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* [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately
@ 2011-07-23  7:41 ` Paul Mackerras
  0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-07-23  7:41 UTC (permalink / raw)
  To: linuxppc-dev, kvm-ppc, Alexander Graf

This makes arch/powerpc/kvm/book3s_rmhandlers.S and
arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
separate compilation units rather than having them #included in
arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
conditional branches between the exception prologs in
exceptions-64s.S and the KVM handlers, so there is no need to
keep their contents close together in the vmlinux image.

In their current location, they are using up part of the limited
space between the first-level interrupt handlers and the firmware
NMI data area at offset 0x7000, and with some kernel configurations
this area will overflow (e.g. allyesconfig), leading to an
"attempt to .org backwards" error when compiling exceptions-64s.S.

Moving them out requires that we add some #includes that the
book3s_{,hv_}rmhandlers.S code was previously getting implicitly
via exceptions-64s.S.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kernel/exceptions-64s.S    |   10 ----------
 arch/powerpc/kvm/Makefile               |    3 +++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |    3 +++
 arch/powerpc/kvm/book3s_rmhandlers.S    |    3 +++
 4 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 41b02c7..29ddd8b 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -427,16 +427,6 @@ slb_miss_user_pseries:
 	b	.				/* prevent spec. execution */
 #endif /* __DISABLED__ */
 
-/* KVM's trampoline code needs to be close to the interrupt handlers */
-
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-#ifdef CONFIG_KVM_BOOK3S_PR
-#include "../kvm/book3s_rmhandlers.S"
-#else
-#include "../kvm/book3s_hv_rmhandlers.S"
-#endif
-#endif
-
 	.align	7
 	.globl	__end_interrupts
 __end_interrupts:
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 08428e2..e161680 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -49,12 +49,15 @@ kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_PR) := \
 	book3s_64_mmu_host.o \
 	book3s_64_mmu.o \
 	book3s_32_mmu.o
+kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_PR) := \
+	book3s_rmhandlers.o
 
 kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
 	book3s_hv.o \
 	book3s_hv_interrupts.o \
 	book3s_64_mmu_hv.o
 kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
+	book3s_hv_rmhandlers.o \
 	book3s_hv_rm_mmu.o \
 	book3s_64_vio_hv.o \
 	book3s_hv_builtin.o
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 6dd3358..543ee50 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -20,7 +20,10 @@
 #include <asm/ppc_asm.h>
 #include <asm/kvm_asm.h>
 #include <asm/reg.h>
+#include <asm/mmu.h>
 #include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/hvcall.h>
 #include <asm/asm-offsets.h>
 #include <asm/exception-64s.h>
 
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index c1f877c..5ee66ed 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -20,6 +20,7 @@
 #include <asm/ppc_asm.h>
 #include <asm/kvm_asm.h>
 #include <asm/reg.h>
+#include <asm/mmu.h>
 #include <asm/page.h>
 #include <asm/asm-offsets.h>
 
@@ -39,6 +40,7 @@
 #define MSR_NOIRQ		MSR_KERNEL & ~(MSR_IR | MSR_DR)
 #define FUNC(name) 		GLUE(.,name)
 
+	.globl	kvmppc_skip_interrupt
 kvmppc_skip_interrupt:
 	/*
 	 * Here all GPRs are unchanged from when the interrupt happened
@@ -51,6 +53,7 @@ kvmppc_skip_interrupt:
 	rfid
 	b	.
 
+	.globl	kvmppc_skip_Hinterrupt
 kvmppc_skip_Hinterrupt:
 	/*
 	 * Here all GPRs are unchanged from when the interrupt happened
-- 
1.7.5.4

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately
@ 2011-07-23  7:41 ` Paul Mackerras
  0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-07-23  7:41 UTC (permalink / raw)
  To: linuxppc-dev, kvm-ppc, Alexander Graf

This makes arch/powerpc/kvm/book3s_rmhandlers.S and
arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
separate compilation units rather than having them #included in
arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
conditional branches between the exception prologs in
exceptions-64s.S and the KVM handlers, so there is no need to
keep their contents close together in the vmlinux image.

In their current location, they are using up part of the limited
space between the first-level interrupt handlers and the firmware
NMI data area at offset 0x7000, and with some kernel configurations
this area will overflow (e.g. allyesconfig), leading to an
"attempt to .org backwards" error when compiling exceptions-64s.S.

Moving them out requires that we add some #includes that the
book3s_{,hv_}rmhandlers.S code was previously getting implicitly
via exceptions-64s.S.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kernel/exceptions-64s.S    |   10 ----------
 arch/powerpc/kvm/Makefile               |    3 +++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |    3 +++
 arch/powerpc/kvm/book3s_rmhandlers.S    |    3 +++
 4 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 41b02c7..29ddd8b 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -427,16 +427,6 @@ slb_miss_user_pseries:
 	b	.				/* prevent spec. execution */
 #endif /* __DISABLED__ */
 
-/* KVM's trampoline code needs to be close to the interrupt handlers */
-
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-#ifdef CONFIG_KVM_BOOK3S_PR
-#include "../kvm/book3s_rmhandlers.S"
-#else
-#include "../kvm/book3s_hv_rmhandlers.S"
-#endif
-#endif
-
 	.align	7
 	.globl	__end_interrupts
 __end_interrupts:
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 08428e2..e161680 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -49,12 +49,15 @@ kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_PR) := \
 	book3s_64_mmu_host.o \
 	book3s_64_mmu.o \
 	book3s_32_mmu.o
+kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_PR) := \
+	book3s_rmhandlers.o
 
 kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
 	book3s_hv.o \
 	book3s_hv_interrupts.o \
 	book3s_64_mmu_hv.o
 kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
+	book3s_hv_rmhandlers.o \
 	book3s_hv_rm_mmu.o \
 	book3s_64_vio_hv.o \
 	book3s_hv_builtin.o
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 6dd3358..543ee50 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -20,7 +20,10 @@
 #include <asm/ppc_asm.h>
 #include <asm/kvm_asm.h>
 #include <asm/reg.h>
+#include <asm/mmu.h>
 #include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/hvcall.h>
 #include <asm/asm-offsets.h>
 #include <asm/exception-64s.h>
 
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index c1f877c..5ee66ed 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -20,6 +20,7 @@
 #include <asm/ppc_asm.h>
 #include <asm/kvm_asm.h>
 #include <asm/reg.h>
+#include <asm/mmu.h>
 #include <asm/page.h>
 #include <asm/asm-offsets.h>
 
@@ -39,6 +40,7 @@
 #define MSR_NOIRQ		MSR_KERNEL & ~(MSR_IR | MSR_DR)
 #define FUNC(name) 		GLUE(.,name)
 
+	.globl	kvmppc_skip_interrupt
 kvmppc_skip_interrupt:
 	/*
 	 * Here all GPRs are unchanged from when the interrupt happened
@@ -51,6 +53,7 @@ kvmppc_skip_interrupt:
 	rfid
 	b	.
 
+	.globl	kvmppc_skip_Hinterrupt
 kvmppc_skip_Hinterrupt:
 	/*
 	 * Here all GPRs are unchanged from when the interrupt happened
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH 2/3] KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode
  2011-07-23  7:41 ` Paul Mackerras
@ 2011-07-23  7:41   ` Paul Mackerras
  -1 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-07-23  7:41 UTC (permalink / raw)
  To: linuxppc-dev, kvm-ppc, Alexander Graf

This simplifies the way that the book3s_pr makes the transition to
real mode when entering the guest.  We now call kvmppc_entry_trampoline
(renamed from kvmppc_rmcall) in the base kernel using a normal function
call instead of doing an indirect call through a pointer in the vcpu.
If kvm is a module, the module loader takes care of generating a
trampoline as it does for other calls to functions outside the module.

kvmppc_entry_trampoline then disables interrupts and jumps to
kvmppc_handler_trampoline_enter in real mode using an rfi[d].
That then uses the link register as the address to return to
(potentially in module space) when the guest exits.

This also simplifies the way that we call the Linux interrupt handler
when we exit the guest due to an external, decrementer or performance
monitor interrupt.  Instead of turning on the MMU, then deciding that
we need to call the Linux handler and turning the MMU back off again,
we now go straight to the handler at the point where we would turn the
MMU on.  The handler will then return to the virtual-mode code
(potentially in the module).

Along the way, this moves the setting and clearing of the HID5 DCBZ32
bit into real-mode interrupts-off code, and also makes sure that
we clear the MSR[RI] bit before loading values into SRR0/1.

The net result is that we no longer need any code addresses to be
stored in vcpu->arch.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/kvm_book3s.h     |    4 +-
 arch/powerpc/include/asm/kvm_book3s_asm.h |    1 +
 arch/powerpc/include/asm/kvm_host.h       |    8 --
 arch/powerpc/kernel/asm-offsets.c         |    7 +--
 arch/powerpc/kvm/book3s_32_sr.S           |    2 +-
 arch/powerpc/kvm/book3s_64_slb.S          |    2 +-
 arch/powerpc/kvm/book3s_exports.c         |    4 +-
 arch/powerpc/kvm/book3s_interrupts.S      |  129 +---------------------------
 arch/powerpc/kvm/book3s_pr.c              |   12 ---
 arch/powerpc/kvm/book3s_rmhandlers.S      |   51 ++++--------
 arch/powerpc/kvm/book3s_segment.S         |  112 ++++++++++++++++++++-----
 11 files changed, 120 insertions(+), 212 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 98da010..a70c0e6 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -139,9 +139,7 @@ extern void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr);
 extern int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu);
 extern pfn_t kvmppc_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
 
-extern void kvmppc_handler_lowmem_trampoline(void);
-extern void kvmppc_handler_trampoline_enter(void);
-extern void kvmppc_rmcall(ulong srr0, ulong srr1);
+extern void kvmppc_entry_trampoline(void);
 extern void kvmppc_hv_entry_trampoline(void);
 extern void kvmppc_load_up_fpu(void);
 extern void kvmppc_load_up_altivec(void);
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index ef7b368..af73469 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -75,6 +75,7 @@ struct kvmppc_host_state {
 	ulong scratch0;
 	ulong scratch1;
 	u8 in_guest;
+	u8 restore_hid5;
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	struct kvm_vcpu *kvm_vcpu;
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index cc22b28..db15384 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -258,14 +258,6 @@ struct kvm_vcpu_arch {
 	ulong host_stack;
 	u32 host_pid;
 #ifdef CONFIG_PPC_BOOK3S
-	ulong host_msr;
-	ulong host_r2;
-	void *host_retip;
-	ulong trampoline_lowmem;
-	ulong trampoline_enter;
-	ulong highmem_handler;
-	ulong rmcall;
-	ulong host_paca_phys;
 	struct kvmppc_slb slb[64];
 	int slb_max;		/* 1 + index of last valid entry in slb[] */
 	int slb_nr;		/* total number of entries in SLB */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 54b935f..d34cd32 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -446,8 +446,6 @@ int main(void)
 #ifdef CONFIG_PPC_BOOK3S
 	DEFINE(VCPU_KVM, offsetof(struct kvm_vcpu, kvm));
 	DEFINE(VCPU_VCPUID, offsetof(struct kvm_vcpu, vcpu_id));
-	DEFINE(VCPU_HOST_RETIP, offsetof(struct kvm_vcpu, arch.host_retip));
-	DEFINE(VCPU_HOST_MSR, offsetof(struct kvm_vcpu, arch.host_msr));
 	DEFINE(VCPU_PURR, offsetof(struct kvm_vcpu, arch.purr));
 	DEFINE(VCPU_SPURR, offsetof(struct kvm_vcpu, arch.spurr));
 	DEFINE(VCPU_DSCR, offsetof(struct kvm_vcpu, arch.dscr));
@@ -455,10 +453,6 @@ int main(void)
 	DEFINE(VCPU_UAMOR, offsetof(struct kvm_vcpu, arch.uamor));
 	DEFINE(VCPU_CTRL, offsetof(struct kvm_vcpu, arch.ctrl));
 	DEFINE(VCPU_DABR, offsetof(struct kvm_vcpu, arch.dabr));
-	DEFINE(VCPU_TRAMPOLINE_LOWMEM, offsetof(struct kvm_vcpu, arch.trampoline_lowmem));
-	DEFINE(VCPU_TRAMPOLINE_ENTER, offsetof(struct kvm_vcpu, arch.trampoline_enter));
-	DEFINE(VCPU_HIGHMEM_HANDLER, offsetof(struct kvm_vcpu, arch.highmem_handler));
-	DEFINE(VCPU_RMCALL, offsetof(struct kvm_vcpu, arch.rmcall));
 	DEFINE(VCPU_HFLAGS, offsetof(struct kvm_vcpu, arch.hflags));
 	DEFINE(VCPU_DEC, offsetof(struct kvm_vcpu, arch.dec));
 	DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires));
@@ -534,6 +528,7 @@ int main(void)
 	HSTATE_FIELD(HSTATE_SCRATCH0, scratch0);
 	HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
 	HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
+	HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
diff --git a/arch/powerpc/kvm/book3s_32_sr.S b/arch/powerpc/kvm/book3s_32_sr.S
index 3608471..7e06a6f 100644
--- a/arch/powerpc/kvm/book3s_32_sr.S
+++ b/arch/powerpc/kvm/book3s_32_sr.S
@@ -31,7 +31,7 @@
 	 * R1 = host R1
 	 * R2 = host R2
 	 * R3 = shadow vcpu
-	 * all other volatile GPRS = free
+	 * all other volatile GPRS = free except R4, R6
 	 * SVCPU[CR]  = guest CR
 	 * SVCPU[XER] = guest XER
 	 * SVCPU[CTR] = guest CTR
diff --git a/arch/powerpc/kvm/book3s_64_slb.S b/arch/powerpc/kvm/book3s_64_slb.S
index 04e7d3b..f2e6e48 100644
--- a/arch/powerpc/kvm/book3s_64_slb.S
+++ b/arch/powerpc/kvm/book3s_64_slb.S
@@ -53,7 +53,7 @@ slb_exit_skip_ ## num:
 	 * R1 = host R1
 	 * R2 = host R2
 	 * R3 = shadow vcpu
-	 * all other volatile GPRS = free
+	 * all other volatile GPRS = free except R4, R6
 	 * SVCPU[CR]  = guest CR
 	 * SVCPU[XER] = guest XER
 	 * SVCPU[CTR] = guest CTR
diff --git a/arch/powerpc/kvm/book3s_exports.c b/arch/powerpc/kvm/book3s_exports.c
index 88c8f26..f7f63a0 100644
--- a/arch/powerpc/kvm/book3s_exports.c
+++ b/arch/powerpc/kvm/book3s_exports.c
@@ -23,9 +23,7 @@
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 EXPORT_SYMBOL_GPL(kvmppc_hv_entry_trampoline);
 #else
-EXPORT_SYMBOL_GPL(kvmppc_handler_trampoline_enter);
-EXPORT_SYMBOL_GPL(kvmppc_handler_lowmem_trampoline);
-EXPORT_SYMBOL_GPL(kvmppc_rmcall);
+EXPORT_SYMBOL_GPL(kvmppc_entry_trampoline);
 EXPORT_SYMBOL_GPL(kvmppc_load_up_fpu);
 #ifdef CONFIG_ALTIVEC
 EXPORT_SYMBOL_GPL(kvmppc_load_up_altivec);
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index c54b0e3..0a8515a 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -29,27 +29,11 @@
 #define ULONG_SIZE 		8
 #define FUNC(name) 		GLUE(.,name)
 
-#define GET_SHADOW_VCPU_R13
-
-#define DISABLE_INTERRUPTS	\
-	mfmsr   r0;		\
-	rldicl  r0,r0,48,1;	\
-	rotldi  r0,r0,16;	\
-	mtmsrd  r0,1;		\
-
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
 #define ULONG_SIZE              4
 #define FUNC(name)		name
 
-#define GET_SHADOW_VCPU_R13	\
-	lwz	r13, (THREAD + THREAD_KVM_SVCPU)(r2)
-
-#define DISABLE_INTERRUPTS	\
-	mfmsr   r0;		\
-	rlwinm  r0,r0,0,17,15;	\
-	mtmsr   r0;		\
-
 #endif /* CONFIG_PPC_BOOK3S_XX */
 
 
@@ -108,44 +92,17 @@ kvm_start_entry:
 
 kvm_start_lightweight:
 
-	GET_SHADOW_VCPU_R13
-	PPC_LL	r3, VCPU_HIGHMEM_HANDLER(r4)
-	PPC_STL	r3, HSTATE_VMHANDLER(r13)
-
-	PPC_LL	r10, VCPU_SHADOW_MSR(r4)	/* r10 = vcpu->arch.shadow_msr */
-
-	DISABLE_INTERRUPTS
-
 #ifdef CONFIG_PPC_BOOK3S_64
-	/* Some guests may need to have dcbz set to 32 byte length.
-	 *
-	 * Usually we ensure that by patching the guest's instructions
-	 * to trap on dcbz and emulate it in the hypervisor.
-	 *
-	 * If we can, we should tell the CPU to use 32 byte dcbz though,
-	 * because that's a lot faster.
-	 */
-
 	PPC_LL	r3, VCPU_HFLAGS(r4)
-	rldicl.	r3, r3, 0, 63		/* CR = ((r3 & 1) == 0) */
-	beq	no_dcbz32_on
-
-	mfspr   r3,SPRN_HID5
-	ori     r3, r3, 0x80		/* XXX HID5_dcbz32 = 0x80 */
-	mtspr   SPRN_HID5,r3
-
-no_dcbz32_on:
-
+	rldicl	r3, r3, 0, 63		/* r3 &= 1 */
+	stb	r3, HSTATE_RESTORE_HID5(r13)
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
-	PPC_LL	r6, VCPU_RMCALL(r4)
-	mtctr	r6
-
-	PPC_LL	r3, VCPU_TRAMPOLINE_ENTER(r4)
-	LOAD_REG_IMMEDIATE(r4, MSR_KERNEL & ~(MSR_IR | MSR_DR))
+	PPC_LL	r4, VCPU_SHADOW_MSR(r4)	/* get shadow_msr */
 
 	/* Jump to segment patching handler and into our guest */
-	bctr
+	bl	FUNC(kvmppc_entry_trampoline)
+	nop
 
 /*
  * This is the handler in module memory. It gets jumped at from the
@@ -170,21 +127,6 @@ kvmppc_handler_highmem:
 	/* R7 = vcpu */
 	PPC_LL	r7, GPR4(r1)
 
-#ifdef CONFIG_PPC_BOOK3S_64
-
-	PPC_LL	r5, VCPU_HFLAGS(r7)
-	rldicl.	r5, r5, 0, 63		/* CR = ((r5 & 1) == 0) */
-	beq	no_dcbz32_off
-
-	li	r4, 0
-	mfspr   r5,SPRN_HID5
-	rldimi  r5,r4,6,56
-	mtspr   SPRN_HID5,r5
-
-no_dcbz32_off:
-
-#endif /* CONFIG_PPC_BOOK3S_64 */
-
 	PPC_STL	r14, VCPU_GPR(r14)(r7)
 	PPC_STL	r15, VCPU_GPR(r15)(r7)
 	PPC_STL	r16, VCPU_GPR(r16)(r7)
@@ -204,67 +146,6 @@ no_dcbz32_off:
 	PPC_STL	r30, VCPU_GPR(r30)(r7)
 	PPC_STL	r31, VCPU_GPR(r31)(r7)
 
-	/* Restore host msr -> SRR1 */
-	PPC_LL	r6, VCPU_HOST_MSR(r7)
-
-	/*
-	 * For some interrupts, we need to call the real Linux
-	 * handler, so it can do work for us. This has to happen
-	 * as if the interrupt arrived from the kernel though,
-	 * so let's fake it here where most state is restored.
-	 *
-	 * Call Linux for hardware interrupts/decrementer
-	 * r3 = address of interrupt handler (exit reason)
-	 */
-
-	cmpwi	r12, BOOK3S_INTERRUPT_EXTERNAL
-	beq	call_linux_handler
-	cmpwi	r12, BOOK3S_INTERRUPT_DECREMENTER
-	beq	call_linux_handler
-	cmpwi	r12, BOOK3S_INTERRUPT_PERFMON
-	beq	call_linux_handler
-
-	/* Back to EE=1 */
-	mtmsr	r6
-	sync
-	b	kvm_return_point
-
-call_linux_handler:
-
-	/*
-	 * If we land here we need to jump back to the handler we
-	 * came from.
-	 *
-	 * We have a page that we can access from real mode, so let's
-	 * jump back to that and use it as a trampoline to get back into the
-	 * interrupt handler!
-	 *
-	 * R3 still contains the exit code,
-	 * R5 VCPU_HOST_RETIP and
-	 * R6 VCPU_HOST_MSR
-	 */
-
-	/* Restore host IP -> SRR0 */
-	PPC_LL	r5, VCPU_HOST_RETIP(r7)
-
-	/* XXX Better move to a safe function?
-	 *     What if we get an HTAB flush in between mtsrr0 and mtsrr1? */
-
-	mtlr	r12
-
-	PPC_LL	r4, VCPU_TRAMPOLINE_LOWMEM(r7)
-	mtsrr0	r4
-	LOAD_REG_IMMEDIATE(r3, MSR_KERNEL & ~(MSR_IR | MSR_DR))
-	mtsrr1	r3
-
-	RFI
-
-.global kvm_return_point
-kvm_return_point:
-
-	/* Jump back to lightweight entry if we're supposed to */
-	/* go back into the guest */
-
 	/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
 	mr	r5, r12
 
