1 files changed, 229 insertions, 261 deletions

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 9be211d68b15..96a69edddbe5 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Virtio SCSI HBA driver
  *
@@ -7,10 +8,6 @@
  * Authors:
  *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
  *  Paolo Bonzini   <pbonzini@redhat.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -25,18 +22,25 @@
 #include <linux/virtio_scsi.h>
 #include <linux/cpu.h>
 #include <linux/blkdev.h>
+#include <linux/blk-integrity.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsi_devinfo.h>
 #include <linux/seqlock.h>
-#include <linux/blk-mq-virtio.h>
+
+#include "sd.h"
 
 #define VIRTIO_SCSI_MEMPOOL_SZ 64
 #define VIRTIO_SCSI_EVENT_LEN 8
 #define VIRTIO_SCSI_VQ_BASE 2
 
+static unsigned int virtscsi_poll_queues;
+module_param(virtscsi_poll_queues, uint, 0644);
+MODULE_PARM_DESC(virtscsi_poll_queues,
+		 "The number of dedicated virtqueues for polling I/O");
+
 /* Command queue element */
 struct virtio_scsi_cmd {
 	struct scsi_cmnd *sc;
@@ -68,36 +72,6 @@ struct virtio_scsi_vq {
 	struct virtqueue *vq;
 };
 
-/*
- * Per-target queue state.
- *
- * This struct holds the data needed by the queue steering policy.  When a
- * target is sent multiple requests, we need to drive them to the same queue so
- * that FIFO processing order is kept.  However, if a target was idle, we can
- * choose a queue arbitrarily.  In this case the queue is chosen according to
- * the current VCPU, so the driver expects the number of request queues to be
- * equal to the number of VCPUs.  This makes it easy and fast to select the
- * queue, and also lets the driver optimize the IRQ affinity for the virtqueues
- * (each virtqueue's affinity is set to the CPU that "owns" the queue).
- *
- * tgt_seq is held to serialize reading and writing req_vq.
- *
- * Decrements of reqs are never concurrent with writes of req_vq: before the
- * decrement reqs will be != 0; after the decrement the virtqueue completion
- * routine will not use the req_vq so it can be changed by a new request.
- * Thus they can happen outside the tgt_seq, provided of course we make reqs
- * an atomic_t.
- */
-struct virtio_scsi_target_state {
-	seqcount_t tgt_seq;
-
-	/* Count of outstanding requests. */
-	atomic_t reqs;
-
-	/* Currently active virtqueue for requests sent to this target. */
-	struct virtio_scsi_vq *req_vq;
-};
-
 /* Driver instance state */
 struct virtio_scsi {
 	struct virtio_device *vdev;
@@ -106,9 +80,7 @@ struct virtio_scsi {
 	struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
 
 	u32 num_queues;
-
-	/* If the affinity hint is set for virtqueues */
-	bool affinity_hint_set;
+	int io_queues[HCTX_MAX_TYPES];
 
 	struct hlist_node node;
 
@@ -130,19 +102,11 @@ static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
 
 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
 {
-	if (!resid)
-		return;
-
-	if (!scsi_bidi_cmnd(sc)) {
-		scsi_set_resid(sc, resid);
-		return;
-	}
-
-	scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
-	scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
+	if (resid)
+		scsi_set_resid(sc, min(resid, scsi_bufflen(sc)));
 }
 
-/**
+/*
  * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
  *
  * Called with vq_lock held.
@@ -152,8 +116,6 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
 	struct virtio_scsi_cmd *cmd = buf;
 	struct scsi_cmnd *sc = cmd->sc;
 	struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
-	struct virtio_scsi_target_state *tgt =
-				scsi_target(sc->device)->hostdata;
 
 	dev_dbg(&sc->device->sdev_gendev,
 		"cmd %p response %u status %#02x sense_len %u\n",
@@ -184,15 +146,15 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
 		set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
 		break;
 	case VIRTIO_SCSI_S_TARGET_FAILURE:
-		set_host_byte(sc, DID_TARGET_FAILURE);
+		set_host_byte(sc, DID_BAD_TARGET);
 		break;
 	case VIRTIO_SCSI_S_NEXUS_FAILURE:
-		set_host_byte(sc, DID_NEXUS_FAILURE);
+		set_status_byte(sc, SAM_STAT_RESERVATION_CONFLICT);
 		break;
 	default:
 		scmd_printk(KERN_WARNING, sc, "Unknown response %d",
 			    resp->response);
-		/* fall through */
+		fallthrough;
 	case VIRTIO_SCSI_S_FAILURE:
 		set_host_byte(sc, DID_ERROR);
 		break;
@@ -200,18 +162,14 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
 
