1 files changed, 272 insertions, 65 deletions

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 1b3843117268..c7030fbee79c 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -25,6 +25,7 @@
 #include <scsi/scsi_cmnd.h>
 
 #define VIRTIO_SCSI_MEMPOOL_SZ 64
+#define VIRTIO_SCSI_EVENT_LEN 8
 
 /* Command queue element */
 struct virtio_scsi_cmd {
@@ -43,20 +44,42 @@ struct virtio_scsi_cmd {
 	} resp;
 } ____cacheline_aligned_in_smp;
 
-/* Driver instance state */
-struct virtio_scsi {
-	/* Protects ctrl_vq, req_vq and sg[] */
+struct virtio_scsi_event_node {
+	struct virtio_scsi *vscsi;
+	struct virtio_scsi_event event;
+	struct work_struct work;
+};
+
+struct virtio_scsi_vq {
+	/* Protects vq */
 	spinlock_t vq_lock;
 
-	struct virtio_device *vdev;
-	struct virtqueue *ctrl_vq;
-	struct virtqueue *event_vq;
-	struct virtqueue *req_vq;
+	struct virtqueue *vq;
+};
+
+/* Per-target queue state */
+struct virtio_scsi_target_state {
+	/* Protects sg.  Lock hierarchy is tgt_lock -> vq_lock.  */
+	spinlock_t tgt_lock;
 
 	/* For sglist construction when adding commands to the virtqueue.  */
 	struct scatterlist sg[];
 };
 
+/* Driver instance state */
+struct virtio_scsi {
+	struct virtio_device *vdev;
+
+	struct virtio_scsi_vq ctrl_vq;
+	struct virtio_scsi_vq event_vq;
+	struct virtio_scsi_vq req_vq;
+
+	/* Get some buffers ready for event vq */
+	struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
+
+	struct virtio_scsi_target_state *tgt[];
+};
+
 static struct kmem_cache *virtscsi_cmd_cache;
 static mempool_t *virtscsi_cmd_pool;
 
@@ -147,26 +170,25 @@ static void virtscsi_complete_cmd(void *buf)
 
 static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
 {
-	struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
-	struct virtio_scsi *vscsi = shost_priv(sh);
 	void *buf;
-	unsigned long flags;
 	unsigned int len;
 
-	spin_lock_irqsave(&vscsi->vq_lock, flags);
-
 	do {
 		virtqueue_disable_cb(vq);
 		while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
 			fn(buf);
 	} while (!virtqueue_enable_cb(vq));
-
-	spin_unlock_irqrestore(&vscsi->vq_lock, flags);
 }
 
 static void virtscsi_req_done(struct virtqueue *vq)
 {
+	struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
+	struct virtio_scsi *vscsi = shost_priv(sh);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vscsi->req_vq.vq_lock, flags);
 	virtscsi_vq_done(vq, virtscsi_complete_cmd);
+	spin_unlock_irqrestore(&vscsi->req_vq.vq_lock, flags);
 };
 
 static void virtscsi_complete_free(void *buf)
@@ -181,12 +203,123 @@ static void virtscsi_complete_free(void *buf)
 
 static void virtscsi_ctrl_done(struct virtqueue *vq)
 {
+	struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
+	struct virtio_scsi *vscsi = shost_priv(sh);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vscsi->ctrl_vq.vq_lock, flags);
 	virtscsi_vq_done(vq, virtscsi_complete_free);
+	spin_unlock_irqrestore(&vscsi->ctrl_vq.vq_lock, flags);
 };
 
