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KVM: VMX: Add helper to check if the guest PMU has PERF_GLOBAL_CTRL
[ Upstream commit b663f0b5f3
]
Add a helper to check of the guest PMU has PERF_GLOBAL_CTRL, which is
unintuitive _and_ diverges from Intel's architecturally defined behavior.
Even worse, KVM currently implements the check using two different (but
equivalent) checks, _and_ there has been at least one attempt to add a
_third_ flavor.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
2a323fb4be
commit
3237e7d1be
2 changed files with 14 additions and 2 deletions
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@ -98,7 +98,7 @@ static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
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{
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struct kvm_pmu *pmu = pmc_to_pmu(pmc);
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if (pmu->version < 2)
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if (!intel_pmu_has_perf_global_ctrl(pmu))
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return true;
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return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
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@ -215,7 +215,7 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
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case MSR_CORE_PERF_GLOBAL_STATUS:
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case MSR_CORE_PERF_GLOBAL_CTRL:
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case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
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ret = pmu->version > 1;
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return intel_pmu_has_perf_global_ctrl(pmu);
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break;
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default:
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ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
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@ -92,6 +92,18 @@ union vmx_exit_reason {
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u32 full;
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};
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static inline bool intel_pmu_has_perf_global_ctrl(struct kvm_pmu *pmu)
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{
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/*
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* Architecturally, Intel's SDM states that IA32_PERF_GLOBAL_CTRL is
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* supported if "CPUID.0AH: EAX[7:0] > 0", i.e. if the PMU version is
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* greater than zero. However, KVM only exposes and emulates the MSR
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* to/for the guest if the guest PMU supports at least "Architectural
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* Performance Monitoring Version 2".
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*/
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return pmu->version > 1;
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}
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#define vcpu_to_lbr_desc(vcpu) (&to_vmx(vcpu)->lbr_desc)
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#define vcpu_to_lbr_records(vcpu) (&to_vmx(vcpu)->lbr_desc.records)
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