 	WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
 		VIRTIO_SCSI_SENSE_SIZE);
-	if (sc->sense_buffer) {
+	if (resp->sense_len) {
 		memcpy(sc->sense_buffer, resp->sense,
 		       min_t(u32,
 			     virtio32_to_cpu(vscsi->vdev, resp->sense_len),
 			     VIRTIO_SCSI_SENSE_SIZE));
-		if (resp->sense_len)
-			set_driver_byte(sc, DRIVER_SENSE);
 	}
 
-	sc->scsi_done(sc);
-
-	atomic_dec(&tgt->reqs);
+	scsi_done(sc);
 }
 
 static void virtscsi_vq_done(struct virtio_scsi *vscsi,
@@ -229,8 +187,6 @@ static void virtscsi_vq_done(struct virtio_scsi *vscsi,
 		while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
 			fn(vscsi, buf);
 
-		if (unlikely(virtqueue_is_broken(vq)))
-			break;
 	} while (!virtqueue_enable_cb(vq));
 	spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
 }
@@ -330,7 +286,12 @@ static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
 
 	switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
 	case VIRTIO_SCSI_EVT_RESET_RESCAN:
-		scsi_add_device(shost, 0, target, lun);
+		if (lun == 0) {
+			scsi_scan_target(&shost->shost_gendev, 0, target,
+					 SCAN_WILD_CARD, SCSI_SCAN_INITIAL);
+		} else {
+			scsi_add_device(shost, 0, target, lun);
+		}
 		break;
 	case VIRTIO_SCSI_EVT_RESET_REMOVED:
 		sdev = scsi_device_lookup(shost, 0, target, lun);
@@ -343,7 +304,7 @@ static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
 		}
 		break;
 	default:
-		pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
+		pr_info("Unsupported virtio scsi event reason %x\n", event->reason);
 	}
 }
 
@@ -367,11 +328,53 @@ static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
 	/* Handle "Parameters changed", "Mode parameters changed", and
 	   "Capacity data has changed".  */
 	if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
-		scsi_rescan_device(&sdev->sdev_gendev);
+		scsi_rescan_device(sdev);
 
 	scsi_device_put(sdev);
 }
 
+static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
+{
+	struct scsi_device *sdev;
+	struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+	unsigned char scsi_cmd[MAX_COMMAND_SIZE];
+	int result, inquiry_len, inq_result_len = 256;
+	char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
+
+	if (!inq_result)
+		return -ENOMEM;
+
+	shost_for_each_device(sdev, shost) {
+		inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
+
+		memset(scsi_cmd, 0, sizeof(scsi_cmd));
+		scsi_cmd[0] = INQUIRY;
+		scsi_cmd[4] = (unsigned char) inquiry_len;
+
+		memset(inq_result, 0, inq_result_len);
+
+		result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN,
+					  inq_result, inquiry_len,
+					  SD_TIMEOUT, SD_MAX_RETRIES, NULL);
+
+		if (result == 0 && inq_result[0] >> 5) {
+			/* PQ indicates the LUN is not attached */
+			scsi_remove_device(sdev);
+		} else if (result > 0 && host_byte(result) == DID_BAD_TARGET) {
+			/*
+			 * If all LUNs of a virtio-scsi device are unplugged
+			 * it will respond with BAD TARGET on any INQUIRY
+			 * command.
+			 * Remove the device in this case as well.
+			 */
+			scsi_remove_device(sdev);
+		}
+	}
+
+	kfree(inq_result);
+	return 0;
+}
+
 static void virtscsi_handle_event(struct work_struct *work)
 {
 	struct virtio_scsi_event_node *event_node =
@@ -381,8 +384,13 @@ static void virtscsi_handle_event(struct work_struct *work)
 
 	if (event->event &
 	    cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
+		int ret;
+
 		event->event &= ~cpu_to_virtio32(vscsi->vdev,
 						   VIRTIO_SCSI_T_EVENTS_MISSED);
+		ret = virtscsi_rescan_hotunplug(vscsi);
+		if (ret)
+			return;
 		scsi_scan_host(virtio_scsi_host(vscsi->vdev));
 	}
 
