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/interrupt.h>
22 #include <linux/virtio.h>
23 #include <linux/virtio_ids.h>
24 #include <linux/virtio_config.h>
25 #include <linux/virtio_scsi.h>
26 #include <linux/cpu.h>
27 #include <linux/blkdev.h>
28 #include <scsi/scsi_host.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_cmnd.h>
31 #include <scsi/scsi_tcq.h>
32 #include <scsi/scsi_devinfo.h>
33 #include <linux/seqlock.h>
34 #include <linux/blk-mq-virtio.h>
36 #define VIRTIO_SCSI_MEMPOOL_SZ 64
37 #define VIRTIO_SCSI_EVENT_LEN 8
38 #define VIRTIO_SCSI_VQ_BASE 2
40 /* Command queue element */
41 struct virtio_scsi_cmd {
43 struct completion *comp;
45 struct virtio_scsi_cmd_req cmd;
46 struct virtio_scsi_cmd_req_pi cmd_pi;
47 struct virtio_scsi_ctrl_tmf_req tmf;
48 struct virtio_scsi_ctrl_an_req an;
51 struct virtio_scsi_cmd_resp cmd;
52 struct virtio_scsi_ctrl_tmf_resp tmf;
53 struct virtio_scsi_ctrl_an_resp an;
54 struct virtio_scsi_event evt;
56 } ____cacheline_aligned_in_smp;
58 struct virtio_scsi_event_node {
59 struct virtio_scsi *vscsi;
60 struct virtio_scsi_event event;
61 struct work_struct work;
64 struct virtio_scsi_vq {
72 * Per-target queue state.
74 * This struct holds the data needed by the queue steering policy. When a
75 * target is sent multiple requests, we need to drive them to the same queue so
76 * that FIFO processing order is kept. However, if a target was idle, we can
77 * choose a queue arbitrarily. In this case the queue is chosen according to
78 * the current VCPU, so the driver expects the number of request queues to be
79 * equal to the number of VCPUs. This makes it easy and fast to select the
80 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues
81 * (each virtqueue's affinity is set to the CPU that "owns" the queue).
83 * tgt_seq is held to serialize reading and writing req_vq.
85 * Decrements of reqs are never concurrent with writes of req_vq: before the
86 * decrement reqs will be != 0; after the decrement the virtqueue completion
87 * routine will not use the req_vq so it can be changed by a new request.
88 * Thus they can happen outside the tgt_seq, provided of course we make reqs
91 struct virtio_scsi_target_state {
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 struct hlist_node node;
112 /* Protected by event_vq lock */
115 struct virtio_scsi_vq ctrl_vq;
116 struct virtio_scsi_vq event_vq;
117 struct virtio_scsi_vq req_vqs[];
120 static struct kmem_cache *virtscsi_cmd_cache;
121 static mempool_t *virtscsi_cmd_pool;
123 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
128 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
133 if (!scsi_bidi_cmnd(sc)) {
134 scsi_set_resid(sc, resid);
138 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
139 scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
143 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
145 * Called with vq_lock held.
