2 * Virtio SCSI HBA driver
4 * Copyright IBM Corp. 2010
5 * Copyright Red Hat, Inc. 2011
8 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
9 * Paolo Bonzini <pbonzini@redhat.com>
11 * This work is licensed under the terms of the GNU GPL, version 2 or later.
12 * See the COPYING file in the top-level directory.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/mempool.h>
21 #include <linux/virtio.h>
22 #include <linux/virtio_ids.h>
23 #include <linux/virtio_config.h>
24 #include <linux/virtio_scsi.h>
25 #include <linux/cpu.h>
26 #include <linux/blkdev.h>
27 #include <scsi/scsi_host.h>
28 #include <scsi/scsi_device.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_tcq.h>
31 #include <linux/seqlock.h>
33 #define VIRTIO_SCSI_MEMPOOL_SZ 64
34 #define VIRTIO_SCSI_EVENT_LEN 8
35 #define VIRTIO_SCSI_VQ_BASE 2
37 /* Command queue element */
38 struct virtio_scsi_cmd {
40 struct completion *comp;
42 struct virtio_scsi_cmd_req cmd;
43 struct virtio_scsi_cmd_req_pi cmd_pi;
44 struct virtio_scsi_ctrl_tmf_req tmf;
45 struct virtio_scsi_ctrl_an_req an;
48 struct virtio_scsi_cmd_resp cmd;
49 struct virtio_scsi_ctrl_tmf_resp tmf;
50 struct virtio_scsi_ctrl_an_resp an;
51 struct virtio_scsi_event evt;
53 } ____cacheline_aligned_in_smp;
55 struct virtio_scsi_event_node {
56 struct virtio_scsi *vscsi;
57 struct virtio_scsi_event event;
58 struct work_struct work;
61 struct virtio_scsi_vq {
69 * Per-target queue state.
71 * This struct holds the data needed by the queue steering policy. When a
72 * target is sent multiple requests, we need to drive them to the same queue so
73 * that FIFO processing order is kept. However, if a target was idle, we can
74 * choose a queue arbitrarily. In this case the queue is chosen according to
75 * the current VCPU, so the driver expects the number of request queues to be
76 * equal to the number of VCPUs. This makes it easy and fast to select the
77 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues
78 * (each virtqueue's affinity is set to the CPU that "owns" the queue).
80 * tgt_seq is held to serialize reading and writing req_vq.
82 * Decrements of reqs are never concurrent with writes of req_vq: before the
83 * decrement reqs will be != 0; after the decrement the virtqueue completion
84 * routine will not use the req_vq so it can be changed by a new request.
85 * Thus they can happen outside the tgt_seq, provided of course we make reqs
88 struct virtio_scsi_target_state {
91 /* Count of outstanding requests. */
94 /* Currently active virtqueue for requests sent to this target. */
95 struct virtio_scsi_vq *req_vq;
98 /* Driver instance state */
100 struct virtio_device *vdev;
102 /* Get some buffers ready for event vq */
103 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
107 /* If the affinity hint is set for virtqueues */
108 bool affinity_hint_set;
110 /* CPU hotplug notifier */
111 struct notifier_block nb;
113 /* Protected by event_vq lock */
116 struct virtio_scsi_vq ctrl_vq;
117 struct virtio_scsi_vq event_vq;
118 struct virtio_scsi_vq req_vqs[];
121 static struct kmem_cache *virtscsi_cmd_cache;
122 static mempool_t *virtscsi_cmd_pool;
124 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
129 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
134 if (!scsi_bidi_cmnd(sc)) {
135 scsi_set_resid(sc, resid);
139 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
140 scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
144 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
146 * Called with vq_lock held.
