KVM: arm/arm64: vgic: Only set underflow when actually out of LRs (90cac1f5) · Commits · 戴 / test

We currently assume that all the interrupts in our AP list will be queued to LRs, but that's not necessarily the case, because some of them could have been migrated away to different VCPUs and only the VCPU thread itself can remove interrupts from its AP list. Therefore, slightly change the logic to only setting the underflow interrupt when we actually run out of LRs. As it turns out, this allows us to further simplify the handling in vgic_sync_hwstate in later patches. Acked-by:

Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:

Christoffer Dall <cdall@linaro.org>

virt/kvm/arm/vgic/vgic.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -601,10 +601,8 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)

		DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));

		if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr) {
		vgic_set_underflow(vcpu);
		if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr)
		vgic_sort_ap_list(vcpu);
		}

		list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
		spin_lock(&irq->irq_lock);
		@@ -623,9 +621,13 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
		next:
		spin_unlock(&irq->irq_lock);

		if (count == kvm_vgic_global_state.nr_lr)
		if (count == kvm_vgic_global_state.nr_lr) {
		if (!list_is_last(&irq->ap_list,
		&vgic_cpu->ap_list_head))
		vgic_set_underflow(vcpu);
		break;
		}
		}

		vcpu->arch.vgic_cpu.used_lrs = count;

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