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Date: Thu, 22 Jul 2021 13:41:46 +0800 From: Zhu Lingshan <lingshan.zhu@...el.com> To: peterz@...radead.org, pbonzini@...hat.com Cc: bp@...en8.de, seanjc@...gle.com, vkuznets@...hat.com, wanpengli@...cent.com, jmattson@...gle.com, joro@...tes.org, kan.liang@...ux.intel.com, ak@...ux.intel.com, wei.w.wang@...el.com, eranian@...gle.com, liuxiangdong5@...wei.com, linux-kernel@...r.kernel.org, x86@...nel.org, kvm@...r.kernel.org, like.xu.linux@...il.com, boris.ostrvsky@...cle.com, Like Xu <like.xu@...ux.intel.com>, Yao Yuan <yuan.yao@...el.com>, Venkatesh Srinivas <venkateshs@...omium.org>, Zhu Lingshan <lingshan.zhu@...el.com> Subject: [PATCH V9 05/18] KVM: x86/pmu: Set MSR_IA32_MISC_ENABLE_EMON bit when vPMU is enabled From: Like Xu <like.xu@...ux.intel.com> On Intel platforms, the software can use the IA32_MISC_ENABLE[7] bit to detect whether the processor supports performance monitoring facility. It depends on the PMU is enabled for the guest, and a software write operation to this available bit will be ignored. The proposal to ignore the toggle in KVM is the way to go and that behavior matches bare metal. Cc: Yao Yuan <yuan.yao@...el.com> Signed-off-by: Like Xu <like.xu@...ux.intel.com> Reviewed-by: Venkatesh Srinivas <venkateshs@...omium.org> Signed-off-by: Zhu Lingshan <lingshan.zhu@...el.com> --- arch/x86/kvm/vmx/pmu_intel.c | 1 + arch/x86/kvm/x86.c | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 9efc1a6b8693..d9dbebe03cae 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -488,6 +488,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu) if (!pmu->version) return; + vcpu->arch.ia32_misc_enable_msr |= MSR_IA32_MISC_ENABLE_EMON; perf_get_x86_pmu_capability(&x86_pmu); pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 429cb4c22097..2f5d1ed00e4a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3321,6 +3321,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) } break; case MSR_IA32_MISC_ENABLE: + data &= ~MSR_IA32_MISC_ENABLE_EMON; if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT) && ((vcpu->arch.ia32_misc_enable_msr ^ data) & MSR_IA32_MISC_ENABLE_MWAIT)) { if (!guest_cpuid_has(vcpu, X86_FEATURE_XMM3)) -- 2.27.0
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