[RFC PATCH 8/8] vhost-scsi: hook vhost-scsi into vring set cpu support

[Mike Christie <michael.christie@oracle.com>]

This hooks vhost-scsi into the vring set cpu ioctl support by
just replacing it's existing workqueue use with the vhost
support.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/vhost/scsi.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 8005a7f..29b139c 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -101,8 +101,6 @@ struct vhost_scsi_cmd {
 	struct vhost_scsi_nexus *tvc_nexus;
 	/* The TCM I/O descriptor that is accessed via container_of() */
 	struct se_cmd tvc_se_cmd;
-	/* work item used for cmwq dispatch to vhost_scsi_submission_work() */
-	struct work_struct work;
 	/* Copy of the incoming SCSI command descriptor block (CDB) */
 	unsigned char tvc_cdb[VHOST_SCSI_MAX_CDB_SIZE];
 	/* Sense buffer that will be mapped into outgoing status */
@@ -778,10 +776,8 @@ static int vhost_scsi_to_tcm_attr(int attr)
 	return TCM_SIMPLE_TAG;
 }
 
-static void vhost_scsi_submission_work(struct work_struct *work)
+static void vhost_scsi_target_submit(struct vhost_scsi_cmd *cmd)
 {
-	struct vhost_scsi_cmd *cmd =
-		container_of(work, struct vhost_scsi_cmd, work);
 	struct vhost_scsi_nexus *tv_nexus;
 	struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 	struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
@@ -1128,14 +1124,7 @@ static u16 vhost_buf_to_lun(u8 *lun_buf)
 		 * vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
 		 */
 		cmd->tvc_vq_desc = vc.head;
-		/*
-		 * Dispatch cmd descriptor for cmwq execution in process
-		 * context provided by vhost_scsi_workqueue.  This also ensures
-		 * cmd is executed on the same kworker CPU as this vhost
-		 * thread to gain positive L2 cache locality effects.
-		 */
-		INIT_WORK(&cmd->work, vhost_scsi_submission_work);
-		queue_work(vhost_scsi_workqueue, &cmd->work);
+		vhost_scsi_target_submit(cmd);
 		ret = 0;
 err:
 		/*
@@ -1811,6 +1800,15 @@ static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
 	return 0;
 }
 
+static struct workqueue_struct *vhost_scsi_get_workqueue(void)
+{
+	return vhost_scsi_workqueue;
+}
+
+static struct vhost_dev_ops vhost_scsi_dev_ops = {
+	.get_workqueue = vhost_scsi_get_workqueue,	
+};
+
 static int vhost_scsi_open(struct inode *inode, struct file *f)
 {
 	struct vhost_scsi_virtqueue *svq;
@@ -1849,7 +1847,7 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
 		svq->vq.handle_kick = vhost_scsi_handle_kick;
 	}
 	vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
-		       VHOST_SCSI_WEIGHT, 0, true, NULL);
+		       VHOST_SCSI_WEIGHT, 0, true, &vhost_scsi_dev_ops);
 
 	vhost_scsi_init_inflight(vs, NULL);
 
@@ -2502,7 +2500,7 @@ static int __init vhost_scsi_init(void)
 	 * Use our own dedicated workqueue for submitting I/O into
 	 * target core to avoid contention within system_wq.
 	 */
-	vhost_scsi_workqueue = alloc_workqueue("vhost_scsi", 0, 0);
+	vhost_scsi_workqueue = alloc_workqueue("vhost_scsi", WQ_SYSFS, 0);
 	if (!vhost_scsi_workqueue)
 		goto out;
 
-- 
1.8.3.1