147 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
149 struct virtio_scsi_cmd *cmd = buf;
150 struct scsi_cmnd *sc = cmd->sc;
151 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
153 dev_dbg(&sc->device->sdev_gendev,
154 "cmd %p response %u status %#02x sense_len %u\n",
155 sc, resp->response, resp->status, resp->sense_len);
157 sc->result = resp->status;
158 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid));
159 switch (resp->response) {
160 case VIRTIO_SCSI_S_OK:
161 set_host_byte(sc, DID_OK);
163 case VIRTIO_SCSI_S_OVERRUN:
164 set_host_byte(sc, DID_ERROR);
166 case VIRTIO_SCSI_S_ABORTED:
167 set_host_byte(sc, DID_ABORT);
169 case VIRTIO_SCSI_S_BAD_TARGET:
170 set_host_byte(sc, DID_BAD_TARGET);
172 case VIRTIO_SCSI_S_RESET:
173 set_host_byte(sc, DID_RESET);
175 case VIRTIO_SCSI_S_BUSY:
176 set_host_byte(sc, DID_BUS_BUSY);
178 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
179 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
181 case VIRTIO_SCSI_S_TARGET_FAILURE:
182 set_host_byte(sc, DID_TARGET_FAILURE);
184 case VIRTIO_SCSI_S_NEXUS_FAILURE:
185 set_host_byte(sc, DID_NEXUS_FAILURE);
188 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
191 case VIRTIO_SCSI_S_FAILURE:
192 set_host_byte(sc, DID_ERROR);
196 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
197 VIRTIO_SCSI_SENSE_SIZE);
198 if (sc->sense_buffer) {
199 memcpy(sc->sense_buffer, resp->sense,
201 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
202 VIRTIO_SCSI_SENSE_SIZE));
204 set_driver_byte(sc, DRIVER_SENSE);
210 static void virtscsi_vq_done(struct virtio_scsi *vscsi,
211 struct virtio_scsi_vq *virtscsi_vq,
212 void (*fn)(struct virtio_scsi *vscsi, void *buf))
217 struct virtqueue *vq = virtscsi_vq->vq;
219 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
221 virtqueue_disable_cb(vq);
222 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
225 if (unlikely(virtqueue_is_broken(vq)))
227 } while (!virtqueue_enable_cb(vq));
228 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
231 static void virtscsi_req_done(struct virtqueue *vq)
233 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
234 struct virtio_scsi *vscsi = shost_priv(sh);
235 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
236 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
238 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
241 static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
245 num_vqs = vscsi->num_queues;
246 for (i = 0; i < num_vqs; i++)
247 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
248 virtscsi_complete_cmd);
251 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
253 struct virtio_scsi_cmd *cmd = buf;
259 static void virtscsi_ctrl_done(struct virtqueue *vq)
261 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
262 struct virtio_scsi *vscsi = shost_priv(sh);
264 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
267 static void virtscsi_handle_event(struct work_struct *work);
269 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
270 struct virtio_scsi_event_node *event_node)
273 struct scatterlist sg;
276 INIT_WORK(&event_node->work, virtscsi_handle_event);
277 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
279 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
281 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
284 virtqueue_kick(vscsi->event_vq.vq);
286 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
291 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
295 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
296 vscsi->event_list[i].vscsi = vscsi;
297 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
303 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
307 /* Stop scheduling work before calling cancel_work_sync. */
308 spin_lock_irq(&vscsi->event_vq.vq_lock);
309 vscsi->stop_events = true;
310 spin_unlock_irq(&vscsi->event_vq.vq_lock);
312 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
313 cancel_work_sync(&vscsi->event_list[i].work);
316 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
317 struct virtio_scsi_event *event)
319 struct scsi_device *sdev;
320 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
321 unsigned int target = event->lun[1];
322 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
324 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
325 case VIRTIO_SCSI_EVT_RESET_RESCAN:
326 scsi_add_device(shost, 0, target, lun);
328 case VIRTIO_SCSI_EVT_RESET_REMOVED:
329 sdev = scsi_device_lookup(shost, 0, target, lun);
331 scsi_remove_device(sdev);
332 scsi_device_put(sdev);
334 pr_err("SCSI device %d 0 %d %d not found\n",
335 shost->host_no, target, lun);
339 pr_info("Unsupported virtio scsi event reason %x\n", event->reason);
343 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
344 struct virtio_scsi_event *event)
346 struct scsi_device *sdev;
347 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
348 unsigned int target = event->lun[1];
349 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
350 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255;