148 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
150 struct virtio_scsi_cmd *cmd = buf;
151 struct scsi_cmnd *sc = cmd->sc;
152 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
153 struct virtio_scsi_target_state *tgt =
154 scsi_target(sc->device)->hostdata;
156 dev_dbg(&sc->device->sdev_gendev,
157 "cmd %p response %u status %#02x sense_len %u\n",
158 sc, resp->response, resp->status, resp->sense_len);
160 sc->result = resp->status;
161 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid));
162 switch (resp->response) {
163 case VIRTIO_SCSI_S_OK:
164 set_host_byte(sc, DID_OK);
166 case VIRTIO_SCSI_S_OVERRUN:
167 set_host_byte(sc, DID_ERROR);
169 case VIRTIO_SCSI_S_ABORTED:
170 set_host_byte(sc, DID_ABORT);
172 case VIRTIO_SCSI_S_BAD_TARGET:
173 set_host_byte(sc, DID_BAD_TARGET);
175 case VIRTIO_SCSI_S_RESET:
176 set_host_byte(sc, DID_RESET);
178 case VIRTIO_SCSI_S_BUSY:
179 set_host_byte(sc, DID_BUS_BUSY);
181 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
182 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
184 case VIRTIO_SCSI_S_TARGET_FAILURE:
185 set_host_byte(sc, DID_TARGET_FAILURE);
187 case VIRTIO_SCSI_S_NEXUS_FAILURE:
188 set_host_byte(sc, DID_NEXUS_FAILURE);
191 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
194 case VIRTIO_SCSI_S_FAILURE:
195 set_host_byte(sc, DID_ERROR);
199 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
200 VIRTIO_SCSI_SENSE_SIZE);
201 if (sc->sense_buffer) {
202 memcpy(sc->sense_buffer, resp->sense,
204 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
205 VIRTIO_SCSI_SENSE_SIZE));
207 set_driver_byte(sc, DRIVER_SENSE);
212 atomic_dec(&tgt->reqs);
215 static void virtscsi_vq_done(struct virtio_scsi *vscsi,
216 struct virtio_scsi_vq *virtscsi_vq,
217 void (*fn)(struct virtio_scsi *vscsi, void *buf))
222 struct virtqueue *vq = virtscsi_vq->vq;
224 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
226 virtqueue_disable_cb(vq);
227 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
230 if (unlikely(virtqueue_is_broken(vq)))
232 } while (!virtqueue_enable_cb(vq));
233 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
236 static void virtscsi_req_done(struct virtqueue *vq)
238 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
239 struct virtio_scsi *vscsi = shost_priv(sh);
240 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
241 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
243 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
246 static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
250 num_vqs = vscsi->num_queues;
251 for (i = 0; i < num_vqs; i++)
252 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
253 virtscsi_complete_cmd);
256 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
258 struct virtio_scsi_cmd *cmd = buf;
261 complete_all(cmd->comp);
264 static void virtscsi_ctrl_done(struct virtqueue *vq)
266 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
267 struct virtio_scsi *vscsi = shost_priv(sh);
269 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
272 static void virtscsi_handle_event(struct work_struct *work);
274 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
275 struct virtio_scsi_event_node *event_node)
278 struct scatterlist sg;
281 INIT_WORK(&event_node->work, virtscsi_handle_event);
282 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
284 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
286 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
289 virtqueue_kick(vscsi->event_vq.vq);
291 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
296 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
300 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
301 vscsi->event_list[i].vscsi = vscsi;
302 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
308 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
312 /* Stop scheduling work before calling cancel_work_sync. */
313 spin_lock_irq(&vscsi->event_vq.vq_lock);
314 vscsi->stop_events = true;
315 spin_unlock_irq(&vscsi->event_vq.vq_lock);
317 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
318 cancel_work_sync(&vscsi->event_list[i].work);
321 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
322 struct virtio_scsi_event *event)
324 struct scsi_device *sdev;
325 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
326 unsigned int target = event->lun[1];
327 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
