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arm64: KVM: Fix perf cycle counter support for VHE

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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: 39e3406a09 ("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>
This commit is contained in:
Andrew Murray 2019-04-29 20:13:05 +01:00 committed by Marc Zyngier
parent a9bf3130eb
commit 21137301de
1 changed files with 9 additions and 2 deletions
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11
arch/arm64/kvm/pmu.c
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@ -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);
}