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[v3,3/4] KVM: arm64: PMU: Don't advertise the STALL_SLOT event

Message ID 20230819043947.4100985-4-reijiw@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: PMU: Fix PMUver related handling of vPMU support | expand

Commit Message

Reiji Watanabe Aug. 19, 2023, 4:39 a.m. UTC 
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 <oliver.upton@linux.dev>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
---
 arch/arm64/kvm/pmu-emul.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index eaeb8fea7971..b9633deff32a 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;
 	}