329 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
330 case VIRTIO_SCSI_EVT_RESET_RESCAN:
331 scsi_add_device(shost, 0, target, lun);
333 case VIRTIO_SCSI_EVT_RESET_REMOVED:
334 sdev = scsi_device_lookup(shost, 0, target, lun);
336 scsi_remove_device(sdev);
337 scsi_device_put(sdev);
339 pr_err("SCSI device %d 0 %d %d not found\n",
340 shost->host_no, target, lun);
344 pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
348 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
349 struct virtio_scsi_event *event)
351 struct scsi_device *sdev;
352 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
353 unsigned int target = event->lun[1];
354 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
355 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255;
356 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8;
358 sdev = scsi_device_lookup(shost, 0, target, lun);
360 pr_err("SCSI device %d 0 %d %d not found\n",
361 shost->host_no, target, lun);
365 /* Handle "Parameters changed", "Mode parameters changed", and
366 "Capacity data has changed". */
367 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
368 scsi_rescan_device(&sdev->sdev_gendev);
370 scsi_device_put(sdev);
373 static void virtscsi_handle_event(struct work_struct *work)
375 struct virtio_scsi_event_node *event_node =
376 container_of(work, struct virtio_scsi_event_node, work);
377 struct virtio_scsi *vscsi = event_node->vscsi;
378 struct virtio_scsi_event *event = &event_node->event;
381 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
382 event->event &= ~cpu_to_virtio32(vscsi->vdev,
383 VIRTIO_SCSI_T_EVENTS_MISSED);
384 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
387 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
388 case VIRTIO_SCSI_T_NO_EVENT:
390 case VIRTIO_SCSI_T_TRANSPORT_RESET:
391 virtscsi_handle_transport_reset(vscsi, event);
393 case VIRTIO_SCSI_T_PARAM_CHANGE:
394 virtscsi_handle_param_change(vscsi, event);
397 pr_err("Unsupport virtio scsi event %x\n", event->event);
399 virtscsi_kick_event(vscsi, event_node);
402 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
404 struct virtio_scsi_event_node *event_node = buf;
406 if (!vscsi->stop_events)
407 queue_work(system_freezable_wq, &event_node->work);
410 static void virtscsi_event_done(struct virtqueue *vq)
412 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
413 struct virtio_scsi *vscsi = shost_priv(sh);
415 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
419 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
420 * @vq : the struct virtqueue we're talking about
421 * @cmd : command structure
422 * @req_size : size of the request buffer
423 * @resp_size : size of the response buffer
425 static int virtscsi_add_cmd(struct virtqueue *vq,
426 struct virtio_scsi_cmd *cmd,
427 size_t req_size, size_t resp_size)
429 struct scsi_cmnd *sc = cmd->sc;
430 struct scatterlist *sgs[6], req, resp;
431 struct sg_table *out, *in;
432 unsigned out_num = 0, in_num = 0;
436 if (sc && sc->sc_data_direction != DMA_NONE) {
437 if (sc->sc_data_direction != DMA_FROM_DEVICE)
438 out = &scsi_out(sc)->table;
439 if (sc->sc_data_direction != DMA_TO_DEVICE)
440 in = &scsi_in(sc)->table;
443 /* Request header. */
444 sg_init_one(&req, &cmd->req, req_size);
445 sgs[out_num++] = &req;
447 /* Data-out buffer. */
449 /* Place WRITE protection SGLs before Data OUT payload */
450 if (scsi_prot_sg_count(sc))
451 sgs[out_num++] = scsi_prot_sglist(sc);
452 sgs[out_num++] = out->sgl;
455 /* Response header. */
456 sg_init_one(&resp, &cmd->resp, resp_size);
457 sgs[out_num + in_num++] = &resp;
461 /* Place READ protection SGLs before Data IN payload */
462 if (scsi_prot_sg_count(sc))
463 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
464 sgs[out_num + in_num++] = in->sgl;
467 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
470 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
471 struct virtio_scsi_cmd *cmd,
472 size_t req_size, size_t resp_size)
476 bool needs_kick = false;
478 spin_lock_irqsave(&vq->vq_lock, flags);
479 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
481 needs_kick = virtqueue_kick_prepare(vq->vq);
483 spin_unlock_irqrestore(&vq->vq_lock, flags);
486 virtqueue_notify(vq->vq);
490 static void virtio_scsi_init_hdr(struct virtio_device *vdev,
491 struct virtio_scsi_cmd_req *cmd,
492 struct scsi_cmnd *sc)