@@ -396,7 +404,7 @@ static void virtscsi_handle_event(struct work_struct *work)
 		virtscsi_handle_param_change(vscsi, event);
 		break;
 	default:
-		pr_err("Unsupport virtio scsi event %x\n", event->event);
+		pr_err("Unsupported virtio scsi event %x\n", event->event);
 	}
 	virtscsi_kick_event(vscsi, event_node);
 }
@@ -417,14 +425,7 @@ static void virtscsi_event_done(struct virtqueue *vq)
 	virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
 };
 
-/**
- * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
- * @vq		: the struct virtqueue we're talking about
- * @cmd		: command structure
- * @req_size	: size of the request buffer
- * @resp_size	: size of the response buffer
- */
-static int virtscsi_add_cmd(struct virtqueue *vq,
+static int __virtscsi_add_cmd(struct virtqueue *vq,
 			    struct virtio_scsi_cmd *cmd,
 			    size_t req_size, size_t resp_size)
 {
@@ -437,9 +438,9 @@ static int virtscsi_add_cmd(struct virtqueue *vq,
 
 	if (sc && sc->sc_data_direction != DMA_NONE) {
 		if (sc->sc_data_direction != DMA_FROM_DEVICE)
-			out = &scsi_out(sc)->table;
+			out = &sc->sdb.table;
 		if (sc->sc_data_direction != DMA_TO_DEVICE)
-			in = &scsi_in(sc)->table;
+			in = &sc->sdb.table;
 	}
 
 	/* Request header.  */
@@ -469,17 +470,39 @@ static int virtscsi_add_cmd(struct virtqueue *vq,
 	return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
 }
 
-static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
+static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
+{
+	bool needs_kick;
+	unsigned long flags;
+
+	spin_lock_irqsave(&vq->vq_lock, flags);
+	needs_kick = virtqueue_kick_prepare(vq->vq);
+	spin_unlock_irqrestore(&vq->vq_lock, flags);
+
+	if (needs_kick)
+		virtqueue_notify(vq->vq);
+}
+
+/**
+ * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
+ * @vq		: the struct virtqueue we're talking about
+ * @cmd		: command structure
+ * @req_size	: size of the request buffer
+ * @resp_size	: size of the response buffer
+ * @kick	: whether to kick the virtqueue immediately
+ */
+static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
 			     struct virtio_scsi_cmd *cmd,
-			     size_t req_size, size_t resp_size)
+			     size_t req_size, size_t resp_size,
+			     bool kick)
 {
 	unsigned long flags;
 	int err;
 	bool needs_kick = false;
 
 	spin_lock_irqsave(&vq->vq_lock, flags);
-	err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
-	if (!err)
+	err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
+	if (!err && kick)
 		needs_kick = virtqueue_kick_prepare(vq->vq);
 
 	spin_unlock_irqrestore(&vq->vq_lock, flags);
@@ -508,7 +531,7 @@ static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
 				    struct virtio_scsi_cmd_req_pi *cmd_pi,
 				    struct scsi_cmnd *sc)
 {
-	struct request *rq = sc->request;
+	struct request *rq = scsi_cmd_to_rq(sc);
 	struct blk_integrity *bi;
 
 	virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
@@ -516,25 +539,35 @@ static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
 	if (!rq || !scsi_prot_sg_count(sc))
 		return;
 
-	bi = blk_get_integrity(rq->rq_disk);
+	bi = blk_get_integrity(rq->q->disk);
 
 	if (sc->sc_data_direction == DMA_TO_DEVICE)
 		cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
-							blk_rq_sectors(rq) *
-							bi->tuple_size);
+						      bio_integrity_bytes(bi,
+							blk_rq_sectors(rq)));
 	else if (sc->sc_data_direction == DMA_FROM_DEVICE)
 		cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
-						       blk_rq_sectors(rq) *
-						       bi->tuple_size);
+						     bio_integrity_bytes(bi,
+							blk_rq_sectors(rq)));
 }
 #endif
 
