[PATCH v2 02/10] vhost-scsi: Fix vhost_scsi_send_bad_target()

[Dongli Zhang <dongli.zhang@oracle.com>]

Although the support of VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 was
signaled by the commit 664ed90e621c ("vhost/scsi: Set
VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits"),
vhost_scsi_send_bad_target() still assumes the response in a single
descriptor.

In addition, although vhost_scsi_send_bad_target() is used by both I/O
queue and control queue, the response header is always
virtio_scsi_cmd_resp. It is required to use virtio_scsi_ctrl_tmf_resp or
virtio_scsi_ctrl_an_resp for control queue.

Fixes: 664ed90e621c ("vhost/scsi: Set VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits")
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
---
Changed since v1:
  - Move this bugfix patch to before dirty log tracking patches.

 drivers/vhost/scsi.c | 48 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 11 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index f846f2aa7c87..59d907b94c5e 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1015,23 +1015,46 @@ vhost_scsi_send_status(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
 		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
@@ -1395,7 +1418,7 @@ 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,
 					       SAM_STAT_TASK_SET_FULL);
@@ -1631,7 +1654,10 @@ 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);
-- 
2.39.3