From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Dapeng Mi <dapeng1.mi@linux.intel.com>,
Mingwei Zhang <mizhang@google.com>,
Roman Kagan <rkagan@amazon.de>,
Jim Mattson <jmattson@google.com>,
Like Xu <like.xu.linux@gmail.com>
Subject: [PATCH v2 3/6] KVM: x86/pmu: Stop calling kvm_pmu_reset() at RESET (it's redundant)
Date: Fri, 3 Nov 2023 16:05:38 -0700 [thread overview]
Message-ID: <20231103230541.352265-4-seanjc@google.com> (raw)
In-Reply-To: <20231103230541.352265-1-seanjc@google.com>
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>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/pmu.c | 2 +-
arch/x86/kvm/pmu.h | 1 -
arch/x86/kvm/x86.c | 1 -
3 files changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index dc8e8e907cfb..458e836c6efe 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -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;
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index a46aa9b25150..db9a12c0a2ef 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -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);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2c924075f6f1..efbf52a9dc83 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12207,7 +12207,6 @@ 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;
--
2.42.0.869.gea05f2083d-goog
next prev parent reply other threads:[~2023-11-03 23:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-03 23:05 [PATCH v2 0/6] KVM: x86/pmu: Clean up emulated PMC event handling Sean Christopherson
2023-11-03 23:05 ` [PATCH v2 1/6] KVM: x86/pmu: Move PMU reset logic to common x86 code Sean Christopherson
2023-11-03 23:05 ` [PATCH v2 2/6] KVM: x86/pmu: Reset the PMU, i.e. stop counters, before refreshing Sean Christopherson
2023-11-03 23:05 ` Sean Christopherson [this message]
2023-11-03 23:05 ` [PATCH v2 4/6] KVM: x86/pmu: Remove manual clearing of fields in kvm_pmu_init() Sean Christopherson
2023-11-03 23:05 ` [PATCH v2 5/6] KVM: x86/pmu: Update sample period in pmc_write_counter() Sean Christopherson
2023-11-03 23:05 ` [PATCH v2 6/6] KVM: x86/pmu: Track emulated counter events instead of previous counter Sean Christopherson
2023-11-03 23:21 ` Mingwei Zhang
2023-12-01 1:52 ` [PATCH v2 0/6] KVM: x86/pmu: Clean up emulated PMC event handling Sean Christopherson
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