Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 259/593] KVM: arm64: Dont zero the cycle count register when PMCR_EL0.P is set | Date | Mon, 12 Jul 2021 08:06:59 +0200 |
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From: Alexandru Elisei <alexandru.elisei@arm.com>
[ Upstream commit 2a71fabf6a1bc9162a84e18d6ab991230ca4d588 ]
According to ARM DDI 0487G.a, page D13-3895, setting the PMCR_EL0.P bit to 1 has the following effect:
"Reset all event counters accessible in the current Exception level, not including PMCCNTR_EL0, to zero."
Similar behaviour is described for AArch32 on page G8-7022. Make it so.
Fixes: c01d6a18023b ("KVM: arm64: pmu: Only handle supported event counters") Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210618105139.83795-1-alexandru.elisei@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/arm64/kvm/pmu-emul.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 2dd164bb1c5a..4b30260e1abf 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -578,6 +578,7 @@ 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) { + mask &= ~BIT(ARMV8_PMU_CYCLE_IDX); for_each_set_bit(i, &mask, 32) kvm_pmu_set_counter_value(vcpu, i, 0); } -- 2.30.2
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