[PATCH v6 07/16] KVM: x86/pmu: Check mediated PMU counter enablement before event filters

[Yosry Ahmed <yosry@kernel.org>]

If the guest disables the counter (by clearing
ARCH_PERFMON_EVENTSEL_ENABLE), KVM still performs the PMU filter lookup,
even though it doesn't end up changing eventsel_hw.  Check if the
counter is enabled by the guest before doing the potentially expensive
PMU filter lookup.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
---
 arch/x86/kvm/pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index afbc731e72174..67dbbd4c73036 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -532,7 +532,7 @@ static bool pmc_is_event_allowed(struct kvm_pmc *pmc)
 
 static void kvm_mediated_pmu_refresh_event_filter(struct kvm_pmc *pmc)
 {
-	bool allowed = pmc_is_event_allowed(pmc);
+	bool allowed = pmc_is_locally_enabled(pmc) && pmc_is_event_allowed(pmc);
 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 
 	if (pmc_is_gp(pmc)) {
-- 
2.54.0.545.g6539524ca2-goog