
+extern int kvmppc_load_last_inst(struct kvm_vcpu *vcpu,
+ enum instruction_type type, u32 *inst);
+
extern int kvmppc_emulate_instruction(struct kvm_run *run,
struct kvm_vcpu *vcpu);
extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu);
@@ -234,6 +242,29 @@ struct kvmppc_ops {
extern struct kvmppc_ops *kvmppc_hv_ops;
extern struct kvmppc_ops *kvmppc_pr_ops;
+static inline int kvmppc_get_last_inst(struct kvm_vcpu *vcpu,
+ enum instruction_type type, u32 *inst)
+{
+ int ret = EMULATE_DONE;
+ u32 fetched_inst;
+
+ /* Load the instruction manually if it failed to do so in the
+ * exit path */
+ if (vcpu->arch.last_inst = KVM_INST_FETCH_FAILED)
+ ret = kvmppc_load_last_inst(vcpu, type, &vcpu->arch.last_inst);
+
+ /* Write fetch_failed unswapped if the fetch failed */
+ if (ret = EMULATE_DONE)
+ fetched_inst = kvmppc_need_byteswap(vcpu) ?
+ swab32(vcpu->arch.last_inst) :
+ vcpu->arch.last_inst;
+ else
+ fetched_inst = vcpu->arch.last_inst;
+
+ *inst = fetched_inst;
+ return ret;
+}
+
static inline bool is_kvmppc_hv_enabled(struct kvm *kvm)
{
return kvm->arch.kvm_ops = kvmppc_hv_ops;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 31facfc..37ca8a0 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -488,6 +488,23 @@ mmio:
}
EXPORT_SYMBOL_GPL(kvmppc_ld);
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *inst)
+{
+ ulong pc = kvmppc_get_pc(vcpu);
+ int r;
+
+ if (type = INST_SC)
+ pc -= 4;
+
+ r = kvmppc_ld(vcpu, &pc, sizeof(u32), inst, false);
+ if (r = EMULATE_DONE)
+ return r;
+ else
+ return EMULATE_AGAIN;
+}
+EXPORT_SYMBOL_GPL(kvmppc_load_last_inst);
+
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
return 0;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 2d154d9..fa944a3 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -530,21 +530,14 @@ static int instruction_is_store(unsigned int instr)
static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long gpa, gva_t ea, int is_store)
{
- int ret;
u32 last_inst;
- unsigned long srr0 = kvmppc_get_pc(vcpu);
- /* We try to load the last instruction. We don't let
- * emulate_instruction do it as it doesn't check what
- * kvmppc_ld returns.
+ /*
* If we fail, we just return to the guest and try executing it again.
*/
- if (vcpu->arch.last_inst = KVM_INST_FETCH_FAILED) {
- ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
- if (ret != EMULATE_DONE || last_inst = KVM_INST_FETCH_FAILED)
- return RESUME_GUEST;
- vcpu->arch.last_inst = last_inst;
- }
+ if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !+ EMULATE_DONE)
+ return RESUME_GUEST;
/*
* WARNING: We do not know for sure whether the instruction we just
@@ -558,7 +551,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
* we just return and retry the instruction.
*/
- if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store)
+ if (instruction_is_store(last_inst) != !!is_store)
return RESUME_GUEST;
/*
diff --git a/arch/powerpc/kvm/book3s_paired_singles.c b/arch/powerpc/kvm/book3s_paired_singles.c
index 6c8011f..bfb8035 100644
--- a/arch/powerpc/kvm/book3s_paired_singles.c
+++ b/arch/powerpc/kvm/book3s_paired_singles.c
@@ -639,26 +639,36 @@ static int kvmppc_ps_one_in(struct kvm_vcpu *vcpu, bool rc,
int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
- u32 inst = kvmppc_get_last_inst(vcpu);
+ u32 inst;
enum emulation_result emulated = EMULATE_DONE;
+ int ax_rd, ax_ra, ax_rb, ax_rc;
+ short full_d;
+ u64 *fpr_d, *fpr_a, *fpr_b, *fpr_c;
- int ax_rd = inst_get_field(inst, 6, 10);
- int ax_ra = inst_get_field(inst, 11, 15);
- int ax_rb = inst_get_field(inst, 16, 20);
- int ax_rc = inst_get_field(inst, 21, 25);
- short full_d = inst_get_field(inst, 16, 31);
-
- u64 *fpr_d = &VCPU_FPR(vcpu, ax_rd);
- u64 *fpr_a = &VCPU_FPR(vcpu, ax_ra);
- u64 *fpr_b = &VCPU_FPR(vcpu, ax_rb);
- u64 *fpr_c = &VCPU_FPR(vcpu, ax_rc);
-
- bool rcomp = (inst & 1) ? true : false;
- u32 cr = kvmppc_get_cr(vcpu);
+ bool rcomp;
+ u32 cr;
#ifdef DEBUG
int i;
#endif
+ emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
+ if (emulated != EMULATE_DONE)
+ return emulated;
+
+ ax_rd = inst_get_field(inst, 6, 10);
+ ax_ra = inst_get_field(inst, 11, 15);
+ ax_rb = inst_get_field(inst, 16, 20);
+ ax_rc = inst_get_field(inst, 21, 25);
+ full_d = inst_get_field(inst, 16, 31);
+
+ fpr_d = &VCPU_FPR(vcpu, ax_rd);
+ fpr_a = &VCPU_FPR(vcpu, ax_ra);
+ fpr_b = &VCPU_FPR(vcpu, ax_rb);
+ fpr_c = &VCPU_FPR(vcpu, ax_rc);
+
+ rcomp = (inst & 1) ? true : false;
+ cr = kvmppc_get_cr(vcpu);
+
if (!kvmppc_inst_is_paired_single(vcpu, inst))
return EMULATE_FAIL;
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index e76aec3..b18f2d4 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -1018,15 +1018,24 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
{
enum emulation_result er;
ulong flags;
+ u32 last_inst;
+ int emul;
program_interrupt:
flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
+ emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
+ if (emul != EMULATE_DONE) {
+ r = RESUME_GUEST;
+ break;
+ }
+
if (kvmppc_get_msr(vcpu) & MSR_PR) {
#ifdef EXIT_DEBUG
- printk(KERN_INFO "Userspace triggered 0x700 exception at 0x%lx (0x%x)\n", kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu));
+ pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",
+ kvmppc_get_pc(vcpu), last_inst);
#endif
- if ((kvmppc_get_last_inst(vcpu) & 0xff0007ff) !+ if ((last_inst & 0xff0007ff) ! (INS_DCBZ & 0xfffffff7)) {
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
@@ -1045,7 +1054,7 @@ program_interrupt:
break;
case EMULATE_FAIL:
printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",
- __func__, kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu));
+ __func__, kvmppc_get_pc(vcpu), last_inst);
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
break;
@@ -1062,8 +1071,23 @@ program_interrupt:
break;
}
case BOOK3S_INTERRUPT_SYSCALL:
+ {
+ u32 last_sc;
+ int emul;
+