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 0c0d3f2..d7ab552 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -841,8 +841,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	if (!p)
 		goto uninit_vcpu;
 
-	vcpu->arch.host_retip = kvm_return_point;
-	vcpu->arch.host_msr = mfmsr();
 #ifdef CONFIG_PPC_BOOK3S_64
 	/* default to book3s_64 (970fx) */
 	vcpu->arch.pvr = 0x3C0301;
@@ -853,16 +851,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	kvmppc_set_pvr(vcpu, vcpu->arch.pvr);
 	vcpu->arch.slb_nr = 64;
 
-	/* remember where some real-mode handlers are */
-	vcpu->arch.trampoline_lowmem = __pa(kvmppc_handler_lowmem_trampoline);
-	vcpu->arch.trampoline_enter = __pa(kvmppc_handler_trampoline_enter);
-	vcpu->arch.highmem_handler = (ulong)kvmppc_handler_highmem;
-#ifdef CONFIG_PPC_BOOK3S_64
-	vcpu->arch.rmcall = *(ulong*)kvmppc_rmcall;
-#else
-	vcpu->arch.rmcall = (ulong)kvmppc_rmcall;
-#endif
-
 	vcpu->arch.shadow_msr = MSR_USER64;
 
 	err = kvmppc_mmu_init(vcpu);
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index 5ee66ed..3418758 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -36,9 +36,8 @@
 
 #if defined(CONFIG_PPC_BOOK3S_64)
 
-#define LOAD_SHADOW_VCPU(reg)	GET_PACA(reg)					
-#define MSR_NOIRQ		MSR_KERNEL & ~(MSR_IR | MSR_DR)
 #define FUNC(name) 		GLUE(.,name)
+#define MTMSR_EERI(reg)		mtmsrd	(reg),1
 
 	.globl	kvmppc_skip_interrupt
 kvmppc_skip_interrupt:
@@ -68,8 +67,8 @@ kvmppc_skip_Hinterrupt:
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
-#define MSR_NOIRQ		MSR_KERNEL
 #define FUNC(name)		name
+#define MTMSR_EERI(reg)		mtmsr	(reg)
 
 .macro INTERRUPT_TRAMPOLINE intno
 
@@ -170,40 +169,24 @@ kvmppc_handler_skip_ins:
 #endif
 
 /*
- * This trampoline brings us back to a real mode handler
- *
- * Input Registers:
- *
- * R5 = SRR0
- * R6 = SRR1
- * LR = real-mode IP
+ * Call kvmppc_handler_trampoline_enter in real mode
  *
+ * On entry, r4 contains the guest shadow MSR
  */
-.global kvmppc_handler_lowmem_trampoline
-kvmppc_handler_lowmem_trampoline:
-
-	mtsrr0	r5
+_GLOBAL(kvmppc_entry_trampoline)
+	mfmsr	r5
+	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
+	toreal(r7)
+
+	li	r9, MSR_RI
+	ori	r9, r9, MSR_EE
+	andc	r9, r5, r9	/* Clear EE and RI in MSR value */
+	li	r6, MSR_IR | MSR_DR
+	ori	r6, r6, MSR_EE
+	andc	r6, r5, r6	/* Clear EE, DR and IR in MSR value */
+	MTMSR_EERI(r9)		/* Clear EE and RI in MSR */
+	mtsrr0	r7		/* before we set srr0/1 */
 	mtsrr1	r6
-	blr
-kvmppc_handler_lowmem_trampoline_end:
-
-/*
- * Call a function in real mode
- *
- * Input Registers:
- *
- * R3 = function
- * R4 = MSR
- * R5 = scratch register
- *
- */
-_GLOBAL(kvmppc_rmcall)
-	LOAD_REG_IMMEDIATE(r5, MSR_NOIRQ)
-	mtmsr	r5		/* Disable relocation and interrupts, so mtsrr
-				   doesn't get interrupted */
-	sync
-	mtsrr0	r3
-	mtsrr1	r4
 	RFI
 
 #if defined(CONFIG_PPC_BOOK3S_32)
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index aed32e5..3663564 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -23,6 +23,7 @@
 
 #define GET_SHADOW_VCPU(reg)    \
 	mr	reg, r13
+#define MTMSR_EERI(reg)		mtmsrd	(reg),1
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
@@ -30,6 +31,7 @@
 	tophys(reg, r2);       			\
 	lwz     reg, (THREAD + THREAD_KVM_SVCPU)(reg);	\
 	tophys(reg, reg)
+#define MTMSR_EERI(reg)		mtmsr	(reg)
 
 #endif
 
@@ -57,10 +59,12 @@ kvmppc_handler_trampoline_enter:
 	/* Required state:
 	 *
 	 * MSR = ~IR|DR
-	 * R13 = PACA
 	 * R1 = host R1
 	 * R2 = host R2
-	 * R10 = guest MSR
+	 * R4 = guest shadow MSR
+	 * R5 = normal host MSR
+	 * R6 = current host MSR (EE, IR, DR off)
+	 * LR = highmem guest exit code
 	 * all other volatile GPRS = free
 	 * SVCPU[CR] = guest CR
 	 * SVCPU[XER] = guest XER
@@ -71,15 +75,15 @@ kvmppc_handler_trampoline_enter:
 	/* r3 = shadow vcpu */
 	GET_SHADOW_VCPU(r3)
 
+	/* Save guest exit handler address and MSR */
+	mflr	r0
+	PPC_STL	r0, HSTATE_VMHANDLER(r3)
+	PPC_STL	r5, HSTATE_HOST_MSR(r3)
+
 	/* Save R1/R2 in the PACA (64-bit) or shadow_vcpu (32-bit) */
 	PPC_STL	r1, HSTATE_HOST_R1(r3)
 	PPC_STL	r2, HSTATE_HOST_R2(r3)
 
-	/* Move SRR0 and SRR1 into the respective regs */
-	PPC_LL  r9, SVCPU_PC(r3)
-	mtsrr0	r9
-	mtsrr1	r10
-
 	/* Activate guest mode, so faults get handled by KVM */
 	li	r11, KVM_GUEST_MODE_GUEST
 	stb	r11, HSTATE_IN_GUEST(r3)
@@ -87,17 +91,46 @@ kvmppc_handler_trampoline_enter:
 	/* Switch to guest segment. This is subarch specific. */
 	LOAD_GUEST_SEGMENTS
 
+#ifdef CONFIG_PPC_BOOK3S_64
+	/* Some guests may need to have dcbz set to 32 byte length.
+	 *
+	 * Usually we ensure that by patching the guest's instructions
+	 * to trap on dcbz and emulate it in the hypervisor.
+	 *
+	 * If we can, we should tell the CPU to use 32 byte dcbz though,
+	 * because that's a lot faster.
+	 */
+	lbz	r0, HSTATE_RESTORE_HID5(r3)
+	cmpwi	r0, 0
+	beq	no_dcbz32_on
+
+	mfspr   r0,SPRN_HID5
+	ori     r0, r0, 0x80		/* XXX HID5_dcbz32 = 0x80 */
+	mtspr   SPRN_HID5,r0
+no_dcbz32_on:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
 	/* Enter guest */
 
-	PPC_LL	r4, SVCPU_CTR(r3)
-	PPC_LL	r5, SVCPU_LR(r3)
-	lwz	r6, SVCPU_CR(r3)
-	lwz	r7, SVCPU_XER(r3)
+	PPC_LL	r8, SVCPU_CTR(r3)
+	PPC_LL	r9, SVCPU_LR(r3)
+	lwz	r10, SVCPU_CR(r3)
+	lwz	r11, SVCPU_XER(r3)
+
+	mtctr	r8
+	mtlr	r9
+	mtcr	r10
+	mtxer	r11
 
-	mtctr	r4
-	mtlr	r5
-	mtcr	r6
-	mtxer	r7
+	/* Move SRR0 and SRR1 into the respective regs */
+	PPC_LL  r9, SVCPU_PC(r3)
+	/* First clear RI in our current MSR value */
+	li	r0, MSR_RI
+	andc	r6, r6, r0
+	MTMSR_EERI(r6)
+	mtsrr0	r9
+	mtsrr1	r4
 
 	PPC_LL	r0, SVCPU_R0(r3)
 	PPC_LL	r1, SVCPU_R1(r3)
@@ -254,6 +287,43 @@ no_ld_last_inst:
 	/* Switch back to host MMU */
 	LOAD_HOST_SEGMENTS
 
+#ifdef CONFIG_PPC_BOOK3S_64
+
+	lbz	r5, HSTATE_RESTORE_HID5(r13)
+	cmpwi	r5, 0
+	beq	no_dcbz32_off
+
+	li	r4, 0
+	mfspr   r5,SPRN_HID5
+	rldimi  r5,r4,6,56
+	mtspr   SPRN_HID5,r5
+
+no_dcbz32_off:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+	/*
+	 * For some interrupts, we need to call the real Linux
+	 * handler, so it can do work for us. This has to happen
+	 * as if the interrupt arrived from the kernel though,
+	 * so let's fake it here where most state is restored.
+	 *
+	 * Having set up SRR0/1 with the address where we want
+	 * to continue with relocation on (potentially in module
+	 * space), we either just go straight there with rfi[d],
+	 * or we jump to an interrupt handler with bctr if there
+	 * is an interrupt to be handled first.  In the latter
+	 * case, the rfi[d] at the end of the interrupt handler
+	 * will get us back to where we want to continue.
+	 */
+
+	cmpwi	r12, BOOK3S_INTERRUPT_EXTERNAL
+	beq	1f
+	cmpwi	r12, BOOK3S_INTERRUPT_DECREMENTER
+	beq	1f
+	cmpwi	r12, BOOK3S_INTERRUPT_PERFMON
+1:	mtctr	r12
+
 	/* Register usage at this point:
 	 *
 	 * R1       = host R1
@@ -264,13 +334,15 @@ no_ld_last_inst:
 	 *
 	 */
 
-	/* RFI into the highmem handler */
-	mfmsr	r7
-	ori	r7, r7, MSR_IR|MSR_DR|MSR_RI|MSR_ME	/* Enable paging */
-	mtsrr1	r7
-	/* Load highmem handler address */
+	PPC_LL	r6, HSTATE_HOST_MSR(r13)
 	PPC_LL	r8, HSTATE_VMHANDLER(r13)
+
+	/* Restore host msr -> SRR1 */
+	mtsrr1	r6
+	/* Load highmem handler address */
 	mtsrr0	r8
 
+	/* RFI into the highmem handler, or jump to interrupt handler */
+	beqctr
 	RFI
 kvmppc_handler_trampoline_exit_end:
-- 
1.7.5.4

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH 2/3] KVM: PPC: book3s_pr: Simplify transitions between
@ 2011-07-23  7:41   ` Paul Mackerras
  0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-07-23  7:41 UTC (permalink / raw)
  To: linuxppc-dev, kvm-ppc, Alexander Graf

This simplifies the way that the book3s_pr makes the transition to
real mode when entering the guest.  We now call kvmppc_entry_trampoline
(renamed from kvmppc_rmcall) in the base kernel using a normal function
call instead of doing an indirect call through a pointer in the vcpu.
If kvm is a module, the module loader takes care of generating a
trampoline as it does for other calls to functions outside the module.

kvmppc_entry_trampoline then disables interrupts and jumps to
kvmppc_handler_trampoline_enter in real mode using an rfi[d].
That then uses the link register as the address to return to
(potentially in module space) when the guest exits.

This also simplifies the way that we call the Linux interrupt handler
when we exit the guest due to an external, decrementer or performance
monitor interrupt.  Instead of turning on the MMU, then deciding that
we need to call the Linux handler and turning the MMU back off again,
we now go straight to the handler at the point where we would turn the
MMU on.  The handler will then return to the virtual-mode code
(potentially in the module).

Along the way, this moves the setting and clearing of the HID5 DCBZ32
bit into real-mode interrupts-off code, and also makes sure that
we clear the MSR[RI] bit before loading values into SRR0/1.

The net result is that we no longer need any code addresses to be
stored in vcpu->arch.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/kvm_book3s.h     |    4 +-
 arch/powerpc/include/asm/kvm_book3s_asm.h |    1 +
 arch/powerpc/include/asm/kvm_host.h       |    8 --
 arch/powerpc/kernel/asm-offsets.c         |    7 +--
 arch/powerpc/kvm/book3s_32_sr.S           |    2 +-
 arch/powerpc/kvm/book3s_64_slb.S          |    2 +-
 arch/powerpc/kvm/book3s_exports.c         |    4 +-
 arch/powerpc/kvm/book3s_interrupts.S      |  129 +---------------------------
 arch/powerpc/kvm/book3s_pr.c              |   12 ---
 arch/powerpc/kvm/book3s_rmhandlers.S      |   51 ++++--------
 arch/powerpc/kvm/book3s_segment.S         |  112 ++++++++++++++++++++-----
 11 files changed, 120 insertions(+), 212 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 98da010..a70c0e6 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -139,9 +139,7 @@ extern void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr);
 extern int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu);
 extern pfn_t kvmppc_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
 
-extern void kvmppc_handler_lowmem_trampoline(void);
-extern void kvmppc_handler_trampoline_enter(void);
-extern void kvmppc_rmcall(ulong srr0, ulong srr1);
+extern void kvmppc_entry_trampoline(void);
 extern void kvmppc_hv_entry_trampoline(void);
 extern void kvmppc_load_up_fpu(void);
 extern void kvmppc_load_up_altivec(void);
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index ef7b368..af73469 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -75,6 +75,7 @@ struct kvmppc_host_state {
 	ulong scratch0;
 	ulong scratch1;
 	u8 in_guest;
+	u8 restore_hid5;
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	struct kvm_vcpu *kvm_vcpu;
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index cc22b28..db15384 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -258,14 +258,6 @@ struct kvm_vcpu_arch {
 	ulong host_stack;
 	u32 host_pid;
 #ifdef CONFIG_PPC_BOOK3S
-	ulong host_msr;
-	ulong host_r2;
-	void *host_retip;
-	ulong trampoline_lowmem;
-	ulong trampoline_enter;
-	ulong highmem_handler;
-	ulong rmcall;
-	ulong host_paca_phys;
 	struct kvmppc_slb slb[64];
 	int slb_max;		/* 1 + index of last valid entry in slb[] */
 	int slb_nr;		/* total number of entries in SLB */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 54b935f..d34cd32 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -446,8 +446,6 @@ int main(void)
 #ifdef CONFIG_PPC_BOOK3S
 	DEFINE(VCPU_KVM, offsetof(struct kvm_vcpu, kvm));
 	DEFINE(VCPU_VCPUID, offsetof(struct kvm_vcpu, vcpu_id));
-	DEFINE(VCPU_HOST_RETIP, offsetof(struct kvm_vcpu, arch.host_retip));
-	DEFINE(VCPU_HOST_MSR, offsetof(struct kvm_vcpu, arch.host_msr));
 	DEFINE(VCPU_PURR, offsetof(struct kvm_vcpu, arch.purr));
 	DEFINE(VCPU_SPURR, offsetof(struct kvm_vcpu, arch.spurr));
 	DEFINE(VCPU_DSCR, offsetof(struct kvm_vcpu, arch.dscr));
@@ -455,10 +453,6 @@ int main(void)
 	DEFINE(VCPU_UAMOR, offsetof(struct kvm_vcpu, arch.uamor));
 	DEFINE(VCPU_CTRL, offsetof(struct kvm_vcpu, arch.ctrl));
 	DEFINE(VCPU_DABR, offsetof(struct kvm_vcpu, arch.dabr));
-	DEFINE(VCPU_TRAMPOLINE_LOWMEM, offsetof(struct kvm_vcpu, arch.trampoline_lowmem));
-	DEFINE(VCPU_TRAMPOLINE_ENTER, offsetof(struct kvm_vcpu, arch.trampoline_enter));
-	DEFINE(VCPU_HIGHMEM_HANDLER, offsetof(struct kvm_vcpu, arch.highmem_handler));
-	DEFINE(VCPU_RMCALL, offsetof(struct kvm_vcpu, arch.rmcall));
 	DEFINE(VCPU_HFLAGS, offsetof(struct kvm_vcpu, arch.hflags));
 	DEFINE(VCPU_DEC, offsetof(struct kvm_vcpu, arch.dec));
 	DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires));
@@ -534,6 +528,7 @@ int main(void)
 	HSTATE_FIELD(HSTATE_SCRATCH0, scratch0);
 	HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
 	HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
+	HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
diff --git a/arch/powerpc/kvm/book3s_32_sr.S b/arch/powerpc/kvm/book3s_32_sr.S
index 3608471..7e06a6f 100644
--- a/arch/powerpc/kvm/book3s_32_sr.S
+++ b/arch/powerpc/kvm/book3s_32_sr.S
@@ -31,7 +31,7 @@
 	 * R1 = host R1
 	 * R2 = host R2
 	 * R3 = shadow vcpu
-	 * all other volatile GPRS = free
+	 * all other volatile GPRS = free except R4, R6
 	 * SVCPU[CR]  = guest CR
 	 * SVCPU[XER] = guest XER
 	 * SVCPU[CTR] = guest CTR
diff --git a/arch/powerpc/kvm/book3s_64_slb.S b/arch/powerpc/kvm/book3s_64_slb.S
index 04e7d3b..f2e6e48 100644
--- a/arch/powerpc/kvm/book3s_64_slb.S
+++ b/arch/powerpc/kvm/book3s_64_slb.S
@@ -53,7 +53,7 @@ slb_exit_skip_ ## num:
 	 * R1 = host R1
 	 * R2 = host R2
 	 * R3 = shadow vcpu
-	 * all other volatile GPRS = free
+	 * all other volatile GPRS = free except R4, R6
 	 * SVCPU[CR]  = guest CR
 	 * SVCPU[XER] = guest XER
 	 * SVCPU[CTR] = guest CTR
diff --git a/arch/powerpc/kvm/book3s_exports.c b/arch/powerpc/kvm/book3s_exports.c
index 88c8f26..f7f63a0 100644
--- a/arch/powerpc/kvm/book3s_exports.c
+++ b/arch/powerpc/kvm/book3s_exports.c
@@ -23,9 +23,7 @@
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 EXPORT_SYMBOL_GPL(kvmppc_hv_entry_trampoline);
 #else
-EXPORT_SYMBOL_GPL(kvmppc_handler_trampoline_enter);
-EXPORT_SYMBOL_GPL(kvmppc_handler_lowmem_trampoline);
-EXPORT_SYMBOL_GPL(kvmppc_rmcall);
+EXPORT_SYMBOL_GPL(kvmppc_entry_trampoline);
 EXPORT_SYMBOL_GPL(kvmppc_load_up_fpu);
 #ifdef CONFIG_ALTIVEC
 EXPORT_SYMBOL_GPL(kvmppc_load_up_altivec);
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index c54b0e3..0a8515a 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -29,27 +29,11 @@
 #define ULONG_SIZE 		8
 #define FUNC(name) 		GLUE(.,name)
 
-#define GET_SHADOW_VCPU_R13
-
-#define DISABLE_INTERRUPTS	\
-	mfmsr   r0;		\
-	rldicl  r0,r0,48,1;	\
-	rotldi  r0,r0,16;	\
-	mtmsrd  r0,1;		\
-
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
 #define ULONG_SIZE              4
 #define FUNC(name)		name
 
-#define GET_SHADOW_VCPU_R13	\
-	lwz	r13, (THREAD + THREAD_KVM_SVCPU)(r2)
-
-#define DISABLE_INTERRUPTS	\
-	mfmsr   r0;		\
-	rlwinm  r0,r0,0,17,15;	\
-	mtmsr   r0;		\
-
 #endif /* CONFIG_PPC_BOOK3S_XX */
 
 
@@ -108,44 +92,17 @@ kvm_start_entry:
 
 kvm_start_lightweight:
 
-	GET_SHADOW_VCPU_R13
-	PPC_LL	r3, VCPU_HIGHMEM_HANDLER(r4)
-	PPC_STL	r3, HSTATE_VMHANDLER(r13)
-
-	PPC_LL	r10, VCPU_SHADOW_MSR(r4)	/* r10 = vcpu->arch.shadow_msr */
-
-	DISABLE_INTERRUPTS
-
 #ifdef CONFIG_PPC_BOOK3S_64
-	/* Some guests may need to have dcbz set to 32 byte length.
-	 *
-	 * Usually we ensure that by patching the guest's instructions
-	 * to trap on dcbz and emulate it in the hypervisor.
-	 *
-	 * If we can, we should tell the CPU to use 32 byte dcbz though,
-	 * because that's a lot faster.
-	 */
-
 	PPC_LL	r3, VCPU_HFLAGS(r4)
-	rldicl.	r3, r3, 0, 63		/* CR = ((r3 & 1) = 0) */
-	beq	no_dcbz32_on
-
-	mfspr   r3,SPRN_HID5
-	ori     r3, r3, 0x80		/* XXX HID5_dcbz32 = 0x80 */
-	mtspr   SPRN_HID5,r3
-
-no_dcbz32_on:
-
+	rldicl	r3, r3, 0, 63		/* r3 &= 1 */
+	stb	r3, HSTATE_RESTORE_HID5(r13)
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
-	PPC_LL	r6, VCPU_RMCALL(r4)
-	mtctr	r6
-
-	PPC_LL	r3, VCPU_TRAMPOLINE_ENTER(r4)
-	LOAD_REG_IMMEDIATE(r4, MSR_KERNEL & ~(MSR_IR | MSR_DR))
+	PPC_LL	r4, VCPU_SHADOW_MSR(r4)	/* get shadow_msr */
 
