[PATCH v7 11/20] KVM: arm64: Enforce PMU event filter at vcpu_load()

[wuyifan]

Hi Colton,

On 5/5/2026 5:18 AM, Colton Lewis wrote:
> +	for_each_set_bit(i, &guest_counters, ARMPMU_MAX_HWEVENTS) {
> +		if (i == ARMV8_PMU_CYCLE_IDX) {
> +			val = __vcpu_sys_reg(vcpu, PMCCFILTR_EL0);
> +			evsel = ARMV8_PMUV3_PERFCTR_CPU_CYCLES;
> +		} else {
> +			val = __vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i);
> +			evsel = val & kvm_pmu_event_mask(vcpu->kvm);
> +		}
> +
> +		guest_include_el2 = (val & ARMV8_PMU_INCLUDE_EL2);
> +		val &= ~evtyper_clr;
> +
> +		if (unlikely(is_hyp_ctxt(vcpu)) && guest_include_el2)
> +			val &= ~ARMV8_PMU_EXCLUDE_EL1;
> +
> +		if (vcpu->kvm->arch.pmu_filter &&
> +		    !test_bit(evsel, vcpu->kvm->arch.pmu_filter))
> +			val |= evtyper_set;
> +
> +		if (i == ARMV8_PMU_CYCLE_IDX) {
> +			write_sysreg(val, pmccntr_el0);
This should be pmccfiltr_el0.
Writing the filter bits to pmccntr_el0 would corrupt the cycle count value.
> +		} else {
> +			write_sysreg(i, pmselr_el0);
> +			write_sysreg(val, pmxevtyper_el0);
> +		}
> +	}
> +}
Thanks,
Yifan