+ /* Get last sc for papr */
+ if (vcpu->arch.papr_enabled) {
+ /* The sc instuction points SRR0 to the next inst */
+ emul = kvmppc_get_last_inst(vcpu, INST_SC, &last_sc);
+ if (emul != EMULATE_DONE) {
+ kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) - 4);
+ r = RESUME_GUEST;
+ break;
+ }
+ }
+
if (vcpu->arch.papr_enabled &&
- (kvmppc_get_last_sc(vcpu) = 0x44000022) &&
+ (last_sc = 0x44000022) &&
!(kvmppc_get_msr(vcpu) & MSR_PR)) {
/* SC 1 papr hypercalls */
ulong cmd = kvmppc_get_gpr(vcpu, 3);
@@ -1108,21 +1132,19 @@ program_interrupt:
r = RESUME_GUEST;
}
break;
+ }
case BOOK3S_INTERRUPT_FP_UNAVAIL:
case BOOK3S_INTERRUPT_ALTIVEC:
case BOOK3S_INTERRUPT_VSX:
{
int ext_msr = 0;
int emul;
- ulong pc;
u32 last_inst;
if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
/* Do paired single instruction emulation */
- pc = kvmppc_get_pc(vcpu);
- last_inst = kvmppc_get_last_inst(vcpu);
- emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,
- false);
+ emul = kvmppc_get_last_inst(vcpu, INST_GENERIC,
+ &last_inst);
if (emul = EMULATE_DONE)
goto program_interrupt;
else
@@ -1151,9 +1173,8 @@ program_interrupt:
}
case BOOK3S_INTERRUPT_ALIGNMENT:
{
- ulong pc = kvmppc_get_pc(vcpu);
- u32 last_inst = kvmppc_get_last_inst(vcpu);
- int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);
+ u32 last_inst;
+ int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul = EMULATE_DONE) {
u32 dsisr;
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index ab62109..34a42b9 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -752,6 +752,9 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
* they were actually modified by emulation. */
return RESUME_GUEST_NV;
+ case EMULATE_AGAIN:
+ return RESUME_GUEST;
+
case EMULATE_DO_DCR:
run->exit_reason = KVM_EXIT_DCR;
return RESUME_HOST;
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 79677d7..4385c14 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -610,6 +610,12 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
}
}
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *instr)
+{
+ return EMULATE_AGAIN;
+}
+
/************* MMU Notifiers *************/
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index da86d9b..c5c64b6 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -224,19 +224,25 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
* from opcode tables in the future. */
int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
- u32 inst = kvmppc_get_last_inst(vcpu);
- int ra = get_ra(inst);
- int rs = get_rs(inst);
- int rt = get_rt(inst);
- int sprn = get_sprn(inst);
- enum emulation_result emulated = EMULATE_DONE;
+ u32 inst;
+ int ra, rs, rt, sprn;
+ enum emulation_result emulated;
int advance = 1;
/* this default type might be overwritten by subcategories */
kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
+ emulated = kvmppc_get_last_inst(vcpu, false, &inst);
+ if (emulated != EMULATE_DONE)
+ return emulated;
+
pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
+ ra = get_ra(inst);
+ rs = get_rs(inst);
+ rt = get_rt(inst);
+ sprn = get_sprn(inst);
+
switch (get_op(inst)) {
case OP_TRAP:
#ifdef CONFIG_PPC_BOOK3S
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index fe0257a..cfa6cfa 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -280,6 +280,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
* actually modified. */
r = RESUME_GUEST_NV;
break;
+ case EMULATE_AGAIN:
+ r = RESUME_GUEST;
+ break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
/* We must reload nonvolatiles because "update" load/store
@@ -289,11 +292,15 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
r = RESUME_HOST_NV;
break;
case EMULATE_FAIL:
+ {
+ u32 last_inst;
+
+ kvmppc_get_last_inst(vcpu, false, &last_inst);
/* XXX Deliver Program interrupt to guest. */
- printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
- kvmppc_get_last_inst(vcpu));
+ pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst);
r = RESUME_HOST;
break;
+ }
default:
WARN_ON(1);
r = RESUME_GUEST;
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 5/5] KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
2014-07-23 16:06 ` Mihai Caraman
(?)
@ 2014-07-23 16:06 ` Mihai Caraman
-1 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
On book3e, KVM uses load external pid (lwepx) dedicated instruction to read
guest last instruction on the exit path. lwepx exceptions (DTLB_MISS, DSI
and LRAT), generated by loading a guest address, needs to be handled by KVM.
These exceptions are generated in a substituted guest translation context
(EPLC[EGS] = 1) from host context (MSR[GS] = 0).
Currently, KVM hooks only interrupts generated from guest context (MSR[GS] = 1),
doing minimal checks on the fast path to avoid host performance degradation.
lwepx exceptions originate from host state (MSR[GS] = 0) which implies
additional checks in DO_KVM macro (beside the current MSR[GS] = 1) by looking
at the Exception Syndrome Register (ESR[EPID]) and the External PID Load Context
Register (EPLC[EGS]). Doing this on each Data TLB miss exception is obvious
too intrusive for the host.
Read guest last instruction from kvmppc_load_last_inst() by searching for the
physical address and kmap it. This address the TODO for TLB eviction and
execute-but-not-read entries, and allow us to get rid of lwepx until we are
able to handle failures.
A simple stress benchmark shows a 1% sys performance degradation compared with
previous approach (lwepx without failure handling):
time for i in `seq 1 10000`; do /bin/echo > /dev/null; done
real 0m 8.85s
user 0m 4.34s
sys 0m 4.48s
vs
real 0m 8.84s
user 0m 4.36s
sys 0m 4.44s
A solution to use lwepx and to handle its exceptions in KVM would be to temporary
highjack the interrupt vector from host. This imposes additional synchronizations
for cores like FSL e6500 that shares host IVOR registers between hardware threads.