 	/* Jump to segment patching handler and into our guest */
-	bctr
+	bl	FUNC(kvmppc_entry_trampoline)
+	nop
 
 /*
  * This is the handler in module memory. It gets jumped at from the
@@ -170,21 +127,6 @@ kvmppc_handler_highmem:
 	/* R7 = vcpu */
 	PPC_LL	r7, GPR4(r1)
 
-#ifdef CONFIG_PPC_BOOK3S_64
-
-	PPC_LL	r5, VCPU_HFLAGS(r7)
-	rldicl.	r5, r5, 0, 63		/* CR = ((r5 & 1) = 0) */
-	beq	no_dcbz32_off
-
-	li	r4, 0
-	mfspr   r5,SPRN_HID5
-	rldimi  r5,r4,6,56
-	mtspr   SPRN_HID5,r5
-
-no_dcbz32_off:
-
-#endif /* CONFIG_PPC_BOOK3S_64 */
-
 	PPC_STL	r14, VCPU_GPR(r14)(r7)
 	PPC_STL	r15, VCPU_GPR(r15)(r7)
 	PPC_STL	r16, VCPU_GPR(r16)(r7)
@@ -204,67 +146,6 @@ no_dcbz32_off:
 	PPC_STL	r30, VCPU_GPR(r30)(r7)
 	PPC_STL	r31, VCPU_GPR(r31)(r7)
 
-	/* Restore host msr -> SRR1 */
-	PPC_LL	r6, VCPU_HOST_MSR(r7)
-
-	/*
-	 * For some interrupts, we need to call the real Linux
-	 * handler, so it can do work for us. This has to happen
-	 * as if the interrupt arrived from the kernel though,
-	 * so let's fake it here where most state is restored.
-	 *
-	 * Call Linux for hardware interrupts/decrementer
-	 * r3 = address of interrupt handler (exit reason)
-	 */
-
-	cmpwi	r12, BOOK3S_INTERRUPT_EXTERNAL
-	beq	call_linux_handler
-	cmpwi	r12, BOOK3S_INTERRUPT_DECREMENTER
-	beq	call_linux_handler
-	cmpwi	r12, BOOK3S_INTERRUPT_PERFMON
-	beq	call_linux_handler
-
-	/* Back to EE=1 */
-	mtmsr	r6
-	sync
-	b	kvm_return_point
-
-call_linux_handler:
-
-	/*
-	 * If we land here we need to jump back to the handler we
-	 * came from.
-	 *
-	 * We have a page that we can access from real mode, so let's
-	 * jump back to that and use it as a trampoline to get back into the
-	 * interrupt handler!
-	 *
-	 * R3 still contains the exit code,
-	 * R5 VCPU_HOST_RETIP and
-	 * R6 VCPU_HOST_MSR
-	 */
-
-	/* Restore host IP -> SRR0 */
-	PPC_LL	r5, VCPU_HOST_RETIP(r7)
-
-	/* XXX Better move to a safe function?
-	 *     What if we get an HTAB flush in between mtsrr0 and mtsrr1? */
-
-	mtlr	r12
-
-	PPC_LL	r4, VCPU_TRAMPOLINE_LOWMEM(r7)
-	mtsrr0	r4
-	LOAD_REG_IMMEDIATE(r3, MSR_KERNEL & ~(MSR_IR | MSR_DR))
-	mtsrr1	r3
-
-	RFI
-
-.global kvm_return_point
-kvm_return_point:
-
-	/* Jump back to lightweight entry if we're supposed to */
-	/* go back into the guest */
-
 	/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
 	mr	r5, r12
 
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 0c0d3f2..d7ab552 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -841,8 +841,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	if (!p)
 		goto uninit_vcpu;
 
-	vcpu->arch.host_retip = kvm_return_point;
-	vcpu->arch.host_msr = mfmsr();
 #ifdef CONFIG_PPC_BOOK3S_64
 	/* default to book3s_64 (970fx) */
 	vcpu->arch.pvr = 0x3C0301;
@@ -853,16 +851,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	kvmppc_set_pvr(vcpu, vcpu->arch.pvr);
 	vcpu->arch.slb_nr = 64;
 
-	/* remember where some real-mode handlers are */
-	vcpu->arch.trampoline_lowmem = __pa(kvmppc_handler_lowmem_trampoline);
-	vcpu->arch.trampoline_enter = __pa(kvmppc_handler_trampoline_enter);
-	vcpu->arch.highmem_handler = (ulong)kvmppc_handler_highmem;
-#ifdef CONFIG_PPC_BOOK3S_64
-	vcpu->arch.rmcall = *(ulong*)kvmppc_rmcall;
-#else
-	vcpu->arch.rmcall = (ulong)kvmppc_rmcall;
-#endif
-
 	vcpu->arch.shadow_msr = MSR_USER64;
 
 	err = kvmppc_mmu_init(vcpu);
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index 5ee66ed..3418758 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -36,9 +36,8 @@
 
 #if defined(CONFIG_PPC_BOOK3S_64)
 
-#define LOAD_SHADOW_VCPU(reg)	GET_PACA(reg)					
-#define MSR_NOIRQ		MSR_KERNEL & ~(MSR_IR | MSR_DR)
 #define FUNC(name) 		GLUE(.,name)
+#define MTMSR_EERI(reg)		mtmsrd	(reg),1
 
 	.globl	kvmppc_skip_interrupt
 kvmppc_skip_interrupt:
@@ -68,8 +67,8 @@ kvmppc_skip_Hinterrupt:
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
-#define MSR_NOIRQ		MSR_KERNEL
 #define FUNC(name)		name
+#define MTMSR_EERI(reg)		mtmsr	(reg)
 
 .macro INTERRUPT_TRAMPOLINE intno
 
@@ -170,40 +169,24 @@ kvmppc_handler_skip_ins:
 #endif
 
 /*
- * This trampoline brings us back to a real mode handler
- *
- * Input Registers:
- *
- * R5 = SRR0
- * R6 = SRR1
- * LR = real-mode IP
+ * Call kvmppc_handler_trampoline_enter in real mode
  *
+ * On entry, r4 contains the guest shadow MSR
  */
-.global kvmppc_handler_lowmem_trampoline
-kvmppc_handler_lowmem_trampoline:
-
-	mtsrr0	r5
+_GLOBAL(kvmppc_entry_trampoline)
+	mfmsr	r5
+	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
+	toreal(r7)
+
+	li	r9, MSR_RI
+	ori	r9, r9, MSR_EE
+	andc	r9, r5, r9	/* Clear EE and RI in MSR value */
+	li	r6, MSR_IR | MSR_DR
+	ori	r6, r6, MSR_EE
+	andc	r6, r5, r6	/* Clear EE, DR and IR in MSR value */
+	MTMSR_EERI(r9)		/* Clear EE and RI in MSR */
+	mtsrr0	r7		/* before we set srr0/1 */
 	mtsrr1	r6
-	blr
-kvmppc_handler_lowmem_trampoline_end:
-
-/*
- * Call a function in real mode
- *
- * Input Registers:
- *
- * R3 = function
- * R4 = MSR
- * R5 = scratch register
- *
- */
-_GLOBAL(kvmppc_rmcall)
-	LOAD_REG_IMMEDIATE(r5, MSR_NOIRQ)
-	mtmsr	r5		/* Disable relocation and interrupts, so mtsrr
-				   doesn't get interrupted */
-	sync
-	mtsrr0	r3
-	mtsrr1	r4
 	RFI
 
 #if defined(CONFIG_PPC_BOOK3S_32)
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index aed32e5..3663564 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -23,6 +23,7 @@
 
 #define GET_SHADOW_VCPU(reg)    \
 	mr	reg, r13
+#define MTMSR_EERI(reg)		mtmsrd	(reg),1
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
@@ -30,6 +31,7 @@
 	tophys(reg, r2);       			\
 	lwz     reg, (THREAD + THREAD_KVM_SVCPU)(reg);	\
 	tophys(reg, reg)
+#define MTMSR_EERI(reg)		mtmsr	(reg)
 
 #endif
 
@@ -57,10 +59,12 @@ kvmppc_handler_trampoline_enter:
 	/* Required state:
 	 *
 	 * MSR = ~IR|DR
-	 * R13 = PACA
 	 * R1 = host R1
 	 * R2 = host R2
-	 * R10 = guest MSR
+	 * R4 = guest shadow MSR
+	 * R5 = normal host MSR
+	 * R6 = current host MSR (EE, IR, DR off)
+	 * LR = highmem guest exit code
 	 * all other volatile GPRS = free
 	 * SVCPU[CR] = guest CR
 	 * SVCPU[XER] = guest XER
@@ -71,15 +75,15 @@ kvmppc_handler_trampoline_enter:
 	/* r3 = shadow vcpu */
 	GET_SHADOW_VCPU(r3)
 
+	/* Save guest exit handler address and MSR */
+	mflr	r0
+	PPC_STL	r0, HSTATE_VMHANDLER(r3)
+	PPC_STL	r5, HSTATE_HOST_MSR(r3)
+
 	/* Save R1/R2 in the PACA (64-bit) or shadow_vcpu (32-bit) */
 	PPC_STL	r1, HSTATE_HOST_R1(r3)
 	PPC_STL	r2, HSTATE_HOST_R2(r3)
 
-	/* Move SRR0 and SRR1 into the respective regs */
-	PPC_LL  r9, SVCPU_PC(r3)
-	mtsrr0	r9
-	mtsrr1	r10
-
 	/* Activate guest mode, so faults get handled by KVM */
 	li	r11, KVM_GUEST_MODE_GUEST
 	stb	r11, HSTATE_IN_GUEST(r3)
@@ -87,17 +91,46 @@ kvmppc_handler_trampoline_enter:
 	/* Switch to guest segment. This is subarch specific. */
 	LOAD_GUEST_SEGMENTS
 
+#ifdef CONFIG_PPC_BOOK3S_64
+	/* Some guests may need to have dcbz set to 32 byte length.
+	 *
+	 * Usually we ensure that by patching the guest's instructions
+	 * to trap on dcbz and emulate it in the hypervisor.
+	 *
+	 * If we can, we should tell the CPU to use 32 byte dcbz though,
+	 * because that's a lot faster.
+	 */
+	lbz	r0, HSTATE_RESTORE_HID5(r3)
+	cmpwi	r0, 0
+	beq	no_dcbz32_on
+
+	mfspr   r0,SPRN_HID5
+	ori     r0, r0, 0x80		/* XXX HID5_dcbz32 = 0x80 */
+	mtspr   SPRN_HID5,r0
+no_dcbz32_on:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
 	/* Enter guest */
 
-	PPC_LL	r4, SVCPU_CTR(r3)
-	PPC_LL	r5, SVCPU_LR(r3)
-	lwz	r6, SVCPU_CR(r3)
-	lwz	r7, SVCPU_XER(r3)
+	PPC_LL	r8, SVCPU_CTR(r3)
+	PPC_LL	r9, SVCPU_LR(r3)
+	lwz	r10, SVCPU_CR(r3)
+	lwz	r11, SVCPU_XER(r3)
+
+	mtctr	r8
+	mtlr	r9
+	mtcr	r10
+	mtxer	r11
 
-	mtctr	r4
-	mtlr	r5
-	mtcr	r6
-	mtxer	r7
+	/* Move SRR0 and SRR1 into the respective regs */
+	PPC_LL  r9, SVCPU_PC(r3)
+	/* First clear RI in our current MSR value */
+	li	r0, MSR_RI
+	andc	r6, r6, r0
+	MTMSR_EERI(r6)
+	mtsrr0	r9
+	mtsrr1	r4
 
 	PPC_LL	r0, SVCPU_R0(r3)
 	PPC_LL	r1, SVCPU_R1(r3)
@@ -254,6 +287,43 @@ no_ld_last_inst:
 	/* Switch back to host MMU */
 	LOAD_HOST_SEGMENTS
 
+#ifdef CONFIG_PPC_BOOK3S_64
+
+	lbz	r5, HSTATE_RESTORE_HID5(r13)
+	cmpwi	r5, 0
+	beq	no_dcbz32_off
+
+	li	r4, 0
+	mfspr   r5,SPRN_HID5
+	rldimi  r5,r4,6,56
+	mtspr   SPRN_HID5,r5
+
+no_dcbz32_off:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+	/*
+	 * For some interrupts, we need to call the real Linux
+	 * handler, so it can do work for us. This has to happen
+	 * as if the interrupt arrived from the kernel though,
+	 * so let's fake it here where most state is restored.
+	 *
+	 * Having set up SRR0/1 with the address where we want
+	 * to continue with relocation on (potentially in module
+	 * space), we either just go straight there with rfi[d],
+	 * or we jump to an interrupt handler with bctr if there
+	 * is an interrupt to be handled first.  In the latter
+	 * case, the rfi[d] at the end of the interrupt handler
+	 * will get us back to where we want to continue.
+	 */
+
+	cmpwi	r12, BOOK3S_INTERRUPT_EXTERNAL
+	beq	1f
+	cmpwi	r12, BOOK3S_INTERRUPT_DECREMENTER
+	beq	1f
+	cmpwi	r12, BOOK3S_INTERRUPT_PERFMON
+1:	mtctr	r12
+
 	/* Register usage at this point:
 	 *
 	 * R1       = host R1
@@ -264,13 +334,15 @@ no_ld_last_inst:
 	 *
 	 */
 
-	/* RFI into the highmem handler */
-	mfmsr	r7
-	ori	r7, r7, MSR_IR|MSR_DR|MSR_RI|MSR_ME	/* Enable paging */
-	mtsrr1	r7
-	/* Load highmem handler address */
+	PPC_LL	r6, HSTATE_HOST_MSR(r13)
 	PPC_LL	r8, HSTATE_VMHANDLER(r13)
+
+	/* Restore host msr -> SRR1 */
+	mtsrr1	r6
+	/* Load highmem handler address */
 	mtsrr0	r8
 
+	/* RFI into the highmem handler, or jump to interrupt handler */
+	beqctr
 	RFI
 kvmppc_handler_trampoline_exit_end:
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code
  2011-07-23  7:41 ` Paul Mackerras
@ 2011-07-23  7:42   ` Paul Mackerras
  -1 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-07-23  7:42 UTC (permalink / raw)
  To: linuxppc-dev, kvm-ppc, Alexander Graf

With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per
core), whenever a CPU goes idle, we have to pull all the other
hardware threads in the core out of the guest, because the H_CEDE
hcall is handled in the kernel.  This is inefficient.

This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall
in real mode.  When a guest vcpu does an H_CEDE hcall, we now only
exit to the kernel if all the other vcpus in the same core are also
idle.  Otherwise we mark this vcpu as napping, save state that could
be lost in nap mode (mainly GPRs and FPRs), and execute the nap
instruction.  When the thread wakes up, because of a decrementer or
external interrupt, we come back in at kvm_start_guest (from the
system reset interrupt vector), find the `napping' flag set in the
paca, and go to the resume path.

This has some other ramifications.  First, when starting a core, we
now start all the threads, both those that are immediately runnable and
those that are idle.  This is so that we don't have to pull all the
threads out of the guest when an idle thread gets a decrementer interrupt
and wants to start running.  In fact the idle threads will all start
with the H_CEDE hcall returning; being idle they will just do another
H_CEDE immediately and go to nap mode.

This required some changes to kvmppc_run_core() and kvmppc_run_vcpu().
These functions have been restructured to make them simpler and clearer.
We introduce a level of indirection in the wait queue that gets woken
when external and decrementer interrupts get generated for a vcpu, so
that we can have the 4 vcpus in a vcore using the same wait queue.
We need this because the 4 vcpus are being handled by one thread.

Secondly, when we need to exit from the guest to the kernel, we now
have to generate an IPI for any napping threads, because an HDEC
interrupt doesn't wake up a napping thread.

Thirdly, we now need to be able to handle virtual external interrupts
and decrementer interrupts becoming pending while a thread is napping,
and deliver those interrupts to the guest when the thread wakes.
This is done in kvmppc_cede_reentry, just before fast_guest_return.

Finally, since we are not using the generic kvm_vcpu_block for book3s_hv,
and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef
from kvm_arch_vcpu_runnable.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/kvm_book3s_asm.h |    1 +
 arch/powerpc/include/asm/kvm_host.h       |   19 ++-
 arch/powerpc/kernel/asm-offsets.c         |    6 +
 arch/powerpc/kvm/book3s_hv.c              |  335 ++++++++++++++++-------------
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   |  297 ++++++++++++++++++++++---
 arch/powerpc/kvm/powerpc.c                |   21 +-
 6 files changed, 483 insertions(+), 196 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index af73469..1f2f5b6 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -76,6 +76,7 @@ struct kvmppc_host_state {
 	ulong scratch1;
 	u8 in_guest;
 	u8 restore_hid5;
+	u8 napping;
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	struct kvm_vcpu *kvm_vcpu;
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index db15384..652b05f 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -198,21 +198,29 @@ struct kvm_arch {
  */
 struct kvmppc_vcore {
 	int n_runnable;
-	int n_blocked;
+	int n_busy;
 	int num_threads;
 	int entry_exit_count;
 	int n_woken;
 	int nap_count;
+	int napping_threads;
 	u16 pcpu;
-	u8 vcore_running;
+	u8 vcore_state;
 	u8 in_guest;
 	struct list_head runnable_threads;
 	spinlock_t lock;
+	wait_queue_head_t wq;
 };
 
 #define VCORE_ENTRY_COUNT(vc)	((vc)->entry_exit_count & 0xff)
 #define VCORE_EXIT_COUNT(vc)	((vc)->entry_exit_count >> 8)
 
+/* Values for vcore_state */
+#define VCORE_INACTIVE	0
+#define VCORE_RUNNING	1
+#define VCORE_EXITING	2
+#define VCORE_SLEEPING	3
+
 struct kvmppc_pte {
 	ulong eaddr;
 	u64 vpage;
@@ -400,11 +408,13 @@ struct kvm_vcpu_arch {
 	struct dtl *dtl;
 	struct dtl *dtl_end;
 
+	wait_queue_head_t *wqp;
 	struct kvmppc_vcore *vcore;
 	int ret;
 	int trap;
 	int state;
 	int ptid;
+	bool timer_running;
 	wait_queue_head_t cpu_run;
 
 	struct kvm_vcpu_arch_shared *shared;
@@ -420,8 +430,9 @@ struct kvm_vcpu_arch {
 #endif
 };
 
-#define KVMPPC_VCPU_BUSY_IN_HOST	0
-#define KVMPPC_VCPU_BLOCKED		1
+/* Values for vcpu->arch.state */
+#define KVMPPC_VCPU_STOPPED		0
+#define KVMPPC_VCPU_BUSY_IN_HOST	1
 #define KVMPPC_VCPU_RUNNABLE		2
 
 #endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index d34cd32..833021c 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -44,6 +44,7 @@
 #include <asm/compat.h>
 #include <asm/mmu.h>
 #include <asm/hvcall.h>
+#include <asm/xics.h>
 #endif
 #ifdef CONFIG_PPC_ISERIES
 #include <asm/iseries/alpaca.h>
@@ -457,6 +458,8 @@ int main(void)
 	DEFINE(VCPU_DEC, offsetof(struct kvm_vcpu, arch.dec));
 	DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires));
 	DEFINE(VCPU_PENDING_EXC, offsetof(struct kvm_vcpu, arch.pending_exceptions));
+	DEFINE(VCPU_CEDED, offsetof(struct kvm_vcpu, arch.ceded));
+	DEFINE(VCPU_PRODDED, offsetof(struct kvm_vcpu, arch.prodded));
 	DEFINE(VCPU_VPA, offsetof(struct kvm_vcpu, arch.vpa));
 	DEFINE(VCPU_MMCR, offsetof(struct kvm_vcpu, arch.mmcr));
 	DEFINE(VCPU_PMC, offsetof(struct kvm_vcpu, arch.pmc));
@@ -472,6 +475,7 @@ int main(void)
 	DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_count));
 	DEFINE(VCORE_NAP_COUNT, offsetof(struct kvmppc_vcore, nap_count));
 	DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest));
+	DEFINE(VCORE_NAPPING_THREADS, offsetof(struct kvmppc_vcore, napping_threads));
 	DEFINE(VCPU_SVCPU, offsetof(struct kvmppc_vcpu_book3s, shadow_vcpu) -
 			   offsetof(struct kvmppc_vcpu_book3s, vcpu));
 	DEFINE(VCPU_SLB_E, offsetof(struct kvmppc_slb, orige));
@@ -529,6 +533,7 @@ int main(void)
 	HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
 	HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
 	HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
+	HSTATE_FIELD(HSTATE_NAPPING, napping);
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
@@ -541,6 +546,7 @@ int main(void)
 	HSTATE_FIELD(HSTATE_DSCR, host_dscr);
 	HSTATE_FIELD(HSTATE_DABR, dabr);
 	HSTATE_FIELD(HSTATE_DECEXP, dec_expires);
+	DEFINE(IPI_PRIORITY, IPI_PRIORITY);
 #endif /* CONFIG_KVM_BOOK3S_64_HV */
 
