From 8c694f557fd80ca9815ddb1cf5de10d8bf168110 Mon Sep 17 00:00:00 2001 From: Reiji Watanabe Date: Fri, 18 Aug 2023 21:39:46 -0700 Subject: [PATCH] KVM: arm64: PMU: Don't advertise the STALL_SLOT event Currently, KVM hides the STALL_SLOT event for guests if the host PMU version is PMUv3p4 or newer, as PMMIR_EL1 is handled as RAZ for the guests. But, this should be based on the guests' PMU version (instead of the host PMU version), as an older PMU that doesn't support PMMIR_EL1 could support the STALL_SLOT event, according to the Arm ARM. Exposing the STALL_SLOT event without PMMIR_EL1 won't be very useful anyway though. Stop advertising the STALL_SLOT event for guests unconditionally, rather than fixing or keeping the inaccurate checking to advertise the event for the case, where it is not very useful. Suggested-by: Oliver Upton Signed-off-by: Reiji Watanabe Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230819043947.4100985-4-reijiw@google.com --- arch/arm64/kvm/pmu-emul.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index eaeb8fe..b9633de 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -761,8 +761,7 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) * Don't advertise STALL_SLOT, as PMMIR_EL0 is handled * as RAZ */ - if (vcpu->kvm->arch.arm_pmu->pmuver >= ID_AA64DFR0_EL1_PMUVer_V3P4) - val &= ~BIT_ULL(ARMV8_PMUV3_PERFCTR_STALL_SLOT - 32); + val &= ~BIT_ULL(ARMV8_PMUV3_PERFCTR_STALL_SLOT - 32); base = 32; } -- 2.7.4