This optimized solution can be later developed on top of this patch.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- no change
v5:
- return ENULATE_AGAIN in case of failure
v4:
- add switch and new function when getting last inst earlier
- use enum instead of prev semnatic
- get rid of mas0, optimize mas7_mas3
- give more context in visible messages
- check storage attributes mismatch on MMUv2
- get rid of pfn_valid check
v3:
- reworked patch description
- use unaltered kmap addr for kunmap
- get last instruction before beeing preempted
v2:
- reworked patch description
- used pr_* functions
- addressed cosmetic feedback
arch/powerpc/kvm/booke.c | 44 +++++++++++++++++
arch/powerpc/kvm/bookehv_interrupts.S | 37 ++++----------
arch/powerpc/kvm/e500_mmu_host.c | 92 +++++++++++++++++++++++++++++++++++
3 files changed, 145 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 34a42b9..843077b 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -869,6 +869,28 @@ static void kvmppc_restart_interrupt(struct kvm_vcpu *vcpu,
}
}
+static int kvmppc_resume_inst_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ enum emulation_result emulated, u32 last_inst)
+{
+ switch (emulated) {
+ case EMULATE_AGAIN:
+ return RESUME_GUEST;
+
+ case EMULATE_FAIL:
+ pr_debug("%s: load instruction from guest address %lx failed\n",
+ __func__, vcpu->arch.pc);
+ /* For debugging, encode the failing instruction and
+ * report it to userspace. */
+ run->hw.hardware_exit_reason = ~0ULL << 32;
+ run->hw.hardware_exit_reason |= last_inst;
+ kvmppc_core_queue_program(vcpu, ESR_PIL);
+ return RESUME_HOST;
+
+ default:
+ BUG();
+ }
+}
+
/**
* kvmppc_handle_exit
*
@@ -880,6 +902,8 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
int r = RESUME_HOST;
int s;
int idx;
+ u32 last_inst = KVM_INST_FETCH_FAILED;
+ enum emulation_result emulated = EMULATE_DONE;
/* update before a new last_exit_type is rewritten */
kvmppc_update_timing_stats(vcpu);
@@ -887,6 +911,20 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
/* restart interrupts if they were meant for the host */
kvmppc_restart_interrupt(vcpu, exit_nr);
+ /*
+ * get last instruction before beeing preempted
+ * TODO: for e6500 check also BOOKE_INTERRUPT_LRAT_ERROR & ESR_DATA
+ */
+ switch (exit_nr) {
+ case BOOKE_INTERRUPT_DATA_STORAGE:
+ case BOOKE_INTERRUPT_DTLB_MISS:
+ case BOOKE_INTERRUPT_HV_PRIV:
+ emulated = kvmppc_get_last_inst(vcpu, false, &last_inst);
+ break;
+ default:
+ break;
+ }
+
local_irq_enable();
trace_kvm_exit(exit_nr, vcpu);
@@ -895,6 +933,11 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
run->exit_reason = KVM_EXIT_UNKNOWN;
run->ready_for_interrupt_injection = 1;
+ if (emulated != EMULATE_DONE) {
+ r = kvmppc_resume_inst_load(run, vcpu, emulated, last_inst);
+ goto out;
+ }
+
switch (exit_nr) {
case BOOKE_INTERRUPT_MACHINE_CHECK:
printk("MACHINE CHECK: %lx\n", mfspr(SPRN_MCSR));
@@ -1184,6 +1227,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
BUG();
}
+out:
/*
* To avoid clobbering exit_reason, only check for signals if we
* aren't already exiting to userspace for some other reason.
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index 6ff4480..e000b39 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -121,38 +121,14 @@
1:
.if \flags & NEED_EMU
- /*
- * This assumes you have external PID support.
- * To support a bookehv CPU without external PID, you'll
- * need to look up the TLB entry and create a temporary mapping.
- *
- * FIXME: we don't currently handle if the lwepx faults. PR-mode
- * booke doesn't handle it either. Since Linux doesn't use
- * broadcast tlbivax anymore, the only way this should happen is
- * if the guest maps its memory execute-but-not-read, or if we
- * somehow take a TLB miss in the middle of this entry code and
- * evict the relevant entry. On e500mc, all kernel lowmem is
- * bolted into TLB1 large page mappings, and we don't use
- * broadcast invalidates, so we should not take a TLB miss here.
- *
- * Later we'll need to deal with faults here. Disallowing guest
- * mappings that are execute-but-not-read could be an option on
- * e500mc, but not on chips with an LRAT if it is used.
- */
-
- mfspr r3, SPRN_EPLC /* will already have correct ELPID and EGS */
PPC_STL r15, VCPU_GPR(R15)(r4)
PPC_STL r16, VCPU_GPR(R16)(r4)
PPC_STL r17, VCPU_GPR(R17)(r4)
PPC_STL r18, VCPU_GPR(R18)(r4)
PPC_STL r19, VCPU_GPR(R19)(r4)
- mr r8, r3
PPC_STL r20, VCPU_GPR(R20)(r4)
- rlwimi r8, r6, EPC_EAS_SHIFT - MSR_IR_LG, EPC_EAS
PPC_STL r21, VCPU_GPR(R21)(r4)
- rlwimi r8, r6, EPC_EPR_SHIFT - MSR_PR_LG, EPC_EPR
PPC_STL r22, VCPU_GPR(R22)(r4)
- rlwimi r8, r10, EPC_EPID_SHIFT, EPC_EPID
PPC_STL r23, VCPU_GPR(R23)(r4)
PPC_STL r24, VCPU_GPR(R24)(r4)
PPC_STL r25, VCPU_GPR(R25)(r4)
@@ -162,10 +138,15 @@
PPC_STL r29, VCPU_GPR(R29)(r4)
PPC_STL r30, VCPU_GPR(R30)(r4)
PPC_STL r31, VCPU_GPR(R31)(r4)
- mtspr SPRN_EPLC, r8
- isync
- lwepx r9, 0, r5
- mtspr SPRN_EPLC, r3
+
+ /*
+ * We don't use external PID support. lwepx faults would need to be
+ * handled by KVM and this implies aditional code in DO_KVM (for
+ * DTB_MISS, DSI and LRAT) to check ESR[EPID] and EPLC[EGS] which
+ * is too intrusive for the host. Get last instuction in
+ * kvmppc_get_last_inst().