 #else /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index cc0d7f1..81c384d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -62,6 +62,8 @@
 /* #define EXIT_DEBUG_SIMPLE */
 /* #define EXIT_DEBUG_INT */
 
+static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
+
 void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	local_paca->kvm_hstate.kvm_vcpu = vcpu;
@@ -72,40 +74,10 @@ void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
 {
 }
 
-static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu);
-static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu);
-
-void kvmppc_vcpu_block(struct kvm_vcpu *vcpu)
-{
-	u64 now;
-	unsigned long dec_nsec;
-
-	now = get_tb();
-	if (now >= vcpu->arch.dec_expires && !kvmppc_core_pending_dec(vcpu))
-		kvmppc_core_queue_dec(vcpu);
-	if (vcpu->arch.pending_exceptions)
-		return;
-	if (vcpu->arch.dec_expires != ~(u64)0) {
-		dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC /
-			tb_ticks_per_sec;
-		hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
-			      HRTIMER_MODE_REL);
-	}
-
-	kvmppc_vcpu_blocked(vcpu);
-
-	kvm_vcpu_block(vcpu);
-	vcpu->stat.halt_wakeup++;
-
-	if (vcpu->arch.dec_expires != ~(u64)0)
-		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
-
-	kvmppc_vcpu_unblocked(vcpu);
-}
-
 void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr)
 {
 	vcpu->arch.shregs.msr = msr;
+	kvmppc_end_cede(vcpu);
 }
 
 void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
@@ -257,15 +229,6 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 
 	switch (req) {
 	case H_CEDE:
-		vcpu->arch.shregs.msr |= MSR_EE;
-		vcpu->arch.ceded = 1;
-		smp_mb();
-		if (!vcpu->arch.prodded)
-			kvmppc_vcpu_block(vcpu);
-		else
-			vcpu->arch.prodded = 0;
-		smp_mb();
-		vcpu->arch.ceded = 0;
 		break;
 	case H_PROD:
 		target = kvmppc_get_gpr(vcpu, 4);
@@ -388,20 +351,6 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		break;
 	}
 
-
-	if (!(r & RESUME_HOST)) {
-		/* To avoid clobbering exit_reason, only check for signals if
-		 * we aren't already exiting to userspace for some other
-		 * reason. */
-		if (signal_pending(tsk)) {
-			vcpu->stat.signal_exits++;
-			run->exit_reason = KVM_EXIT_INTR;
-			r = -EINTR;
-		} else {
-			kvmppc_core_deliver_interrupts(vcpu);
-		}
-	}
-
 	return r;
 }
 
@@ -479,13 +428,9 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	kvmppc_mmu_book3s_hv_init(vcpu);
 
 	/*
-	 * Some vcpus may start out in stopped state.  If we initialize
-	 * them to busy-in-host state they will stop other vcpus in the
-	 * vcore from running.  Instead we initialize them to blocked
-	 * state, effectively considering them to be stopped until we
-	 * see the first run ioctl for them.
+	 * We consider the vcpu stopped until we see the first run ioctl for it.
 	 */
-	vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
+	vcpu->arch.state = KVMPPC_VCPU_STOPPED;
 
 	init_waitqueue_head(&vcpu->arch.cpu_run);
 
@@ -496,6 +441,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 		if (vcore) {
 			INIT_LIST_HEAD(&vcore->runnable_threads);
 			spin_lock_init(&vcore->lock);
+			init_waitqueue_head(&vcore->wq);
 		}
 		kvm->arch.vcores[core] = vcore;
 	}
@@ -506,7 +452,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 
 	spin_lock(&vcore->lock);
 	++vcore->num_threads;
-	++vcore->n_blocked;
 	spin_unlock(&vcore->lock);
 	vcpu->arch.vcore = vcore;
 
@@ -524,30 +469,31 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
 	kfree(vcpu);
 }
 
-static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu)
+static void kvmppc_set_timer(struct kvm_vcpu *vcpu)
 {
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	unsigned long dec_nsec, now;
 
-	spin_lock(&vc->lock);
-	vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
-	++vc->n_blocked;
-	if (vc->n_runnable > 0 &&
-	    vc->n_runnable + vc->n_blocked == vc->num_threads) {
-		vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
-					arch.run_list);
-		wake_up(&vcpu->arch.cpu_run);
+	now = get_tb();
+	if (now > vcpu->arch.dec_expires) {
+		/* decrementer has already gone negative */
+		kvmppc_core_queue_dec(vcpu);
+		kvmppc_core_deliver_interrupts(vcpu);
+		return;
 	}
-	spin_unlock(&vc->lock);
+	dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC
+		   / tb_ticks_per_sec;
+	hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
+		      HRTIMER_MODE_REL);
+	vcpu->arch.timer_running = 1;
 }
 
-static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu)
+static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
 {
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-
-	spin_lock(&vc->lock);
-	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
-	--vc->n_blocked;
-	spin_unlock(&vc->lock);
+	vcpu->arch.ceded = 0;
+	if (vcpu->arch.timer_running) {
+		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+		vcpu->arch.timer_running = 0;
+	}
 }
 
 extern int __kvmppc_vcore_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
@@ -562,6 +508,7 @@ static void kvmppc_remove_runnable(struct kvmppc_vcore *vc,
 		return;
 	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
 	--vc->n_runnable;
+	++vc->n_busy;
 	/* decrement the physical thread id of each following vcpu */
 	v = vcpu;
 	list_for_each_entry_continue(v, &vc->runnable_threads, arch.run_list)
@@ -575,15 +522,20 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu)
 	struct paca_struct *tpaca;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 
+	if (vcpu->arch.timer_running) {
+		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+		vcpu->arch.timer_running = 0;
+	}
 	cpu = vc->pcpu + vcpu->arch.ptid;
 	tpaca = &paca[cpu];
 	tpaca->kvm_hstate.kvm_vcpu = vcpu;
 	tpaca->kvm_hstate.kvm_vcore = vc;
+	tpaca->kvm_hstate.napping = 0;
+	vcpu->cpu = vc->pcpu;
 	smp_wmb();
 #ifdef CONFIG_PPC_ICP_NATIVE
 	if (vcpu->arch.ptid) {
 		tpaca->cpu_start = 0x80;
-		tpaca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST;
 		wmb();
 		xics_wake_cpu(cpu);
 		++vc->n_woken;
@@ -631,9 +583,10 @@ static int on_primary_thread(void)
  */
 static int kvmppc_run_core(struct kvmppc_vcore *vc)
 {
-	struct kvm_vcpu *vcpu, *vnext;
+	struct kvm_vcpu *vcpu, *vcpu0, *vnext;
 	long ret;
 	u64 now;
+	int ptid;
 
 	/* don't start if any threads have a signal pending */
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
@@ -652,29 +605,50 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 		goto out;
 	}
 
+	/*
+	 * Assign physical thread IDs, first to non-ceded vcpus
+	 * and then to ceded ones.
+	 */
+	ptid = 0;
+	vcpu0 = NULL;
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
+		if (!vcpu->arch.ceded) {
+			if (!ptid)
+				vcpu0 = vcpu;
+			vcpu->arch.ptid = ptid++;
+		}
+	}
+	if (!vcpu0)
+		return 0;		/* nothing to run */
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+		if (vcpu->arch.ceded)
+			vcpu->arch.ptid = ptid++;
+
 	vc->n_woken = 0;
 	vc->nap_count = 0;
 	vc->entry_exit_count = 0;
-	vc->vcore_running = 1;
+	vc->vcore_state = VCORE_RUNNING;
 	vc->in_guest = 0;
 	vc->pcpu = smp_processor_id();
+	vc->napping_threads = 0;
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
 		kvmppc_start_thread(vcpu);
-	vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
-				arch.run_list);
 
+	preempt_disable();
 	spin_unlock(&vc->lock);
 
-	preempt_disable();
 	kvm_guest_enter();
-	__kvmppc_vcore_entry(NULL, vcpu);
+	__kvmppc_vcore_entry(NULL, vcpu0);
 
-	/* wait for secondary threads to finish writing their state to memory */
 	spin_lock(&vc->lock);
+	/* disable sending of IPIs on virtual external irqs */
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+		vcpu->cpu = -1;
+	/* wait for secondary threads to finish writing their state to memory */
 	if (vc->nap_count < vc->n_woken)
 		kvmppc_wait_for_nap(vc);
 	/* prevent other vcpu threads from doing kvmppc_start_thread() now */
-	vc->vcore_running = 2;
+	vc->vcore_state = VCORE_EXITING;
 	spin_unlock(&vc->lock);
 
 	/* make sure updates to secondary vcpu structs are visible now */
@@ -690,22 +664,26 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 		if (now < vcpu->arch.dec_expires &&
 		    kvmppc_core_pending_dec(vcpu))
 			kvmppc_core_dequeue_dec(vcpu);
-		if (!vcpu->arch.trap) {
-			if (signal_pending(vcpu->arch.run_task)) {
-				vcpu->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
-				vcpu->arch.ret = -EINTR;
-			}
-			continue;		/* didn't get to run */
-		}
-		ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
-					 vcpu->arch.run_task);
+
+		ret = RESUME_GUEST;
+		if (vcpu->arch.trap)
+			ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
+						 vcpu->arch.run_task);
+
 		vcpu->arch.ret = ret;
 		vcpu->arch.trap = 0;
+
+		if (vcpu->arch.ceded) {
+			if (ret != RESUME_GUEST)
+				kvmppc_end_cede(vcpu);
+			else
+				kvmppc_set_timer(vcpu);
+		}
 	}
 
 	spin_lock(&vc->lock);
  out:
-	vc->vcore_running = 0;
+	vc->vcore_state = VCORE_INACTIVE;
 	list_for_each_entry_safe(vcpu, vnext, &vc->runnable_threads,
 				 arch.run_list) {
 		if (vcpu->arch.ret != RESUME_GUEST) {
@@ -717,82 +695,130 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 	return 1;
 }
 
-static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
+/*
+ * Wait for some other vcpu thread to execute us, and
+ * wake us up when we need to handle something in the host.
+ */
+static void kvmppc_wait_for_exec(struct kvm_vcpu *vcpu, int wait_state)
 {
-	int ptid;
-	int wait_state;
-	struct kvmppc_vcore *vc;
 	DEFINE_WAIT(wait);
 
-	/* No need to go into the guest when all we do is going out */
-	if (signal_pending(current)) {
-		kvm_run->exit_reason = KVM_EXIT_INTR;
-		return -EINTR;
+	prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
+	if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE)
+		schedule();
+	finish_wait(&vcpu->arch.cpu_run, &wait);
+}
+
+/*
+ * All the vcpus in this vcore are idle, so wait for a decrementer
+ * or external interrupt to one of the vcpus.  vc->lock is held.
+ */
+static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
+{
+	DEFINE_WAIT(wait);
+	struct kvm_vcpu *v;
+	int all_idle = 1;
+
+	prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+	vc->vcore_state = VCORE_SLEEPING;
+	spin_unlock(&vc->lock);
+	list_for_each_entry(v, &vc->runnable_threads, arch.run_list) {
+		if (!v->arch.ceded || v->arch.pending_exceptions) {
+			all_idle = 0;
+			break;
+		}
 	}
+	if (all_idle)
+		schedule();
+	finish_wait(&vc->wq, &wait);
+	spin_lock(&vc->lock);
+	vc->vcore_state = VCORE_INACTIVE;
+}
 
-	/* On PPC970, check that we have an RMA region */
-	if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
-		return -EPERM;
+static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
+{
+	int n_ceded;
+	int prev_state;
+	struct kvmppc_vcore *vc;
+	struct kvm_vcpu *v, *vn;
 
 	kvm_run->exit_reason = 0;
 	vcpu->arch.ret = RESUME_GUEST;
 	vcpu->arch.trap = 0;
 
-	flush_fp_to_thread(current);
-	flush_altivec_to_thread(current);
-	flush_vsx_to_thread(current);
-
 	/*
 	 * Synchronize with other threads in this virtual core
 	 */
 	vc = vcpu->arch.vcore;
 	spin_lock(&vc->lock);
-	/* This happens the first time this is called for a vcpu */
-	if (vcpu->arch.state == KVMPPC_VCPU_BLOCKED)
-		--vc->n_blocked;
-	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
-	ptid = vc->n_runnable;
+	vcpu->arch.ceded = 0;
 	vcpu->arch.run_task = current;
 	vcpu->arch.kvm_run = kvm_run;
-	vcpu->arch.ptid = ptid;
+	prev_state = vcpu->arch.state;
+	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
 	list_add_tail(&vcpu->arch.run_list, &vc->runnable_threads);
 	++vc->n_runnable;
 
-	wait_state = TASK_INTERRUPTIBLE;
-	while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
-		if (signal_pending(current)) {
-			if (!vc->vcore_running) {
-				kvm_run->exit_reason = KVM_EXIT_INTR;
-				vcpu->arch.ret = -EINTR;
-				break;
-			}
-			/* have to wait for vcore to stop executing guest */
-			wait_state = TASK_UNINTERRUPTIBLE;
-			smp_send_reschedule(vc->pcpu);
+	/*
+	 * This happens the first time this is called for a vcpu.
+	 * If the vcore is already running, we may be able to start
+	 * this thread straight away and have it join in.
+	 */
+	if (prev_state == KVMPPC_VCPU_STOPPED) {
+		if (vc->vcore_state == VCORE_RUNNING &&
+		    VCORE_EXIT_COUNT(vc) == 0) {
+			vcpu->arch.ptid = vc->n_runnable - 1;
+			kvmppc_start_thread(vcpu);
 		}
 
-		if (!vc->vcore_running &&
-		    vc->n_runnable + vc->n_blocked == vc->num_threads) {
-			/* we can run now */
-			if (kvmppc_run_core(vc))
-				continue;
-		}
+	} else if (prev_state == KVMPPC_VCPU_BUSY_IN_HOST)
+		--vc->n_busy;
 
-		if (vc->vcore_running == 1 && VCORE_EXIT_COUNT(vc) == 0)
-			kvmppc_start_thread(vcpu);
+	while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE &&
+	       !signal_pending(current)) {
+		if (vc->n_busy || vc->vcore_state != VCORE_INACTIVE) {
+			spin_unlock(&vc->lock);
+			kvmppc_wait_for_exec(vcpu, TASK_INTERRUPTIBLE);
+			spin_lock(&vc->lock);
+			continue;
+		}
+		n_ceded = 0;
+		list_for_each_entry(v, &vc->runnable_threads, arch.run_list)
+			n_ceded += v->arch.ceded;
+		if (n_ceded == vc->n_runnable)
+			kvmppc_vcore_blocked(vc);
+		else
+			kvmppc_run_core(vc);
+
+		list_for_each_entry_safe(v, vn, &vc->runnable_threads,
+					 arch.run_list) {
+			kvmppc_core_deliver_interrupts(v);
+			if (signal_pending(v->arch.run_task)) {
+				kvmppc_remove_runnable(vc, v);
+				v->stat.signal_exits++;
+				v->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
+				v->arch.ret = -EINTR;
+				wake_up(&v->arch.cpu_run);
+			}
+		}
+	}
 
-		/* wait for other threads to come in, or wait for vcore */
-		prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
-		spin_unlock(&vc->lock);
-		schedule();
-		finish_wait(&vcpu->arch.cpu_run, &wait);
-		spin_lock(&vc->lock);
+	if (signal_pending(current)) {
+		if (vc->vcore_state == VCORE_RUNNING ||
+		    vc->vcore_state == VCORE_EXITING) {
+			spin_unlock(&vc->lock);
+			kvmppc_wait_for_exec(vcpu, TASK_UNINTERRUPTIBLE);
+			spin_lock(&vc->lock);
+		}
+		if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
+			kvmppc_remove_runnable(vc, vcpu);
+			vcpu->stat.signal_exits++;
+			kvm_run->exit_reason = KVM_EXIT_INTR;
+			vcpu->arch.ret = -EINTR;
+		}
 	}
 
-	if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE)
-		kvmppc_remove_runnable(vc, vcpu);
 	spin_unlock(&vc->lock);
-
 	return vcpu->arch.ret;
 }
 
@@ -800,6 +826,21 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
 	int r;
 
+	/* No need to go into the guest when all we'll do is come back out */
+	if (signal_pending(current)) {
+		run->exit_reason = KVM_EXIT_INTR;
+		return -EINTR;
+	}
+
+	/* On PPC970, check that we have an RMA region */
+	if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
+		return -EPERM;
+
+	flush_fp_to_thread(current);
+	flush_altivec_to_thread(current);
+	flush_vsx_to_thread(current);
+	vcpu->arch.wqp = &vcpu->arch.vcore->wq;
+
 	do {
 		r = kvmppc_run_vcpu(run, vcpu);
 
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 543ee50..0e2ea04 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -52,7 +52,7 @@ kvmppc_skip_Hinterrupt:
 	b	.
 
 /*
- * Call kvmppc_handler_trampoline_enter in real mode.
+ * Call kvmppc_hv_entry in real mode.
  * Must be called with interrupts hard-disabled.
  *
  * Input Registers:
@@ -92,6 +92,12 @@ _GLOBAL(kvmppc_hv_entry_trampoline)
 kvm_start_guest:
 	ld	r1,PACAEMERGSP(r13)
 	subi	r1,r1,STACK_FRAME_OVERHEAD
+	ld	r2,PACATOC(r13)
+
+	/* were we napping due to cede? */
+	lbz	r0,HSTATE_NAPPING(r13)
+	cmpwi	r0,0
+	bne	kvm_end_cede
 
 	/* get vcpu pointer */
 	ld	r4, HSTATE_KVM_VCPU(r13)
@@ -279,15 +285,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	cmpwi	r0,0
 	beq	20b
 
-	/* Set LPCR.  Set the MER bit if there is a pending external irq. */
+	/* Set LPCR and RMOR. */
 10:	ld	r8,KVM_LPCR(r9)
-	ld	r0,VCPU_PENDING_EXC(r4)
-	li	r7,(1 << BOOK3S_IRQPRIO_EXTERNAL)
-	oris	r7,r7,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
-	and.	r0,r0,r7
-	beq	11f
-	ori	r8,r8,LPCR_MER
-11:	mtspr	SPRN_LPCR,r8
+	mtspr	SPRN_LPCR,r8
 	ld	r8,KVM_RMOR(r9)
 	mtspr	SPRN_RMOR,r8
 	isync
@@ -451,19 +451,50 @@ toc_tlbie_lock:
 	mtctr	r6
 	mtxer	r7
 
-	/* Move SRR0 and SRR1 into the respective regs */
+kvmppc_cede_reentry:		/* r4 = vcpu, r13 = paca */
 	ld	r6, VCPU_SRR0(r4)
 	ld	r7, VCPU_SRR1(r4)
-	mtspr	SPRN_SRR0, r6
-	mtspr	SPRN_SRR1, r7
-
 	ld	r10, VCPU_PC(r4)
+	ld	r11, VCPU_MSR(r4)	/* r11 = vcpu->arch.msr & ~MSR_HV */
 
-	ld	r11, VCPU_MSR(r4)	/* r10 = vcpu->arch.msr & ~MSR_HV */
 	rldicl	r11, r11, 63 - MSR_HV_LG, 1
 	rotldi	r11, r11, 1 + MSR_HV_LG
 	ori	r11, r11, MSR_ME
 
+	/* Check if we can deliver an external or decrementer interrupt now */
+	ld	r0,VCPU_PENDING_EXC(r4)
+	li	r8,(1 << BOOK3S_IRQPRIO_EXTERNAL)
+	oris	r8,r8,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
+	and	r0,r0,r8
+	cmpdi	cr1,r0,0
+	andi.	r0,r11,MSR_EE
+	beq	cr1,11f
+BEGIN_FTR_SECTION
+	mfspr	r8,SPRN_LPCR
+	ori	r8,r8,LPCR_MER
+	mtspr	SPRN_LPCR,r8
+	isync
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
+	beq	5f
+	li	r0,BOOK3S_INTERRUPT_EXTERNAL
+12:	mr	r6,r10
+	mr	r10,r0
+	mr	r7,r11
+	li	r11,(MSR_ME << 1) | 1	/* synthesize MSR_SF | MSR_ME */
+	rotldi	r11,r11,63
+	b	5f
+11:	beq	5f
+	mfspr	r0,SPRN_DEC
+	cmpwi	r0,0
+	li	r0,BOOK3S_INTERRUPT_DECREMENTER
+	blt	12b
+
+	/* Move SRR0 and SRR1 into the respective regs */
+5:	mtspr	SPRN_SRR0, r6
+	mtspr	SPRN_SRR1, r7
+	li	r0,0
+	stb	r0,VCPU_CEDED(r4)	/* cancel cede */
+
 fast_guest_return:
 	mtspr	SPRN_HSRR0,r10
 	mtspr	SPRN_HSRR1,r11
@@ -577,21 +608,20 @@ kvmppc_interrupt:
 	/* See if this is something we can handle in real mode */
 	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
 	beq	hcall_try_real_mode
-hcall_real_cont:
 