-static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
-				 struct virtio_scsi_vq *req_vq,
+static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
+						  struct scsi_cmnd *sc)
+{
+	u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc));
+	u16 hwq = blk_mq_unique_tag_to_hwq(tag);
+
+	return &vscsi->req_vqs[hwq];
+}
+
+static int virtscsi_queuecommand(struct Scsi_Host *shost,
 				 struct scsi_cmnd *sc)
 {
-	struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+	struct virtio_scsi *vscsi = shost_priv(shost);
+	struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
 	struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
+	bool kick;
 	unsigned long flags;
 	int req_size;
 	int ret;
@@ -564,7 +597,8 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
 		req_size = sizeof(cmd->req.cmd);
 	}
 
-	ret = virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd));
+	kick = (sc->flags & SCMD_LAST) != 0;
+	ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick);
 	if (ret == -EIO) {
 		cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 		spin_lock_irqsave(&req_vq->vq_lock, flags);
@@ -576,87 +610,14 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
 	return 0;
 }
 
-static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
-					struct scsi_cmnd *sc)
-{
-	struct virtio_scsi *vscsi = shost_priv(sh);
-	struct virtio_scsi_target_state *tgt =
-				scsi_target(sc->device)->hostdata;
-
-	atomic_inc(&tgt->reqs);
-	return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc);
-}
-
-static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
-						  struct scsi_cmnd *sc)
-{
-	u32 tag = blk_mq_unique_tag(sc->request);
-	u16 hwq = blk_mq_unique_tag_to_hwq(tag);
-
-	return &vscsi->req_vqs[hwq];
-}
-
-static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi,
-					       struct virtio_scsi_target_state *tgt)
-{
-	struct virtio_scsi_vq *vq;
-	unsigned long flags;
-	u32 queue_num;
-
-	local_irq_save(flags);
-	if (atomic_inc_return(&tgt->reqs) > 1) {
-		unsigned long seq;
-
-		do {
-			seq = read_seqcount_begin(&tgt->tgt_seq);
-			vq = tgt->req_vq;
-		} while (read_seqcount_retry(&tgt->tgt_seq, seq));
-	} else {
-		/* no writes can be concurrent because of atomic_t */
-		write_seqcount_begin(&tgt->tgt_seq);
-
-		/* keep previous req_vq if a reader just arrived */
-		if (unlikely(atomic_read(&tgt->reqs) > 1)) {
-			vq = tgt->req_vq;
-			goto unlock;
-		}
-
-		queue_num = smp_processor_id();
-		while (unlikely(queue_num >= vscsi->num_queues))
-			queue_num -= vscsi->num_queues;
-		tgt->req_vq = vq = &vscsi->req_vqs[queue_num];
- unlock:
-		write_seqcount_end(&tgt->tgt_seq);
-	}
-	local_irq_restore(flags);
-
-	return vq;
-}
-
-static int virtscsi_queuecommand_multi(struct Scsi_Host *sh,
-				       struct scsi_cmnd *sc)
-{
-	struct virtio_scsi *vscsi = shost_priv(sh);
-	struct virtio_scsi_target_state *tgt =
-				scsi_target(sc->device)->hostdata;
-	struct virtio_scsi_vq *req_vq;
-
-	if (shost_use_blk_mq(sh))
-		req_vq = virtscsi_pick_vq_mq(vscsi, sc);
-	else
-		req_vq = virtscsi_pick_vq(vscsi, tgt);
-
-	return virtscsi_queuecommand(vscsi, req_vq, sc);
-}
-
 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
 {
 	DECLARE_COMPLETION_ONSTACK(comp);
 	int ret = FAILED;
 
 	cmd->comp = &comp;
-	if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
-			      sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
+	if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd,
+			      sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0)
 		goto out;
 
 	wait_for_completion(&comp);
@@ -670,9 +631,8 @@ static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
 	 * we're using independent interrupts (e.g. MSI).  Poll the
 	 * virtqueues once.
 	 *
-	 * In the abort case, sc->scsi_done will do nothing, because
-	 * the block layer must have detected a timeout and as a result
-	 * REQ_ATOM_COMPLETE has been set.
+	 * In the abort case, scsi_done() will do nothing, because the
+	 * command timed out and hence SCMD_STATE_COMPLETE has been set.
 	 */
 	virtscsi_poll_requests(vscsi);
 