+ */
+ li r9, KVM_INST_FETCH_FAILED
stw r9, VCPU_LAST_INST(r4)
.endif
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 4385c14..4150826 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -610,11 +610,103 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
}
}
+#ifdef CONFIG_KVM_BOOKE_HV
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *instr)
+{
+ gva_t geaddr;
+ hpa_t addr;
+ hfn_t pfn;
+ hva_t eaddr;
+ u32 mas1, mas2, mas3;
+ u64 mas7_mas3;
+ struct page *page;
+ unsigned int addr_space, psize_shift;
+ bool pr;
+ unsigned long flags;
+
+ /* Search TLB for guest pc to get the real address */
+ geaddr = kvmppc_get_pc(vcpu);
+
+ addr_space = (vcpu->arch.shared->msr & MSR_IS) >> MSR_IR_LG;
+
+ local_irq_save(flags);
+ mtspr(SPRN_MAS6, (vcpu->arch.pid << MAS6_SPID_SHIFT) | addr_space);
+ mtspr(SPRN_MAS5, MAS5_SGS | vcpu->kvm->arch.lpid);
+ asm volatile("tlbsx 0, %[geaddr]\n" : :
+ [geaddr] "r" (geaddr));
+ mtspr(SPRN_MAS5, 0);
+ mtspr(SPRN_MAS8, 0);
+ mas1 = mfspr(SPRN_MAS1);
+ mas2 = mfspr(SPRN_MAS2);
+ mas3 = mfspr(SPRN_MAS3);
+#ifdef CONFIG_64BIT
+ mas7_mas3 = mfspr(SPRN_MAS7_MAS3);
+#else
+ mas7_mas3 = ((u64)mfspr(SPRN_MAS7) << 32) | mas3;
+#endif
+ local_irq_restore(flags);
+
+ /*
+ * If the TLB entry for guest pc was evicted, return to the guest.
+ * There are high chances to find a valid TLB entry next time.
+ */
+ if (!(mas1 & MAS1_VALID))
+ return EMULATE_AGAIN;
+
+ /*
+ * Another thread may rewrite the TLB entry in parallel, don't
+ * execute from the address if the execute permission is not set
+ */
+ pr = vcpu->arch.shared->msr & MSR_PR;
+ if (unlikely((pr && !(mas3 & MAS3_UX)) ||
+ (!pr && !(mas3 & MAS3_SX)))) {
+ pr_err_ratelimited(
+ "%s: Instuction emulation from guest addres %08lx without execute permission\n",
+ __func__, geaddr);
+ return EMULATE_AGAIN;
+ }
+
+ /*
+ * The real address will be mapped by a cacheable, memory coherent,
+ * write-back page. Check for mismatches when LRAT is used.
+ */
+ if (has_feature(vcpu, VCPU_FTR_MMU_V2) &&
+ unlikely((mas2 & MAS2_I) || (mas2 & MAS2_W) || !(mas2 & MAS2_M))) {
+ pr_err_ratelimited(
+ "%s: Instuction emulation from guest addres %08lx mismatches storage attributes\n",
+ __func__, geaddr);
+ return EMULATE_AGAIN;
+ }
+
+ /* Get pfn */
+ psize_shift = MAS1_GET_TSIZE(mas1) + 10;
+ addr = (mas7_mas3 & (~0ULL << psize_shift)) |
+ (geaddr & ((1ULL << psize_shift) - 1ULL));
+ pfn = addr >> PAGE_SHIFT;
+
+ /* Guard against emulation from devices area */
+ if (unlikely(!page_is_ram(pfn))) {
+ pr_err_ratelimited("%s: Instruction emulation from non-RAM host addres %08llx is not supported\n",
+ __func__, addr);
+ return EMULATE_AGAIN;
+ }
+
+ /* Map a page and get guest's instruction */
+ page = pfn_to_page(pfn);
+ eaddr = (unsigned long)kmap_atomic(page);
+ *instr = *(u32 *)(eaddr | (unsigned long)(addr & ~PAGE_MASK));
+ kunmap_atomic((u32 *)eaddr);
+
+ return EMULATE_DONE;
+}
+#else
int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
u32 *instr)
{
return EMULATE_AGAIN;
}
+#endif
/************* MMU Notifiers *************/
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 5/5] KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: Mihai Caraman, linuxppc-dev, kvm
On book3e, KVM uses load external pid (lwepx) dedicated instruction to read
guest last instruction on the exit path. lwepx exceptions (DTLB_MISS, DSI
and LRAT), generated by loading a guest address, needs to be handled by KVM.
These exceptions are generated in a substituted guest translation context
(EPLC[EGS] = 1) from host context (MSR[GS] = 0).
Currently, KVM hooks only interrupts generated from guest context (MSR[GS] = 1),
doing minimal checks on the fast path to avoid host performance degradation.
lwepx exceptions originate from host state (MSR[GS] = 0) which implies
additional checks in DO_KVM macro (beside the current MSR[GS] = 1) by looking
at the Exception Syndrome Register (ESR[EPID]) and the External PID Load Context
Register (EPLC[EGS]). Doing this on each Data TLB miss exception is obvious
too intrusive for the host.
Read guest last instruction from kvmppc_load_last_inst() by searching for the
physical address and kmap it. This address the TODO for TLB eviction and
execute-but-not-read entries, and allow us to get rid of lwepx until we are
able to handle failures.
A simple stress benchmark shows a 1% sys performance degradation compared with
previous approach (lwepx without failure handling):
time for i in `seq 1 10000`; do /bin/echo > /dev/null; done
real 0m 8.85s
user 0m 4.34s
sys 0m 4.48s
vs
real 0m 8.84s
user 0m 4.36s
sys 0m 4.44s
A solution to use lwepx and to handle its exceptions in KVM would be to temporary
highjack the interrupt vector from host. This imposes additional synchronizations
for cores like FSL e6500 that shares host IVOR registers between hardware threads.
