linux-kernel - [PATCH 4/4] KVM: x86/pmu: Move .hw_event_available() check out of PMC filter helper

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Date:   Tue,  6 Jun 2023 18:02:06 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Aaron Lewis <aaronlewis@...gle.com>,
        Like Xu <like.xu.linux@...il.com>
Subject: [PATCH 4/4] KVM: x86/pmu: Move .hw_event_available() check out of PMC
 filter helper

Move the call to kvm_x86_pmu.hw_event_available(), which has nothing to
with the userspace PMU filter, out of check_pmu_event_filter() and into
its sole caller pmc_event_is_allowed().  pmc_event_is_allowed() didn't
exist when commit 7aadaa988c5e ("KVM: x86/pmu: Drop amd_event_mapping[]
in the KVM context"), so presumably the motivation for invoking
.hw_event_available() from check_pmu_event_filter() was to avoid having
to add multiple call sites.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/pmu.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 1690d41c1830..2a32dc6aa3f7 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -387,9 +387,6 @@ static bool check_pmu_event_filter(struct kvm_pmc *pmc)
 	struct kvm_x86_pmu_event_filter *filter;
 	struct kvm *kvm = pmc->vcpu->kvm;
 
-	if (!static_call(kvm_x86_pmu_hw_event_available)(pmc))
-		return false;
-
 	filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
 	if (!filter)
 		return true;
@@ -403,6 +400,7 @@ static bool check_pmu_event_filter(struct kvm_pmc *pmc)
 static bool pmc_event_is_allowed(struct kvm_pmc *pmc)
 {
 	return pmc_is_globally_enabled(pmc) && pmc_speculative_in_use(pmc) &&
+	       static_call(kvm_x86_pmu_hw_event_available)(pmc) &&
 	       check_pmu_event_filter(pmc);
 }
 
-- 
2.41.0.162.gfafddb0af9-goog