@@ -692,7 +652,6 @@ static int virtscsi_device_reset(struct scsi_cmnd *sc)
 		return FAILED;
 
 	memset(cmd, 0, sizeof(*cmd));
-	cmd->sc = sc;
 	cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
 		.type = VIRTIO_SCSI_T_TMF,
 		.subtype = cpu_to_virtio32(vscsi->vdev,
@@ -751,7 +710,6 @@ static int virtscsi_abort(struct scsi_cmnd *sc)
 		return FAILED;
 
 	memset(cmd, 0, sizeof(*cmd));
-	cmd->sc = sc;
 	cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
 		.type = VIRTIO_SCSI_T_TMF,
 		.subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
@@ -764,35 +722,59 @@ static int virtscsi_abort(struct scsi_cmnd *sc)
 	return virtscsi_tmf(vscsi, cmd);
 }
 
-static int virtscsi_target_alloc(struct scsi_target *starget)
+static void virtscsi_map_queues(struct Scsi_Host *shost)
 {
-	struct Scsi_Host *sh = dev_to_shost(starget->dev.parent);
-	struct virtio_scsi *vscsi = shost_priv(sh);
+	struct virtio_scsi *vscsi = shost_priv(shost);
+	int i, qoff;
+
+	for (i = 0, qoff = 0; i < shost->nr_maps; i++) {
+		struct blk_mq_queue_map *map = &shost->tag_set.map[i];
+
+		map->nr_queues = vscsi->io_queues[i];
+		map->queue_offset = qoff;
+		qoff += map->nr_queues;
+
+		if (map->nr_queues == 0)
+			continue;
+
+		/*
+		 * Regular queues have interrupts and hence CPU affinity is
+		 * defined by the core virtio code, but polling queues have
+		 * no interrupts so we let the block layer assign CPU affinity.
+		 */
+		if (i == HCTX_TYPE_POLL)
+			blk_mq_map_queues(map);
+		else
+			blk_mq_map_hw_queues(map, &vscsi->vdev->dev, 2);
+	}
+}
 
-	struct virtio_scsi_target_state *tgt =
-				kmalloc(sizeof(*tgt), GFP_KERNEL);
-	if (!tgt)
-		return -ENOMEM;
+static int virtscsi_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
+{
+	struct virtio_scsi *vscsi = shost_priv(shost);
+	struct virtio_scsi_vq *virtscsi_vq = &vscsi->req_vqs[queue_num];
+	unsigned long flags;
+	unsigned int len;
+	int found = 0;
+	void *buf;
 
-	seqcount_init(&tgt->tgt_seq);
-	atomic_set(&tgt->reqs, 0);
-	tgt->req_vq = &vscsi->req_vqs[0];
+	spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
 
-	starget->hostdata = tgt;
-	return 0;
-}
+	while ((buf = virtqueue_get_buf(virtscsi_vq->vq, &len)) != NULL) {
+		virtscsi_complete_cmd(vscsi, buf);
+		found++;
+	}
 
-static void virtscsi_target_destroy(struct scsi_target *starget)
-{
-	struct virtio_scsi_target_state *tgt = starget->hostdata;
-	kfree(tgt);
+	spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
+
+	return found;
 }
 
-static int virtscsi_map_queues(struct Scsi_Host *shost)
+static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
 {
 	struct virtio_scsi *vscsi = shost_priv(shost);
 
-	return blk_mq_virtio_map_queues(&shost->tag_set, vscsi->vdev, 2);
+	virtscsi_kick_vq(&vscsi->req_vqs[hwq]);
 }
 
 /*
@@ -800,64 +782,41 @@ static int virtscsi_map_queues(struct Scsi_Host *shost)
  * latencies might be higher than on bare metal.  Reset the timer
  * unconditionally to give the host a chance to perform EH.
  */
-static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
+static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
 {
-	return BLK_EH_RESET_TIMER;
+	return SCSI_EH_RESET_TIMER;
 }
 