This optimized solution can be later developed on top of this patch.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- no change
v5:
- return ENULATE_AGAIN in case of failure
v4:
- add switch and new function when getting last inst earlier
- use enum instead of prev semnatic
- get rid of mas0, optimize mas7_mas3
- give more context in visible messages
- check storage attributes mismatch on MMUv2
- get rid of pfn_valid check
v3:
- reworked patch description
- use unaltered kmap addr for kunmap
- get last instruction before beeing preempted
v2:
- reworked patch description
- used pr_* functions
- addressed cosmetic feedback
arch/powerpc/kvm/booke.c | 44 +++++++++++++++++
arch/powerpc/kvm/bookehv_interrupts.S | 37 ++++----------
arch/powerpc/kvm/e500_mmu_host.c | 92 +++++++++++++++++++++++++++++++++++
3 files changed, 145 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 34a42b9..843077b 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -869,6 +869,28 @@ static void kvmppc_restart_interrupt(struct kvm_vcpu *vcpu,
}
}
+static int kvmppc_resume_inst_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ enum emulation_result emulated, u32 last_inst)
+{
+ switch (emulated) {
+ case EMULATE_AGAIN:
+ return RESUME_GUEST;
+
+ case EMULATE_FAIL:
+ pr_debug("%s: load instruction from guest address %lx failed\n",
+ __func__, vcpu->arch.pc);
+ /* For debugging, encode the failing instruction and
+ * report it to userspace. */
+ run->hw.hardware_exit_reason = ~0ULL << 32;
+ run->hw.hardware_exit_reason |= last_inst;
+ kvmppc_core_queue_program(vcpu, ESR_PIL);
+ return RESUME_HOST;
+
+ default:
+ BUG();
+ }
+}
+
/**
* kvmppc_handle_exit
*
@@ -880,6 +902,8 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
int r = RESUME_HOST;
int s;
int idx;
+ u32 last_inst = KVM_INST_FETCH_FAILED;
+ enum emulation_result emulated = EMULATE_DONE;
/* update before a new last_exit_type is rewritten */
kvmppc_update_timing_stats(vcpu);
@@ -887,6 +911,20 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
/* restart interrupts if they were meant for the host */
kvmppc_restart_interrupt(vcpu, exit_nr);
+ /*
+ * get last instruction before beeing preempted
+ * TODO: for e6500 check also BOOKE_INTERRUPT_LRAT_ERROR & ESR_DATA
+ */
+ switch (exit_nr) {
+ case BOOKE_INTERRUPT_DATA_STORAGE:
+ case BOOKE_INTERRUPT_DTLB_MISS:
+ case BOOKE_INTERRUPT_HV_PRIV:
+ emulated = kvmppc_get_last_inst(vcpu, false, &last_inst);
+ break;
+ default:
+ break;
+ }
+
local_irq_enable();
trace_kvm_exit(exit_nr, vcpu);
@@ -895,6 +933,11 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
run->exit_reason = KVM_EXIT_UNKNOWN;
run->ready_for_interrupt_injection = 1;
+ if (emulated != EMULATE_DONE) {
+ r = kvmppc_resume_inst_load(run, vcpu, emulated, last_inst);
+ goto out;
+ }
+
switch (exit_nr) {
case BOOKE_INTERRUPT_MACHINE_CHECK:
printk("MACHINE CHECK: %lx\n", mfspr(SPRN_MCSR));
@@ -1184,6 +1227,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
BUG();
}
+out:
/*
* To avoid clobbering exit_reason, only check for signals if we
* aren't already exiting to userspace for some other reason.
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index 6ff4480..e000b39 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -121,38 +121,14 @@
1:
.if \flags & NEED_EMU
- /*
- * This assumes you have external PID support.
- * To support a bookehv CPU without external PID, you'll
- * need to look up the TLB entry and create a temporary mapping.
- *
- * FIXME: we don't currently handle if the lwepx faults. PR-mode
- * booke doesn't handle it either. Since Linux doesn't use
- * broadcast tlbivax anymore, the only way this should happen is
- * if the guest maps its memory execute-but-not-read, or if we
- * somehow take a TLB miss in the middle of this entry code and
- * evict the relevant entry. On e500mc, all kernel lowmem is
- * bolted into TLB1 large page mappings, and we don't use
- * broadcast invalidates, so we should not take a TLB miss here.
- *
- * Later we'll need to deal with faults here. Disallowing guest
- * mappings that are execute-but-not-read could be an option on
- * e500mc, but not on chips with an LRAT if it is used.
- */
-
- mfspr r3, SPRN_EPLC /* will already have correct ELPID and EGS */
PPC_STL r15, VCPU_GPR(R15)(r4)
PPC_STL r16, VCPU_GPR(R16)(r4)
PPC_STL r17, VCPU_GPR(R17)(r4)
PPC_STL r18, VCPU_GPR(R18)(r4)
PPC_STL r19, VCPU_GPR(R19)(r4)
- mr r8, r3
PPC_STL r20, VCPU_GPR(R20)(r4)
- rlwimi r8, r6, EPC_EAS_SHIFT - MSR_IR_LG, EPC_EAS
PPC_STL r21, VCPU_GPR(R21)(r4)
- rlwimi r8, r6, EPC_EPR_SHIFT - MSR_PR_LG, EPC_EPR
PPC_STL r22, VCPU_GPR(R22)(r4)
- rlwimi r8, r10, EPC_EPID_SHIFT, EPC_EPID
PPC_STL r23, VCPU_GPR(R23)(r4)
PPC_STL r24, VCPU_GPR(R24)(r4)
PPC_STL r25, VCPU_GPR(R25)(r4)
@@ -162,10 +138,15 @@
PPC_STL r29, VCPU_GPR(R29)(r4)
PPC_STL r30, VCPU_GPR(R30)(r4)
PPC_STL r31, VCPU_GPR(R31)(r4)
- mtspr SPRN_EPLC, r8
- isync
- lwepx r9, 0, r5
- mtspr SPRN_EPLC, r3
+
+ /*
+ * We don't use external PID support. lwepx faults would need to be
+ * handled by KVM and this implies aditional code in DO_KVM (for
+ * DTB_MISS, DSI and LRAT) to check ESR[EPID] and EPLC[EGS] which
+ * is too intrusive for the host. Get last instuction in
+ * kvmppc_get_last_inst().
+ */
+ li r9, KVM_INST_FETCH_FAILED
stw r9, VCPU_LAST_INST(r4)
.endif
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 4385c14..4150826 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -610,11 +610,103 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
}
}
+#ifdef CONFIG_KVM_BOOKE_HV
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *instr)
+{
+ gva_t geaddr;
+ hpa_t addr;
+ hfn_t pfn;
+ hva_t eaddr;
+ u32 mas1, mas2, mas3;
+ u64 mas7_mas3;
+ struct page *page;
+ unsigned int addr_space, psize_shift;
+ bool pr;
+ unsigned long flags;
+
+ /* Search TLB for guest pc to get the real address */
+ geaddr = kvmppc_get_pc(vcpu);
+
+ addr_space = (vcpu->arch.shared->msr & MSR_IS) >> MSR_IR_LG;
+
+ local_irq_save(flags);
+ mtspr(SPRN_MAS6, (vcpu->arch.pid << MAS6_SPID_SHIFT) | addr_space);
+ mtspr(SPRN_MAS5, MAS5_SGS | vcpu->kvm->arch.lpid);
+ asm volatile("tlbsx 0, %[geaddr]\n" : :
+ [geaddr] "r" (geaddr));
+ mtspr(SPRN_MAS5, 0);
+ mtspr(SPRN_MAS8, 0);
+ mas1 = mfspr(SPRN_MAS1);
+ mas2 = mfspr(SPRN_MAS2);
+ mas3 = mfspr(SPRN_MAS3);
+#ifdef CONFIG_64BIT
+ mas7_mas3 = mfspr(SPRN_MAS7_MAS3);
+#else
+ mas7_mas3 = ((u64)mfspr(SPRN_MAS7) << 32) | mas3;
+#endif
+ local_irq_restore(flags);
+
+ /*
+ * If the TLB entry for guest pc was evicted, return to the guest.
