[PATCH 19/23] KVM: arm64: pmu: Don't increment SW_INCR if PMCR.E is unset
From: Marc Zyngier <maz@kernel.org>
Date: 2020-01-30 13:29:57
Also in:
kvm, kvmarm
Subsystem:
kernel virtual machine (kvm), the rest · Maintainers:
Paolo Bonzini, Linus Torvalds
From: Eric Auger <eric.auger@redhat.com>
The specification says PMSWINC increments PMEVCNTR<n>_EL1 by 1
if PMEVCNTR<n>_EL0 is enabled and configured to count SW_INCR.
For PMEVCNTR<n>_EL0 to be enabled, we need both PMCNTENSET to
be set for the corresponding event counter but we also need
the PMCR.E bit to be set.
Fixes: 7a0adc7064b8 ("arm64: KVM: Add access handler for PMSWINC register")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Murray <redacted>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200124142535.29386-2-eric.auger@redhat.com (local)
---
virt/kvm/arm/pmu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 8731dfeced8b..c3f8b059881e 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c@@ -486,6 +486,9 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) if (val == 0) return; + if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E)) + return; + enable = __vcpu_sys_reg(vcpu, PMCNTENSET_EL0); for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) { if (!(val & BIT(i)))
--
2.20.1
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