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KVM: arm64: pmu: Fix chained SW_INCR counters

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At the moment a SW_INCR counter always overflows on 32-bit
boundary, independently on whether the n+1th counter is
programmed as CHAIN.

Check whether the SW_INCR counter is a 64b counter and if so,
implement the 64b logic.

Fixes: 80f393a23b ("KVM: arm/arm64: Support chained PMU counters")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200124142535.29386-4-eric.auger@redhat.com
This commit is contained in:
Eric Auger 2020-01-24 15:25:34 +01:00 committed by Marc Zyngier
parent 76c9fc56dd
commit aa76829171
1 changed files with 30 additions and 13 deletions
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37
virt/kvm/arm/pmu.c
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@ -477,27 +477,44 @@ static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
*/
void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
{
struct kvm_pmu *pmu = &vcpu->arch.pmu;
int i;
u64 type, enable, reg;
if (val == 0)
return;
if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E))
return;
enable = __vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
/* Weed out disabled counters */
val &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) {
u64 type, reg;
if (!(val & BIT(i)))
continue;
type = __vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i)
& ARMV8_PMU_EVTYPE_EVENT;
if ((type == ARMV8_PMUV3_PERFCTR_SW_INCR)
&& (enable & BIT(i))) {
/* PMSWINC only applies to ... SW_INC! */
type = __vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i);
type &= ARMV8_PMU_EVTYPE_EVENT;
if (type != ARMV8_PMUV3_PERFCTR_SW_INCR)
continue;
/* increment this even SW_INC counter */
reg = __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) + 1;
reg = lower_32_bits(reg);
__vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg;
if (!reg)
if (reg) /* no overflow on the low part */
continue;
if (kvm_pmu_pmc_is_chained(&pmu->pmc[i])) {
/* increment the high counter */
reg = __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i + 1) + 1;
reg = lower_32_bits(reg);
__vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i + 1) = reg;
if (!reg) /* mark overflow on the high counter */
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i + 1);
} else {
/* mark overflow on low counter */
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i);
}
}