351 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8;
353 sdev = scsi_device_lookup(shost, 0, target, lun);
355 pr_err("SCSI device %d 0 %d %d not found\n",
356 shost->host_no, target, lun);
360 /* Handle "Parameters changed", "Mode parameters changed", and
361 "Capacity data has changed". */
362 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
363 scsi_rescan_device(&sdev->sdev_gendev);
365 scsi_device_put(sdev);
368 static void virtscsi_handle_event(struct work_struct *work)
370 struct virtio_scsi_event_node *event_node =
371 container_of(work, struct virtio_scsi_event_node, work);
372 struct virtio_scsi *vscsi = event_node->vscsi;
373 struct virtio_scsi_event *event = &event_node->event;
376 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
377 event->event &= ~cpu_to_virtio32(vscsi->vdev,
378 VIRTIO_SCSI_T_EVENTS_MISSED);
379 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
382 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
383 case VIRTIO_SCSI_T_NO_EVENT:
385 case VIRTIO_SCSI_T_TRANSPORT_RESET:
386 virtscsi_handle_transport_reset(vscsi, event);
388 case VIRTIO_SCSI_T_PARAM_CHANGE:
389 virtscsi_handle_param_change(vscsi, event);
392 pr_err("Unsupported virtio scsi event %x\n", event->event);
394 virtscsi_kick_event(vscsi, event_node);
397 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
399 struct virtio_scsi_event_node *event_node = buf;
401 if (!vscsi->stop_events)
402 queue_work(system_freezable_wq, &event_node->work);
405 static void virtscsi_event_done(struct virtqueue *vq)
407 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
408 struct virtio_scsi *vscsi = shost_priv(sh);
410 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
414 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
415 * @vq : the struct virtqueue we're talking about
416 * @cmd : command structure
417 * @req_size : size of the request buffer
418 * @resp_size : size of the response buffer
420 static int virtscsi_add_cmd(struct virtqueue *vq,
421 struct virtio_scsi_cmd *cmd,
422 size_t req_size, size_t resp_size)
424 struct scsi_cmnd *sc = cmd->sc;
425 struct scatterlist *sgs[6], req, resp;
426 struct sg_table *out, *in;
427 unsigned out_num = 0, in_num = 0;
431 if (sc && sc->sc_data_direction != DMA_NONE) {
432 if (sc->sc_data_direction != DMA_FROM_DEVICE)
433 out = &scsi_out(sc)->table;
434 if (sc->sc_data_direction != DMA_TO_DEVICE)
435 in = &scsi_in(sc)->table;
438 /* Request header. */
439 sg_init_one(&req, &cmd->req, req_size);
440 sgs[out_num++] = &req;
442 /* Data-out buffer. */
444 /* Place WRITE protection SGLs before Data OUT payload */
445 if (scsi_prot_sg_count(sc))
446 sgs[out_num++] = scsi_prot_sglist(sc);
447 sgs[out_num++] = out->sgl;
450 /* Response header. */
451 sg_init_one(&resp, &cmd->resp, resp_size);
452 sgs[out_num + in_num++] = &resp;
456 /* Place READ protection SGLs before Data IN payload */
457 if (scsi_prot_sg_count(sc))
458 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
459 sgs[out_num + in_num++] = in->sgl;
462 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
465 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
466 struct virtio_scsi_cmd *cmd,
467 size_t req_size, size_t resp_size)
471 bool needs_kick = false;
473 spin_lock_irqsave(&vq->vq_lock, flags);
474 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
476 needs_kick = virtqueue_kick_prepare(vq->vq);
478 spin_unlock_irqrestore(&vq->vq_lock, flags);
481 virtqueue_notify(vq->vq);
485 static void virtio_scsi_init_hdr(struct virtio_device *vdev,
486 struct virtio_scsi_cmd_req *cmd,
487 struct scsi_cmnd *sc)
490 cmd->lun[1] = sc->device->id;
491 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
492 cmd->lun[3] = sc->device->lun & 0xff;
493 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
494 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
499 #ifdef CONFIG_BLK_DEV_INTEGRITY
500 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
501 struct virtio_scsi_cmd_req_pi *cmd_pi,
502 struct scsi_cmnd *sc)
504 struct request *rq = sc->request;
505 struct blk_integrity *bi;
507 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
509 if (!rq || !scsi_prot_sg_count(sc))
512 bi = blk_get_integrity(rq->rq_disk);
514 if (sc->sc_data_direction == DMA_TO_DEVICE)
515 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
518 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
519 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
525 static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
526 struct virtio_scsi_vq *req_vq,
527 struct scsi_cmnd *sc)
529 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
530 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
535 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
537 /* TODO: check feature bit and fail if unsupported? */
538 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
540 dev_dbg(&sc->device->sdev_gendev,
541 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
545 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
547 #ifdef CONFIG_BLK_DEV_INTEGRITY