495 cmd->lun[1] = sc->device->id;
496 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
497 cmd->lun[3] = sc->device->lun & 0xff;
498 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
499 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
504 #ifdef CONFIG_BLK_DEV_INTEGRITY
505 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
506 struct virtio_scsi_cmd_req_pi *cmd_pi,
507 struct scsi_cmnd *sc)
509 struct request *rq = sc->request;
510 struct blk_integrity *bi;
512 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
514 if (!rq || !scsi_prot_sg_count(sc))
517 bi = blk_get_integrity(rq->rq_disk);
519 if (sc->sc_data_direction == DMA_TO_DEVICE)
520 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
523 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
524 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
530 static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
531 struct virtio_scsi_vq *req_vq,
532 struct scsi_cmnd *sc)
534 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
535 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
538 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
540 /* TODO: check feature bit and fail if unsupported? */
541 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
543 dev_dbg(&sc->device->sdev_gendev,
544 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
546 memset(cmd, 0, sizeof(*cmd));
549 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
551 #ifdef CONFIG_BLK_DEV_INTEGRITY
552 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
553 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
554 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
555 req_size = sizeof(cmd->req.cmd_pi);
559 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
560 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
561 req_size = sizeof(cmd->req.cmd);
564 if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0)
565 return SCSI_MLQUEUE_HOST_BUSY;
569 static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
570 struct scsi_cmnd *sc)
572 struct virtio_scsi *vscsi = shost_priv(sh);
573 struct virtio_scsi_target_state *tgt =
574 scsi_target(sc->device)->hostdata;
576 atomic_inc(&tgt->reqs);
577 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc);
580 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
581 struct scsi_cmnd *sc)
583 u32 tag = blk_mq_unique_tag(sc->request);
584 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
586 return &vscsi->req_vqs[hwq];
589 static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi,
590 struct virtio_scsi_target_state *tgt)
592 struct virtio_scsi_vq *vq;
596 local_irq_save(flags);
597 if (atomic_inc_return(&tgt->reqs) > 1) {
601 seq = read_seqcount_begin(&tgt->tgt_seq);
603 } while (read_seqcount_retry(&tgt->tgt_seq, seq));
605 /* no writes can be concurrent because of atomic_t */
606 write_seqcount_begin(&tgt->tgt_seq);
608 /* keep previous req_vq if a reader just arrived */
609 if (unlikely(atomic_read(&tgt->reqs) > 1)) {
614 queue_num = smp_processor_id();
615 while (unlikely(queue_num >= vscsi->num_queues))
616 queue_num -= vscsi->num_queues;
617 tgt->req_vq = vq = &vscsi->req_vqs[queue_num];
619 write_seqcount_end(&tgt->tgt_seq);
621 local_irq_restore(flags);
626 static int virtscsi_queuecommand_multi(struct Scsi_Host *sh,
627 struct scsi_cmnd *sc)
629 struct virtio_scsi *vscsi = shost_priv(sh);
630 struct virtio_scsi_target_state *tgt =
631 scsi_target(sc->device)->hostdata;
632 struct virtio_scsi_vq *req_vq;
634 if (shost_use_blk_mq(sh))
635 req_vq = virtscsi_pick_vq_mq(vscsi, sc);
637 req_vq = virtscsi_pick_vq(vscsi, tgt);
639 return virtscsi_queuecommand(vscsi, req_vq, sc);
642 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
644 DECLARE_COMPLETION_ONSTACK(comp);
648 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
649 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
652 wait_for_completion(&comp);
653 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
654 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
658 * The spec guarantees that all requests related to the TMF have
659 * been completed, but the callback might not have run yet if
660 * we're using independent interrupts (e.g. MSI). Poll the
663 * In the abort case, sc->scsi_done will do nothing, because
664 * the block layer must have detected a timeout and as a result
665 * REQ_ATOM_COMPLETE has been set.
