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From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Like Xu <likexu@tencent.com>
Subject: [PATCH 5/7] KVM: VMX: Use vcpu_get_perf_capabilities() to get guest-visible value
Date: Sat, 11 Jun 2022 00:57:53 +0000	[thread overview]
Message-ID: <20220611005755.753273-6-seanjc@google.com> (raw)
In-Reply-To: <20220611005755.753273-1-seanjc@google.com>

Use vcpu_get_perf_capabilities() when querying MSR_IA32_PERF_CAPABILITIES
from the guest's perspective, e.g. to update the vPMU and to determine
which MSRs exist.  If userspace ignores MSR_IA32_PERF_CAPABILITIES but
clear X86_FEATURE_PDCM, the guest should see '0'.

Fixes: 902caeb6841a ("KVM: x86/pmu: Add PEBS_DATA_CFG MSR emulation to support adaptive PEBS")
Fixes: c59a1f106f5c ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS")
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index b1aae60cf061..53ccba896e77 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -199,7 +199,7 @@ static bool intel_pmu_is_valid_lbr_msr(struct kvm_vcpu *vcpu, u32 index)
 static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
-	u64 perf_capabilities = vcpu->arch.perf_capabilities;
+	u64 perf_capabilities;
 	int ret;
 
 	switch (msr) {
@@ -210,12 +210,13 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 		ret = pmu->version > 1;
 		break;
 	case MSR_IA32_PEBS_ENABLE:
-		ret = perf_capabilities & PERF_CAP_PEBS_FORMAT;
+		ret = vcpu_get_perf_capabilities(vcpu) & PERF_CAP_PEBS_FORMAT;
 		break;
 	case MSR_IA32_DS_AREA:
 		ret = guest_cpuid_has(vcpu, X86_FEATURE_DS);
 		break;
 	case MSR_PEBS_DATA_CFG:
+		perf_capabilities = vcpu_get_perf_capabilities(vcpu);
 		ret = (perf_capabilities & PERF_CAP_PEBS_BASELINE) &&
 			((perf_capabilities & PERF_CAP_PEBS_FORMAT) > 3);
 		break;
@@ -515,6 +516,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	struct kvm_cpuid_entry2 *entry;
 	union cpuid10_eax eax;
 	union cpuid10_edx edx;
+	u64 perf_capabilities;
 	u64 counter_mask;
 	int i;
 
@@ -599,8 +601,9 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	if (lbr_desc->records.nr)
 		bitmap_set(pmu->all_valid_pmc_idx, INTEL_PMC_IDX_FIXED_VLBR, 1);
 
-	if (vcpu->arch.perf_capabilities & PERF_CAP_PEBS_FORMAT) {
-		if (vcpu->arch.perf_capabilities & PERF_CAP_PEBS_BASELINE) {
+	perf_capabilities = vcpu_get_perf_capabilities(vcpu);
+	if (perf_capabilities & PERF_CAP_PEBS_FORMAT) {
+		if (perf_capabilities & PERF_CAP_PEBS_BASELINE) {
 			pmu->pebs_enable_mask = counter_mask;
 			pmu->reserved_bits &= ~ICL_EVENTSEL_ADAPTIVE;
 			for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
-- 
2.36.1.476.g0c4daa206d-goog


  parent reply	other threads:[~2022-06-11  0:58 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-11  0:57 [PATCH 0/7] KVM: x86: Attempt to wrangle PEBS/PMU into submission Sean Christopherson
2022-06-11  0:57 ` [PATCH 1/7] KVM: x86: Give host userspace full control of MSR_IA32_MISC_ENABLES Sean Christopherson
2022-06-11  0:57 ` [PATCH 2/7] KVM: VMX: Give host userspace full control of MSR_IA32_PERF_CAPABILITIES Sean Christopherson
2022-06-11  0:57 ` [PATCH 3/7] Revert "KVM: x86/pmu: Accept 0 for absent PMU MSRs when host-initiated if !enable_pmu" Sean Christopherson
2022-06-11  0:57 ` [PATCH 4/7] Revert "KVM: x86: always allow host-initiated writes to PMU MSRs" Sean Christopherson
2022-06-11  0:57 ` Sean Christopherson [this message]
2022-06-11  0:57 ` [PATCH 6/7] KVM: x86: Ignore benign host accesses to "unsupported" PEBS and BTS MSRs Sean Christopherson
2022-06-13 14:09   ` Sean Christopherson
2022-06-20 14:29     ` Paolo Bonzini
2022-06-14  7:45   ` Vitaly Kuznetsov
2022-06-11  0:57 ` [PATCH 7/7] KVM: x86: Ignore benign host writes to "unsupported" F15H_PERF_CTL MSRs Sean Christopherson
2022-06-20 14:31 ` [PATCH 0/7] KVM: x86: Attempt to wrangle PEBS/PMU into submission Paolo Bonzini

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