Re: [PATCH v5 21/24] KVM: arm64: Inject recorded guest interrupts

In no situation should KVM be injecting a "recorded" IRQ. The overflow
condition of the PMU is well defined in the architecture and we should
implement *exactly* that.

On Tue, Dec 09, 2025 at 08:51:18PM +0000, Colton Lewis wrote:

+/**
+ * kvm_pmu_part_overflow_status() - Determine if any guest counters have overflowed
+ * @vcpu: Ponter to struct kvm_vcpu
+ *
+ * Determine if any guest counters have overflowed and therefore an
+ * IRQ needs to be injected into the guest.
+ *
+ * Return: True if there was an overflow, false otherwise
+ */
+bool kvm_pmu_part_overflow_status(struct kvm_vcpu *vcpu)
+{
+	struct arm_pmu *pmu = vcpu->kvm->arch.arm_pmu;
+	u64 mask = kvm_pmu_guest_counter_mask(pmu);
+	u64 pmovs = __vcpu_sys_reg(vcpu, PMOVSSET_EL0);
+	u64 pmint = read_pmintenset();
+	u64 pmcr = read_pmcr();

How do we know that the vPMU has been loaded on the CPU at this point?

+
+	return (pmcr & ARMV8_PMU_PMCR_E) && (mask & pmovs & pmint);
+}

I'd rather reuse kvm_pmu_overflow_status(), relying on the accessors to
abstract away the implementation / location of the guest PMU context.

Thanks,
Oliver