667 virtscsi_poll_requests(vscsi);
670 mempool_free(cmd, virtscsi_cmd_pool);
674 static int virtscsi_device_reset(struct scsi_cmnd *sc)
676 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
677 struct virtio_scsi_cmd *cmd;
679 sdev_printk(KERN_INFO, sc->device, "device reset\n");
680 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
684 memset(cmd, 0, sizeof(*cmd));
686 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
687 .type = VIRTIO_SCSI_T_TMF,
688 .subtype = cpu_to_virtio32(vscsi->vdev,
689 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
691 .lun[1] = sc->device->id,
692 .lun[2] = (sc->device->lun >> 8) | 0x40,
693 .lun[3] = sc->device->lun & 0xff,
695 return virtscsi_tmf(vscsi, cmd);
699 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
700 * @sdev: Virtscsi target whose queue depth to change
701 * @qdepth: New queue depth
703 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
705 struct Scsi_Host *shost = sdev->host;
706 int max_depth = shost->cmd_per_lun;
708 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
711 static int virtscsi_abort(struct scsi_cmnd *sc)
713 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
714 struct virtio_scsi_cmd *cmd;
716 scmd_printk(KERN_INFO, sc, "abort\n");
717 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
721 memset(cmd, 0, sizeof(*cmd));
723 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
724 .type = VIRTIO_SCSI_T_TMF,
725 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
727 .lun[1] = sc->device->id,
728 .lun[2] = (sc->device->lun >> 8) | 0x40,
729 .lun[3] = sc->device->lun & 0xff,
730 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
732 return virtscsi_tmf(vscsi, cmd);
735 static int virtscsi_target_alloc(struct scsi_target *starget)
737 struct Scsi_Host *sh = dev_to_shost(starget->dev.parent);
738 struct virtio_scsi *vscsi = shost_priv(sh);
740 struct virtio_scsi_target_state *tgt =
741 kmalloc(sizeof(*tgt), GFP_KERNEL);
745 seqcount_init(&tgt->tgt_seq);
746 atomic_set(&tgt->reqs, 0);
747 tgt->req_vq = &vscsi->req_vqs[0];
749 starget->hostdata = tgt;
753 static void virtscsi_target_destroy(struct scsi_target *starget)
755 struct virtio_scsi_target_state *tgt = starget->hostdata;
759 static struct scsi_host_template virtscsi_host_template_single = {
760 .module = THIS_MODULE,
761 .name = "Virtio SCSI HBA",
762 .proc_name = "virtio_scsi",
764 .cmd_size = sizeof(struct virtio_scsi_cmd),
765 .queuecommand = virtscsi_queuecommand_single,
766 .change_queue_depth = virtscsi_change_queue_depth,
767 .eh_abort_handler = virtscsi_abort,
768 .eh_device_reset_handler = virtscsi_device_reset,
771 .dma_boundary = UINT_MAX,
772 .use_clustering = ENABLE_CLUSTERING,
773 .target_alloc = virtscsi_target_alloc,
774 .target_destroy = virtscsi_target_destroy,
775 .track_queue_depth = 1,
778 static struct scsi_host_template virtscsi_host_template_multi = {
779 .module = THIS_MODULE,
780 .name = "Virtio SCSI HBA",
781 .proc_name = "virtio_scsi",
783 .cmd_size = sizeof(struct virtio_scsi_cmd),
784 .queuecommand = virtscsi_queuecommand_multi,
785 .change_queue_depth = virtscsi_change_queue_depth,
786 .eh_abort_handler = virtscsi_abort,
787 .eh_device_reset_handler = virtscsi_device_reset,
790 .dma_boundary = UINT_MAX,
791 .use_clustering = ENABLE_CLUSTERING,
792 .target_alloc = virtscsi_target_alloc,
793 .target_destroy = virtscsi_target_destroy,
794 .track_queue_depth = 1,
797 #define virtscsi_config_get(vdev, fld) \
799 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
800 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
804 #define virtscsi_config_set(vdev, fld, val) \
806 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
807 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
810 static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
815 /* In multiqueue mode, when the number of cpu is equal
816 * to the number of request queues, we let the qeueues
817 * to be private to one cpu by setting the affinity hint
818 * to eliminate the contention.
