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KVM: x86/pmu: Stop calling kvm_pmu_reset() at RESET (it's redundant)

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Drop kvm_vcpu_reset()'s call to kvm_pmu_reset(), the call is performed
only for RESET, which is really just the same thing as vCPU creation,
and kvm_arch_vcpu_create() *just* called kvm_pmu_init(), i.e. there can't
possibly be any work to do.

Unlike Intel, AMD's amd_pmu_refresh() does fill all_valid_pmc_idx even if
guest CPUID is empty, but everything that is at all dynamic is guaranteed
to be '0'/NULL, e.g. it should be impossible for KVM to have already
created a perf event.

Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20231103230541.352265-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson 2023-11-03 16:05:38 -07:00
parent 1647b52757
commit f2f63f7ec6
3 changed files with 1 additions and 3 deletions
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2
arch/x86/kvm/pmu.c
View File

@ -657,7 +657,7 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 0;
}
void kvm_pmu_reset(struct kvm_vcpu *vcpu)
static void kvm_pmu_reset(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;

1
arch/x86/kvm/pmu.h
View File

@ -243,7 +243,6 @@ bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr);
int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
void kvm_pmu_refresh(struct kvm_vcpu *vcpu);
void kvm_pmu_reset(struct kvm_vcpu *vcpu);
void kvm_pmu_init(struct kvm_vcpu *vcpu);
void kvm_pmu_cleanup(struct kvm_vcpu *vcpu);
void kvm_pmu_destroy(struct kvm_vcpu *vcpu);

1
arch/x86/kvm/x86.c
View File

@ -12221,7 +12221,6 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
}
if (!init_event) {
kvm_pmu_reset(vcpu);
vcpu->arch.smbase = 0x30000;
vcpu->arch.msr_misc_features_enables = 0;