From afd80d85aefac27e6e2f9dc10f60515357c504d2 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 28 Mar 2013 17:18:35 +0100 Subject: [PATCH] pmu: prepare for migration support In order to migrate the PMU state correctly, we need to restore the values of MSR_CORE_PERF_GLOBAL_STATUS (a read-only register) and MSR_CORE_PERF_GLOBAL_OVF_CTRL (which has side effects when written). We also need to write the full 40-bit value of the performance counter, which would only be possible with a v3 architectural PMU's full-width counter MSRs. To distinguish host-initiated writes from the guest's, pass the full struct msr_data to kvm_pmu_set_msr. Signed-off-by: Paolo Bonzini Signed-off-by: Gleb Natapov --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/pmu.c | 14 +++++++++++--- arch/x86/kvm/x86.c | 4 ++-- 3 files changed, 14 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b5a64621d5af..3dd84c996d56 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1030,7 +1030,7 @@ void kvm_pmu_reset(struct kvm_vcpu *vcpu); void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu); bool kvm_pmu_msr(struct kvm_vcpu *vcpu, u32 msr); int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data); -int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data); +int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info); int kvm_pmu_read_pmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data); void kvm_handle_pmu_event(struct kvm_vcpu *vcpu); void kvm_deliver_pmi(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index cfc258a6bf97..c53e797e7369 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -360,10 +360,12 @@ int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data) return 1; } -int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) +int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { struct kvm_pmu *pmu = &vcpu->arch.pmu; struct kvm_pmc *pmc; + u32 index = msr_info->index; + u64 data = msr_info->data; switch (index) { case MSR_CORE_PERF_FIXED_CTR_CTRL: @@ -375,6 +377,10 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) } break; case MSR_CORE_PERF_GLOBAL_STATUS: + if (msr_info->host_initiated) { + pmu->global_status = data; + return 0; + } break; /* RO MSR */ case MSR_CORE_PERF_GLOBAL_CTRL: if (pmu->global_ctrl == data) @@ -386,7 +392,8 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) break; case MSR_CORE_PERF_GLOBAL_OVF_CTRL: if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) { - pmu->global_status &= ~data; + if (!msr_info->host_initiated) + pmu->global_status &= ~data; pmu->global_ovf_ctrl = data; return 0; } @@ -394,7 +401,8 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) default: if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) || (pmc = get_fixed_pmc(pmu, index))) { - data = (s64)(s32)data; + if (!msr_info->host_initiated) + data = (s64)(s32)data; pmc->counter += data - read_pmc(pmc); return 0; } else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2aaba814f1c8..78c6f90a60cc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2040,7 +2040,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_P6_EVNTSEL0: case MSR_P6_EVNTSEL1: if (kvm_pmu_msr(vcpu, msr)) - return kvm_pmu_set_msr(vcpu, msr, data); + return kvm_pmu_set_msr(vcpu, msr_info); if (pr || data != 0) vcpu_unimpl(vcpu, "disabled perfctr wrmsr: " @@ -2086,7 +2086,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (msr && (msr == vcpu->kvm->arch.xen_hvm_config.msr)) return xen_hvm_config(vcpu, data); if (kvm_pmu_msr(vcpu, msr)) - return kvm_pmu_set_msr(vcpu, msr, data); + return kvm_pmu_set_msr(vcpu, msr_info); if (!ignore_msrs) { vcpu_unimpl(vcpu, "unhandled wrmsr: 0x%x data %llx\n", msr, data); -- 2.30.2