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KVM: arm64: Only apply PMCR_EL0.P to the guest range of counters

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An important distinction from other registers affected by HPMN is that
PMCR_EL0 only affects the guest range of counters, regardless of the EL
from which it is accessed. Ensure that PMCR_EL0.P is always applied to
'guest' counters by manually computing the mask rather than deriving it
from the current context.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241217175611.3658290-1-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
This commit is contained in:
Oliver Upton 2024-12-17 09:56:11 -08:00
parent d3ba35b69e
commit e96d8b80af
1 changed files with 8 additions and 2 deletions
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10
arch/arm64/kvm/pmu-emul.c
View file

@ -617,8 +617,14 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
kvm_pmu_set_counter_value(vcpu, ARMV8_PMU_CYCLE_IDX, 0);
if (val & ARMV8_PMU_PMCR_P) {
unsigned long mask = kvm_pmu_accessible_counter_mask(vcpu);
mask &= ~BIT(ARMV8_PMU_CYCLE_IDX);
/*
* Unlike other PMU sysregs, the controls in PMCR_EL0 always apply
* to the 'guest' range of counters and never the 'hyp' range.
*/
unsigned long mask = kvm_pmu_implemented_counter_mask(vcpu) &
~kvm_pmu_hyp_counter_mask(vcpu) &
~BIT(ARMV8_PMU_CYCLE_IDX);
for_each_set_bit(i, &mask, 32)
kvm_pmu_set_pmc_value(kvm_vcpu_idx_to_pmc(vcpu, i), 0, true);
}