From 21137301de5a5bd8be7b0de7896c3f139b7eb859 Mon Sep 17 00:00:00 2001 From: Andrew Murray Date: Mon, 29 Apr 2019 20:13:05 +0100 Subject: [PATCH] arm64: KVM: Fix perf cycle counter support for VHE The kvm_vcpu_pmu_{read,write}_evtype_direct functions do not handle the cycle counter use-case, this leads to inaccurate counts and a WARN message when using perf with the cycle counter (-e cycle). Let's fix this by adding a use case for pmccfiltr_el0. Fixes: 39e3406a090a ("arm64: KVM: Avoid isb's by using direct pmxevtyper sysreg") Reported-by: Suzuki K Poulose Signed-off-by: Andrew Murray Signed-off-by: Marc Zyngier --- arch/arm64/kvm/pmu.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c index cd49db845ef4..3da94a5bb6b7 100644 --- a/arch/arm64/kvm/pmu.c +++ b/arch/arm64/kvm/pmu.c @@ -134,12 +134,15 @@ void __hyp_text __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt) PMEVTYPER_##readwrite##_CASE(30) /* - * Read a value direct from PMEVTYPER + * Read a value direct from PMEVTYPER where idx is 0-30 + * or PMCCFILTR_EL0 where idx is ARMV8_PMU_CYCLE_IDX (31). */ static u64 kvm_vcpu_pmu_read_evtype_direct(int idx) { switch (idx) { PMEVTYPER_CASES(READ); + case ARMV8_PMU_CYCLE_IDX: + return read_sysreg(pmccfiltr_el0); default: WARN_ON(1); } @@ -148,12 +151,16 @@ static u64 kvm_vcpu_pmu_read_evtype_direct(int idx) } /* - * Write a value direct to PMEVTYPER + * Write a value direct to PMEVTYPER where idx is 0-30 + * or PMCCFILTR_EL0 where idx is ARMV8_PMU_CYCLE_IDX (31). */ static void kvm_vcpu_pmu_write_evtype_direct(int idx, u32 val) { switch (idx) { PMEVTYPER_CASES(WRITE); + case ARMV8_PMU_CYCLE_IDX: + write_sysreg(val, pmccfiltr_el0); + break; default: WARN_ON(1); } -- 2.30.2