+ * There are high chances to find a valid TLB entry next time.
+ */
+ if (!(mas1 & MAS1_VALID))
+ return EMULATE_AGAIN;
+
+ /*
+ * Another thread may rewrite the TLB entry in parallel, don't
+ * execute from the address if the execute permission is not set
+ */
+ pr = vcpu->arch.shared->msr & MSR_PR;
+ if (unlikely((pr && !(mas3 & MAS3_UX)) ||
+ (!pr && !(mas3 & MAS3_SX)))) {
+ pr_err_ratelimited(
+ "%s: Instuction emulation from guest addres %08lx without execute permission\n",
+ __func__, geaddr);
+ return EMULATE_AGAIN;
+ }
+
+ /*
+ * The real address will be mapped by a cacheable, memory coherent,
+ * write-back page. Check for mismatches when LRAT is used.
+ */
+ if (has_feature(vcpu, VCPU_FTR_MMU_V2) &&
+ unlikely((mas2 & MAS2_I) || (mas2 & MAS2_W) || !(mas2 & MAS2_M))) {
+ pr_err_ratelimited(
+ "%s: Instuction emulation from guest addres %08lx mismatches storage attributes\n",
+ __func__, geaddr);
+ return EMULATE_AGAIN;
+ }
+
+ /* Get pfn */
+ psize_shift = MAS1_GET_TSIZE(mas1) + 10;
+ addr = (mas7_mas3 & (~0ULL << psize_shift)) |
+ (geaddr & ((1ULL << psize_shift) - 1ULL));
+ pfn = addr >> PAGE_SHIFT;
+
+ /* Guard against emulation from devices area */
+ if (unlikely(!page_is_ram(pfn))) {
+ pr_err_ratelimited("%s: Instruction emulation from non-RAM host addres %08llx is not supported\n",
+ __func__, addr);
+ return EMULATE_AGAIN;
+ }
+
+ /* Map a page and get guest's instruction */
+ page = pfn_to_page(pfn);
+ eaddr = (unsigned long)kmap_atomic(page);
+ *instr = *(u32 *)(eaddr | (unsigned long)(addr & ~PAGE_MASK));
+ kunmap_atomic((u32 *)eaddr);
+
+ return EMULATE_DONE;
+}
+#else
int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
u32 *instr)
{
return EMULATE_AGAIN;
}
+#endif
/************* MMU Notifiers *************/
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v6 5/5] KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
@ 2014-07-23 16:06 ` Mihai Caraman
0 siblings, 0 replies; 21+ messages in thread
From: Mihai Caraman @ 2014-07-23 16:06 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm, linuxppc-dev, Mihai Caraman
On book3e, KVM uses load external pid (lwepx) dedicated instruction to read
guest last instruction on the exit path. lwepx exceptions (DTLB_MISS, DSI
and LRAT), generated by loading a guest address, needs to be handled by KVM.
These exceptions are generated in a substituted guest translation context
(EPLC[EGS] = 1) from host context (MSR[GS] = 0).
Currently, KVM hooks only interrupts generated from guest context (MSR[GS] = 1),
doing minimal checks on the fast path to avoid host performance degradation.
lwepx exceptions originate from host state (MSR[GS] = 0) which implies
additional checks in DO_KVM macro (beside the current MSR[GS] = 1) by looking
at the Exception Syndrome Register (ESR[EPID]) and the External PID Load Context
Register (EPLC[EGS]). Doing this on each Data TLB miss exception is obvious
too intrusive for the host.
Read guest last instruction from kvmppc_load_last_inst() by searching for the
physical address and kmap it. This address the TODO for TLB eviction and
execute-but-not-read entries, and allow us to get rid of lwepx until we are
able to handle failures.
A simple stress benchmark shows a 1% sys performance degradation compared with
previous approach (lwepx without failure handling):
time for i in `seq 1 10000`; do /bin/echo > /dev/null; done
real 0m 8.85s
user 0m 4.34s
sys 0m 4.48s
vs
real 0m 8.84s
user 0m 4.36s
sys 0m 4.44s
A solution to use lwepx and to handle its exceptions in KVM would be to temporary
highjack the interrupt vector from host. This imposes additional synchronizations
for cores like FSL e6500 that shares host IVOR registers between hardware threads.
