1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Virtio SCSI HBA driver
5 * Copyright IBM Corp. 2010
6 * Copyright Red Hat, Inc. 2011
9 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
10 * Paolo Bonzini <pbonzini@redhat.com>
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/mempool.h>
18 #include <linux/interrupt.h>
19 #include <linux/virtio.h>
20 #include <linux/virtio_ids.h>
21 #include <linux/virtio_config.h>
22 #include <linux/virtio_scsi.h>
23 #include <linux/cpu.h>
24 #include <linux/blkdev.h>
25 #include <linux/blk-integrity.h>
26 #include <scsi/scsi_host.h>
27 #include <scsi/scsi_device.h>
28 #include <scsi/scsi_cmnd.h>
29 #include <scsi/scsi_tcq.h>
30 #include <scsi/scsi_devinfo.h>
31 #include <linux/seqlock.h>
32 #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 {
71 /* Driver instance state */
73 struct virtio_device *vdev;
75 /* Get some buffers ready for event vq */
76 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
80 struct hlist_node node;
82 /* Protected by event_vq lock */
85 struct virtio_scsi_vq ctrl_vq;
86 struct virtio_scsi_vq event_vq;
87 struct virtio_scsi_vq req_vqs[];
90 static struct kmem_cache *virtscsi_cmd_cache;
91 static mempool_t *virtscsi_cmd_pool;
93 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
98 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
101 scsi_set_resid(sc, min(resid, scsi_bufflen(sc)));
105 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
107 * Called with vq_lock held.
109 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
111 struct virtio_scsi_cmd *cmd = buf;
112 struct scsi_cmnd *sc = cmd->sc;
113 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
115 dev_dbg(&sc->device->sdev_gendev,
116 "cmd %p response %u status %#02x sense_len %u\n",
117 sc, resp->response, resp->status, resp->sense_len);
119 sc->result = resp->status;
120 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid));
121 switch (resp->response) {
122 case VIRTIO_SCSI_S_OK:
123 set_host_byte(sc, DID_OK);
125 case VIRTIO_SCSI_S_OVERRUN:
126 set_host_byte(sc, DID_ERROR);
128 case VIRTIO_SCSI_S_ABORTED:
129 set_host_byte(sc, DID_ABORT);
131 case VIRTIO_SCSI_S_BAD_TARGET:
132 set_host_byte(sc, DID_BAD_TARGET);
134 case VIRTIO_SCSI_S_RESET:
135 set_host_byte(sc, DID_RESET);
137 case VIRTIO_SCSI_S_BUSY:
138 set_host_byte(sc, DID_BUS_BUSY);
140 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
141 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
143 case VIRTIO_SCSI_S_TARGET_FAILURE:
144 set_host_byte(sc, DID_BAD_TARGET);
146 case VIRTIO_SCSI_S_NEXUS_FAILURE:
147 set_status_byte(sc, SAM_STAT_RESERVATION_CONFLICT);
150 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
153 case VIRTIO_SCSI_S_FAILURE:
154 set_host_byte(sc, DID_ERROR);
158 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
159 VIRTIO_SCSI_SENSE_SIZE);
160 if (resp->sense_len) {
161 memcpy(sc->sense_buffer, resp->sense,
163 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
164 VIRTIO_SCSI_SENSE_SIZE));
170 static void virtscsi_vq_done(struct virtio_scsi *vscsi,
171 struct virtio_scsi_vq *virtscsi_vq,
172 void (*fn)(struct virtio_scsi *vscsi, void *buf))
177 struct virtqueue *vq = virtscsi_vq->vq;
179 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
181 virtqueue_disable_cb(vq);
182 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
185 if (unlikely(virtqueue_is_broken(vq)))
187 } while (!virtqueue_enable_cb(vq));
188 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
191 static void virtscsi_req_done(struct virtqueue *vq)
193 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
194 struct virtio_scsi *vscsi = shost_priv(sh);
195 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
196 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
198 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
201 static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
205 num_vqs = vscsi->num_queues;
206 for (i = 0; i < num_vqs; i++)
207 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
208 virtscsi_complete_cmd);
