1 files changed, 28 insertions, 7 deletions

diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
index eedecbbbcf31..c7de6154627c 100644
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -336,6 +336,22 @@ void vgic_v4_teardown(struct kvm *kvm)
 	its_vm->vpes = NULL;
 }
 
+static inline bool vgic_v4_want_doorbell(struct kvm_vcpu *vcpu)
+{
+	if (vcpu_get_flag(vcpu, IN_WFI))
+		return true;
+
+	if (likely(!vcpu_has_nv(vcpu)))
+		return false;
+
+	/*
+	 * GICv4 hardware is only ever used for the L1. Mark the vPE (i.e. the
+	 * L1 context) nonresident and request a doorbell to kick us out of the
+	 * L2 when an IRQ becomes pending.
+	 */
+	return vcpu_get_flag(vcpu, IN_NESTED_ERET);
+}
+
 int vgic_v4_put(struct kvm_vcpu *vcpu)
 {
 	struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
@@ -343,7 +359,7 @@ int vgic_v4_put(struct kvm_vcpu *vcpu)
 	if (!vgic_supports_direct_msis(vcpu->kvm) || !vpe->resident)
 		return 0;
 
-	return its_make_vpe_non_resident(vpe, !!vcpu_get_flag(vcpu, IN_WFI));
+	return its_make_vpe_non_resident(vpe, vgic_v4_want_doorbell(vcpu));
 }
 
 int vgic_v4_load(struct kvm_vcpu *vcpu)
@@ -415,7 +431,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 	struct vgic_irq *irq;
 	struct its_vlpi_map map;
 	unsigned long flags;
-	int ret;
+	int ret = 0;
 
 	if (!vgic_supports_direct_msis(kvm))
 		return 0;
@@ -430,10 +446,15 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 
 	mutex_lock(&its->its_lock);
 
-	/* Perform the actual DevID/EventID -> LPI translation. */
-	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
-				   irq_entry->msi.data, &irq);
-	if (ret)
+	/*
+	 * Perform the actual DevID/EventID -> LPI translation.
+	 *
+	 * Silently exit if translation fails as the guest (or userspace!) has
+	 * managed to do something stupid. Emulated LPI injection will still
+	 * work if the guest figures itself out at a later time.
+	 */
+	if (vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
+				 irq_entry->msi.data, &irq))
 		goto out;
 
 	/* Silently exit if the vLPI is already mapped */
@@ -512,7 +533,7 @@ int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq,
 	if (ret)
 		goto out;
 
-	WARN_ON(!(irq->hw && irq->host_irq == virq));
+	WARN_ON(irq->hw && irq->host_irq != virq);
 	if (irq->hw) {
 		atomic_dec(&irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count);
 		irq->hw = false;