[PATCH V7 13/18] KVM: x86: Set PEBS_UNAVAIL in IA32_MISC_ENABLE when PEBS is enabled
From: Zhu Lingshan <hidden>
Date: 2021-06-22 09:44:48
Also in:
lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Like Xu <redacted> 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 <redacted> Signed-off-by: Zhu Lingshan <redacted> --- arch/x86/kvm/vmx/pmu_intel.c | 2 ++ arch/x86/kvm/x86.c | 4 ++++ 2 files changed, 6 insertions(+)
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 58f32a55cc2e..296246bf253d 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c@@ -588,6 +588,7 @@ 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;
@@ -601,6 +602,7 @@ 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 33eecb508d8b..8a905c098787 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -3214,6 +3214,10 @@ 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 (!msr_info->host_initiated && + (vcpu->arch.perf_capabilities & PERF_CAP_PEBS_FORMAT) && + (data & MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL)) + return 1; 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))
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2.27.0