211 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
213 struct virtio_scsi_cmd *cmd = buf;
219 static void virtscsi_ctrl_done(struct virtqueue *vq)
221 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
222 struct virtio_scsi *vscsi = shost_priv(sh);
224 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
227 static void virtscsi_handle_event(struct work_struct *work);
229 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
230 struct virtio_scsi_event_node *event_node)
233 struct scatterlist sg;
236 INIT_WORK(&event_node->work, virtscsi_handle_event);
237 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
239 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
241 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
244 virtqueue_kick(vscsi->event_vq.vq);
246 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
251 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
255 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
256 vscsi->event_list[i].vscsi = vscsi;
257 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
263 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
267 /* Stop scheduling work before calling cancel_work_sync. */
268 spin_lock_irq(&vscsi->event_vq.vq_lock);
269 vscsi->stop_events = true;
270 spin_unlock_irq(&vscsi->event_vq.vq_lock);
272 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
273 cancel_work_sync(&vscsi->event_list[i].work);
276 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
277 struct virtio_scsi_event *event)
279 struct scsi_device *sdev;
280 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
281 unsigned int target = event->lun[1];
282 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
284 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
285 case VIRTIO_SCSI_EVT_RESET_RESCAN:
287 scsi_scan_target(&shost->shost_gendev, 0, target,
288 SCAN_WILD_CARD, SCSI_SCAN_INITIAL);
290 scsi_add_device(shost, 0, target, lun);
293 case VIRTIO_SCSI_EVT_RESET_REMOVED:
294 sdev = scsi_device_lookup(shost, 0, target, lun);
296 scsi_remove_device(sdev);
297 scsi_device_put(sdev);
299 pr_err("SCSI device %d 0 %d %d not found\n",
300 shost->host_no, target, lun);
304 pr_info("Unsupported virtio scsi event reason %x\n", event->reason);
308 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
309 struct virtio_scsi_event *event)
311 struct scsi_device *sdev;
312 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
313 unsigned int target = event->lun[1];
314 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
315 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255;
316 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8;
318 sdev = scsi_device_lookup(shost, 0, target, lun);
320 pr_err("SCSI device %d 0 %d %d not found\n",
321 shost->host_no, target, lun);
325 /* Handle "Parameters changed", "Mode parameters changed", and
326 "Capacity data has changed". */
327 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
328 scsi_rescan_device(&sdev->sdev_gendev);
330 scsi_device_put(sdev);
333 static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
335 struct scsi_device *sdev;
336 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
337 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
338 int result, inquiry_len, inq_result_len = 256;
339 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
346 shost_for_each_device(sdev, shost) {
347 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
349 memset(scsi_cmd, 0, sizeof(scsi_cmd));
350 scsi_cmd[0] = INQUIRY;
351 scsi_cmd[4] = (unsigned char) inquiry_len;
353 memset(inq_result, 0, inq_result_len);
355 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN,
356 inq_result, inquiry_len,
357 SD_TIMEOUT, SD_MAX_RETRIES, NULL);
359 if (result == 0 && inq_result[0] >> 5) {
360 /* PQ indicates the LUN is not attached */
361 scsi_remove_device(sdev);
362 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) {
364 * If all LUNs of a virtio-scsi device are unplugged
365 * it will respond with BAD TARGET on any INQUIRY
367 * Remove the device in this case as well.
