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From: Sean Christopherson <seanjc@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, Like Xu <like.xu.linux@gmail.com>
Subject: [PATCH v5 8/8] KVM: x86: Directly query supported PERF_CAPABILITIES for WRMSR checks
Date: Thu,  6 Oct 2022 00:03:14 +0000	[thread overview]
Message-ID: <20221006000314.73240-9-seanjc@google.com> (raw)
In-Reply-To: <20221006000314.73240-1-seanjc@google.com>

Use kvm_caps.supported_perf_cap directly instead of bouncing through
kvm_get_msr_feature() when checking the incoming value for writes to
PERF_CAPABILITIES.

Note, kvm_get_msr_feature() is guaranteed to succeed when getting
PERF_CAPABILITIES, i.e. dropping that check is a nop.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/x86.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9443ddb358e6..3afe5f4b1a40 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3568,20 +3568,15 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			return 1;
 		vcpu->arch.arch_capabilities = data;
 		break;
-	case MSR_IA32_PERF_CAPABILITIES: {
-		struct kvm_msr_entry msr_ent = {.index = msr, .data = 0};
-
+	case MSR_IA32_PERF_CAPABILITIES:
 		if (!msr_info->host_initiated)
 			return 1;
-		if (kvm_get_msr_feature(&msr_ent))
-			return 1;
-		if (data & ~msr_ent.data)
+		if (data & ~kvm_caps.supported_perf_cap)
 			return 1;
 
 		vcpu->arch.perf_capabilities = data;
 		kvm_pmu_refresh(vcpu);
 		return 0;
-	}
 	case MSR_EFER:
 		return set_efer(vcpu, msr_info);
 	case MSR_K7_HWCR:
-- 
2.38.0.rc1.362.ged0d419d3c-goog


  parent reply	other threads:[~2022-10-06  0:04 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-06  0:03 [PATCH v5 0/8] KVM: x86: Intel LBR related perf cleanups Sean Christopherson
2022-10-06  0:03 ` [PATCH v5 1/8] perf/x86/core: Zero @lbr instead of returning -1 in x86_perf_get_lbr() stub Sean Christopherson
2022-10-06  0:03 ` [PATCH v5 2/8] KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs Sean Christopherson
2022-10-06  0:03 ` [PATCH v5 3/8] KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl() Sean Christopherson
2022-10-06  0:03 ` [PATCH v5 4/8] KVM: VMX: Ignore guest CPUID for host userspace writes to DEBUGCTL Sean Christopherson
2022-10-06  0:03 ` [PATCH v5 5/8] KVM: x86: Track supported PERF_CAPABILITIES in kvm_caps Sean Christopherson
2022-10-14  9:25   ` Like Xu
2022-10-06  0:03 ` [PATCH v5 6/8] KVM: x86: Init vcpu->arch.perf_capabilities in common x86 code Sean Christopherson
2022-10-06  0:03 ` [PATCH v5 7/8] KVM: x86: Handle PERF_CAPABILITIES in common x86's kvm_get_msr_feature() Sean Christopherson
2022-10-06  0:03 ` Sean Christopherson [this message]
2022-11-02 17:18 ` [PATCH v5 0/8] KVM: x86: Intel LBR related perf cleanups Paolo Bonzini

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