548 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
549 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
550 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
551 req_size = sizeof(cmd->req.cmd_pi);
555 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
556 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
557 req_size = sizeof(cmd->req.cmd);
560 ret = virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd));
562 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
563 spin_lock_irqsave(&req_vq->vq_lock, flags);
564 virtscsi_complete_cmd(vscsi, cmd);
565 spin_unlock_irqrestore(&req_vq->vq_lock, flags);
566 } else if (ret != 0) {
567 return SCSI_MLQUEUE_HOST_BUSY;
572 static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
573 struct scsi_cmnd *sc)
575 struct virtio_scsi *vscsi = shost_priv(sh);
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 int virtscsi_queuecommand_multi(struct Scsi_Host *sh,
590 struct scsi_cmnd *sc)
592 struct virtio_scsi *vscsi = shost_priv(sh);
593 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
595 return virtscsi_queuecommand(vscsi, req_vq, sc);
598 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
600 DECLARE_COMPLETION_ONSTACK(comp);
604 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
605 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
608 wait_for_completion(&comp);
609 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
610 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
614 * The spec guarantees that all requests related to the TMF have
615 * been completed, but the callback might not have run yet if
616 * we're using independent interrupts (e.g. MSI). Poll the
619 * In the abort case, sc->scsi_done will do nothing, because
620 * the block layer must have detected a timeout and as a result
621 * REQ_ATOM_COMPLETE has been set.
623 virtscsi_poll_requests(vscsi);
626 mempool_free(cmd, virtscsi_cmd_pool);
630 static int virtscsi_device_reset(struct scsi_cmnd *sc)
632 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
633 struct virtio_scsi_cmd *cmd;
635 sdev_printk(KERN_INFO, sc->device, "device reset\n");
636 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
640 memset(cmd, 0, sizeof(*cmd));
641 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
642 .type = VIRTIO_SCSI_T_TMF,
643 .subtype = cpu_to_virtio32(vscsi->vdev,
644 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
646 .lun[1] = sc->device->id,
647 .lun[2] = (sc->device->lun >> 8) | 0x40,
648 .lun[3] = sc->device->lun & 0xff,
650 return virtscsi_tmf(vscsi, cmd);
653 static int virtscsi_device_alloc(struct scsi_device *sdevice)
656 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
657 * may have transfer limits which come from the host SCSI
658 * controller or something on the host side other than the
661 * To make this work properly, the hypervisor can adjust the
662 * target's VPD information to advertise these limits. But
663 * for that to work, the guest has to look at the VPD pages,
664 * which we won't do by default if it is an SPC-2 device, even
665 * if it does actually support it.
667 * So, set the blist to always try to read the VPD pages.
669 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
676 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
677 * @sdev: Virtscsi target whose queue depth to change
678 * @qdepth: New queue depth
680 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
682 struct Scsi_Host *shost = sdev->host;
683 int max_depth = shost->cmd_per_lun;
685 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
688 static int virtscsi_abort(struct scsi_cmnd *sc)
690 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
691 struct virtio_scsi_cmd *cmd;
693 scmd_printk(KERN_INFO, sc, "abort\n");
694 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
698 memset(cmd, 0, sizeof(*cmd));
699 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
700 .type = VIRTIO_SCSI_T_TMF,
701 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
703 .lun[1] = sc->device->id,
704 .lun[2] = (sc->device->lun >> 8) | 0x40,
705 .lun[3] = sc->device->lun & 0xff,
706 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
708 return virtscsi_tmf(vscsi, cmd);
711 static int virtscsi_target_alloc(struct scsi_target *starget)
713 struct Scsi_Host *sh = dev_to_shost(starget->dev.parent);
714 struct virtio_scsi *vscsi = shost_priv(sh);
716 struct virtio_scsi_target_state *tgt =
717 kmalloc(sizeof(*tgt), GFP_KERNEL);
721 seqcount_init(&tgt->tgt_seq);
722 tgt->req_vq = &vscsi->req_vqs[0];
724 starget->hostdata = tgt;
728 static void virtscsi_target_destroy(struct scsi_target *starget)
730 struct virtio_scsi_target_state *tgt = starget->hostdata;
734 static int virtscsi_map_queues(struct Scsi_Host *shost)
736 struct virtio_scsi *vscsi = shost_priv(shost);
738 return blk_mq_virtio_map_queues(&shost->tag_set, vscsi->vdev, 2);
742 * The host guarantees to respond to each command, although I/O
743 * latencies might be higher than on bare metal. Reset the timer
744 * unconditionally to give the host a chance to perform EH.