820 if ((vscsi->num_queues == 1 ||
821 vscsi->num_queues != num_online_cpus()) && affinity) {
822 if (vscsi->affinity_hint_set)
830 for_each_online_cpu(cpu) {
831 virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu);
835 vscsi->affinity_hint_set = true;
837 for (i = 0; i < vscsi->num_queues; i++) {
838 if (!vscsi->req_vqs[i].vq)
841 virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1);
844 vscsi->affinity_hint_set = false;
848 static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
851 __virtscsi_set_affinity(vscsi, affinity);
855 static int virtscsi_cpu_callback(struct notifier_block *nfb,
856 unsigned long action, void *hcpu)
858 struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb);
861 case CPU_ONLINE_FROZEN:
863 case CPU_DEAD_FROZEN:
864 __virtscsi_set_affinity(vscsi, true);
872 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
873 struct virtqueue *vq)
875 spin_lock_init(&virtscsi_vq->vq_lock);
876 virtscsi_vq->vq = vq;
879 static void virtscsi_remove_vqs(struct virtio_device *vdev)
881 struct Scsi_Host *sh = virtio_scsi_host(vdev);
882 struct virtio_scsi *vscsi = shost_priv(sh);
884 virtscsi_set_affinity(vscsi, false);
886 /* Stop all the virtqueues. */
887 vdev->config->reset(vdev);
889 vdev->config->del_vqs(vdev);
892 static int virtscsi_init(struct virtio_device *vdev,
893 struct virtio_scsi *vscsi)
898 vq_callback_t **callbacks;
900 struct virtqueue **vqs;
902 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
903 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL);
904 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL);
905 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL);
907 if (!callbacks || !vqs || !names) {
912 callbacks[0] = virtscsi_ctrl_done;
913 callbacks[1] = virtscsi_event_done;
914 names[0] = "control";
916 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
917 callbacks[i] = virtscsi_req_done;
918 names[i] = "request";
921 /* Discover virtqueues and write information to configuration. */
922 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
926 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
927 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
928 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
929 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
932 virtscsi_set_affinity(vscsi, true);
934 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
935 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
944 virtscsi_remove_vqs(vdev);
948 static int virtscsi_probe(struct virtio_device *vdev)
950 struct Scsi_Host *shost;
951 struct virtio_scsi *vscsi;
953 u32 sg_elems, num_targets;
956 struct scsi_host_template *hostt;
958 if (!vdev->config->get) {
959 dev_err(&vdev->dev, "%s failure: config access disabled\n",
964 /* We need to know how many queues before we allocate. */
965 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
967 num_targets = virtscsi_config_get(vdev, max_target) + 1;
970 hostt = &virtscsi_host_template_single;
972 hostt = &virtscsi_host_template_multi;
974 shost = scsi_host_alloc(hostt,
975 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
979 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
980 shost->sg_tablesize = sg_elems;
981 vscsi = shost_priv(shost);
983 vscsi->num_queues = num_queues;
986 err = virtscsi_init(vdev, vscsi);
988 goto virtscsi_init_failed;
990 vscsi->nb.notifier_call = &virtscsi_cpu_callback;
991 err = register_hotcpu_notifier(&vscsi->nb);
993 pr_err("registering cpu notifier failed\n");
994 goto scsi_add_host_failed;
997 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
998 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
999 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