 	/* Check for mediated interrupts (could be done earlier really ...) */
 BEGIN_FTR_SECTION
 	cmpwi	r12,BOOK3S_INTERRUPT_EXTERNAL
 	bne+	1f
-	ld	r5,VCPU_KVM(r9)
-	ld	r5,KVM_LPCR(r5)
 	andi.	r0,r11,MSR_EE
 	beq	1f
+	mfspr	r5,SPRN_LPCR
 	andi.	r0,r5,LPCR_MER
 	bne	bounce_ext_interrupt
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
 
+hcall_real_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	/* Save DEC */
 	mfspr	r5,SPRN_DEC
 	mftb	r6
@@ -685,7 +715,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_201)
 	slbia
 	ptesync
 
-hdec_soon:
+hdec_soon:			/* r9 = vcpu, r12 = trap, r13 = paca */
 BEGIN_FTR_SECTION
 	b	32f
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
@@ -703,6 +733,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	addi	r0,r3,0x100
 	stwcx.	r0,0,r6
 	bne	41b
+	lwsync
 
 	/*
 	 * At this point we have an interrupt that we have to pass
@@ -716,18 +747,39 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	 * interrupt, since the other threads will already be on their
 	 * way here in that case.
 	 */
+	cmpwi	r3,0x100	/* Are we the first here? */
+	bge	43f
+	cmpwi	r3,1		/* Are any other threads in the guest? */
+	ble	43f
 	cmpwi	r12,BOOK3S_INTERRUPT_HV_DECREMENTER
 	beq	40f
-	cmpwi	r3,0x100	/* Are we the first here? */
-	bge	40f
-	cmpwi	r3,1
-	ble	40f
 	li	r0,0
 	mtspr	SPRN_HDEC,r0
 40:
+	/*
+	 * Send an IPI to any napping threads, since an HDEC interrupt
+	 * doesn't wake CPUs up from nap.
+	 */
+	lwz	r3,VCORE_NAPPING_THREADS(r5)
+	lwz	r4,VCPU_PTID(r9)
+	li	r0,1
+	sldi	r0,r0,r4
+	andc.	r3,r3,r0		/* no sense IPI'ing ourselves */
+	beq	43f
+	mulli	r4,r4,PACA_SIZE		/* get paca for thread 0 */
+	subf	r6,r4,r13
+42:	andi.	r0,r3,1
+	beq	44f
+	ld	r8,HSTATE_XICS_PHYS(r6)	/* get thread's XICS reg addr */
+	li	r0,IPI_PRIORITY
+	li	r7,XICS_QIRR
+	stbcix	r0,r7,r8		/* trigger the IPI */
+44:	srdi.	r3,r3,1
+	addi	r6,r6,PACA_SIZE
+	bne	42b
 
 	/* Secondary threads wait for primary to do partition switch */
-	ld	r4,VCPU_KVM(r9)		/* pointer to struct kvm */
+43:	ld	r4,VCPU_KVM(r9)		/* pointer to struct kvm */
 	ld	r5,HSTATE_KVM_VCORE(r13)
 	lwz	r3,VCPU_PTID(r9)
 	cmpwi	r3,0
@@ -1080,7 +1132,6 @@ hcall_try_real_mode:
 hcall_real_fallback:
 	li	r12,BOOK3S_INTERRUPT_SYSCALL
 	ld	r9, HSTATE_KVM_VCPU(r13)
-	ld	r11, VCPU_MSR(r9)
 
 	b	hcall_real_cont
 
@@ -1142,7 +1193,7 @@ hcall_real_table:
 	.long	0		/* 0xd4 */
 	.long	0		/* 0xd8 */
 	.long	0		/* 0xdc */
-	.long	0		/* 0xe0 */
+	.long	.kvmppc_h_cede - hcall_real_table
 	.long	0		/* 0xe4 */
 	.long	0		/* 0xe8 */
 	.long	0		/* 0xec */
@@ -1171,7 +1222,8 @@ bounce_ext_interrupt:
 	mtspr	SPRN_SRR0,r10
 	mtspr	SPRN_SRR1,r11
 	li	r10,BOOK3S_INTERRUPT_EXTERNAL
-	LOAD_REG_IMMEDIATE(r11,MSR_SF | MSR_ME);
+	li	r11,(MSR_ME << 1) | 1	/* synthesize MSR_SF | MSR_ME */
+	rotldi	r11,r11,63
 	b	fast_guest_return
 
 _GLOBAL(kvmppc_h_set_dabr)
@@ -1180,6 +1232,178 @@ _GLOBAL(kvmppc_h_set_dabr)
 	li	r3,0
 	blr
 
+_GLOBAL(kvmppc_h_cede)
+	ori	r11,r11,MSR_EE
+	std	r11,VCPU_MSR(r3)
+	li	r0,1
+	stb	r0,VCPU_CEDED(r3)
+	sync			/* order setting ceded vs. testing prodded */
+	lbz	r5,VCPU_PRODDED(r3)
+	cmpwi	r5,0
+	bne	1f
+	li	r0,0		/* set trap to 0 to say hcall is handled */
+	stw	r0,VCPU_TRAP(r3)
+	li	r0,H_SUCCESS
+	std	r0,VCPU_GPR(r3)(r3)
+BEGIN_FTR_SECTION
+	b	2f		/* just send it up to host on 970 */
+END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
+
+	/*
+	 * Set our bit in the bitmask of napping threads unless all the
+	 * other threads are already napping, in which case we send this
+	 * up to the host.
+	 */
+	ld	r5,HSTATE_KVM_VCORE(r13)
+	lwz	r6,VCPU_PTID(r3)
+	lwz	r8,VCORE_ENTRY_EXIT(r5)
+	clrldi	r8,r8,56
+	li	r0,1
+	sld	r0,r0,r6
+	addi	r6,r5,VCORE_NAPPING_THREADS
+31:	lwarx	r4,0,r6
+	or	r4,r4,r0
+	popcntw	r7,r4
+	cmpw	r7,r8
+	bge	2f
+	stwcx.	r4,0,r6
+	bne	31b
+	li	r0,1
+	stb	r0,HSTATE_NAPPING(r13)
+	/* order napping_threads update vs testing entry_exit_count */
+	lwsync
+	mr	r4,r3
+	lwz	r7,VCORE_ENTRY_EXIT(r5)
+	cmpwi	r7,0x100
+	bge	33f		/* another thread already exiting */
+
+/*
+ * Although not specifically required by the architecture, POWER7
+ * preserves the following registers in nap mode, even if an SMT mode
+ * switch occurs: SLB entries, PURR, SPURR, AMOR, UAMOR, AMR, SPRG0-3,
+ * DAR, DSISR, DABR, DABRX, DSCR, PMCx, MMCRx, SIAR, SDAR.
+ */
+	/* Save non-volatile GPRs */
+	std	r14, VCPU_GPR(r14)(r3)
+	std	r15, VCPU_GPR(r15)(r3)
+	std	r16, VCPU_GPR(r16)(r3)
+	std	r17, VCPU_GPR(r17)(r3)
+	std	r18, VCPU_GPR(r18)(r3)
+	std	r19, VCPU_GPR(r19)(r3)
+	std	r20, VCPU_GPR(r20)(r3)
+	std	r21, VCPU_GPR(r21)(r3)
+	std	r22, VCPU_GPR(r22)(r3)
+	std	r23, VCPU_GPR(r23)(r3)
+	std	r24, VCPU_GPR(r24)(r3)
+	std	r25, VCPU_GPR(r25)(r3)
+	std	r26, VCPU_GPR(r26)(r3)
+	std	r27, VCPU_GPR(r27)(r3)
+	std	r28, VCPU_GPR(r28)(r3)
+	std	r29, VCPU_GPR(r29)(r3)
+	std	r30, VCPU_GPR(r30)(r3)
+	std	r31, VCPU_GPR(r31)(r3)
+
+	/* save FP state */
+	bl	.kvmppc_save_fp
+
+	/*
+	 * Take a nap until a decrementer or external interrupt occurs,
+	 * with PECE1 (wake on decr) and PECE0 (wake on external) set in LPCR
+	 */
+	li	r0,0x80
+	stb	r0,PACAPROCSTART(r13)
+	mfspr	r5,SPRN_LPCR
+	ori	r5,r5,LPCR_PECE0 | LPCR_PECE1
+	mtspr	SPRN_LPCR,r5
+	isync
+	li	r0, 0
+	std	r0, HSTATE_SCRATCH0(r13)
+	ptesync
+	ld	r0, HSTATE_SCRATCH0(r13)
+1:	cmpd	r0, r0
+	bne	1b
+	nap
+	b	.
+
+kvm_end_cede:
+	/* Woken by external or decrementer interrupt */
+	ld	r1, HSTATE_HOST_R1(r13)
+	ld	r2, PACATOC(r13)
+
+	/* If we're a secondary thread and we got here by an IPI, ack it */
+	ld	r4,HSTATE_KVM_VCPU(r13)
+	lwz	r3,VCPU_PTID(r4)
+	cmpwi	r3,0
+	beq	27f
+	mfspr	r3,SPRN_SRR1
+	rlwinm	r3,r3,44-31,0x7		/* extract wake reason field */
+	cmpwi	r3,4			/* was it an external interrupt? */
+	bne	27f
+	ld	r5, HSTATE_XICS_PHYS(r13)
+	li	r0,0xff
+	li	r6,XICS_QIRR
+	li	r7,XICS_XIRR
+	lwzcix	r8,r5,r7		/* ack the interrupt */
+	sync
+	stbcix	r0,r5,r6		/* clear it */
+	stwcix	r8,r5,r7		/* EOI it */
+27:
+	/* load up FP state */
+	bl	kvmppc_load_fp
+
+	/* Load NV GPRS */
+	ld	r14, VCPU_GPR(r14)(r4)
+	ld	r15, VCPU_GPR(r15)(r4)
+	ld	r16, VCPU_GPR(r16)(r4)
+	ld	r17, VCPU_GPR(r17)(r4)
+	ld	r18, VCPU_GPR(r18)(r4)
+	ld	r19, VCPU_GPR(r19)(r4)
+	ld	r20, VCPU_GPR(r20)(r4)
+	ld	r21, VCPU_GPR(r21)(r4)
+	ld	r22, VCPU_GPR(r22)(r4)
+	ld	r23, VCPU_GPR(r23)(r4)
+	ld	r24, VCPU_GPR(r24)(r4)
+	ld	r25, VCPU_GPR(r25)(r4)
+	ld	r26, VCPU_GPR(r26)(r4)
+	ld	r27, VCPU_GPR(r27)(r4)
+	ld	r28, VCPU_GPR(r28)(r4)
+	ld	r29, VCPU_GPR(r29)(r4)
+	ld	r30, VCPU_GPR(r30)(r4)
+	ld	r31, VCPU_GPR(r31)(r4)
+
+	/* clear our bit in vcore->napping_threads */
+33:	ld	r5,HSTATE_KVM_VCORE(r13)
+	lwz	r3,VCPU_PTID(r4)
+	li	r0,1
+	sld	r0,r0,r3
+	addi	r6,r5,VCORE_NAPPING_THREADS
+32:	lwarx	r7,0,r6
+	andc	r7,r7,r0
+	stwcx.	r7,0,r6
+	bne	32b
+	li	r0,0
+	stb	r0,HSTATE_NAPPING(r13)
+
+	/* see if any other thread is already exiting */
+	lwz	r0,VCORE_ENTRY_EXIT(r5)
+	cmpwi	r0,0x100
+	blt	kvmppc_cede_reentry	/* if not go back to guest */
+
+	/* some threads are exiting, so go to the guest exit path */
+	b	hcall_real_fallback
+
+	/* cede when already previously prodded case */
+1:	li	r0,0
+	stb	r0,VCPU_PRODDED(r3)
+	sync			/* order testing prodded vs. clearing ceded */
+	stb	r0,VCPU_CEDED(r3)
+	li	r3,H_SUCCESS
+	blr
+
+	/* we've ceded but we want to give control to the host */
+2:	li	r3,H_TOO_HARD
+	blr
+
 secondary_too_late:
 	ld	r5,HSTATE_KVM_VCORE(r13)
 	HMT_LOW
@@ -1197,14 +1421,20 @@ secondary_too_late:
 	slbmte	r6,r5
 1:	addi	r11,r11,16
 	.endr
-	b	50f
 
 secondary_nap:
-	/* Clear any pending IPI */
-50:	ld	r5, HSTATE_XICS_PHYS(r13)
+	/* Clear any pending IPI - assume we're a secondary thread */
+	ld	r5, HSTATE_XICS_PHYS(r13)
+	li	r7, XICS_XIRR
+	lwzcix	r3, r5, r7		/* ack any pending interrupt */
+	rlwinm.	r0, r3, 0, 0xffffff	/* any pending? */
+	beq	37f
+	sync
 	li	r0, 0xff
 	li	r6, XICS_QIRR
-	stbcix	r0, r5, r6
+	stbcix	r0, r5, r6		/* clear the IPI */
+	stwcix	r3, r5, r7		/* EOI it */
+37:	sync
 
 	/* increment the nap count and then go to nap mode */
 	ld	r4, HSTATE_KVM_VCORE(r13)
@@ -1214,13 +1444,12 @@ secondary_nap:
 	addi	r3, r3, 1
 	stwcx.	r3, 0, r4
 	bne	51b
-	isync
 
+	li	r3, LPCR_PECE0
 	mfspr	r4, SPRN_LPCR
-	li	r0, LPCR_PECE
-	andc	r4, r4, r0
-	ori	r4, r4, LPCR_PECE0	/* exit nap on interrupt */
+	rlwimi	r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
 	mtspr	SPRN_LPCR, r4
+	isync
 	li	r0, 0
 	std	r0, HSTATE_SCRATCH0(r13)
 	ptesync
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index a107c9b..cd0e3e5 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -39,12 +39,8 @@
 
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
-#ifndef CONFIG_KVM_BOOK3S_64_HV
 	return !(v->arch.shared->msr & MSR_WE) ||
 	       !!(v->arch.pending_exceptions);
-#else
-	return !(v->arch.ceded) || !!(v->arch.pending_exceptions);
-#endif
 }
 
 int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
@@ -258,6 +254,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 {
 	struct kvm_vcpu *vcpu;
 	vcpu = kvmppc_core_vcpu_create(kvm, id);
+	vcpu->arch.wqp = &vcpu->wq;
 	if (!IS_ERR(vcpu))
 		kvmppc_create_vcpu_debugfs(vcpu, id);
 	return vcpu;
@@ -289,8 +286,8 @@ static void kvmppc_decrementer_func(unsigned long data)
 
 	kvmppc_core_queue_dec(vcpu);
 
-	if (waitqueue_active(&vcpu->wq)) {
-		wake_up_interruptible(&vcpu->wq);
+	if (waitqueue_active(vcpu->arch.wqp)) {
+		wake_up_interruptible(vcpu->arch.wqp);
 		vcpu->stat.halt_wakeup++;
 	}
 }
@@ -543,13 +540,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
 {
-	if (irq->irq == KVM_INTERRUPT_UNSET)
+	if (irq->irq == KVM_INTERRUPT_UNSET) {
 		kvmppc_core_dequeue_external(vcpu, irq);
-	else
-		kvmppc_core_queue_external(vcpu, irq);
+		return 0;
+	}
+
+	kvmppc_core_queue_external(vcpu, irq);
 
-	if (waitqueue_active(&vcpu->wq)) {
-		wake_up_interruptible(&vcpu->wq);
+	if (waitqueue_active(vcpu->arch.wqp)) {
+		wake_up_interruptible(vcpu->arch.wqp);
 		vcpu->stat.halt_wakeup++;
 	} else if (vcpu->cpu != -1) {
 		smp_send_reschedule(vcpu->cpu);
-- 
1.7.5.4

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in
@ 2011-07-23  7:42   ` Paul Mackerras
  0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-07-23  7:42 UTC (permalink / raw)
  To: linuxppc-dev, kvm-ppc, Alexander Graf

With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per
core), whenever a CPU goes idle, we have to pull all the other
hardware threads in the core out of the guest, because the H_CEDE
hcall is handled in the kernel.  This is inefficient.

This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall
in real mode.  When a guest vcpu does an H_CEDE hcall, we now only
exit to the kernel if all the other vcpus in the same core are also
idle.  Otherwise we mark this vcpu as napping, save state that could
be lost in nap mode (mainly GPRs and FPRs), and execute the nap
instruction.  When the thread wakes up, because of a decrementer or
external interrupt, we come back in at kvm_start_guest (from the
system reset interrupt vector), find the `napping' flag set in the
paca, and go to the resume path.

This has some other ramifications.  First, when starting a core, we
now start all the threads, both those that are immediately runnable and
those that are idle.  This is so that we don't have to pull all the
threads out of the guest when an idle thread gets a decrementer interrupt
and wants to start running.  In fact the idle threads will all start
with the H_CEDE hcall returning; being idle they will just do another
H_CEDE immediately and go to nap mode.

This required some changes to kvmppc_run_core() and kvmppc_run_vcpu().
These functions have been restructured to make them simpler and clearer.
We introduce a level of indirection in the wait queue that gets woken
when external and decrementer interrupts get generated for a vcpu, so
that we can have the 4 vcpus in a vcore using the same wait queue.
We need this because the 4 vcpus are being handled by one thread.

Secondly, when we need to exit from the guest to the kernel, we now
have to generate an IPI for any napping threads, because an HDEC
interrupt doesn't wake up a napping thread.

Thirdly, we now need to be able to handle virtual external interrupts
and decrementer interrupts becoming pending while a thread is napping,
and deliver those interrupts to the guest when the thread wakes.
This is done in kvmppc_cede_reentry, just before fast_guest_return.

Finally, since we are not using the generic kvm_vcpu_block for book3s_hv,
and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef
from kvm_arch_vcpu_runnable.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/kvm_book3s_asm.h |    1 +
 arch/powerpc/include/asm/kvm_host.h       |   19 ++-
 arch/powerpc/kernel/asm-offsets.c         |    6 +
 arch/powerpc/kvm/book3s_hv.c              |  335 ++++++++++++++++-------------
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   |  297 ++++++++++++++++++++++---
 arch/powerpc/kvm/powerpc.c                |   21 +-
 6 files changed, 483 insertions(+), 196 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index af73469..1f2f5b6 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -76,6 +76,7 @@ struct kvmppc_host_state {
 	ulong scratch1;
 	u8 in_guest;
 	u8 restore_hid5;
+	u8 napping;
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	struct kvm_vcpu *kvm_vcpu;
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index db15384..652b05f 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -198,21 +198,29 @@ struct kvm_arch {
  */
 struct kvmppc_vcore {
 	int n_runnable;
-	int n_blocked;
+	int n_busy;
 	int num_threads;
 	int entry_exit_count;
 	int n_woken;
 	int nap_count;
+	int napping_threads;
 	u16 pcpu;
-	u8 vcore_running;
+	u8 vcore_state;
 	u8 in_guest;
 	struct list_head runnable_threads;
 	spinlock_t lock;
+	wait_queue_head_t wq;
 };
 
 #define VCORE_ENTRY_COUNT(vc)	((vc)->entry_exit_count & 0xff)
 #define VCORE_EXIT_COUNT(vc)	((vc)->entry_exit_count >> 8)
 
+/* Values for vcore_state */
+#define VCORE_INACTIVE	0
+#define VCORE_RUNNING	1
+#define VCORE_EXITING	2
+#define VCORE_SLEEPING	3
+
 struct kvmppc_pte {
 	ulong eaddr;
 	u64 vpage;
@@ -400,11 +408,13 @@ struct kvm_vcpu_arch {
 	struct dtl *dtl;
 	struct dtl *dtl_end;
 
+	wait_queue_head_t *wqp;
 	struct kvmppc_vcore *vcore;
 	int ret;
 	int trap;
 	int state;
 	int ptid;
+	bool timer_running;
 	wait_queue_head_t cpu_run;
 
 	struct kvm_vcpu_arch_shared *shared;
@@ -420,8 +430,9 @@ struct kvm_vcpu_arch {
 #endif
 };
 
-#define KVMPPC_VCPU_BUSY_IN_HOST	0
-#define KVMPPC_VCPU_BLOCKED		1
+/* Values for vcpu->arch.state */
+#define KVMPPC_VCPU_STOPPED		0
+#define KVMPPC_VCPU_BUSY_IN_HOST	1
 #define KVMPPC_VCPU_RUNNABLE		2
 
