KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on specific commands

The LPI translation cache needs to be discarded when an ITS command
may affect the translation of an LPI (DISCARD, MAPC and MAPD with V=0)
or the routing of an LPI to a redistributor with disabled LPIs (MOVI,
MOVALL).

We decide to perform a full invalidation of the cache, irrespective
of the LPI that is affected. Commands are supposed to be rare enough
that it doesn't matter.
Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

virt/kvm/arm/vgic/vgic-its.c

@@ -722,6 +722,8 @@ static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its,
 		 * don't bother here since we clear the ITTE anyway and the
 		 * pending state is a property of the ITTE struct.
 		 */
+		vgic_its_invalidate_cache(kvm);
+
 		its_free_ite(kvm, ite);
 		return 0;
 	}
@@ -757,6 +759,8 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
 	ite->collection = collection;
 	vcpu = kvm_get_vcpu(kvm, collection->target_addr);
 
+	vgic_its_invalidate_cache(kvm);
+
 	return update_affinity(ite->irq, vcpu);
 }
 
@@ -985,6 +989,8 @@ static void vgic_its_free_device(struct kvm *kvm, struct its_device *device)
 	list_for_each_entry_safe(ite, temp, &device->itt_head, ite_list)
 		its_free_ite(kvm, ite);
 
+	vgic_its_invalidate_cache(kvm);
+
 	list_del(&device->dev_list);
 	kfree(device);
 }
@@ -1090,6 +1096,7 @@ static int vgic_its_cmd_handle_mapc(struct kvm *kvm, struct vgic_its *its,
 
 	if (!valid) {
 		vgic_its_free_collection(its, coll_id);
+		vgic_its_invalidate_cache(kvm);
 	} else {
 		collection = find_collection(its, coll_id);
 
@@ -1238,6 +1245,8 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
 		vgic_put_irq(kvm, irq);
 	}
 
+	vgic_its_invalidate_cache(kvm);
+
 	kfree(intids);
 	return 0;
 }