1001 /* LUNs > 256 are reported with format 1, so they go in the range
1004 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
1005 shost->max_id = num_targets;
1006 shost->max_channel = 0;
1007 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
1008 shost->nr_hw_queues = num_queues;
1010 #ifdef CONFIG_BLK_DEV_INTEGRITY
1011 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
1014 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
1015 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
1016 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
1018 scsi_host_set_prot(shost, host_prot);
1019 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
1023 err = scsi_add_host(shost, &vdev->dev);
1025 goto scsi_add_host_failed;
1027 virtio_device_ready(vdev);
1029 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
1030 virtscsi_kick_event_all(vscsi);
1032 scsi_scan_host(shost);
1035 scsi_add_host_failed:
1036 vdev->config->del_vqs(vdev);
1037 virtscsi_init_failed:
1038 scsi_host_put(shost);
1042 static void virtscsi_remove(struct virtio_device *vdev)
1044 struct Scsi_Host *shost = virtio_scsi_host(vdev);
1045 struct virtio_scsi *vscsi = shost_priv(shost);
1047 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
1048 virtscsi_cancel_event_work(vscsi);
1050 scsi_remove_host(shost);
1052 unregister_hotcpu_notifier(&vscsi->nb);
1054 virtscsi_remove_vqs(vdev);
1055 scsi_host_put(shost);
1058 #ifdef CONFIG_PM_SLEEP
1059 static int virtscsi_freeze(struct virtio_device *vdev)
1061 struct Scsi_Host *sh = virtio_scsi_host(vdev);
1062 struct virtio_scsi *vscsi = shost_priv(sh);
1064 unregister_hotcpu_notifier(&vscsi->nb);
1065 virtscsi_remove_vqs(vdev);
1069 static int virtscsi_restore(struct virtio_device *vdev)
1071 struct Scsi_Host *sh = virtio_scsi_host(vdev);
1072 struct virtio_scsi *vscsi = shost_priv(sh);
1075 err = virtscsi_init(vdev, vscsi);
1079 err = register_hotcpu_notifier(&vscsi->nb);
1081 vdev->config->del_vqs(vdev);
1085 virtio_device_ready(vdev);
1087 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
1088 virtscsi_kick_event_all(vscsi);
1094 static struct virtio_device_id id_table[] = {
1095 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
1099 static unsigned int features[] = {
1100 VIRTIO_SCSI_F_HOTPLUG,
1101 VIRTIO_SCSI_F_CHANGE,
1102 #ifdef CONFIG_BLK_DEV_INTEGRITY
1103 VIRTIO_SCSI_F_T10_PI,
1107 static struct virtio_driver virtio_scsi_driver = {
1108 .feature_table = features,
1109 .feature_table_size = ARRAY_SIZE(features),
1110 .driver.name = KBUILD_MODNAME,
1111 .driver.owner = THIS_MODULE,
1112 .id_table = id_table,
1113 .probe = virtscsi_probe,
1114 #ifdef CONFIG_PM_SLEEP
1115 .freeze = virtscsi_freeze,
1116 .restore = virtscsi_restore,
1118 .remove = virtscsi_remove,
1121 static int __init init(void)
1125 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1126 if (!virtscsi_cmd_cache) {
1127 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1133 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1134 virtscsi_cmd_cache);
1135 if (!virtscsi_cmd_pool) {
1136 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1139 ret = register_virtio_driver(&virtio_scsi_driver);
1146 if (virtscsi_cmd_pool) {
1147 mempool_destroy(virtscsi_cmd_pool);
1148 virtscsi_cmd_pool = NULL;
1150 if (virtscsi_cmd_cache) {
1151 kmem_cache_destroy(virtscsi_cmd_cache);
1152 virtscsi_cmd_cache = NULL;
1157 static void __exit fini(void)
1159 unregister_virtio_driver(&virtio_scsi_driver);
1160 mempool_destroy(virtscsi_cmd_pool);
1161 kmem_cache_destroy(virtscsi_cmd_cache);
1166 MODULE_DEVICE_TABLE(virtio, id_table);
1167 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1168 MODULE_LICENSE("GPL");