 #endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index d34cd32..833021c 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -44,6 +44,7 @@
 #include <asm/compat.h>
 #include <asm/mmu.h>
 #include <asm/hvcall.h>
+#include <asm/xics.h>
 #endif
 #ifdef CONFIG_PPC_ISERIES
 #include <asm/iseries/alpaca.h>
@@ -457,6 +458,8 @@ int main(void)
 	DEFINE(VCPU_DEC, offsetof(struct kvm_vcpu, arch.dec));
 	DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires));
 	DEFINE(VCPU_PENDING_EXC, offsetof(struct kvm_vcpu, arch.pending_exceptions));
+	DEFINE(VCPU_CEDED, offsetof(struct kvm_vcpu, arch.ceded));
+	DEFINE(VCPU_PRODDED, offsetof(struct kvm_vcpu, arch.prodded));
 	DEFINE(VCPU_VPA, offsetof(struct kvm_vcpu, arch.vpa));
 	DEFINE(VCPU_MMCR, offsetof(struct kvm_vcpu, arch.mmcr));
 	DEFINE(VCPU_PMC, offsetof(struct kvm_vcpu, arch.pmc));
@@ -472,6 +475,7 @@ int main(void)
 	DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_count));
 	DEFINE(VCORE_NAP_COUNT, offsetof(struct kvmppc_vcore, nap_count));
 	DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest));
+	DEFINE(VCORE_NAPPING_THREADS, offsetof(struct kvmppc_vcore, napping_threads));
 	DEFINE(VCPU_SVCPU, offsetof(struct kvmppc_vcpu_book3s, shadow_vcpu) -
 			   offsetof(struct kvmppc_vcpu_book3s, vcpu));
 	DEFINE(VCPU_SLB_E, offsetof(struct kvmppc_slb, orige));
@@ -529,6 +533,7 @@ int main(void)
 	HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
 	HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
 	HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
+	HSTATE_FIELD(HSTATE_NAPPING, napping);
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
@@ -541,6 +546,7 @@ int main(void)
 	HSTATE_FIELD(HSTATE_DSCR, host_dscr);
 	HSTATE_FIELD(HSTATE_DABR, dabr);
 	HSTATE_FIELD(HSTATE_DECEXP, dec_expires);
+	DEFINE(IPI_PRIORITY, IPI_PRIORITY);
 #endif /* CONFIG_KVM_BOOK3S_64_HV */
 
 #else /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index cc0d7f1..81c384d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -62,6 +62,8 @@
 /* #define EXIT_DEBUG_SIMPLE */
 /* #define EXIT_DEBUG_INT */
 
+static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
+
 void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	local_paca->kvm_hstate.kvm_vcpu = vcpu;
@@ -72,40 +74,10 @@ void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
 {
 }
 
-static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu);
-static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu);
-
-void kvmppc_vcpu_block(struct kvm_vcpu *vcpu)
-{
-	u64 now;
-	unsigned long dec_nsec;
-
-	now = get_tb();
-	if (now >= vcpu->arch.dec_expires && !kvmppc_core_pending_dec(vcpu))
-		kvmppc_core_queue_dec(vcpu);
-	if (vcpu->arch.pending_exceptions)
-		return;
-	if (vcpu->arch.dec_expires != ~(u64)0) {
-		dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC /
-			tb_ticks_per_sec;
-		hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
-			      HRTIMER_MODE_REL);
-	}
-
-	kvmppc_vcpu_blocked(vcpu);
-
-	kvm_vcpu_block(vcpu);
-	vcpu->stat.halt_wakeup++;
-
-	if (vcpu->arch.dec_expires != ~(u64)0)
-		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
-
-	kvmppc_vcpu_unblocked(vcpu);
-}
-
 void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr)
 {
 	vcpu->arch.shregs.msr = msr;
+	kvmppc_end_cede(vcpu);
 }
 
 void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
@@ -257,15 +229,6 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 
 	switch (req) {
 	case H_CEDE:
-		vcpu->arch.shregs.msr |= MSR_EE;
-		vcpu->arch.ceded = 1;
-		smp_mb();
-		if (!vcpu->arch.prodded)
-			kvmppc_vcpu_block(vcpu);
-		else
-			vcpu->arch.prodded = 0;
-		smp_mb();
-		vcpu->arch.ceded = 0;
 		break;
 	case H_PROD:
 		target = kvmppc_get_gpr(vcpu, 4);
@@ -388,20 +351,6 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		break;
 	}
 
-
-	if (!(r & RESUME_HOST)) {
-		/* To avoid clobbering exit_reason, only check for signals if
-		 * we aren't already exiting to userspace for some other
-		 * reason. */
-		if (signal_pending(tsk)) {
-			vcpu->stat.signal_exits++;
-			run->exit_reason = KVM_EXIT_INTR;
-			r = -EINTR;
-		} else {
-			kvmppc_core_deliver_interrupts(vcpu);
-		}
-	}
-
 	return r;
 }
 
@@ -479,13 +428,9 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	kvmppc_mmu_book3s_hv_init(vcpu);
 
 	/*
-	 * Some vcpus may start out in stopped state.  If we initialize
-	 * them to busy-in-host state they will stop other vcpus in the
-	 * vcore from running.  Instead we initialize them to blocked
-	 * state, effectively considering them to be stopped until we
-	 * see the first run ioctl for them.
+	 * We consider the vcpu stopped until we see the first run ioctl for it.
 	 */
-	vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
+	vcpu->arch.state = KVMPPC_VCPU_STOPPED;
 
 	init_waitqueue_head(&vcpu->arch.cpu_run);
 
@@ -496,6 +441,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 		if (vcore) {
 			INIT_LIST_HEAD(&vcore->runnable_threads);
 			spin_lock_init(&vcore->lock);
+			init_waitqueue_head(&vcore->wq);
 		}
 		kvm->arch.vcores[core] = vcore;
 	}
@@ -506,7 +452,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 
 	spin_lock(&vcore->lock);
 	++vcore->num_threads;
-	++vcore->n_blocked;
 	spin_unlock(&vcore->lock);
 	vcpu->arch.vcore = vcore;
 
@@ -524,30 +469,31 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
 	kfree(vcpu);
 }
 
-static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu)
+static void kvmppc_set_timer(struct kvm_vcpu *vcpu)
 {
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	unsigned long dec_nsec, now;
 
-	spin_lock(&vc->lock);
-	vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
-	++vc->n_blocked;
-	if (vc->n_runnable > 0 &&
-	    vc->n_runnable + vc->n_blocked = vc->num_threads) {
-		vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
-					arch.run_list);
-		wake_up(&vcpu->arch.cpu_run);
+	now = get_tb();
+	if (now > vcpu->arch.dec_expires) {
+		/* decrementer has already gone negative */
+		kvmppc_core_queue_dec(vcpu);
+		kvmppc_core_deliver_interrupts(vcpu);
+		return;
 	}
-	spin_unlock(&vc->lock);
+	dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC
+		   / tb_ticks_per_sec;
+	hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
+		      HRTIMER_MODE_REL);
+	vcpu->arch.timer_running = 1;
 }
 
-static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu)
+static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
 {
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-
-	spin_lock(&vc->lock);
-	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
-	--vc->n_blocked;
-	spin_unlock(&vc->lock);
+	vcpu->arch.ceded = 0;
+	if (vcpu->arch.timer_running) {
+		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+		vcpu->arch.timer_running = 0;
+	}
 }
 
 extern int __kvmppc_vcore_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
@@ -562,6 +508,7 @@ static void kvmppc_remove_runnable(struct kvmppc_vcore *vc,
 		return;
 	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
 	--vc->n_runnable;
+	++vc->n_busy;
 	/* decrement the physical thread id of each following vcpu */
 	v = vcpu;
 	list_for_each_entry_continue(v, &vc->runnable_threads, arch.run_list)
@@ -575,15 +522,20 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu)
 	struct paca_struct *tpaca;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 
+	if (vcpu->arch.timer_running) {
+		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+		vcpu->arch.timer_running = 0;
+	}
 	cpu = vc->pcpu + vcpu->arch.ptid;
 	tpaca = &paca[cpu];
 	tpaca->kvm_hstate.kvm_vcpu = vcpu;
 	tpaca->kvm_hstate.kvm_vcore = vc;
+	tpaca->kvm_hstate.napping = 0;
+	vcpu->cpu = vc->pcpu;
 	smp_wmb();
 #ifdef CONFIG_PPC_ICP_NATIVE
 	if (vcpu->arch.ptid) {
 		tpaca->cpu_start = 0x80;
-		tpaca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST;
 		wmb();
 		xics_wake_cpu(cpu);
 		++vc->n_woken;
@@ -631,9 +583,10 @@ static int on_primary_thread(void)
  */
 static int kvmppc_run_core(struct kvmppc_vcore *vc)
 {
-	struct kvm_vcpu *vcpu, *vnext;
+	struct kvm_vcpu *vcpu, *vcpu0, *vnext;
 	long ret;
 	u64 now;
+	int ptid;
 
 	/* don't start if any threads have a signal pending */
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
@@ -652,29 +605,50 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 		goto out;
 	}
 
+	/*
+	 * Assign physical thread IDs, first to non-ceded vcpus
+	 * and then to ceded ones.
+	 */
+	ptid = 0;
+	vcpu0 = NULL;
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
+		if (!vcpu->arch.ceded) {
+			if (!ptid)
+				vcpu0 = vcpu;
+			vcpu->arch.ptid = ptid++;
+		}
+	}
+	if (!vcpu0)
+		return 0;		/* nothing to run */
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+		if (vcpu->arch.ceded)
+			vcpu->arch.ptid = ptid++;
+
 	vc->n_woken = 0;
 	vc->nap_count = 0;
 	vc->entry_exit_count = 0;
-	vc->vcore_running = 1;
+	vc->vcore_state = VCORE_RUNNING;
 	vc->in_guest = 0;
 	vc->pcpu = smp_processor_id();
+	vc->napping_threads = 0;
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
 		kvmppc_start_thread(vcpu);
-	vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
-				arch.run_list);
 
+	preempt_disable();
 	spin_unlock(&vc->lock);
 
-	preempt_disable();
 	kvm_guest_enter();
-	__kvmppc_vcore_entry(NULL, vcpu);
+	__kvmppc_vcore_entry(NULL, vcpu0);
 
-	/* wait for secondary threads to finish writing their state to memory */
 	spin_lock(&vc->lock);
+	/* disable sending of IPIs on virtual external irqs */
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+		vcpu->cpu = -1;
+	/* wait for secondary threads to finish writing their state to memory */
 	if (vc->nap_count < vc->n_woken)
 		kvmppc_wait_for_nap(vc);
 	/* prevent other vcpu threads from doing kvmppc_start_thread() now */
-	vc->vcore_running = 2;
+	vc->vcore_state = VCORE_EXITING;
 	spin_unlock(&vc->lock);
 
 	/* make sure updates to secondary vcpu structs are visible now */
@@ -690,22 +664,26 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 		if (now < vcpu->arch.dec_expires &&
 		    kvmppc_core_pending_dec(vcpu))
 			kvmppc_core_dequeue_dec(vcpu);
-		if (!vcpu->arch.trap) {
-			if (signal_pending(vcpu->arch.run_task)) {
-				vcpu->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
-				vcpu->arch.ret = -EINTR;
-			}
-			continue;		/* didn't get to run */
-		}
-		ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
-					 vcpu->arch.run_task);
+
+		ret = RESUME_GUEST;
+		if (vcpu->arch.trap)
+			ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
+						 vcpu->arch.run_task);
+
 		vcpu->arch.ret = ret;
 		vcpu->arch.trap = 0;
+
+		if (vcpu->arch.ceded) {
+			if (ret != RESUME_GUEST)
+				kvmppc_end_cede(vcpu);
+			else
+				kvmppc_set_timer(vcpu);
+		}
 	}
 
 	spin_lock(&vc->lock);
  out:
-	vc->vcore_running = 0;
+	vc->vcore_state = VCORE_INACTIVE;
 	list_for_each_entry_safe(vcpu, vnext, &vc->runnable_threads,
 				 arch.run_list) {
 		if (vcpu->arch.ret != RESUME_GUEST) {
@@ -717,82 +695,130 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 	return 1;
 }
 
-static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
+/*
+ * Wait for some other vcpu thread to execute us, and
+ * wake us up when we need to handle something in the host.
+ */
+static void kvmppc_wait_for_exec(struct kvm_vcpu *vcpu, int wait_state)
 {
-	int ptid;
-	int wait_state;
-	struct kvmppc_vcore *vc;
 	DEFINE_WAIT(wait);
 
-	/* No need to go into the guest when all we do is going out */
-	if (signal_pending(current)) {
-		kvm_run->exit_reason = KVM_EXIT_INTR;
-		return -EINTR;
+	prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
+	if (vcpu->arch.state = KVMPPC_VCPU_RUNNABLE)
+		schedule();
+	finish_wait(&vcpu->arch.cpu_run, &wait);
+}
+
+/*
+ * All the vcpus in this vcore are idle, so wait for a decrementer
+ * or external interrupt to one of the vcpus.  vc->lock is held.
+ */
+static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
+{
+	DEFINE_WAIT(wait);
+	struct kvm_vcpu *v;
+	int all_idle = 1;
+
+	prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+	vc->vcore_state = VCORE_SLEEPING;
+	spin_unlock(&vc->lock);
+	list_for_each_entry(v, &vc->runnable_threads, arch.run_list) {
+		if (!v->arch.ceded || v->arch.pending_exceptions) {
+			all_idle = 0;
+			break;
+		}
 	}
+	if (all_idle)
+		schedule();
+	finish_wait(&vc->wq, &wait);
+	spin_lock(&vc->lock);
+	vc->vcore_state = VCORE_INACTIVE;
+}
 
-	/* On PPC970, check that we have an RMA region */
-	if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
-		return -EPERM;
+static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
+{
+	int n_ceded;
+	int prev_state;
+	struct kvmppc_vcore *vc;
+	struct kvm_vcpu *v, *vn;
 
 	kvm_run->exit_reason = 0;
 	vcpu->arch.ret = RESUME_GUEST;
 	vcpu->arch.trap = 0;
 
-	flush_fp_to_thread(current);
-	flush_altivec_to_thread(current);
-	flush_vsx_to_thread(current);
-
 	/*
 	 * Synchronize with other threads in this virtual core
 	 */
 	vc = vcpu->arch.vcore;
 	spin_lock(&vc->lock);
-	/* This happens the first time this is called for a vcpu */
-	if (vcpu->arch.state = KVMPPC_VCPU_BLOCKED)
-		--vc->n_blocked;
-	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
-	ptid = vc->n_runnable;
+	vcpu->arch.ceded = 0;
 	vcpu->arch.run_task = current;
 	vcpu->arch.kvm_run = kvm_run;
-	vcpu->arch.ptid = ptid;
+	prev_state = vcpu->arch.state;
+	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
 	list_add_tail(&vcpu->arch.run_list, &vc->runnable_threads);
 	++vc->n_runnable;
 
-	wait_state = TASK_INTERRUPTIBLE;
-	while (vcpu->arch.state = KVMPPC_VCPU_RUNNABLE) {
-		if (signal_pending(current)) {
-			if (!vc->vcore_running) {
-				kvm_run->exit_reason = KVM_EXIT_INTR;
-				vcpu->arch.ret = -EINTR;
-				break;
-			}
-			/* have to wait for vcore to stop executing guest */
-			wait_state = TASK_UNINTERRUPTIBLE;
-			smp_send_reschedule(vc->pcpu);
+	/*
+	 * This happens the first time this is called for a vcpu.
+	 * If the vcore is already running, we may be able to start
+	 * this thread straight away and have it join in.
+	 */
+	if (prev_state = KVMPPC_VCPU_STOPPED) {
+		if (vc->vcore_state = VCORE_RUNNING &&
+		    VCORE_EXIT_COUNT(vc) = 0) {
+			vcpu->arch.ptid = vc->n_runnable - 1;
+			kvmppc_start_thread(vcpu);
 		}
 
-		if (!vc->vcore_running &&
-		    vc->n_runnable + vc->n_blocked = vc->num_threads) {
-			/* we can run now */
-			if (kvmppc_run_core(vc))
-				continue;
-		}
+	} else if (prev_state = KVMPPC_VCPU_BUSY_IN_HOST)
+		--vc->n_busy;
 
-		if (vc->vcore_running = 1 && VCORE_EXIT_COUNT(vc) = 0)
-			kvmppc_start_thread(vcpu);
+	while (vcpu->arch.state = KVMPPC_VCPU_RUNNABLE &&
+	       !signal_pending(current)) {
+		if (vc->n_busy || vc->vcore_state != VCORE_INACTIVE) {
+			spin_unlock(&vc->lock);
+			kvmppc_wait_for_exec(vcpu, TASK_INTERRUPTIBLE);
+			spin_lock(&vc->lock);
+			continue;
+		}
+		n_ceded = 0;
+		list_for_each_entry(v, &vc->runnable_threads, arch.run_list)
+			n_ceded += v->arch.ceded;
+		if (n_ceded = vc->n_runnable)
+			kvmppc_vcore_blocked(vc);
+		else
+			kvmppc_run_core(vc);
+
+		list_for_each_entry_safe(v, vn, &vc->runnable_threads,
+					 arch.run_list) {
+			kvmppc_core_deliver_interrupts(v);
+			if (signal_pending(v->arch.run_task)) {
+				kvmppc_remove_runnable(vc, v);
+				v->stat.signal_exits++;
+				v->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
+				v->arch.ret = -EINTR;
+				wake_up(&v->arch.cpu_run);
+			}
+		}
+	}
 
-		/* wait for other threads to come in, or wait for vcore */
-		prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
-		spin_unlock(&vc->lock);
-		schedule();
-		finish_wait(&vcpu->arch.cpu_run, &wait);
-		spin_lock(&vc->lock);
+	if (signal_pending(current)) {
+		if (vc->vcore_state = VCORE_RUNNING ||
+		    vc->vcore_state = VCORE_EXITING) {
+			spin_unlock(&vc->lock);
+			kvmppc_wait_for_exec(vcpu, TASK_UNINTERRUPTIBLE);
+			spin_lock(&vc->lock);
+		}
+		if (vcpu->arch.state = KVMPPC_VCPU_RUNNABLE) {
+			kvmppc_remove_runnable(vc, vcpu);
+			vcpu->stat.signal_exits++;
+			kvm_run->exit_reason = KVM_EXIT_INTR;
+			vcpu->arch.ret = -EINTR;
+		}
 	}
 
-	if (vcpu->arch.state = KVMPPC_VCPU_RUNNABLE)
-		kvmppc_remove_runnable(vc, vcpu);
 	spin_unlock(&vc->lock);
-
 	return vcpu->arch.ret;
 }
 
@@ -800,6 +826,21 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
 	int r;
 
+	/* No need to go into the guest when all we'll do is come back out */
+	if (signal_pending(current)) {
+		run->exit_reason = KVM_EXIT_INTR;
+		return -EINTR;
+	}
+
+	/* On PPC970, check that we have an RMA region */
+	if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
+		return -EPERM;
+
+	flush_fp_to_thread(current);
+	flush_altivec_to_thread(current);
+	flush_vsx_to_thread(current);
+	vcpu->arch.wqp = &vcpu->arch.vcore->wq;
+
 	do {
 		r = kvmppc_run_vcpu(run, vcpu);
 
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 543ee50..0e2ea04 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -52,7 +52,7 @@ kvmppc_skip_Hinterrupt:
 	b	.
 
