On 11.07.2013, at 12:51, Paul Mackerras wrote:
> Currently HV-style KVM does not save and restore the SIAR and SDAR
> registers in the PMU (performance monitor unit) on guest entry and
> exit. The result is that performance monitoring tools in the guest
> could get false information about where a program was executing and
> what data it was accessing at the time of a performance monitor
> interrupt. This fixes it by saving and restoring these registers
> along with the other PMU registers on guest entry/exit.
>
> This also provides a way for userspace to access these values for a
> vcpu via the one_reg interface. There is a gap between the values for
> MMCRA and SIAR in order to leave room for two more MMCR registers
> that exist on POWER8.
Can we add the ONE_REG defines for those right away in a prepending patch? No need for the implementation yet if that requires additional work that needs to go through Ben.
>
> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
> ---
> This is against Alex Graf's kvm-ppc-queue branch.
>
> arch/powerpc/include/asm/kvm_host.h | 2 ++
> arch/powerpc/include/uapi/asm/kvm.h | 2 ++
> arch/powerpc/kernel/asm-offsets.c | 2 ++
> arch/powerpc/kvm/book3s_hv.c | 12 ++++++++++++
> arch/powerpc/kvm/book3s_hv_rmhandlers.S | 8 ++++++++
> 5 files changed, 26 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index 3328353..91b833d 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -498,6 +498,8 @@ struct kvm_vcpu_arch {
>
> u64 mmcr[3];
> u32 pmc[8];
> + u64 siar;
> + u64 sdar;
>
> #ifdef CONFIG_KVM_EXIT_TIMING
> struct mutex exit_timing_lock;
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
> index 0fb1a6e..3cf47c8 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -429,6 +429,8 @@ struct kvm_get_htab_header {
> #define KVM_REG_PPC_MMCR0 (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x10)
> #define KVM_REG_PPC_MMCR1 (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x11)
> #define KVM_REG_PPC_MMCRA (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x12)
> +#define KVM_REG_PPC_SIAR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x15)
> +#define KVM_REG_PPC_SDAR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x16)
These are missing entries in Documentation/virtual/kvm/api.txt :).
Otherwise looks good.
Alex
>
> #define KVM_REG_PPC_PMC1 (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x18)
> #define KVM_REG_PPC_PMC2 (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x19)
> diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
> index 6f16ffa..ad66058 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -505,6 +505,8 @@ int main(void)
> DEFINE(VCPU_PRODDED, offsetof(struct kvm_vcpu, arch.prodded));
> DEFINE(VCPU_MMCR, offsetof(struct kvm_vcpu, arch.mmcr));
> DEFINE(VCPU_PMC, offsetof(struct kvm_vcpu, arch.pmc));
> + DEFINE(VCPU_SIAR, offsetof(struct kvm_vcpu, arch.siar));
> + DEFINE(VCPU_SDAR, offsetof(struct kvm_vcpu, arch.sdar));
> DEFINE(VCPU_SLB, offsetof(struct kvm_vcpu, arch.slb));
> DEFINE(VCPU_SLB_MAX, offsetof(struct kvm_vcpu, arch.slb_max));
> DEFINE(VCPU_SLB_NR, offsetof(struct kvm_vcpu, arch.slb_nr));
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 2b95c45..ee2352a 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -750,6 +750,12 @@ int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
> i = id - KVM_REG_PPC_PMC1;
> *val = get_reg_val(id, vcpu->arch.pmc[i]);
> break;
> + case KVM_REG_PPC_SIAR:
> + *val = get_reg_val(id, vcpu->arch.siar);
> + break;
> + case KVM_REG_PPC_SDAR:
> + *val = get_reg_val(id, vcpu->arch.sdar);
> + break;
> #ifdef CONFIG_VSX
> case KVM_REG_PPC_FPR0 ... KVM_REG_PPC_FPR31:
> if (cpu_has_feature(CPU_FTR_VSX)) {
> @@ -834,6 +840,12 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
> i = id - KVM_REG_PPC_PMC1;
> vcpu->arch.pmc[i] = set_reg_val(id, *val);
> break;
> + case KVM_REG_PPC_SIAR:
> + vcpu->arch.siar = set_reg_val(id, *val);
> + break;
> + case KVM_REG_PPC_SDAR:
> + vcpu->arch.sdar = set_reg_val(id, *val);
> + break;
> #ifdef CONFIG_VSX
> case KVM_REG_PPC_FPR0 ... KVM_REG_PPC_FPR31:
> if (cpu_has_feature(CPU_FTR_VSX)) {
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 60dce5b..bfb4b0a 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -196,8 +196,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
> ld r3, VCPU_MMCR(r4)
> ld r5, VCPU_MMCR + 8(r4)
> ld r6, VCPU_MMCR + 16(r4)
> + ld r7, VCPU_SIAR(r4)
> + ld r8, VCPU_SDAR(r4)
> mtspr SPRN_MMCR1, r5
> mtspr SPRN_MMCRA, r6
> + mtspr SPRN_SIAR, r7
> + mtspr SPRN_SDAR, r8
> mtspr SPRN_MMCR0, r3
> isync
>
> @@ -1122,9 +1126,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
> std r3, VCPU_MMCR(r9) /* if not, set saved MMCR0 to FC */
> b 22f
> 21: mfspr r5, SPRN_MMCR1
> + mfspr r7, SPRN_SIAR
> + mfspr r8, SPRN_SDAR
> std r4, VCPU_MMCR(r9)
> std r5, VCPU_MMCR + 8(r9)
> std r6, VCPU_MMCR + 16(r9)
> + std r7, VCPU_SIAR(r9)
> + std r8, VCPU_SDAR(r9)
> mfspr r3, SPRN_PMC1
> mfspr r4, SPRN_PMC2
> mfspr r5, SPRN_PMC3
> --
> 1.7.10.4
>
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