+static int virtscsi_kick_event(struct virtio_scsi *vscsi,
+			       struct virtio_scsi_event_node *event_node)
+{
+	int ret;
+	struct scatterlist sg;
+	unsigned long flags;
+
+	sg_set_buf(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
+
+	spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
+
+	ret = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node, GFP_ATOMIC);
+	if (ret >= 0)
+		virtqueue_kick(vscsi->event_vq.vq);
+
+	spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
+
+	return ret;
+}
+
+static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
+{
+	int i;
+
+	for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
+		vscsi->event_list[i].vscsi = vscsi;
+		virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
+	}
+
+	return 0;
+}
+
+static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
+{
+	int i;
+
+	for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
+		cancel_work_sync(&vscsi->event_list[i].work);
+}
+
+static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
+						struct virtio_scsi_event *event)
+{
+	struct scsi_device *sdev;
+	struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+	unsigned int target = event->lun[1];
+	unsigned int lun = (event->lun[2] << 8) | event->lun[3];
+
+	switch (event->reason) {
+	case VIRTIO_SCSI_EVT_RESET_RESCAN:
+		scsi_add_device(shost, 0, target, lun);
+		break;
+	case VIRTIO_SCSI_EVT_RESET_REMOVED:
+		sdev = scsi_device_lookup(shost, 0, target, lun);
+		if (sdev) {
+			scsi_remove_device(sdev);
+			scsi_device_put(sdev);
+		} else {
+			pr_err("SCSI device %d 0 %d %d not found\n",
+				shost->host_no, target, lun);
+		}
+		break;
+	default:
+		pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
+	}
+}
+
+static void virtscsi_handle_event(struct work_struct *work)
+{
+	struct virtio_scsi_event_node *event_node =
+		container_of(work, struct virtio_scsi_event_node, work);
+	struct virtio_scsi *vscsi = event_node->vscsi;
+	struct virtio_scsi_event *event = &event_node->event;
+
+	if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
+		event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
+		scsi_scan_host(virtio_scsi_host(vscsi->vdev));
+	}
+
+	switch (event->event) {
+	case VIRTIO_SCSI_T_NO_EVENT:
+		break;
+	case VIRTIO_SCSI_T_TRANSPORT_RESET:
+		virtscsi_handle_transport_reset(vscsi, event);
+		break;
+	default:
+		pr_err("Unsupport virtio scsi event %x\n", event->event);
+	}
+	virtscsi_kick_event(vscsi, event_node);
+}
+
+static void virtscsi_complete_event(void *buf)
+{
+	struct virtio_scsi_event_node *event_node = buf;
+
+	INIT_WORK(&event_node->work, virtscsi_handle_event);
+	schedule_work(&event_node->work);
+}
+
 static void virtscsi_event_done(struct virtqueue *vq)
 {
-	virtscsi_vq_done(vq, virtscsi_complete_free);
+	struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
+	struct virtio_scsi *vscsi = shost_priv(sh);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
+	virtscsi_vq_done(vq, virtscsi_complete_event);
+	spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
 };
 
 static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
@@ -212,25 +345,17 @@ static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
  * @req_size	: size of the request buffer
  * @resp_size	: size of the response buffer
  *
- * Called with vq_lock held.
+ * Called with tgt_lock held.
  */
-static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
+static void virtscsi_map_cmd(struct virtio_scsi_target_state *tgt,
 			     struct virtio_scsi_cmd *cmd,
 			     unsigned *out_num, unsigned *in_num,
 			     size_t req_size, size_t resp_size)
 {
 	struct scsi_cmnd *sc = cmd->sc;
-	struct scatterlist *sg = vscsi->sg;
+	struct scatterlist *sg = tgt->sg;
 	unsigned int idx = 0;
 
-	if (sc) {
-		struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
-		BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
-
-		/* TODO: check feature bit and fail if unsupported?  */
-		BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
-	}
-
 	/* Request header.  */
 	sg_set_buf(&sg[idx++], &cmd->req, req_size);
 
@@ -250,7 +375,8 @@ static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
 	*in_num = idx - *out_num;
 }
 
-static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtqueue *vq,
+static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
+			     struct virtio_scsi_vq *vq,
 			     struct virtio_scsi_cmd *cmd,
 			     size_t req_size, size_t resp_size, gfp_t gfp)
 {
@@ -258,24 +384,35 @@ static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtqueue *vq,
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&vscsi->vq_lock, flags);
-
-	virtscsi_map_cmd(vscsi, cmd, &out_num, &in_num, req_size, resp_size);
+	spin_lock_irqsave(&tgt->tgt_lock, flags);
+	virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
 