 /*
- * Call kvmppc_handler_trampoline_enter in real mode.
+ * Call kvmppc_hv_entry in real mode.
  * Must be called with interrupts hard-disabled.
  *
  * Input Registers:
@@ -92,6 +92,12 @@ _GLOBAL(kvmppc_hv_entry_trampoline)
 kvm_start_guest:
 	ld	r1,PACAEMERGSP(r13)
 	subi	r1,r1,STACK_FRAME_OVERHEAD
+	ld	r2,PACATOC(r13)
+
+	/* were we napping due to cede? */
+	lbz	r0,HSTATE_NAPPING(r13)
+	cmpwi	r0,0
+	bne	kvm_end_cede
 
 	/* get vcpu pointer */
 	ld	r4, HSTATE_KVM_VCPU(r13)
@@ -279,15 +285,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	cmpwi	r0,0
 	beq	20b
 
-	/* Set LPCR.  Set the MER bit if there is a pending external irq. */
+	/* Set LPCR and RMOR. */
 10:	ld	r8,KVM_LPCR(r9)
-	ld	r0,VCPU_PENDING_EXC(r4)
-	li	r7,(1 << BOOK3S_IRQPRIO_EXTERNAL)
-	oris	r7,r7,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
-	and.	r0,r0,r7
-	beq	11f
-	ori	r8,r8,LPCR_MER
-11:	mtspr	SPRN_LPCR,r8
+	mtspr	SPRN_LPCR,r8
 	ld	r8,KVM_RMOR(r9)
 	mtspr	SPRN_RMOR,r8
 	isync
@@ -451,19 +451,50 @@ toc_tlbie_lock:
 	mtctr	r6
 	mtxer	r7
 
-	/* Move SRR0 and SRR1 into the respective regs */
+kvmppc_cede_reentry:		/* r4 = vcpu, r13 = paca */
 	ld	r6, VCPU_SRR0(r4)
 	ld	r7, VCPU_SRR1(r4)
-	mtspr	SPRN_SRR0, r6
-	mtspr	SPRN_SRR1, r7
-
 	ld	r10, VCPU_PC(r4)
+	ld	r11, VCPU_MSR(r4)	/* r11 = vcpu->arch.msr & ~MSR_HV */
 
-	ld	r11, VCPU_MSR(r4)	/* r10 = vcpu->arch.msr & ~MSR_HV */
 	rldicl	r11, r11, 63 - MSR_HV_LG, 1
 	rotldi	r11, r11, 1 + MSR_HV_LG
 	ori	r11, r11, MSR_ME
 
+	/* Check if we can deliver an external or decrementer interrupt now */
+	ld	r0,VCPU_PENDING_EXC(r4)
+	li	r8,(1 << BOOK3S_IRQPRIO_EXTERNAL)
+	oris	r8,r8,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
+	and	r0,r0,r8
+	cmpdi	cr1,r0,0
+	andi.	r0,r11,MSR_EE
+	beq	cr1,11f
+BEGIN_FTR_SECTION
+	mfspr	r8,SPRN_LPCR
+	ori	r8,r8,LPCR_MER
+	mtspr	SPRN_LPCR,r8
+	isync
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
+	beq	5f
+	li	r0,BOOK3S_INTERRUPT_EXTERNAL
+12:	mr	r6,r10
+	mr	r10,r0
+	mr	r7,r11
+	li	r11,(MSR_ME << 1) | 1	/* synthesize MSR_SF | MSR_ME */
+	rotldi	r11,r11,63
+	b	5f
+11:	beq	5f
+	mfspr	r0,SPRN_DEC
+	cmpwi	r0,0
+	li	r0,BOOK3S_INTERRUPT_DECREMENTER
+	blt	12b
+
+	/* Move SRR0 and SRR1 into the respective regs */
+5:	mtspr	SPRN_SRR0, r6
+	mtspr	SPRN_SRR1, r7
+	li	r0,0
+	stb	r0,VCPU_CEDED(r4)	/* cancel cede */
+
 fast_guest_return:
 	mtspr	SPRN_HSRR0,r10
 	mtspr	SPRN_HSRR1,r11
@@ -577,21 +608,20 @@ kvmppc_interrupt:
 	/* See if this is something we can handle in real mode */
 	cmpwi	r12,BOOK3S_INTERRUPT_SYSCALL
 	beq	hcall_try_real_mode
-hcall_real_cont:
 
 	/* Check for mediated interrupts (could be done earlier really ...) */
 BEGIN_FTR_SECTION
 	cmpwi	r12,BOOK3S_INTERRUPT_EXTERNAL
 	bne+	1f
-	ld	r5,VCPU_KVM(r9)
-	ld	r5,KVM_LPCR(r5)
 	andi.	r0,r11,MSR_EE
 	beq	1f
+	mfspr	r5,SPRN_LPCR
 	andi.	r0,r5,LPCR_MER
 	bne	bounce_ext_interrupt
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
 
+hcall_real_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	/* Save DEC */
 	mfspr	r5,SPRN_DEC
 	mftb	r6
@@ -685,7 +715,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_201)
 	slbia
 	ptesync
 
-hdec_soon:
+hdec_soon:			/* r9 = vcpu, r12 = trap, r13 = paca */
 BEGIN_FTR_SECTION
 	b	32f
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
@@ -703,6 +733,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	addi	r0,r3,0x100
 	stwcx.	r0,0,r6
 	bne	41b
+	lwsync
 
 	/*
 	 * At this point we have an interrupt that we have to pass
@@ -716,18 +747,39 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	 * interrupt, since the other threads will already be on their
 	 * way here in that case.
 	 */
+	cmpwi	r3,0x100	/* Are we the first here? */
+	bge	43f
+	cmpwi	r3,1		/* Are any other threads in the guest? */
+	ble	43f
 	cmpwi	r12,BOOK3S_INTERRUPT_HV_DECREMENTER
 	beq	40f
-	cmpwi	r3,0x100	/* Are we the first here? */
-	bge	40f
-	cmpwi	r3,1
-	ble	40f
 	li	r0,0
 	mtspr	SPRN_HDEC,r0
 40:
+	/*
+	 * Send an IPI to any napping threads, since an HDEC interrupt
+	 * doesn't wake CPUs up from nap.
+	 */
+	lwz	r3,VCORE_NAPPING_THREADS(r5)
+	lwz	r4,VCPU_PTID(r9)
+	li	r0,1
+	sldi	r0,r0,r4
+	andc.	r3,r3,r0		/* no sense IPI'ing ourselves */
+	beq	43f
+	mulli	r4,r4,PACA_SIZE		/* get paca for thread 0 */
+	subf	r6,r4,r13
+42:	andi.	r0,r3,1
+	beq	44f
+	ld	r8,HSTATE_XICS_PHYS(r6)	/* get thread's XICS reg addr */
+	li	r0,IPI_PRIORITY
+	li	r7,XICS_QIRR
+	stbcix	r0,r7,r8		/* trigger the IPI */
+44:	srdi.	r3,r3,1
+	addi	r6,r6,PACA_SIZE
+	bne	42b
 
 	/* Secondary threads wait for primary to do partition switch */
-	ld	r4,VCPU_KVM(r9)		/* pointer to struct kvm */
+43:	ld	r4,VCPU_KVM(r9)		/* pointer to struct kvm */
 	ld	r5,HSTATE_KVM_VCORE(r13)
 	lwz	r3,VCPU_PTID(r9)
 	cmpwi	r3,0
@@ -1080,7 +1132,6 @@ hcall_try_real_mode:
 hcall_real_fallback:
 	li	r12,BOOK3S_INTERRUPT_SYSCALL
 	ld	r9, HSTATE_KVM_VCPU(r13)
-	ld	r11, VCPU_MSR(r9)
 
 	b	hcall_real_cont
 
@@ -1142,7 +1193,7 @@ hcall_real_table:
 	.long	0		/* 0xd4 */
 	.long	0		/* 0xd8 */
 	.long	0		/* 0xdc */
-	.long	0		/* 0xe0 */
+	.long	.kvmppc_h_cede - hcall_real_table
 	.long	0		/* 0xe4 */
 	.long	0		/* 0xe8 */
 	.long	0		/* 0xec */
@@ -1171,7 +1222,8 @@ bounce_ext_interrupt:
 	mtspr	SPRN_SRR0,r10
 	mtspr	SPRN_SRR1,r11
 	li	r10,BOOK3S_INTERRUPT_EXTERNAL
-	LOAD_REG_IMMEDIATE(r11,MSR_SF | MSR_ME);
+	li	r11,(MSR_ME << 1) | 1	/* synthesize MSR_SF | MSR_ME */
+	rotldi	r11,r11,63
 	b	fast_guest_return
 
 _GLOBAL(kvmppc_h_set_dabr)
@@ -1180,6 +1232,178 @@ _GLOBAL(kvmppc_h_set_dabr)
 	li	r3,0
 	blr
 
+_GLOBAL(kvmppc_h_cede)
+	ori	r11,r11,MSR_EE
+	std	r11,VCPU_MSR(r3)
+	li	r0,1
+	stb	r0,VCPU_CEDED(r3)
+	sync			/* order setting ceded vs. testing prodded */
+	lbz	r5,VCPU_PRODDED(r3)
+	cmpwi	r5,0
+	bne	1f
+	li	r0,0		/* set trap to 0 to say hcall is handled */
+	stw	r0,VCPU_TRAP(r3)
+	li	r0,H_SUCCESS
+	std	r0,VCPU_GPR(r3)(r3)
+BEGIN_FTR_SECTION
+	b	2f		/* just send it up to host on 970 */
+END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
+
+	/*
+	 * Set our bit in the bitmask of napping threads unless all the
+	 * other threads are already napping, in which case we send this
+	 * up to the host.
+	 */
+	ld	r5,HSTATE_KVM_VCORE(r13)
+	lwz	r6,VCPU_PTID(r3)
+	lwz	r8,VCORE_ENTRY_EXIT(r5)
+	clrldi	r8,r8,56
+	li	r0,1
+	sld	r0,r0,r6
+	addi	r6,r5,VCORE_NAPPING_THREADS
+31:	lwarx	r4,0,r6
+	or	r4,r4,r0
+	popcntw	r7,r4
+	cmpw	r7,r8
+	bge	2f
+	stwcx.	r4,0,r6
+	bne	31b
+	li	r0,1
+	stb	r0,HSTATE_NAPPING(r13)
+	/* order napping_threads update vs testing entry_exit_count */
+	lwsync
+	mr	r4,r3
+	lwz	r7,VCORE_ENTRY_EXIT(r5)
+	cmpwi	r7,0x100
+	bge	33f		/* another thread already exiting */
+
+/*
+ * Although not specifically required by the architecture, POWER7
+ * preserves the following registers in nap mode, even if an SMT mode
+ * switch occurs: SLB entries, PURR, SPURR, AMOR, UAMOR, AMR, SPRG0-3,
+ * DAR, DSISR, DABR, DABRX, DSCR, PMCx, MMCRx, SIAR, SDAR.
+ */
+	/* Save non-volatile GPRs */
+	std	r14, VCPU_GPR(r14)(r3)
+	std	r15, VCPU_GPR(r15)(r3)
+	std	r16, VCPU_GPR(r16)(r3)
+	std	r17, VCPU_GPR(r17)(r3)
+	std	r18, VCPU_GPR(r18)(r3)
+	std	r19, VCPU_GPR(r19)(r3)
+	std	r20, VCPU_GPR(r20)(r3)
+	std	r21, VCPU_GPR(r21)(r3)
+	std	r22, VCPU_GPR(r22)(r3)
+	std	r23, VCPU_GPR(r23)(r3)
+	std	r24, VCPU_GPR(r24)(r3)
+	std	r25, VCPU_GPR(r25)(r3)
+	std	r26, VCPU_GPR(r26)(r3)
+	std	r27, VCPU_GPR(r27)(r3)
+	std	r28, VCPU_GPR(r28)(r3)
+	std	r29, VCPU_GPR(r29)(r3)
+	std	r30, VCPU_GPR(r30)(r3)
+	std	r31, VCPU_GPR(r31)(r3)
+
+	/* save FP state */
+	bl	.kvmppc_save_fp
+
+	/*
+	 * Take a nap until a decrementer or external interrupt occurs,
+	 * with PECE1 (wake on decr) and PECE0 (wake on external) set in LPCR
+	 */
+	li	r0,0x80
+	stb	r0,PACAPROCSTART(r13)
+	mfspr	r5,SPRN_LPCR
+	ori	r5,r5,LPCR_PECE0 | LPCR_PECE1
+	mtspr	SPRN_LPCR,r5
+	isync
+	li	r0, 0
+	std	r0, HSTATE_SCRATCH0(r13)
+	ptesync
+	ld	r0, HSTATE_SCRATCH0(r13)
+1:	cmpd	r0, r0
+	bne	1b
+	nap
+	b	.
+
+kvm_end_cede:
+	/* Woken by external or decrementer interrupt */
+	ld	r1, HSTATE_HOST_R1(r13)
+	ld	r2, PACATOC(r13)
+
+	/* If we're a secondary thread and we got here by an IPI, ack it */
+	ld	r4,HSTATE_KVM_VCPU(r13)
+	lwz	r3,VCPU_PTID(r4)
+	cmpwi	r3,0
+	beq	27f
+	mfspr	r3,SPRN_SRR1
+	rlwinm	r3,r3,44-31,0x7		/* extract wake reason field */
+	cmpwi	r3,4			/* was it an external interrupt? */
+	bne	27f
+	ld	r5, HSTATE_XICS_PHYS(r13)
+	li	r0,0xff
+	li	r6,XICS_QIRR
+	li	r7,XICS_XIRR
+	lwzcix	r8,r5,r7		/* ack the interrupt */
+	sync
+	stbcix	r0,r5,r6		/* clear it */
+	stwcix	r8,r5,r7		/* EOI it */
+27:
+	/* load up FP state */
+	bl	kvmppc_load_fp
+
+	/* Load NV GPRS */
+	ld	r14, VCPU_GPR(r14)(r4)
+	ld	r15, VCPU_GPR(r15)(r4)
+	ld	r16, VCPU_GPR(r16)(r4)
+	ld	r17, VCPU_GPR(r17)(r4)
+	ld	r18, VCPU_GPR(r18)(r4)
+	ld	r19, VCPU_GPR(r19)(r4)
+	ld	r20, VCPU_GPR(r20)(r4)
+	ld	r21, VCPU_GPR(r21)(r4)
+	ld	r22, VCPU_GPR(r22)(r4)
+	ld	r23, VCPU_GPR(r23)(r4)
+	ld	r24, VCPU_GPR(r24)(r4)
+	ld	r25, VCPU_GPR(r25)(r4)
+	ld	r26, VCPU_GPR(r26)(r4)
+	ld	r27, VCPU_GPR(r27)(r4)
+	ld	r28, VCPU_GPR(r28)(r4)
+	ld	r29, VCPU_GPR(r29)(r4)
+	ld	r30, VCPU_GPR(r30)(r4)
+	ld	r31, VCPU_GPR(r31)(r4)
+
+	/* clear our bit in vcore->napping_threads */
+33:	ld	r5,HSTATE_KVM_VCORE(r13)
+	lwz	r3,VCPU_PTID(r4)
+	li	r0,1
+	sld	r0,r0,r3
+	addi	r6,r5,VCORE_NAPPING_THREADS
+32:	lwarx	r7,0,r6
+	andc	r7,r7,r0
+	stwcx.	r7,0,r6
+	bne	32b
+	li	r0,0
+	stb	r0,HSTATE_NAPPING(r13)
+
+	/* see if any other thread is already exiting */
+	lwz	r0,VCORE_ENTRY_EXIT(r5)
+	cmpwi	r0,0x100
+	blt	kvmppc_cede_reentry	/* if not go back to guest */
+
+	/* some threads are exiting, so go to the guest exit path */
+	b	hcall_real_fallback
+
+	/* cede when already previously prodded case */
+1:	li	r0,0
+	stb	r0,VCPU_PRODDED(r3)
+	sync			/* order testing prodded vs. clearing ceded */
+	stb	r0,VCPU_CEDED(r3)
+	li	r3,H_SUCCESS
+	blr
+
+	/* we've ceded but we want to give control to the host */
+2:	li	r3,H_TOO_HARD
+	blr
+
 secondary_too_late:
 	ld	r5,HSTATE_KVM_VCORE(r13)
 	HMT_LOW
@@ -1197,14 +1421,20 @@ secondary_too_late:
 	slbmte	r6,r5
 1:	addi	r11,r11,16
 	.endr
-	b	50f
 
 secondary_nap:
-	/* Clear any pending IPI */
-50:	ld	r5, HSTATE_XICS_PHYS(r13)
+	/* Clear any pending IPI - assume we're a secondary thread */
+	ld	r5, HSTATE_XICS_PHYS(r13)
+	li	r7, XICS_XIRR
+	lwzcix	r3, r5, r7		/* ack any pending interrupt */
+	rlwinm.	r0, r3, 0, 0xffffff	/* any pending? */
+	beq	37f
+	sync
 	li	r0, 0xff
 	li	r6, XICS_QIRR
-	stbcix	r0, r5, r6
+	stbcix	r0, r5, r6		/* clear the IPI */
+	stwcix	r3, r5, r7		/* EOI it */
+37:	sync
 
 	/* increment the nap count and then go to nap mode */
 	ld	r4, HSTATE_KVM_VCORE(r13)
@@ -1214,13 +1444,12 @@ secondary_nap:
 	addi	r3, r3, 1
 	stwcx.	r3, 0, r4
 	bne	51b
-	isync
 
+	li	r3, LPCR_PECE0
 	mfspr	r4, SPRN_LPCR
-	li	r0, LPCR_PECE
-	andc	r4, r4, r0
-	ori	r4, r4, LPCR_PECE0	/* exit nap on interrupt */
+	rlwimi	r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
 	mtspr	SPRN_LPCR, r4
+	isync
 	li	r0, 0
 	std	r0, HSTATE_SCRATCH0(r13)
 	ptesync
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index a107c9b..cd0e3e5 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -39,12 +39,8 @@
 
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
-#ifndef CONFIG_KVM_BOOK3S_64_HV
 	return !(v->arch.shared->msr & MSR_WE) ||
 	       !!(v->arch.pending_exceptions);
-#else
-	return !(v->arch.ceded) || !!(v->arch.pending_exceptions);
-#endif
 }
 
 int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
@@ -258,6 +254,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 {
 	struct kvm_vcpu *vcpu;
 	vcpu = kvmppc_core_vcpu_create(kvm, id);
+	vcpu->arch.wqp = &vcpu->wq;
 	if (!IS_ERR(vcpu))
 		kvmppc_create_vcpu_debugfs(vcpu, id);
 	return vcpu;
@@ -289,8 +286,8 @@ static void kvmppc_decrementer_func(unsigned long data)
 
 	kvmppc_core_queue_dec(vcpu);
 
-	if (waitqueue_active(&vcpu->wq)) {
-		wake_up_interruptible(&vcpu->wq);
+	if (waitqueue_active(vcpu->arch.wqp)) {
+		wake_up_interruptible(vcpu->arch.wqp);
 		vcpu->stat.halt_wakeup++;
 	}
 }
@@ -543,13 +540,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
 {
-	if (irq->irq = KVM_INTERRUPT_UNSET)
+	if (irq->irq = KVM_INTERRUPT_UNSET) {
 		kvmppc_core_dequeue_external(vcpu, irq);
-	else
-		kvmppc_core_queue_external(vcpu, irq);
+		return 0;
+	}
+
+	kvmppc_core_queue_external(vcpu, irq);
 
-	if (waitqueue_active(&vcpu->wq)) {
-		wake_up_interruptible(&vcpu->wq);
+	if (waitqueue_active(vcpu->arch.wqp)) {
+		wake_up_interruptible(vcpu->arch.wqp);
 		vcpu->stat.halt_wakeup++;
 	} else if (vcpu->cpu != -1) {
 		smp_send_reschedule(vcpu->cpu);
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] KVM: PPC: Assemble book3s{, _hv}_rmhandlers.S separately
  2011-07-23  7:41 ` Paul Mackerras
@ 2011-08-02 12:20   ` Alexander Graf
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexander Graf @ 2011-08-02 12:20 UTC (permalink / raw)
  To: Paul Mackerras; +Cc: linuxppc-dev, kvm-ppc

On 07/23/2011 09:41 AM, Paul Mackerras wrote:
> This makes arch/powerpc/kvm/book3s_rmhandlers.S and
> arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
> separate compilation units rather than having them #included in
> arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
> conditional branches between the exception prologs in
> exceptions-64s.S and the KVM handlers, so there is no need to
> keep their contents close together in the vmlinux image.
>
> In their current location, they are using up part of the limited
> space between the first-level interrupt handlers and the firmware
> NMI data area at offset 0x7000, and with some kernel configurations
> this area will overflow (e.g. allyesconfig), leading to an
> "attempt to .org backwards" error when compiling exceptions-64s.S.
>
> Moving them out requires that we add some #includes that the
> book3s_{,hv_}rmhandlers.S code was previously getting implicitly
> via exceptions-64s.S.

So what if your kernel binary is bigger than the 24 bits we can jump and 
the KVM code happens to be at the end? Or do we just not care here?


Alex

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately
@ 2011-08-02 12:20   ` Alexander Graf
  0 siblings, 0 replies; 16+ messages in thread
From: Alexander Graf @ 2011-08-02 12:20 UTC (permalink / raw)
  To: Paul Mackerras; +Cc: linuxppc-dev, kvm-ppc

On 07/23/2011 09:41 AM, Paul Mackerras wrote:
> This makes arch/powerpc/kvm/book3s_rmhandlers.S and
> arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
> separate compilation units rather than having them #included in
> arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
> conditional branches between the exception prologs in
> exceptions-64s.S and the KVM handlers, so there is no need to
> keep their contents close together in the vmlinux image.
>
> In their current location, they are using up part of the limited
> space between the first-level interrupt handlers and the firmware
> NMI data area at offset 0x7000, and with some kernel configurations
> this area will overflow (e.g. allyesconfig), leading to an
> "attempt to .org backwards" error when compiling exceptions-64s.S.
>
> Moving them out requires that we add some #includes that the
> book3s_{,hv_}rmhandlers.S code was previously getting implicitly
> via exceptions-64s.S.

So what if your kernel binary is bigger than the 24 bits we can jump and 
the KVM code happens to be at the end? Or do we just not care here?