This optimized solution can be later developed on top of this patch.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v6:
- no change
v5:
- return ENULATE_AGAIN in case of failure
v4:
- add switch and new function when getting last inst earlier
- use enum instead of prev semnatic
- get rid of mas0, optimize mas7_mas3
- give more context in visible messages
- check storage attributes mismatch on MMUv2
- get rid of pfn_valid check
v3:
- reworked patch description
- use unaltered kmap addr for kunmap
- get last instruction before beeing preempted
v2:
- reworked patch description
- used pr_* functions
- addressed cosmetic feedback
arch/powerpc/kvm/booke.c | 44 +++++++++++++++++
arch/powerpc/kvm/bookehv_interrupts.S | 37 ++++----------
arch/powerpc/kvm/e500_mmu_host.c | 92 +++++++++++++++++++++++++++++++++++
3 files changed, 145 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 34a42b9..843077b 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -869,6 +869,28 @@ static void kvmppc_restart_interrupt(struct kvm_vcpu *vcpu,
}
}
+static int kvmppc_resume_inst_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ enum emulation_result emulated, u32 last_inst)
+{
+ switch (emulated) {
+ case EMULATE_AGAIN:
+ return RESUME_GUEST;
+
+ case EMULATE_FAIL:
+ pr_debug("%s: load instruction from guest address %lx failed\n",
+ __func__, vcpu->arch.pc);
+ /* For debugging, encode the failing instruction and
+ * report it to userspace. */
+ run->hw.hardware_exit_reason = ~0ULL << 32;
+ run->hw.hardware_exit_reason |= last_inst;
+ kvmppc_core_queue_program(vcpu, ESR_PIL);
+ return RESUME_HOST;
+
+ default:
+ BUG();
+ }
+}
+
/**
* kvmppc_handle_exit
*
@@ -880,6 +902,8 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
int r = RESUME_HOST;
int s;
int idx;
+ u32 last_inst = KVM_INST_FETCH_FAILED;
+ enum emulation_result emulated = EMULATE_DONE;
/* update before a new last_exit_type is rewritten */
kvmppc_update_timing_stats(vcpu);
@@ -887,6 +911,20 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
/* restart interrupts if they were meant for the host */
kvmppc_restart_interrupt(vcpu, exit_nr);
+ /*
+ * get last instruction before beeing preempted
+ * TODO: for e6500 check also BOOKE_INTERRUPT_LRAT_ERROR & ESR_DATA
+ */
+ switch (exit_nr) {
+ case BOOKE_INTERRUPT_DATA_STORAGE:
+ case BOOKE_INTERRUPT_DTLB_MISS:
+ case BOOKE_INTERRUPT_HV_PRIV:
+ emulated = kvmppc_get_last_inst(vcpu, false, &last_inst);
+ break;
+ default:
+ break;
+ }
+
local_irq_enable();
trace_kvm_exit(exit_nr, vcpu);
@@ -895,6 +933,11 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
run->exit_reason = KVM_EXIT_UNKNOWN;
run->ready_for_interrupt_injection = 1;
+ if (emulated != EMULATE_DONE) {
+ r = kvmppc_resume_inst_load(run, vcpu, emulated, last_inst);
+ goto out;
+ }
+
switch (exit_nr) {
case BOOKE_INTERRUPT_MACHINE_CHECK:
printk("MACHINE CHECK: %lx\n", mfspr(SPRN_MCSR));
@@ -1184,6 +1227,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
BUG();
}
+out:
/*
* To avoid clobbering exit_reason, only check for signals if we
* aren't already exiting to userspace for some other reason.
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index 6ff4480..e000b39 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -121,38 +121,14 @@
1:
.if \flags & NEED_EMU
- /*
- * This assumes you have external PID support.
- * To support a bookehv CPU without external PID, you'll
- * need to look up the TLB entry and create a temporary mapping.
- *
- * FIXME: we don't currently handle if the lwepx faults. PR-mode
- * booke doesn't handle it either. Since Linux doesn't use
- * broadcast tlbivax anymore, the only way this should happen is
- * if the guest maps its memory execute-but-not-read, or if we
- * somehow take a TLB miss in the middle of this entry code and
- * evict the relevant entry. On e500mc, all kernel lowmem is
- * bolted into TLB1 large page mappings, and we don't use
- * broadcast invalidates, so we should not take a TLB miss here.
- *
- * Later we'll need to deal with faults here. Disallowing guest
- * mappings that are execute-but-not-read could be an option on
- * e500mc, but not on chips with an LRAT if it is used.
- */
-
- mfspr r3, SPRN_EPLC /* will already have correct ELPID and EGS */
PPC_STL r15, VCPU_GPR(R15)(r4)
PPC_STL r16, VCPU_GPR(R16)(r4)
PPC_STL r17, VCPU_GPR(R17)(r4)
PPC_STL r18, VCPU_GPR(R18)(r4)
PPC_STL r19, VCPU_GPR(R19)(r4)
- mr r8, r3
PPC_STL r20, VCPU_GPR(R20)(r4)
- rlwimi r8, r6, EPC_EAS_SHIFT - MSR_IR_LG, EPC_EAS
PPC_STL r21, VCPU_GPR(R21)(r4)
- rlwimi r8, r6, EPC_EPR_SHIFT - MSR_PR_LG, EPC_EPR
PPC_STL r22, VCPU_GPR(R22)(r4)
- rlwimi r8, r10, EPC_EPID_SHIFT, EPC_EPID
PPC_STL r23, VCPU_GPR(R23)(r4)
PPC_STL r24, VCPU_GPR(R24)(r4)
PPC_STL r25, VCPU_GPR(R25)(r4)
@@ -162,10 +138,15 @@
PPC_STL r29, VCPU_GPR(R29)(r4)
PPC_STL r30, VCPU_GPR(R30)(r4)
PPC_STL r31, VCPU_GPR(R31)(r4)
- mtspr SPRN_EPLC, r8
- isync
- lwepx r9, 0, r5
- mtspr SPRN_EPLC, r3
+
+ /*
+ * We don't use external PID support. lwepx faults would need to be
+ * handled by KVM and this implies aditional code in DO_KVM (for
+ * DTB_MISS, DSI and LRAT) to check ESR[EPID] and EPLC[EGS] which
+ * is too intrusive for the host. Get last instuction in
+ * kvmppc_get_last_inst().
+ */
+ li r9, KVM_INST_FETCH_FAILED
stw r9, VCPU_LAST_INST(r4)
.endif
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 4385c14..4150826 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -610,11 +610,103 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
}
}
+#ifdef CONFIG_KVM_BOOKE_HV
+int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
+ u32 *instr)
+{
+ gva_t geaddr;
+ hpa_t addr;
+ hfn_t pfn;
+ hva_t eaddr;
+ u32 mas1, mas2, mas3;
+ u64 mas7_mas3;
+ struct page *page;
+ unsigned int addr_space, psize_shift;
+ bool pr;
+ unsigned long flags;
+
+ /* Search TLB for guest pc to get the real address */
+ geaddr = kvmppc_get_pc(vcpu);
+
+ addr_space = (vcpu->arch.shared->msr & MSR_IS) >> MSR_IR_LG;
+
+ local_irq_save(flags);
+ mtspr(SPRN_MAS6, (vcpu->arch.pid << MAS6_SPID_SHIFT) | addr_space);
+ mtspr(SPRN_MAS5, MAS5_SGS | vcpu->kvm->arch.lpid);
+ asm volatile("tlbsx 0, %[geaddr]\n" : :
+ [geaddr] "r" (geaddr));
+ mtspr(SPRN_MAS5, 0);
+ mtspr(SPRN_MAS8, 0);
+ mas1 = mfspr(SPRN_MAS1);
+ mas2 = mfspr(SPRN_MAS2);
+ mas3 = mfspr(SPRN_MAS3);
+#ifdef CONFIG_64BIT
+ mas7_mas3 = mfspr(SPRN_MAS7_MAS3);
+#else
+ mas7_mas3 = ((u64)mfspr(SPRN_MAS7) << 32) | mas3;
+#endif
+ local_irq_restore(flags);
+
+ /*
+ * If the TLB entry for guest pc was evicted, return to the guest.
+ * There are high chances to find a valid TLB entry next time.
