Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/gi…

…t/mst/vhost

Pull virtio fixes from Michael Tsirkin:
 "A small number of fixes:

   - virtgpu is exempt from reset shutdown fow now - a more complete fix
     is in the works

   - spec compliance fixes in:
       - virtio-pci cap commands
       - vhost_scsi_send_bad_target
       - virtio console resize

   - missing locking fix in vhost-scsi

   - virtio ring - a KCSAN false positive fix

   - VHOST_*_OWNER documentation fix"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost-scsi: Fix vhost_scsi_send_status()
  vhost-scsi: Fix vhost_scsi_send_bad_target()
  vhost-scsi: protect vq->log_used with vq->mutex
  vhost_task: fix vhost_task_create() documentation
  virtio_console: fix order of fields cols and rows
  virtio_console: fix missing byte order handling for cols and rows
  virtgpu: don't reset on shutdown
  virtio_ring: Fix data race by tagging event_triggered as racy for KCSAN
  vhost: fix VHOST_*_OWNER documentation
  virtio_pci: Use self group type for cap commands

drivers/char/virtio_console.c

@@ -1576,16 +1576,17 @@ static void handle_control_message(struct virtio_device *vdev,
 		break;
 	case VIRTIO_CONSOLE_RESIZE: {
 		struct {
-			__u16 rows;
-			__u16 cols;
+			__virtio16 cols;
+			__virtio16 rows;
 		} size;
 
 		if (!is_console_port(port))
 			break;
 
 		memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
 		       sizeof(size));
-		set_console_size(port, size.rows, size.cols);
+		set_console_size(port, virtio16_to_cpu(vdev, size.rows),
+				 virtio16_to_cpu(vdev, size.cols));
 
 		port->cons.hvc->irq_requested = 1;
 		resize_console(port);

drivers/gpu/drm/virtio/virtgpu_drv.c

@@ -128,6 +128,14 @@ static void virtio_gpu_remove(struct virtio_device *vdev)
 	drm_dev_put(dev);
 }
 
+static void virtio_gpu_shutdown(struct virtio_device *vdev)
+{
+	/*
+	 * drm does its own synchronization on shutdown.
+	 * Do nothing here, opt out of device reset.
+	 */
+}
+
 static void virtio_gpu_config_changed(struct virtio_device *vdev)
 {
 	struct drm_device *dev = vdev->priv;
@@ -162,6 +170,7 @@ static struct virtio_driver virtio_gpu_driver = {
 	.id_table = id_table,
 	.probe = virtio_gpu_probe,
 	.remove = virtio_gpu_remove,
+	.shutdown = virtio_gpu_shutdown,
 	.config_changed = virtio_gpu_config_changed
 };
 

drivers/vhost/scsi.c

@@ -627,6 +627,9 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 	int ret;
 
 	llnode = llist_del_all(&svq->completion_list);
+
+	mutex_lock(&svq->vq.mutex);
+
 	llist_for_each_entry_safe(cmd, t, llnode, tvc_completion_list) {
 		se_cmd = &cmd->tvc_se_cmd;
 
@@ -660,6 +663,8 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 		vhost_scsi_release_cmd_res(se_cmd);
 	}
 
+	mutex_unlock(&svq->vq.mutex);
+
 	if (signal)
 		vhost_signal(&svq->vs->dev, &svq->vq);
 }
@@ -994,39 +999,66 @@ static void vhost_scsi_target_queue_cmd(struct vhost_scsi_nexus *nexus,
 
 static void
 vhost_scsi_send_status(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
-		       int head, unsigned int out, u8 status)
+		       struct vhost_scsi_ctx *vc, u8 status)
 {
-	struct virtio_scsi_cmd_resp __user *resp;
 	struct virtio_scsi_cmd_resp rsp;
+	struct iov_iter iov_iter;
 	int ret;
 
 	memset(&rsp, 0, sizeof(rsp));
 	rsp.status = status;
-	resp = vq->iov[out].iov_base;
-	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
-	if (!ret)
-		vhost_add_used_and_signal(&vs->dev, vq, head, 0);
+
+	iov_iter_init(&iov_iter, ITER_DEST, &vq->iov[vc->out], vc->in,
+		      sizeof(rsp));
+
+	ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
+
+	if (likely(ret == sizeof(rsp)))
+		vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
 	else
 		pr_err("Faulted on virtio_scsi_cmd_resp\n");
 }
 