Alex


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code
  2011-07-23  7:42   ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in Paul Mackerras
@ 2011-08-02 14:47     ` Alexander Graf
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexander Graf @ 2011-08-02 14:47 UTC (permalink / raw)
  To: Paul Mackerras; +Cc: linuxppc-dev, kvm-ppc

On 07/23/2011 09:42 AM, Paul Mackerras wrote:
> With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per
> core), whenever a CPU goes idle, we have to pull all the other
> hardware threads in the core out of the guest, because the H_CEDE
> hcall is handled in the kernel.  This is inefficient.
>
> This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall
> in real mode.  When a guest vcpu does an H_CEDE hcall, we now only
> exit to the kernel if all the other vcpus in the same core are also
> idle.  Otherwise we mark this vcpu as napping, save state that could
> be lost in nap mode (mainly GPRs and FPRs), and execute the nap
> instruction.  When the thread wakes up, because of a decrementer or
> external interrupt, we come back in at kvm_start_guest (from the
> system reset interrupt vector), find the `napping' flag set in the
> paca, and go to the resume path.
>
> This has some other ramifications.  First, when starting a core, we
> now start all the threads, both those that are immediately runnable and
> those that are idle.  This is so that we don't have to pull all the
> threads out of the guest when an idle thread gets a decrementer interrupt
> and wants to start running.  In fact the idle threads will all start
> with the H_CEDE hcall returning; being idle they will just do another
> H_CEDE immediately and go to nap mode.
>
> This required some changes to kvmppc_run_core() and kvmppc_run_vcpu().
> These functions have been restructured to make them simpler and clearer.
> We introduce a level of indirection in the wait queue that gets woken
> when external and decrementer interrupts get generated for a vcpu, so
> that we can have the 4 vcpus in a vcore using the same wait queue.
> We need this because the 4 vcpus are being handled by one thread.
>
> Secondly, when we need to exit from the guest to the kernel, we now
> have to generate an IPI for any napping threads, because an HDEC
> interrupt doesn't wake up a napping thread.
>
> Thirdly, we now need to be able to handle virtual external interrupts
> and decrementer interrupts becoming pending while a thread is napping,
> and deliver those interrupts to the guest when the thread wakes.
> This is done in kvmppc_cede_reentry, just before fast_guest_return.
>
> Finally, since we are not using the generic kvm_vcpu_block for book3s_hv,
> and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef
> from kvm_arch_vcpu_runnable.
>
> Signed-off-by: Paul Mackerras<paulus@samba.org>
> ---
>   arch/powerpc/include/asm/kvm_book3s_asm.h |    1 +
>   arch/powerpc/include/asm/kvm_host.h       |   19 ++-
>   arch/powerpc/kernel/asm-offsets.c         |    6 +
>   arch/powerpc/kvm/book3s_hv.c              |  335 ++++++++++++++++-------------
>   arch/powerpc/kvm/book3s_hv_rmhandlers.S   |  297 ++++++++++++++++++++++---
>   arch/powerpc/kvm/powerpc.c                |   21 +-
>   6 files changed, 483 insertions(+), 196 deletions(-)
>
>

[...]

> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index a107c9b..cd0e3e5 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -39,12 +39,8 @@
>
>   int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
>   {
> -#ifndef CONFIG_KVM_BOOK3S_64_HV
>   	return !(v->arch.shared->msr&  MSR_WE) ||
>   	       !!(v->arch.pending_exceptions);
> -#else
> -	return !(v->arch.ceded) || !!(v->arch.pending_exceptions);
> -#endif
>   }
>
>   int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
> @@ -258,6 +254,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
>   {
>   	struct kvm_vcpu *vcpu;
>   	vcpu = kvmppc_core_vcpu_create(kvm, id);
> +	vcpu->arch.wqp =&vcpu->wq;
>   	if (!IS_ERR(vcpu))
>   		kvmppc_create_vcpu_debugfs(vcpu, id);
>   	return vcpu;
> @@ -289,8 +286,8 @@ static void kvmppc_decrementer_func(unsigned long data)
>
>   	kvmppc_core_queue_dec(vcpu);
>
> -	if (waitqueue_active(&vcpu->wq)) {
> -		wake_up_interruptible(&vcpu->wq);
> +	if (waitqueue_active(vcpu->arch.wqp)) {
> +		wake_up_interruptible(vcpu->arch.wqp);
>   		vcpu->stat.halt_wakeup++;
>   	}
>   }
> @@ -543,13 +540,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>
>   int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
>   {
> -	if (irq->irq == KVM_INTERRUPT_UNSET)
> +	if (irq->irq == KVM_INTERRUPT_UNSET) {
>   		kvmppc_core_dequeue_external(vcpu, irq);
> -	else
> -		kvmppc_core_queue_external(vcpu, irq);
> +		return 0;
> +	}

Not sure I understand this part. Mind to explain?

Alex

> +
> +	kvmppc_core_queue_external(vcpu, irq);
>
> -	if (waitqueue_active(&vcpu->wq)) {
> -		wake_up_interruptible(&vcpu->wq);
> +	if (waitqueue_active(vcpu->arch.wqp)) {
> +		wake_up_interruptible(vcpu->arch.wqp);
>   		vcpu->stat.halt_wakeup++;
>   	} else if (vcpu->cpu != -1) {
>   		smp_send_reschedule(vcpu->cpu);

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in
@ 2011-08-02 14:47     ` Alexander Graf
  0 siblings, 0 replies; 16+ messages in thread
From: Alexander Graf @ 2011-08-02 14:47 UTC (permalink / raw)
  To: Paul Mackerras; +Cc: linuxppc-dev, kvm-ppc

On 07/23/2011 09:42 AM, Paul Mackerras wrote:
> With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per
> core), whenever a CPU goes idle, we have to pull all the other
> hardware threads in the core out of the guest, because the H_CEDE
> hcall is handled in the kernel.  This is inefficient.
>
> This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall
> in real mode.  When a guest vcpu does an H_CEDE hcall, we now only
> exit to the kernel if all the other vcpus in the same core are also
> idle.  Otherwise we mark this vcpu as napping, save state that could
> be lost in nap mode (mainly GPRs and FPRs), and execute the nap
> instruction.  When the thread wakes up, because of a decrementer or
> external interrupt, we come back in at kvm_start_guest (from the
> system reset interrupt vector), find the `napping' flag set in the
> paca, and go to the resume path.
>
> This has some other ramifications.  First, when starting a core, we
> now start all the threads, both those that are immediately runnable and
> those that are idle.  This is so that we don't have to pull all the
> threads out of the guest when an idle thread gets a decrementer interrupt
> and wants to start running.  In fact the idle threads will all start
> with the H_CEDE hcall returning; being idle they will just do another
> H_CEDE immediately and go to nap mode.
>
> This required some changes to kvmppc_run_core() and kvmppc_run_vcpu().
> These functions have been restructured to make them simpler and clearer.
> We introduce a level of indirection in the wait queue that gets woken
> when external and decrementer interrupts get generated for a vcpu, so
> that we can have the 4 vcpus in a vcore using the same wait queue.
> We need this because the 4 vcpus are being handled by one thread.
>
> Secondly, when we need to exit from the guest to the kernel, we now
> have to generate an IPI for any napping threads, because an HDEC
> interrupt doesn't wake up a napping thread.
>
> Thirdly, we now need to be able to handle virtual external interrupts
> and decrementer interrupts becoming pending while a thread is napping,
> and deliver those interrupts to the guest when the thread wakes.
> This is done in kvmppc_cede_reentry, just before fast_guest_return.
>
> Finally, since we are not using the generic kvm_vcpu_block for book3s_hv,
> and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef
> from kvm_arch_vcpu_runnable.
>
> Signed-off-by: Paul Mackerras<paulus@samba.org>
> ---
>   arch/powerpc/include/asm/kvm_book3s_asm.h |    1 +
>   arch/powerpc/include/asm/kvm_host.h       |   19 ++-
>   arch/powerpc/kernel/asm-offsets.c         |    6 +
>   arch/powerpc/kvm/book3s_hv.c              |  335 ++++++++++++++++-------------
>   arch/powerpc/kvm/book3s_hv_rmhandlers.S   |  297 ++++++++++++++++++++++---
>   arch/powerpc/kvm/powerpc.c                |   21 +-
>   6 files changed, 483 insertions(+), 196 deletions(-)
>
>

[...]

> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index a107c9b..cd0e3e5 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -39,12 +39,8 @@
>
>   int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
>   {
> -#ifndef CONFIG_KVM_BOOK3S_64_HV
>   	return !(v->arch.shared->msr&  MSR_WE) ||
>   	       !!(v->arch.pending_exceptions);
> -#else
> -	return !(v->arch.ceded) || !!(v->arch.pending_exceptions);
> -#endif
>   }
>
>   int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
> @@ -258,6 +254,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
>   {
>   	struct kvm_vcpu *vcpu;
>   	vcpu = kvmppc_core_vcpu_create(kvm, id);
> +	vcpu->arch.wqp =&vcpu->wq;
>   	if (!IS_ERR(vcpu))
>   		kvmppc_create_vcpu_debugfs(vcpu, id);
>   	return vcpu;
> @@ -289,8 +286,8 @@ static void kvmppc_decrementer_func(unsigned long data)
>
>   	kvmppc_core_queue_dec(vcpu);
>
> -	if (waitqueue_active(&vcpu->wq)) {
> -		wake_up_interruptible(&vcpu->wq);
> +	if (waitqueue_active(vcpu->arch.wqp)) {
> +		wake_up_interruptible(vcpu->arch.wqp);
>   		vcpu->stat.halt_wakeup++;
>   	}
>   }
> @@ -543,13 +540,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>
>   int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
>   {
> -	if (irq->irq = KVM_INTERRUPT_UNSET)
> +	if (irq->irq = KVM_INTERRUPT_UNSET) {
>   		kvmppc_core_dequeue_external(vcpu, irq);
> -	else
> -		kvmppc_core_queue_external(vcpu, irq);
> +		return 0;
> +	}

Not sure I understand this part. Mind to explain?

Alex

> +
> +	kvmppc_core_queue_external(vcpu, irq);
>
> -	if (waitqueue_active(&vcpu->wq)) {
> -		wake_up_interruptible(&vcpu->wq);
> +	if (waitqueue_active(vcpu->arch.wqp)) {
> +		wake_up_interruptible(vcpu->arch.wqp);
>   		vcpu->stat.halt_wakeup++;
>   	} else if (vcpu->cpu != -1) {
>   		smp_send_reschedule(vcpu->cpu);


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code
  2011-08-02 14:47     ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in Alexander Graf
@ 2011-08-03  3:31       ` Paul Mackerras
  -1 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-08-03  3:31 UTC (permalink / raw)
  To: Alexander Graf; +Cc: linuxppc-dev, kvm-ppc

On Tue, Aug 02, 2011 at 04:47:08PM +0200, Alexander Graf wrote:

> >  int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
> >  {
> >-	if (irq->irq == KVM_INTERRUPT_UNSET)
> >+	if (irq->irq == KVM_INTERRUPT_UNSET) {
> >  		kvmppc_core_dequeue_external(vcpu, irq);
> >-	else
> >-		kvmppc_core_queue_external(vcpu, irq);
> >+		return 0;
> >+	}
> 
> Not sure I understand this part. Mind to explain?

It's a micro-optimization - we don't really need to wake up or
interrupt the vcpu thread when we're clearing the interrupt.
Unless of course I'm missing something... :)

> 
> Alex
> 
> >+
> >+	kvmppc_core_queue_external(vcpu, irq);
> >
> >-	if (waitqueue_active(&vcpu->wq)) {
> >-		wake_up_interruptible(&vcpu->wq);
> >+	if (waitqueue_active(vcpu->arch.wqp)) {
> >+		wake_up_interruptible(vcpu->arch.wqp);
> >  		vcpu->stat.halt_wakeup++;
> >  	} else if (vcpu->cpu != -1) {
> >  		smp_send_reschedule(vcpu->cpu);

Paul.

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in
@ 2011-08-03  3:31       ` Paul Mackerras
  0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-08-03  3:31 UTC (permalink / raw)
  To: Alexander Graf; +Cc: linuxppc-dev, kvm-ppc

On Tue, Aug 02, 2011 at 04:47:08PM +0200, Alexander Graf wrote:

> >  int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
> >  {
> >-	if (irq->irq = KVM_INTERRUPT_UNSET)
> >+	if (irq->irq = KVM_INTERRUPT_UNSET) {
> >  		kvmppc_core_dequeue_external(vcpu, irq);
> >-	else
> >-		kvmppc_core_queue_external(vcpu, irq);
> >+		return 0;
> >+	}
> 
> Not sure I understand this part. Mind to explain?

It's a micro-optimization - we don't really need to wake up or
interrupt the vcpu thread when we're clearing the interrupt.
Unless of course I'm missing something... :)

> 
> Alex
> 
> >+
> >+	kvmppc_core_queue_external(vcpu, irq);
> >
> >-	if (waitqueue_active(&vcpu->wq)) {
> >-		wake_up_interruptible(&vcpu->wq);
> >+	if (waitqueue_active(vcpu->arch.wqp)) {
> >+		wake_up_interruptible(vcpu->arch.wqp);
> >  		vcpu->stat.halt_wakeup++;
> >  	} else if (vcpu->cpu != -1) {
> >  		smp_send_reschedule(vcpu->cpu);

Paul.

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately
  2011-08-02 12:20   ` [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately Alexander Graf
@ 2011-08-10 23:58     ` Paul Mackerras
  -1 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-08-10 23:58 UTC (permalink / raw)
  To: Alexander Graf; +Cc: linuxppc-dev, kvm-ppc

On Tue, Aug 02, 2011 at 02:20:28PM +0200, Alexander Graf wrote:
> On 07/23/2011 09:41 AM, Paul Mackerras wrote:
> >This makes arch/powerpc/kvm/book3s_rmhandlers.S and
> >arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
> >separate compilation units rather than having them #included in
> >arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
> >conditional branches between the exception prologs in
> >exceptions-64s.S and the KVM handlers, so there is no need to
> >keep their contents close together in the vmlinux image.
> >
> >In their current location, they are using up part of the limited
> >space between the first-level interrupt handlers and the firmware
> >NMI data area at offset 0x7000, and with some kernel configurations
> >this area will overflow (e.g. allyesconfig), leading to an
> >"attempt to .org backwards" error when compiling exceptions-64s.S.
> >
> >Moving them out requires that we add some #includes that the
> >book3s_{,hv_}rmhandlers.S code was previously getting implicitly
> >via exceptions-64s.S.
> 
> So what if your kernel binary is bigger than the 24 bits we can jump
> and the KVM code happens to be at the end? Or do we just not care
> here?

Actually we can jump +/- 32MB (26 bits).  I believe that the linker
inserts trampolines if the branch target is more than 32MB away, so it
should still work if the kernel is really large and the KVM code
happens to be at the end.

Stephen Rothwell has been asking me about this patch.  He wants it in
(or something like it) so that he can get his daily linux-next powerpc
allyesconfig builds to stop failing.

Paul.

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S
@ 2011-08-10 23:58     ` Paul Mackerras
  0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2011-08-10 23:58 UTC (permalink / raw)
  To: Alexander Graf; +Cc: linuxppc-dev, kvm-ppc

On Tue, Aug 02, 2011 at 02:20:28PM +0200, Alexander Graf wrote:
> On 07/23/2011 09:41 AM, Paul Mackerras wrote:
> >This makes arch/powerpc/kvm/book3s_rmhandlers.S and
> >arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
> >separate compilation units rather than having them #included in
> >arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
> >conditional branches between the exception prologs in
> >exceptions-64s.S and the KVM handlers, so there is no need to
> >keep their contents close together in the vmlinux image.
> >
> >In their current location, they are using up part of the limited
> >space between the first-level interrupt handlers and the firmware
> >NMI data area at offset 0x7000, and with some kernel configurations
> >this area will overflow (e.g. allyesconfig), leading to an
> >"attempt to .org backwards" error when compiling exceptions-64s.S.
> >
> >Moving them out requires that we add some #includes that the
> >book3s_{,hv_}rmhandlers.S code was previously getting implicitly
> >via exceptions-64s.S.
> 
> So what if your kernel binary is bigger than the 24 bits we can jump
> and the KVM code happens to be at the end? Or do we just not care
> here?

Actually we can jump +/- 32MB (26 bits).  I believe that the linker
inserts trampolines if the branch target is more than 32MB away, so it
should still work if the kernel is really large and the KVM code
happens to be at the end.

Stephen Rothwell has been asking me about this patch.  He wants it in
(or something like it) so that he can get his daily linux-next powerpc
allyesconfig builds to stop failing.

Paul.

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] KVM: PPC: Assemble book3s{, _hv}_rmhandlers.S separately
  2011-08-10 23:58     ` [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S Paul Mackerras
@ 2011-08-11  1:00       ` Alexander Graf
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexander Graf @ 2011-08-11  1:00 UTC (permalink / raw)
  To: Paul Mackerras; +Cc: linuxppc-dev, kvm-ppc





Am 11.08.2011 um 01:58 schrieb Paul Mackerras <paulus@samba.org>:

> On Tue, Aug 02, 2011 at 02:20:28PM +0200, Alexander Graf wrote:
>> On 07/23/2011 09:41 AM, Paul Mackerras wrote:
>>> This makes arch/powerpc/kvm/book3s_rmhandlers.S and
>>> arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
>>> separate compilation units rather than having them #included in
>>> arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
>>> conditional branches between the exception prologs in
>>> exceptions-64s.S and the KVM handlers, so there is no need to
>>> keep their contents close together in the vmlinux image.
>>>=20
>>> In their current location, they are using up part of the limited
>>> space between the first-level interrupt handlers and the firmware
>>> NMI data area at offset 0x7000, and with some kernel configurations
>>> this area will overflow (e.g. allyesconfig), leading to an
>>> "attempt to .org backwards" error when compiling exceptions-64s.S.
>>>=20
>>> Moving them out requires that we add some #includes that the
>>> book3s_{,hv_}rmhandlers.S code was previously getting implicitly
>>> via exceptions-64s.S.
>>=20
>> So what if your kernel binary is bigger than the 24 bits we can jump
>> and the KVM code happens to be at the end? Or do we just not care
>> here?
>=20
> Actually we can jump +/- 32MB (26 bits).  I believe that the linker
> inserts trampolines if the branch target is more than 32MB away, so it
> should still work if the kernel is really large and the KVM code
> happens to be at the end.
>=20
> Stephen Rothwell has been asking me about this patch.  He wants it in
> (or something like it) so that he can get his daily linux-next powerpc
> allyesconfig builds to stop failing.

Yup, currently running autotest with this and other patches applied. Will se=
nd out a pullreq soon.


Alex

>=20
> Paul.
> --
> To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately
@ 2011-08-11  1:00       ` Alexander Graf
  0 siblings, 0 replies; 16+ messages in thread
From: Alexander Graf @ 2011-08-11  1:00 UTC (permalink / raw)
  To: Paul Mackerras; +Cc: linuxppc-dev, kvm-ppc





Am 11.08.2011 um 01:58 schrieb Paul Mackerras <paulus@samba.org>:

> On Tue, Aug 02, 2011 at 02:20:28PM +0200, Alexander Graf wrote:
>> On 07/23/2011 09:41 AM, Paul Mackerras wrote:
>>> This makes arch/powerpc/kvm/book3s_rmhandlers.S and
>>> arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
>>> separate compilation units rather than having them #included in
>>> arch/powerpc/kernel/exceptions-64s.S.  We no longer have any
>>> conditional branches between the exception prologs in
>>> exceptions-64s.S and the KVM handlers, so there is no need to
>>> keep their contents close together in the vmlinux image.
>>> 
>>> In their current location, they are using up part of the limited
>>> space between the first-level interrupt handlers and the firmware
>>> NMI data area at offset 0x7000, and with some kernel configurations
>>> this area will overflow (e.g. allyesconfig), leading to an
>>> "attempt to .org backwards" error when compiling exceptions-64s.S.
>>> 
>>> Moving them out requires that we add some #includes that the
>>> book3s_{,hv_}rmhandlers.S code was previously getting implicitly
>>> via exceptions-64s.S.
>> 
>> So what if your kernel binary is bigger than the 24 bits we can jump
>> and the KVM code happens to be at the end? Or do we just not care
>> here?
> 
> Actually we can jump +/- 32MB (26 bits).  I believe that the linker
> inserts trampolines if the branch target is more than 32MB away, so it
> should still work if the kernel is really large and the KVM code
> happens to be at the end.
> 
> Stephen Rothwell has been asking me about this patch.  He wants it in
> (or something like it) so that he can get his daily linux-next powerpc
> allyesconfig builds to stop failing.

Yup, currently running autotest with this and other patches applied. Will send out a pullreq soon.


Alex

> 
> Paul.
> --
> To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 16+ messages in thread

end of thread, other threads:[~2011-08-11  1:00 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-07-23  7:41 [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately Paul Mackerras
2011-07-23  7:41 ` Paul Mackerras
2011-07-23  7:41 ` [PATCH 2/3] KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode Paul Mackerras
2011-07-23  7:41   ` [PATCH 2/3] KVM: PPC: book3s_pr: Simplify transitions between Paul Mackerras
2011-07-23  7:42 ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code Paul Mackerras
2011-07-23  7:42   ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in Paul Mackerras
2011-08-02 14:47   ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code Alexander Graf
2011-08-02 14:47     ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in Alexander Graf
2011-08-03  3:31     ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code Paul Mackerras
2011-08-03  3:31       ` [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in Paul Mackerras
2011-08-02 12:20 ` [PATCH 1/3] KVM: PPC: Assemble book3s{, _hv}_rmhandlers.S separately Alexander Graf
2011-08-02 12:20   ` [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately Alexander Graf
2011-08-10 23:58   ` Paul Mackerras
2011-08-10 23:58     ` [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S Paul Mackerras
2011-08-11  1:00     ` [PATCH 1/3] KVM: PPC: Assemble book3s{, _hv}_rmhandlers.S separately Alexander Graf
2011-08-11  1:00       ` [PATCH 1/3] KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately Alexander Graf

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