[PATCH v5 8/8] KVM: x86: Directly query supported PERF_CAPABILITIES for WRMSR checks

From: Sean Christopherson
Date: Wed Oct 05 2022 - 20:04:38 EST


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@xxxxxxxxxx>
---
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