-static struct scsi_host_template virtscsi_host_template_single = {
-	.module = THIS_MODULE,
-	.name = "Virtio SCSI HBA",
-	.proc_name = "virtio_scsi",
-	.this_id = -1,
-	.cmd_size = sizeof(struct virtio_scsi_cmd),
-	.queuecommand = virtscsi_queuecommand_single,
-	.change_queue_depth = virtscsi_change_queue_depth,
-	.eh_abort_handler = virtscsi_abort,
-	.eh_device_reset_handler = virtscsi_device_reset,
-	.eh_timed_out = virtscsi_eh_timed_out,
-	.slave_alloc = virtscsi_device_alloc,
-
-	.can_queue = 1024,
-	.dma_boundary = UINT_MAX,
-	.use_clustering = ENABLE_CLUSTERING,
-	.target_alloc = virtscsi_target_alloc,
-	.target_destroy = virtscsi_target_destroy,
-	.track_queue_depth = 1,
-};
-
-static struct scsi_host_template virtscsi_host_template_multi = {
+static const struct scsi_host_template virtscsi_host_template = {
 	.module = THIS_MODULE,
 	.name = "Virtio SCSI HBA",
 	.proc_name = "virtio_scsi",
 	.this_id = -1,
 	.cmd_size = sizeof(struct virtio_scsi_cmd),
-	.queuecommand = virtscsi_queuecommand_multi,
+	.queuecommand = virtscsi_queuecommand,
+	.mq_poll = virtscsi_mq_poll,
+	.commit_rqs = virtscsi_commit_rqs,
 	.change_queue_depth = virtscsi_change_queue_depth,
 	.eh_abort_handler = virtscsi_abort,
 	.eh_device_reset_handler = virtscsi_device_reset,
 	.eh_timed_out = virtscsi_eh_timed_out,
-	.slave_alloc = virtscsi_device_alloc,
+	.sdev_init = virtscsi_device_alloc,
 
-	.can_queue = 1024,
 	.dma_boundary = UINT_MAX,
-	.use_clustering = ENABLE_CLUSTERING,
-	.target_alloc = virtscsi_target_alloc,
-	.target_destroy = virtscsi_target_destroy,
 	.map_queues = virtscsi_map_queues,
 	.track_queue_depth = 1,
 };
 
 #define virtscsi_config_get(vdev, fld) \
 	({ \
-		typeof(((struct virtio_scsi_config *)0)->fld) __val; \
+		__virtio_native_type(struct virtio_scsi_config, fld) __val; \
 		virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
 		__val; \
 	})
 
 #define virtscsi_config_set(vdev, fld, val) \
 	do { \
-		typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
+		__virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \
 		virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
 	} while(0)
 
@@ -871,7 +830,7 @@ static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
 static void virtscsi_remove_vqs(struct virtio_device *vdev)
 {
 	/* Stop all the virtqueues. */
-	vdev->config->reset(vdev);
+	virtio_reset_device(vdev);
 	vdev->config->del_vqs(vdev);
 }
 
@@ -880,33 +839,46 @@ static int virtscsi_init(struct virtio_device *vdev,
 {
 	int err;
 	u32 i;
-	u32 num_vqs;
-	vq_callback_t **callbacks;
-	const char **names;
+	u32 num_vqs, num_poll_vqs, num_req_vqs;
+	struct virtqueue_info *vqs_info;
 	struct virtqueue **vqs;
 	struct irq_affinity desc = { .pre_vectors = 2 };
 
-	num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
-	vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL);
-	callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL);
-	names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL);
+	num_req_vqs = vscsi->num_queues;
+	num_vqs = num_req_vqs + VIRTIO_SCSI_VQ_BASE;
+	vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
+	vqs_info = kcalloc(num_vqs, sizeof(*vqs_info), GFP_KERNEL);
 
-	if (!callbacks || !vqs || !names) {
+	if (!vqs || !vqs_info) {
 		err = -ENOMEM;
 		goto out;
 	}
 
-	callbacks[0] = virtscsi_ctrl_done;
-	callbacks[1] = virtscsi_event_done;
-	names[0] = "control";
-	names[1] = "event";
-	for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
-		callbacks[i] = virtscsi_req_done;
-		names[i] = "request";
+	num_poll_vqs = min_t(unsigned int, virtscsi_poll_queues,
+			     num_req_vqs - 1);
+	vscsi->io_queues[HCTX_TYPE_DEFAULT] = num_req_vqs - num_poll_vqs;
+	vscsi->io_queues[HCTX_TYPE_READ] = 0;
+	vscsi->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
+
+	dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
+		 vscsi->io_queues[HCTX_TYPE_DEFAULT],
+		 vscsi->io_queues[HCTX_TYPE_READ],
+		 vscsi->io_queues[HCTX_TYPE_POLL]);
+
+	vqs_info[0].callback = virtscsi_ctrl_done;
+	vqs_info[0].name = "control";
+	vqs_info[1].callback = virtscsi_event_done;
+	vqs_info[1].name = "event";
+	for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs - num_poll_vqs; i++) {
+		vqs_info[i].callback = virtscsi_req_done;
+		vqs_info[i].name = "request";
 	}
 
