[v2] kvm: ppc: bookehv: Save restore SPRN_SPRG9 on guest entry exit

Commit Message

Bharat Bhushan July 21, 2014, 5:53 a.m. UTC

SPRN_SPRG is used by debug interrupt handler, so this is required for
debug support.

Signed-off-by: Bharat Bhushan <[e-mail]>
---
v1->v2
 - sprng9 is 64bit, not 32bit

 arch/powerpc/include/asm/kvm_host.h   | 1 +
 arch/powerpc/kernel/asm-offsets.c     | 1 +
 arch/powerpc/kvm/bookehv_interrupts.S | 4 ++++
 3 files changed, 6 insertions(+)

Comments

Alexander Graf July 24, 2014, 1:16 p.m. UTC | #1

On 21.07.14 07:53, Bharat Bhushan wrote:
> SPRN_SPRG is used by debug interrupt handler, so this is required for
> debug support.
>
> Signed-off-by: Bharat Bhushan <[e-mail]>
> ---
> v1->v2
>   - sprng9 is 64bit, not 32bit

Looks very reasonable, but is missing a ONE_REG interface to make the 
register available to user space.


Alex

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Patch

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 372b977..b3e370c 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -588,6 +588,7 @@  struct kvm_vcpu_arch {
 	u32 mmucfg;
 	u32 eptcfg;
 	u32 epr;
+	u64 sprg9;
 	u32 pwrmgtcr0;
 	u32 crit_save;
 	/* guest debug registers*/
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 17ffcb4..ab9ae04 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -668,6 +668,7 @@  int main(void)
 	DEFINE(VCPU_LR, offsetof(struct kvm_vcpu, arch.lr));
 	DEFINE(VCPU_CTR, offsetof(struct kvm_vcpu, arch.ctr));
 	DEFINE(VCPU_PC, offsetof(struct kvm_vcpu, arch.pc));
+	DEFINE(VCPU_SPRG9, offsetof(struct kvm_vcpu, arch.sprg9));
 	DEFINE(VCPU_LAST_INST, offsetof(struct kvm_vcpu, arch.last_inst));
 	DEFINE(VCPU_FAULT_DEAR, offsetof(struct kvm_vcpu, arch.fault_dear));
 	DEFINE(VCPU_FAULT_ESR, offsetof(struct kvm_vcpu, arch.fault_esr));
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index a1712b8..f45da85 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -441,6 +441,7 @@  _GLOBAL(kvmppc_resume_host)
 #ifdef CONFIG_64BIT
 	PPC_LL	r3, PACA_SPRG_VDSO(r13)
 #endif
+	mfspr	r5, SPRN_SPRG9
 	PPC_STD(r6, VCPU_SHARED_SPRG4, r11)
 	mfspr	r8, SPRN_SPRG6
 	PPC_STD(r7, VCPU_SHARED_SPRG5, r11)
@@ -448,6 +449,7 @@  _GLOBAL(kvmppc_resume_host)
 #ifdef CONFIG_64BIT
 	mtspr	SPRN_SPRG_VDSO_WRITE, r3
 #endif
+	PPC_STD(r5, VCPU_SPRG9, r4)
 	PPC_STD(r8, VCPU_SHARED_SPRG6, r11)
 	mfxer	r3
 	PPC_STD(r9, VCPU_SHARED_SPRG7, r11)
@@ -682,7 +684,9 @@  lightweight_exit:
 	mtspr	SPRN_SPRG5W, r6
 	PPC_LD(r8, VCPU_SHARED_SPRG7, r11)
 	mtspr	SPRN_SPRG6W, r7
+	PPC_LD(r5, VCPU_SPRG9, r4)
 	mtspr	SPRN_SPRG7W, r8
+	mtspr	SPRN_SPRG9, r5
 
 	/* Load some guest volatiles. */
 	PPC_LL	r3, VCPU_LR(r4)