+#define TYPE_IO_CMD    0
+#define TYPE_CTRL_TMF  1
+#define TYPE_CTRL_AN   2
+
 static void
 vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 			   struct vhost_virtqueue *vq,
-			   int head, unsigned out)
+			   struct vhost_scsi_ctx *vc, int type)
 {
-	struct virtio_scsi_cmd_resp __user *resp;
-	struct virtio_scsi_cmd_resp rsp;
+	union {
+		struct virtio_scsi_cmd_resp cmd;
+		struct virtio_scsi_ctrl_tmf_resp tmf;
+		struct virtio_scsi_ctrl_an_resp an;
+	} rsp;
+	struct iov_iter iov_iter;
+	size_t rsp_size;
 	int ret;
 
 	memset(&rsp, 0, sizeof(rsp));
-	rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
-	resp = vq->iov[out].iov_base;
-	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
-	if (!ret)
-		vhost_add_used_and_signal(&vs->dev, vq, head, 0);
+
+	if (type == TYPE_IO_CMD) {
+		rsp_size = sizeof(struct virtio_scsi_cmd_resp);
+		rsp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
+	} else if (type == TYPE_CTRL_TMF) {
+		rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp);
+		rsp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
+	} else {
+		rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp);
+		rsp.an.response = VIRTIO_SCSI_S_BAD_TARGET;
+	}
+
+	iov_iter_init(&iov_iter, ITER_DEST, &vq->iov[vc->out], vc->in,
+		      rsp_size);
+
+	ret = copy_to_iter(&rsp, rsp_size, &iov_iter);
+
+	if (likely(ret == rsp_size))
+		vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
 	else
-		pr_err("Faulted on virtio_scsi_cmd_resp\n");
+		pr_err("Faulted on virtio scsi type=%d\n", type);
 }
 
 static int
@@ -1390,9 +1422,9 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 		if (ret == -ENXIO)
 			break;
 		else if (ret == -EIO)
-			vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
+			vhost_scsi_send_bad_target(vs, vq, &vc, TYPE_IO_CMD);
 		else if (ret == -ENOMEM)
-			vhost_scsi_send_status(vs, vq, vc.head, vc.out,
+			vhost_scsi_send_status(vs, vq, &vc,
 					       SAM_STAT_TASK_SET_FULL);
 	} while (likely(!vhost_exceeds_weight(vq, ++c, 0)));
 out:
@@ -1432,8 +1464,11 @@ static void vhost_scsi_tmf_resp_work(struct vhost_work *work)
 	else
 		resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 
+	mutex_lock(&tmf->svq->vq.mutex);
 	vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs,
 				 tmf->vq_desc, &tmf->resp_iov, resp_code);
+	mutex_unlock(&tmf->svq->vq.mutex);
+
 	vhost_scsi_release_tmf_res(tmf);
 }
 
@@ -1623,7 +1658,10 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 		if (ret == -ENXIO)
 			break;
 		else if (ret == -EIO)
-			vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
+			vhost_scsi_send_bad_target(vs, vq, &vc,
+						   v_req.type == VIRTIO_SCSI_T_TMF ?
+						   TYPE_CTRL_TMF :
+						   TYPE_CTRL_AN);
 	} while (likely(!vhost_exceeds_weight(vq, ++c, 0)));
 out:
 	mutex_unlock(&vq->mutex);

drivers/virtio/virtio.c

@@ -407,6 +407,12 @@ static void virtio_dev_shutdown(struct device *_d)
 	if (!drv)
 		return;
 