+ */
+ if (!(mas1 & MAS1_VALID))
+ return EMULATE_AGAIN;
+
+ /*
+ * Another thread may rewrite the TLB entry in parallel, don't
+ * execute from the address if the execute permission is not set
+ */
+ pr = vcpu->arch.shared->msr & MSR_PR;
+ if (unlikely((pr && !(mas3 & MAS3_UX)) ||
+ (!pr && !(mas3 & MAS3_SX)))) {
+ pr_err_ratelimited(
+ "%s: Instuction emulation from guest addres %08lx without execute permission\n",
+ __func__, geaddr);
+ return EMULATE_AGAIN;
+ }
+
+ /*
+ * The real address will be mapped by a cacheable, memory coherent,
+ * write-back page. Check for mismatches when LRAT is used.
+ */
+ if (has_feature(vcpu, VCPU_FTR_MMU_V2) &&
+ unlikely((mas2 & MAS2_I) || (mas2 & MAS2_W) || !(mas2 & MAS2_M))) {
+ pr_err_ratelimited(
+ "%s: Instuction emulation from guest addres %08lx mismatches storage attributes\n",
+ __func__, geaddr);
+ return EMULATE_AGAIN;
+ }
+
+ /* Get pfn */
+ psize_shift = MAS1_GET_TSIZE(mas1) + 10;
+ addr = (mas7_mas3 & (~0ULL << psize_shift)) |
+ (geaddr & ((1ULL << psize_shift) - 1ULL));
+ pfn = addr >> PAGE_SHIFT;
+
+ /* Guard against emulation from devices area */
+ if (unlikely(!page_is_ram(pfn))) {
+ pr_err_ratelimited("%s: Instruction emulation from non-RAM host addres %08llx is not supported\n",
+ __func__, addr);
+ return EMULATE_AGAIN;
+ }
+
+ /* Map a page and get guest's instruction */
+ page = pfn_to_page(pfn);
+ eaddr = (unsigned long)kmap_atomic(page);
+ *instr = *(u32 *)(eaddr | (unsigned long)(addr & ~PAGE_MASK));
+ kunmap_atomic((u32 *)eaddr);
+
+ return EMULATE_DONE;
+}
+#else
int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type,
u32 *instr)
{
return EMULATE_AGAIN;
}
+#endif
/************* MMU Notifiers *************/
--
1.7.11.7
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst()
2014-07-23 16:06 ` Mihai Caraman
(?)
@ 2014-07-24 13:08 ` Alexander Graf
-1 siblings, 0 replies; 21+ messages in thread
From: Alexander Graf @ 2014-07-24 13:08 UTC (permalink / raw)
To: Mihai Caraman, kvm-ppc; +Cc: kvm, linuxppc-dev
On 23.07.14 18:06, Mihai Caraman wrote:
> Read guest last instruction from kvmppc_get_last_inst() allowing the function
> to fail in order to emulate again. On bookehv architecture search for
> the physical address and kmap it, instead of using Load External PID (lwepx)
> instruction. This fixes an infinite loop caused by lwepx's data TLB miss
> exception handled in the host and the TODO for execute-but-not-read entries
> and TLB eviction.
>
> Mihai Caraman (5):
> KVM: PPC: e500mc: Revert "add load inst fixup"
> KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
> KVM: PPC: Book3s: Remove kvmppc_read_inst() function
> KVM: PPC: Alow kvmppc_get_last_inst() to fail
> KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
Thanks, applied to kvm-ppc-queue.
Alex
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst()
@ 2014-07-24 13:08 ` Alexander Graf
0 siblings, 0 replies; 21+ messages in thread
From: Alexander Graf @ 2014-07-24 13:08 UTC (permalink / raw)
To: Mihai Caraman, kvm-ppc; +Cc: linuxppc-dev, kvm
On 23.07.14 18:06, Mihai Caraman wrote:
> Read guest last instruction from kvmppc_get_last_inst() allowing the function
> to fail in order to emulate again. On bookehv architecture search for
> the physical address and kmap it, instead of using Load External PID (lwepx)
> instruction. This fixes an infinite loop caused by lwepx's data TLB miss
> exception handled in the host and the TODO for execute-but-not-read entries
> and TLB eviction.
>
> Mihai Caraman (5):
> KVM: PPC: e500mc: Revert "add load inst fixup"
> KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
> KVM: PPC: Book3s: Remove kvmppc_read_inst() function
> KVM: PPC: Alow kvmppc_get_last_inst() to fail
> KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
Thanks, applied to kvm-ppc-queue.
Alex
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst()
@ 2014-07-24 13:08 ` Alexander Graf
0 siblings, 0 replies; 21+ messages in thread
From: Alexander Graf @ 2014-07-24 13:08 UTC (permalink / raw)
To: Mihai Caraman, kvm-ppc; +Cc: kvm, linuxppc-dev
On 23.07.14 18:06, Mihai Caraman wrote:
> Read guest last instruction from kvmppc_get_last_inst() allowing the function
> to fail in order to emulate again. On bookehv architecture search for
> the physical address and kmap it, instead of using Load External PID (lwepx)
> instruction. This fixes an infinite loop caused by lwepx's data TLB miss
> exception handled in the host and the TODO for execute-but-not-read entries
> and TLB eviction.
>
> Mihai Caraman (5):
> KVM: PPC: e500mc: Revert "add load inst fixup"
> KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1
> KVM: PPC: Book3s: Remove kvmppc_read_inst() function
> KVM: PPC: Alow kvmppc_get_last_inst() to fail
> KVM: PPC: Bookehv: Get vcpu's last instruction for emulation
Thanks, applied to kvm-ppc-queue.
Alex
^ permalink raw reply [flat|nested] 21+ messages in thread
end of thread, other threads:[~2014-07-24 13:08 UTC | newest]
Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-07-23 16:06 [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst() Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` [PATCH v6 1/5] KVM: PPC: e500mc: Revert "add load inst fixup" Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` [PATCH v6 2/5] KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1 Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` [PATCH v6 3/5] KVM: PPC: Book3s: Remove kvmppc_read_inst() function Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` [PATCH v6 4/5] KVM: PPC: Alow kvmppc_get_last_inst() to fail Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` [PATCH v6 5/5] KVM: PPC: Bookehv: Get vcpu's last instruction for emulation Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-23 16:06 ` Mihai Caraman
2014-07-24 13:08 ` [PATCH v6 0/5] Read guest last instruction from kvmppc_get_last_inst() Alexander Graf
2014-07-24 13:08 ` Alexander Graf
2014-07-24 13:08 ` Alexander Graf
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