[PATCH-v2,02/11] vhost/scsi: Convert completion path to use memcpy_toiovecend

Commit Message

Nicholas A. Bellinger Feb. 2, 2015, 4:06 a.m. UTC

From: Nicholas Bellinger <[e-mail]>

Required for ANY_LAYOUT support when the incoming virtio-scsi response
header + fixed size sense buffer payload may span more than a single
iovec entry.

This changes existing code to save cmd->tvc_resp_iod instead of the
first single iovec base pointer from &vq->iov[out].

Cc: Michael S. Tsirkin <[e-mail]>
Cc: Paolo Bonzini <[e-mail]>
Signed-off-by: Nicholas Bellinger <[e-mail]>
---
 drivers/vhost/scsi.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Patch

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 01c01cb..a03ac41 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -87,8 +87,8 @@  struct tcm_vhost_cmd {
 	struct scatterlist *tvc_sgl;
 	struct scatterlist *tvc_prot_sgl;
 	struct page **tvc_upages;
-	/* Pointer to response */
-	struct virtio_scsi_cmd_resp __user *tvc_resp;
+	/* Pointer to response header iovec */
+	struct iovec *tvc_resp_iov;
 	/* Pointer to vhost_scsi for our device */
 	struct vhost_scsi *tvc_vhost;
 	/* Pointer to vhost_virtqueue for the cmd */
@@ -703,7 +703,8 @@  static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 						 se_cmd->scsi_sense_length);
 		memcpy(v_rsp.sense, cmd->tvc_sense_buf,
 		       se_cmd->scsi_sense_length);
-		ret = copy_to_user(cmd->tvc_resp, &v_rsp, sizeof(v_rsp));
+		ret = memcpy_toiovecend(cmd->tvc_resp_iov, (unsigned char *)&v_rsp,
+					0, sizeof(v_rsp));
 		if (likely(ret == 0)) {
 			struct vhost_scsi_virtqueue *q;
 			vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);
@@ -1159,7 +1160,7 @@  vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 
 		cmd->tvc_vhost = vs;
 		cmd->tvc_vq = vq;
-		cmd->tvc_resp = vq->iov[out].iov_base;
+		cmd->tvc_resp_iov = &vq->iov[out];
 
 		pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
 			cmd->tvc_cdb[0], cmd->tvc_lun);