+	/* If the driver has its own shutdown method, use that. */
+	if (drv->shutdown) {
+		drv->shutdown(dev);
+		return;
+	}
+
 	/*
 	 * Some devices get wedged if you kick them after they are
 	 * reset. Mark all vqs as broken to make sure we don't.

drivers/virtio/virtio_pci_modern.c

@@ -247,7 +247,7 @@ virtio_pci_admin_cmd_dev_parts_objects_enable(struct virtio_device *virtio_dev)
 	sg_init_one(&data_sg, get_data, sizeof(*get_data));
 	sg_init_one(&result_sg, result, sizeof(*result));
 	cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_DEVICE_CAP_GET);
-	cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SRIOV);
+	cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SELF);
 	cmd.data_sg = &data_sg;
 	cmd.result_sg = &result_sg;
 	ret = vp_modern_admin_cmd_exec(virtio_dev, &cmd);
@@ -305,7 +305,7 @@ static void virtio_pci_admin_cmd_cap_init(struct virtio_device *virtio_dev)
 
 	sg_init_one(&result_sg, data, sizeof(*data));
 	cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_CAP_ID_LIST_QUERY);
-	cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SRIOV);
+	cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SELF);
 	cmd.result_sg = &result_sg;
 
 	ret = vp_modern_admin_cmd_exec(virtio_dev, &cmd);

drivers/virtio/virtio_ring.c

@@ -2650,7 +2650,7 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
 	struct vring_virtqueue *vq = to_vvq(_vq);
 
 	if (vq->event_triggered)
-		vq->event_triggered = false;
+		data_race(vq->event_triggered = false);
 
 	return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) :
 				 virtqueue_enable_cb_delayed_split(_vq);

include/linux/virtio.h

@@ -220,6 +220,8 @@ size_t virtio_max_dma_size(const struct virtio_device *vdev);
  *    occurs.
  * @reset_done: optional function to call after transport specific reset
  *    operation has finished.
+ * @shutdown: synchronize with the device on shutdown. If provided, replaces
+ *    the virtio core implementation.
  */
 struct virtio_driver {
 	struct device_driver driver;
@@ -237,6 +239,7 @@ struct virtio_driver {
 	int (*restore)(struct virtio_device *dev);
 	int (*reset_prepare)(struct virtio_device *dev);
 	int (*reset_done)(struct virtio_device *dev);
+	void (*shutdown)(struct virtio_device *dev);
 };
 
 #define drv_to_virtio(__drv)	container_of_const(__drv, struct virtio_driver, driver)

include/uapi/linux/vhost.h

@@ -28,10 +28,10 @@
 
 /* Set current process as the (exclusive) owner of this file descriptor.  This
  * must be called before any other vhost command.  Further calls to
- * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
+ * VHOST_SET_OWNER fail until VHOST_RESET_OWNER is called. */
 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
 /* Give up ownership, and reset the device to default values.
- * Allows subsequent call to VHOST_OWNER_SET to succeed. */
+ * Allows subsequent call to VHOST_SET_OWNER to succeed. */
 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
 
 /* Set up/modify memory layout */

include/uapi/linux/virtio_pci.h

@@ -246,6 +246,7 @@ struct virtio_pci_cfg_cap {
 #define VIRTIO_ADMIN_CMD_LIST_USE	0x1
 
 /* Admin command group type. */
+#define VIRTIO_ADMIN_GROUP_TYPE_SELF	0x0
 #define VIRTIO_ADMIN_GROUP_TYPE_SRIOV	0x1
 
 /* Transitional device admin command. */

kernel/vhost_task.c

@@ -111,7 +111,7 @@ EXPORT_SYMBOL_GPL(vhost_task_stop);
  * @arg: data to be passed to fn and handled_kill
  * @name: the thread's name
  *
- * This returns a specialized task for use by the vhost layer or NULL on
+ * This returns a specialized task for use by the vhost layer or ERR_PTR() on
  * failure. The returned task is inactive, and the caller must fire it up
  * through vhost_task_start().
  */