vhost: Create accessors for virtqueues private_data

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Link: https://lore.kernel.org/r/20200331192804.6019-2-eperezma@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vhost/scsi.c

@@ -452,7 +452,7 @@ vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 	unsigned out, in;
 	int head, ret;
 
-	if (!vq->private_data) {
+	if (!vhost_vq_get_backend(vq)) {
 		vs->vs_events_missed = true;
 		return;
 	}
@@ -892,7 +892,7 @@ vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
 	} else {
 		struct vhost_scsi_tpg **vs_tpg, *tpg;
 
-		vs_tpg = vq->private_data;	/* validated at handler entry */
+		vs_tpg = vhost_vq_get_backend(vq);	/* validated at handler entry */
 
 		tpg = READ_ONCE(vs_tpg[*vc->target]);
 		if (unlikely(!tpg)) {
@@ -929,7 +929,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 	 * We can handle the vq only after the endpoint is setup by calling the
 	 * VHOST_SCSI_SET_ENDPOINT ioctl.
 	 */
-	vs_tpg = vq->private_data;
+	vs_tpg = vhost_vq_get_backend(vq);
 	if (!vs_tpg)
 		goto out;
 
@@ -1184,7 +1184,7 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 	 * We can handle the vq only after the endpoint is setup by calling the
 	 * VHOST_SCSI_SET_ENDPOINT ioctl.
 	 */
-	if (!vq->private_data)
+	if (!vhost_vq_get_backend(vq))
 		goto out;
 
 	memset(&vc, 0, sizeof(vc));
@@ -1322,7 +1322,7 @@ static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
 	struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
 
 	mutex_lock(&vq->mutex);
-	if (!vq->private_data)
+	if (!vhost_vq_get_backend(vq))
 		goto out;
 
 	if (vs->vs_events_missed)
@@ -1460,7 +1460,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs,
 		for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
 			vq = &vs->vqs[i].vq;
 			mutex_lock(&vq->mutex);
-			vq->private_data = vs_tpg;
+			vhost_vq_set_backend(vq, vs_tpg);
 			vhost_vq_init_access(vq);
 			mutex_unlock(&vq->mutex);
 		}
@@ -1547,7 +1547,7 @@ vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
 		for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
 			vq = &vs->vqs[i].vq;
 			mutex_lock(&vq->mutex);
-			vq->private_data = NULL;
+			vhost_vq_set_backend(vq, NULL);
 			mutex_unlock(&vq->mutex);
 		}
 	}