746 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
748 return BLK_EH_RESET_TIMER;
751 static struct scsi_host_template virtscsi_host_template_single = {
752 .module = THIS_MODULE,
753 .name = "Virtio SCSI HBA",
754 .proc_name = "virtio_scsi",
756 .cmd_size = sizeof(struct virtio_scsi_cmd),
757 .queuecommand = virtscsi_queuecommand_single,
758 .change_queue_depth = virtscsi_change_queue_depth,
759 .eh_abort_handler = virtscsi_abort,
760 .eh_device_reset_handler = virtscsi_device_reset,
761 .eh_timed_out = virtscsi_eh_timed_out,
762 .slave_alloc = virtscsi_device_alloc,
764 .dma_boundary = UINT_MAX,
765 .use_clustering = ENABLE_CLUSTERING,
766 .target_alloc = virtscsi_target_alloc,
767 .target_destroy = virtscsi_target_destroy,
768 .track_queue_depth = 1,
772 static struct scsi_host_template virtscsi_host_template_multi = {
773 .module = THIS_MODULE,
774 .name = "Virtio SCSI HBA",
775 .proc_name = "virtio_scsi",
777 .cmd_size = sizeof(struct virtio_scsi_cmd),
778 .queuecommand = virtscsi_queuecommand_multi,
779 .change_queue_depth = virtscsi_change_queue_depth,
780 .eh_abort_handler = virtscsi_abort,
781 .eh_device_reset_handler = virtscsi_device_reset,
782 .eh_timed_out = virtscsi_eh_timed_out,
783 .slave_alloc = virtscsi_device_alloc,
785 .dma_boundary = UINT_MAX,
786 .use_clustering = ENABLE_CLUSTERING,
787 .target_alloc = virtscsi_target_alloc,
788 .target_destroy = virtscsi_target_destroy,
789 .map_queues = virtscsi_map_queues,
790 .track_queue_depth = 1,
794 #define virtscsi_config_get(vdev, fld) \
796 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
797 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
801 #define virtscsi_config_set(vdev, fld, val) \
803 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
804 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
807 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
808 struct virtqueue *vq)
810 spin_lock_init(&virtscsi_vq->vq_lock);
811 virtscsi_vq->vq = vq;
814 static void virtscsi_remove_vqs(struct virtio_device *vdev)
816 /* Stop all the virtqueues. */
817 vdev->config->reset(vdev);
818 vdev->config->del_vqs(vdev);
821 static int virtscsi_init(struct virtio_device *vdev,
822 struct virtio_scsi *vscsi)
827 vq_callback_t **callbacks;
829 struct virtqueue **vqs;
830 struct irq_affinity desc = { .pre_vectors = 2 };
832 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
833 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL);
834 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL);
835 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL);
837 if (!callbacks || !vqs || !names) {
842 callbacks[0] = virtscsi_ctrl_done;
843 callbacks[1] = virtscsi_event_done;
844 names[0] = "control";
846 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
847 callbacks[i] = virtscsi_req_done;
848 names[i] = "request";
851 /* Discover virtqueues and write information to configuration. */
852 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
856 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
857 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
858 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
859 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
862 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
863 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
872 virtscsi_remove_vqs(vdev);
876 static int virtscsi_probe(struct virtio_device *vdev)
878 struct Scsi_Host *shost;
879 struct virtio_scsi *vscsi;
881 u32 sg_elems, num_targets;
884 struct scsi_host_template *hostt;
886 if (!vdev->config->get) {
887 dev_err(&vdev->dev, "%s failure: config access disabled\n",
892 /* We need to know how many queues before we allocate. */
893 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
895 num_targets = virtscsi_config_get(vdev, max_target) + 1;
898 hostt = &virtscsi_host_template_single;
900 hostt = &virtscsi_host_template_multi;