+	for (; i < num_vqs; i++)
+		vqs_info[i].name = "request_poll";
+
 	/* Discover virtqueues and write information to configuration.  */
-	err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
+	err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, &desc);
 	if (err)
 		goto out;
 
@@ -922,8 +894,7 @@ static int virtscsi_init(struct virtio_device *vdev,
 	err = 0;
 
 out:
-	kfree(names);
-	kfree(callbacks);
+	kfree(vqs_info);
 	kfree(vqs);
 	if (err)
 		virtscsi_remove_vqs(vdev);
@@ -938,7 +909,6 @@ static int virtscsi_probe(struct virtio_device *vdev)
 	u32 sg_elems, num_targets;
 	u32 cmd_per_lun;
 	u32 num_queues;
-	struct scsi_host_template *hostt;
 
 	if (!vdev->config->get) {
 		dev_err(&vdev->dev, "%s failure: config access disabled\n",
@@ -948,21 +918,19 @@ static int virtscsi_probe(struct virtio_device *vdev)
 
 	/* We need to know how many queues before we allocate. */
 	num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
+	num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
+	num_queues = blk_mq_num_possible_queues(num_queues);
 
 	num_targets = virtscsi_config_get(vdev, max_target) + 1;
 
-	if (num_queues == 1)
-		hostt = &virtscsi_host_template_single;
-	else
-		hostt = &virtscsi_host_template_multi;
-
-	shost = scsi_host_alloc(hostt,
-		sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
+	shost = scsi_host_alloc(&virtscsi_host_template,
+				struct_size(vscsi, req_vqs, num_queues));
 	if (!shost)
 		return -ENOMEM;
 
 	sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
 	shost->sg_tablesize = sg_elems;
+	shost->nr_maps = 1;
 	vscsi = shost_priv(shost);
 	vscsi->vdev = vdev;
 	vscsi->num_queues = num_queues;
@@ -972,6 +940,11 @@ static int virtscsi_probe(struct virtio_device *vdev)
 	if (err)
 		goto virtscsi_init_failed;
 
+	if (vscsi->io_queues[HCTX_TYPE_POLL])
+		shost->nr_maps = HCTX_TYPE_POLL + 1;
+
+	shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
+
 	cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
 	shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
 	shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
@@ -1073,7 +1046,6 @@ static struct virtio_driver virtio_scsi_driver = {
 	.feature_table = features,
 	.feature_table_size = ARRAY_SIZE(features),
 	.driver.name = KBUILD_MODNAME,
-	.driver.owner = THIS_MODULE,
 	.id_table = id_table,
 	.probe = virtscsi_probe,
 #ifdef CONFIG_PM_SLEEP
@@ -1083,7 +1055,7 @@ static struct virtio_driver virtio_scsi_driver = {
 	.remove = virtscsi_remove,
 };
 
-static int __init init(void)
+static int __init virtio_scsi_init(void)
 {
 	int ret = -ENOMEM;
 
@@ -1108,25 +1080,21 @@ static int __init init(void)
 	return 0;
 
 error:
-	if (virtscsi_cmd_pool) {
-		mempool_destroy(virtscsi_cmd_pool);
-		virtscsi_cmd_pool = NULL;
-	}
-	if (virtscsi_cmd_cache) {
-		kmem_cache_destroy(virtscsi_cmd_cache);
-		virtscsi_cmd_cache = NULL;
-	}
+	mempool_destroy(virtscsi_cmd_pool);
+	virtscsi_cmd_pool = NULL;
+	kmem_cache_destroy(virtscsi_cmd_cache);
+	virtscsi_cmd_cache = NULL;
 	return ret;
 }
 
-static void __exit fini(void)
+static void __exit virtio_scsi_fini(void)
 {
 	unregister_virtio_driver(&virtio_scsi_driver);
 	mempool_destroy(virtscsi_cmd_pool);
 	kmem_cache_destroy(virtscsi_cmd_cache);
 }
-module_init(init);
-module_exit(fini);
+module_init(virtio_scsi_init);
+module_exit(virtio_scsi_fini);
 
 MODULE_DEVICE_TABLE(virtio, id_table);
 MODULE_DESCRIPTION("Virtio SCSI HBA driver");