vdpa: skip suspend/resume ops if not DRIVER_OK

If a vdpa device is not in state DRIVER_OK, then there is no driver state
to preserve, so no need to call the suspend and resume driver ops.

Suggested-by: Eugenio Perez Martin <eperezma@redhat.com>"
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Message-Id: <1707834358-165470-1-git-send-email-steven.sistare@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eugenio Pérez <eperezma@redhat.com>

drivers/vhost/vdpa.c

@@ -595,6 +595,9 @@ static long vhost_vdpa_suspend(struct vhost_vdpa *v)
 	const struct vdpa_config_ops *ops = vdpa->config;
 	int ret;
 
+	if (!(ops->get_status(vdpa) & VIRTIO_CONFIG_S_DRIVER_OK))
+		return 0;
+
 	if (!ops->suspend)
 		return -EOPNOTSUPP;
 
@@ -615,6 +618,9 @@ static long vhost_vdpa_resume(struct vhost_vdpa *v)
 	const struct vdpa_config_ops *ops = vdpa->config;
 	int ret;
 
+	if (!(ops->get_status(vdpa) & VIRTIO_CONFIG_S_DRIVER_OK))
+		return 0;
+
 	if (!ops->resume)
 		return -EOPNOTSUPP;