-	ret = virtqueue_add_buf(vq, vscsi->sg, out_num, in_num, cmd, gfp);
+	spin_lock(&vq->vq_lock);
+	ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
+	spin_unlock(&tgt->tgt_lock);
 	if (ret >= 0)
-		virtqueue_kick(vq);
+		ret = virtqueue_kick_prepare(vq->vq);
+
+	spin_unlock_irqrestore(&vq->vq_lock, flags);
 
-	spin_unlock_irqrestore(&vscsi->vq_lock, flags);
+	if (ret > 0)
+		virtqueue_notify(vq->vq);
 	return ret;
 }
 
 static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 {
 	struct virtio_scsi *vscsi = shost_priv(sh);
+	struct virtio_scsi_target_state *tgt = vscsi->tgt[sc->device->id];
 	struct virtio_scsi_cmd *cmd;
 	int ret;
 
+	struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+	BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
+
+	/* TODO: check feature bit and fail if unsupported?  */
+	BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
+
 	dev_dbg(&sc->device->sdev_gendev,
 		"cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
 
@@ -300,7 +437,7 @@ static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 	BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
 	memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
 
-	if (virtscsi_kick_cmd(vscsi, vscsi->req_vq, cmd,
+	if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
 			      sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
 			      GFP_ATOMIC) >= 0)
 		ret = 0;
@@ -312,10 +449,11 @@ out:
 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
 {
 	DECLARE_COMPLETION_ONSTACK(comp);
+	struct virtio_scsi_target_state *tgt = vscsi->tgt[cmd->sc->device->id];
 	int ret = FAILED;
 
 	cmd->comp = &comp;
-	if (virtscsi_kick_cmd(vscsi, vscsi->ctrl_vq, cmd,
+	if (virtscsi_kick_cmd(tgt, &vscsi->ctrl_vq, cmd,
 			      sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
 			      GFP_NOIO) < 0)
 		goto out;
@@ -408,11 +546,63 @@ static struct scsi_host_template virtscsi_host_template = {
 				  &__val, sizeof(__val)); \
 	})
 
+static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
+			     struct virtqueue *vq)
+{
+	spin_lock_init(&virtscsi_vq->vq_lock);
+	virtscsi_vq->vq = vq;
+}
+
+static struct virtio_scsi_target_state *virtscsi_alloc_tgt(
+	struct virtio_device *vdev, int sg_elems)
+{
+	struct virtio_scsi_target_state *tgt;
+	gfp_t gfp_mask = GFP_KERNEL;
+
+	/* We need extra sg elements at head and tail.  */
+	tgt = kmalloc(sizeof(*tgt) + sizeof(tgt->sg[0]) * (sg_elems + 2),
+		      gfp_mask);
+
+	if (!tgt)
+		return NULL;
+
+	spin_lock_init(&tgt->tgt_lock);
+	sg_init_table(tgt->sg, sg_elems + 2);
+	return tgt;
+}
+
+static void virtscsi_scan(struct virtio_device *vdev)
+{
+	struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv;
+
+	scsi_scan_host(shost);
+}
+
+static void virtscsi_remove_vqs(struct virtio_device *vdev)
+{
+	struct Scsi_Host *sh = virtio_scsi_host(vdev);
+	struct virtio_scsi *vscsi = shost_priv(sh);
+	u32 i, num_targets;
+
+	/* Stop all the virtqueues. */
+	vdev->config->reset(vdev);
+
+	num_targets = sh->max_id;
+	for (i = 0; i < num_targets; i++) {
+		kfree(vscsi->tgt[i]);
+		vscsi->tgt[i] = NULL;
+	}
+
+	vdev->config->del_vqs(vdev);
+}
+
 static int virtscsi_init(struct virtio_device *vdev,
-			 struct virtio_scsi *vscsi)
+			 struct virtio_scsi *vscsi, int num_targets)
 {
 	int err;
 	struct virtqueue *vqs[3];
+	u32 i, sg_elems;
+
 	vq_callback_t *callbacks[] = {
 		virtscsi_ctrl_done,
 		virtscsi_event_done,
@@ -429,13 +619,32 @@ static int virtscsi_init(struct virtio_device *vdev,
 	if (err)
 		return err;
 