902 shost = scsi_host_alloc(hostt,
903 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
907 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
908 shost->sg_tablesize = sg_elems;
909 vscsi = shost_priv(shost);
911 vscsi->num_queues = num_queues;
914 err = virtscsi_init(vdev, vscsi);
916 goto virtscsi_init_failed;
918 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
920 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
921 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
922 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
924 /* LUNs > 256 are reported with format 1, so they go in the range
927 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
928 shost->max_id = num_targets;
929 shost->max_channel = 0;
930 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
931 shost->nr_hw_queues = num_queues;
933 #ifdef CONFIG_BLK_DEV_INTEGRITY
934 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
937 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
938 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
939 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
941 scsi_host_set_prot(shost, host_prot);
942 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
946 err = scsi_add_host(shost, &vdev->dev);
948 goto scsi_add_host_failed;
950 virtio_device_ready(vdev);
952 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
953 virtscsi_kick_event_all(vscsi);
955 scsi_scan_host(shost);
958 scsi_add_host_failed:
959 vdev->config->del_vqs(vdev);
960 virtscsi_init_failed:
961 scsi_host_put(shost);
965 static void virtscsi_remove(struct virtio_device *vdev)
967 struct Scsi_Host *shost = virtio_scsi_host(vdev);
968 struct virtio_scsi *vscsi = shost_priv(shost);
970 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
971 virtscsi_cancel_event_work(vscsi);
973 scsi_remove_host(shost);
974 virtscsi_remove_vqs(vdev);
975 scsi_host_put(shost);
978 #ifdef CONFIG_PM_SLEEP
979 static int virtscsi_freeze(struct virtio_device *vdev)
981 virtscsi_remove_vqs(vdev);
985 static int virtscsi_restore(struct virtio_device *vdev)
987 struct Scsi_Host *sh = virtio_scsi_host(vdev);
988 struct virtio_scsi *vscsi = shost_priv(sh);
991 err = virtscsi_init(vdev, vscsi);
995 virtio_device_ready(vdev);
997 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
998 virtscsi_kick_event_all(vscsi);
1004 static struct virtio_device_id id_table[] = {
1005 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
1009 static unsigned int features[] = {
1010 VIRTIO_SCSI_F_HOTPLUG,
1011 VIRTIO_SCSI_F_CHANGE,
1012 #ifdef CONFIG_BLK_DEV_INTEGRITY
1013 VIRTIO_SCSI_F_T10_PI,
1017 static struct virtio_driver virtio_scsi_driver = {
1018 .feature_table = features,
1019 .feature_table_size = ARRAY_SIZE(features),
1020 .driver.name = KBUILD_MODNAME,
1021 .driver.owner = THIS_MODULE,
1022 .id_table = id_table,
1023 .probe = virtscsi_probe,
1024 #ifdef CONFIG_PM_SLEEP
1025 .freeze = virtscsi_freeze,
1026 .restore = virtscsi_restore,
1028 .remove = virtscsi_remove,
1031 static int __init init(void)
1035 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1036 if (!virtscsi_cmd_cache) {
1037 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1043 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1044 virtscsi_cmd_cache);
1045 if (!virtscsi_cmd_pool) {
1046 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1049 ret = register_virtio_driver(&virtio_scsi_driver);
1056 if (virtscsi_cmd_pool) {
1057 mempool_destroy(virtscsi_cmd_pool);
1058 virtscsi_cmd_pool = NULL;
1060 if (virtscsi_cmd_cache) {
1061 kmem_cache_destroy(virtscsi_cmd_cache);
1062 virtscsi_cmd_cache = NULL;
1067 static void __exit fini(void)
1069 unregister_virtio_driver(&virtio_scsi_driver);
1070 mempool_destroy(virtscsi_cmd_pool);
1071 kmem_cache_destroy(virtscsi_cmd_cache);
1076 MODULE_DEVICE_TABLE(virtio, id_table);
1077 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1078 MODULE_LICENSE("GPL");