From: Like Xu Date: Mon, 11 Apr 2022 10:19:41 +0000 (+0800) Subject: KVM: x86: Set PEBS_UNAVAIL in IA32_MISC_ENABLE when PEBS is enabled X-Git-Tag: microblaze-v6.1~132^2~6^2~389^2~35 X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=commitdiff_plain;h=d10551738f6adcc3e6040fc846b171e72e94f0e9 KVM: x86: Set PEBS_UNAVAIL in IA32_MISC_ENABLE when PEBS is enabled The bit 12 represents "Processor Event Based Sampling Unavailable (RO)" : 1 = PEBS is not supported. 0 = PEBS is supported. A write to this PEBS_UNAVL available bit will bring #GP(0) when guest PEBS is enabled. Some PEBS drivers in guest may care about this bit. Signed-off-by: Like Xu Message-Id: <20220411101946.20262-13-likexu@tencent.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 69eb5372c922..02cad8e08ed0 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -605,6 +605,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu) bitmap_set(pmu->all_valid_pmc_idx, INTEL_PMC_IDX_FIXED_VLBR, 1); if (vcpu->arch.perf_capabilities & PERF_CAP_PEBS_FORMAT) { + vcpu->arch.ia32_misc_enable_msr &= ~MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL; if (vcpu->arch.perf_capabilities & PERF_CAP_PEBS_BASELINE) { pmu->pebs_enable_mask = ~pmu->global_ctrl; pmu->reserved_bits &= ~ICL_EVENTSEL_ADAPTIVE; @@ -618,6 +619,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu) ~((1ull << pmu->nr_arch_gp_counters) - 1); } } else { + vcpu->arch.ia32_misc_enable_msr |= MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL; vcpu->arch.perf_capabilities &= ~PERF_CAP_PEBS_MASK; } } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2d9456b4874b..94b92381cc8b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3561,7 +3561,13 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_MISC_ENABLE: { u64 old_val = vcpu->arch.ia32_misc_enable_msr; - u64 pmu_mask = MSR_IA32_MISC_ENABLE_EMON; + u64 pmu_mask = MSR_IA32_MISC_ENABLE_EMON | + MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL; + + /* RO bits */ + if (!msr_info->host_initiated && + ((old_val ^ data) & MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL)) + return 1; /* * For a dummy user space, the order of setting vPMU capabilities and