arm64: KVM: Fix perf cycle counter support for VHE (21137301) · Commits · 戴 / test

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: ("arm64: KVM: Avoid isb's by using direct pmxevtyper sysreg") Reported-by:

Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by:

Andrew Murray <andrew.murray@arm.com> Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com>

arch/arm64/kvm/pmu.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -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<idx>
		* Read a value direct from PMEVTYPER<idx> 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<idx>
		* Write a value direct to PMEVTYPER<idx> 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);
		}

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