From 600f6fa5c90c05b4f2f60cde24fcea6a7239c41f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 11 Apr 2025 12:02:20 +0100 Subject: [PATCH] KVM: arm64: Let kvm_vcpu_read_pmcr() return an EL-dependent value for PMCR_EL0.N When EL2 is present, PMCR_EL0.N is the effective value of MDCR_EL2.HPMN when accessed from EL1 or EL0. Make sure we honor this requirement. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/kvm/pmu-emul.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index efc59f343acc..25c29107f13f 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -1300,8 +1300,12 @@ u8 kvm_arm_pmu_get_pmuver_limit(void) u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu) { u64 pmcr = __vcpu_sys_reg(vcpu, PMCR_EL0); + u64 n = vcpu->kvm->arch.nr_pmu_counters; - return u64_replace_bits(pmcr, vcpu->kvm->arch.nr_pmu_counters, ARMV8_PMU_PMCR_N); + if (vcpu_has_nv(vcpu) && !vcpu_is_el2(vcpu)) + n = FIELD_GET(MDCR_EL2_HPMN, __vcpu_sys_reg(vcpu, MDCR_EL2)); + + return u64_replace_bits(pmcr, n, ARMV8_PMU_PMCR_N); } void kvm_pmu_nested_transition(struct kvm_vcpu *vcpu) -- 2.25.1