-	vscsi->ctrl_vq = vqs[0];
-	vscsi->event_vq = vqs[1];
-	vscsi->req_vq = vqs[2];
+	virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
+	virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
+	virtscsi_init_vq(&vscsi->req_vq, vqs[2]);
 
 	virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
 	virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
-	return 0;
+
+	if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
+		virtscsi_kick_event_all(vscsi);
+
+	/* We need to know how many segments before we allocate.  */
+	sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
+
+	for (i = 0; i < num_targets; i++) {
+		vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
+		if (!vscsi->tgt[i]) {
+			err = -ENOMEM;
+			goto out;
+		}
+	}
+	err = 0;
+
+out:
+	if (err)
+		virtscsi_remove_vqs(vdev);
+	return err;
 }
 
 static int __devinit virtscsi_probe(struct virtio_device *vdev)
@@ -443,31 +652,25 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
 	struct Scsi_Host *shost;
 	struct virtio_scsi *vscsi;
 	int err;
-	u32 sg_elems;
+	u32 sg_elems, num_targets;
 	u32 cmd_per_lun;
 
-	/* We need to know how many segments before we allocate.
-	 * We need an extra sg elements at head and tail.
-	 */
-	sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
-
 	/* Allocate memory and link the structs together.  */
+	num_targets = virtscsi_config_get(vdev, max_target) + 1;
 	shost = scsi_host_alloc(&virtscsi_host_template,
-		sizeof(*vscsi) + sizeof(vscsi->sg[0]) * (sg_elems + 2));
+		sizeof(*vscsi)
+		+ num_targets * sizeof(struct virtio_scsi_target_state));
 
 	if (!shost)
 		return -ENOMEM;
 
+	sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
 	shost->sg_tablesize = sg_elems;
 	vscsi = shost_priv(shost);
 	vscsi->vdev = vdev;
 	vdev->priv = shost;
 
-	/* Random initializations.  */
-	spin_lock_init(&vscsi->vq_lock);
-	sg_init_table(vscsi->sg, sg_elems + 2);
-
-	err = virtscsi_init(vdev, vscsi);
+	err = virtscsi_init(vdev, vscsi, num_targets);
 	if (err)
 		goto virtscsi_init_failed;
 
@@ -475,15 +678,16 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
 	shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
 	shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
 	shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1;
-	shost->max_id = virtscsi_config_get(vdev, max_target) + 1;
+	shost->max_id = num_targets;
 	shost->max_channel = 0;
 	shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
 	err = scsi_add_host(shost, &vdev->dev);
 	if (err)
 		goto scsi_add_host_failed;
-
-	scsi_scan_host(shost);
-
+	/*
+	 * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
+	 * after VIRTIO_CONFIG_S_DRIVER_OK has been set..
+	 */
 	return 0;
 
 scsi_add_host_failed:
@@ -493,17 +697,13 @@ virtscsi_init_failed:
 	return err;
 }
 
-static void virtscsi_remove_vqs(struct virtio_device *vdev)
-{
-	/* Stop all the virtqueues. */
-	vdev->config->reset(vdev);
-
-	vdev->config->del_vqs(vdev);
-}
-
 static void __devexit virtscsi_remove(struct virtio_device *vdev)
 {
 	struct Scsi_Host *shost = virtio_scsi_host(vdev);
+	struct virtio_scsi *vscsi = shost_priv(shost);
+
+	if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
+		virtscsi_cancel_event_work(vscsi);
 
 	scsi_remove_host(shost);
 
@@ -523,7 +723,7 @@ static int virtscsi_restore(struct virtio_device *vdev)
 	struct Scsi_Host *sh = virtio_scsi_host(vdev);
 	struct virtio_scsi *vscsi = shost_priv(sh);
 
-	return virtscsi_init(vdev, vscsi);
+	return virtscsi_init(vdev, vscsi, sh->max_id);
 }
 #endif
 
@@ -532,11 +732,18 @@ static struct virtio_device_id id_table[] = {
 	{ 0 },
 };
 
+static unsigned int features[] = {
+	VIRTIO_SCSI_F_HOTPLUG
+};
+
 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,
+	.scan = virtscsi_scan,
 #ifdef CONFIG_PM
 	.freeze = virtscsi_freeze,
 	.restore = virtscsi_restore,