Commit 33c1f60b authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

KVM: arm64: Move undeliverable interrupts to the end of ap_list 



Interrupts in the ap_list that cannot be acted upon because they
are not enabled, or that their group is not enabled, shouldn't
make it into the LRs if we are space-constrained.

Tested-by: default avatarFuad Tabba <tabba@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Tested-by: default avatarMark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-26-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oupton@kernel.org>
parent 05984ba6

arch/arm64/kvm/vgic/vgic.c

+22 −1
Original line number Diff line number Diff line
@@ -265,6 +265,11 @@ struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq) 
	return NULL;

}



struct vgic_sort_info {

	struct kvm_vcpu *vcpu;

	struct vgic_vmcr vmcr;

};



/*

 * The order of items in the ap_lists defines how we'll pack things in LRs as

 * well, the first items in the list being the first things populated in the
@@ -273,6 +278,7 @@ struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq) 
 * Pending, non-active interrupts must be placed at the head of the list.

 * Otherwise things should be sorted by the priority field and the GIC

 * hardware support will take care of preemption of priority groups etc.

 * Interrupts that are not deliverable should be at the end of the list.

 *

 * Return negative if "a" sorts before "b", 0 to preserve order, and positive

 * to sort "b" before "a".
@@ -282,6 +288,8 @@ static int vgic_irq_cmp(void *priv, const struct list_head *a, 
{

	struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list);

	struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list);

	struct vgic_sort_info *info = priv;

	struct kvm_vcpu *vcpu = info->vcpu;

	bool penda, pendb;

	int ret;
@@ -295,6 +303,17 @@ static int vgic_irq_cmp(void *priv, const struct list_head *a, 
	raw_spin_lock(&irqa->irq_lock);

	raw_spin_lock_nested(&irqb->irq_lock, SINGLE_DEPTH_NESTING);



	/* Undeliverable interrupts should be last */

	ret = (int)(vgic_target_oracle(irqb) == vcpu) - (int)(vgic_target_oracle(irqa) == vcpu);

	if (ret)

		goto out;



	/* Same thing for interrupts targeting a disabled group */

	ret =  (int)(irqb->group ? info->vmcr.grpen1 : info->vmcr.grpen0);

	ret -= (int)(irqa->group ? info->vmcr.grpen1 : info->vmcr.grpen0);

	if (ret)

		goto out;



	penda = irqa->enabled && irq_is_pending(irqa) && !irqa->active;

	pendb = irqb->enabled && irq_is_pending(irqb) && !irqb->active;
@@ -320,10 +339,12 @@ static int vgic_irq_cmp(void *priv, const struct list_head *a, 
static void vgic_sort_ap_list(struct kvm_vcpu *vcpu)

{

	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;

	struct vgic_sort_info info = { .vcpu = vcpu, };



	lockdep_assert_held(&vgic_cpu->ap_list_lock);



	list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp);

	vgic_get_vmcr(vcpu, &info.vmcr);

	list_sort(&info, &vgic_cpu->ap_list_head, vgic_irq_cmp);

}



/*