From acdd8a4e13a008a83c6da88bb53eecbecda9714c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sun, 13 Nov 2022 16:38:19 +0000 Subject: [PATCH] KVM: arm64: PMU: Always advertise the CHAIN event Even when the underlying HW doesn't offer the CHAIN event (which happens with QEMU), we can always support it as we're in control of the counter overflow. Always advertise the event via PMCEID0_EL0. Reviewed-by: Reiji Watanabe Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221113163832.3154370-4-maz@kernel.org --- arch/arm64/kvm/pmu-emul.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 57765be69bea..69b67ab3c4bf 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -701,6 +701,8 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) if (!pmceid1) { val = read_sysreg(pmceid0_el0); + /* always support CHAIN */ + val |= BIT(ARMV8_PMUV3_PERFCTR_CHAIN); base = 0; } else { val = read_sysreg(pmceid1_el0); -- 2.11.0