369 scsi_remove_device(sdev);
377 static void virtscsi_handle_event(struct work_struct *work)
379 struct virtio_scsi_event_node *event_node =
380 container_of(work, struct virtio_scsi_event_node, work);
381 struct virtio_scsi *vscsi = event_node->vscsi;
382 struct virtio_scsi_event *event = &event_node->event;
385 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
388 event->event &= ~cpu_to_virtio32(vscsi->vdev,
389 VIRTIO_SCSI_T_EVENTS_MISSED);
390 ret = virtscsi_rescan_hotunplug(vscsi);
393 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
396 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
397 case VIRTIO_SCSI_T_NO_EVENT:
399 case VIRTIO_SCSI_T_TRANSPORT_RESET:
400 virtscsi_handle_transport_reset(vscsi, event);
402 case VIRTIO_SCSI_T_PARAM_CHANGE:
403 virtscsi_handle_param_change(vscsi, event);
406 pr_err("Unsupported virtio scsi event %x\n", event->event);
408 virtscsi_kick_event(vscsi, event_node);
411 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
413 struct virtio_scsi_event_node *event_node = buf;
415 if (!vscsi->stop_events)
416 queue_work(system_freezable_wq, &event_node->work);
419 static void virtscsi_event_done(struct virtqueue *vq)
421 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
422 struct virtio_scsi *vscsi = shost_priv(sh);
424 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
427 static int __virtscsi_add_cmd(struct virtqueue *vq,
428 struct virtio_scsi_cmd *cmd,
429 size_t req_size, size_t resp_size)
431 struct scsi_cmnd *sc = cmd->sc;
432 struct scatterlist *sgs[6], req, resp;
433 struct sg_table *out, *in;
434 unsigned out_num = 0, in_num = 0;
438 if (sc && sc->sc_data_direction != DMA_NONE) {
439 if (sc->sc_data_direction != DMA_FROM_DEVICE)
440 out = &sc->sdb.table;
441 if (sc->sc_data_direction != DMA_TO_DEVICE)
445 /* Request header. */
446 sg_init_one(&req, &cmd->req, req_size);
447 sgs[out_num++] = &req;
449 /* Data-out buffer. */
451 /* Place WRITE protection SGLs before Data OUT payload */
452 if (scsi_prot_sg_count(sc))
453 sgs[out_num++] = scsi_prot_sglist(sc);
454 sgs[out_num++] = out->sgl;
457 /* Response header. */
458 sg_init_one(&resp, &cmd->resp, resp_size);
459 sgs[out_num + in_num++] = &resp;
463 /* Place READ protection SGLs before Data IN payload */
464 if (scsi_prot_sg_count(sc))
465 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
466 sgs[out_num + in_num++] = in->sgl;
469 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
472 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
477 spin_lock_irqsave(&vq->vq_lock, flags);
478 needs_kick = virtqueue_kick_prepare(vq->vq);
479 spin_unlock_irqrestore(&vq->vq_lock, flags);
482 virtqueue_notify(vq->vq);
486 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
487 * @vq : the struct virtqueue we're talking about
488 * @cmd : command structure
489 * @req_size : size of the request buffer
490 * @resp_size : size of the response buffer
491 * @kick : whether to kick the virtqueue immediately
493 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
494 struct virtio_scsi_cmd *cmd,
495 size_t req_size, size_t resp_size,
500 bool needs_kick = false;
502 spin_lock_irqsave(&vq->vq_lock, flags);
503 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
505 needs_kick = virtqueue_kick_prepare(vq->vq);
507 spin_unlock_irqrestore(&vq->vq_lock, flags);
510 virtqueue_notify(vq->vq);
514 static void virtio_scsi_init_hdr(struct virtio_device *vdev,
515 struct virtio_scsi_cmd_req *cmd,
516 struct scsi_cmnd *sc)
519 cmd->lun[1] = sc->device->id;
520 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
521 cmd->lun[3] = sc->device->lun & 0xff;
522 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
523 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
528 #ifdef CONFIG_BLK_DEV_INTEGRITY
529 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
530 struct virtio_scsi_cmd_req_pi *cmd_pi,
531 struct scsi_cmnd *sc)
533 struct request *rq = scsi_cmd_to_rq(sc);
534 struct blk_integrity *bi;
536 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
538 if (!rq || !scsi_prot_sg_count(sc))
541 bi = blk_get_integrity(rq->q->disk);
543 if (sc->sc_data_direction == DMA_TO_DEVICE)
544 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
545 bio_integrity_bytes(bi,
546 blk_rq_sectors(rq)));
547 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
548 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
549 bio_integrity_bytes(bi,
550 blk_rq_sectors(rq)));
554 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
555 struct scsi_cmnd *sc)
557 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc));
558 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
560 return &vscsi->req_vqs[hwq];
563 static int virtscsi_queuecommand(struct Scsi_Host *shost,
564 struct scsi_cmnd *sc)
566 struct virtio_scsi *vscsi = shost_priv(shost);
567 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
568 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
574 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
576 /* TODO: check feature bit and fail if unsupported? */
577 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
579 dev_dbg(&sc->device->sdev_gendev,
580 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
584 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
586 #ifdef CONFIG_BLK_DEV_INTEGRITY
587 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
588 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
589 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
590 req_size = sizeof(cmd->req.cmd_pi);
594 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
595 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
596 req_size = sizeof(cmd->req.cmd);
599 kick = (sc->flags & SCMD_LAST) != 0;
600 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick);
602 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
603 spin_lock_irqsave(&req_vq->vq_lock, flags);
604 virtscsi_complete_cmd(vscsi, cmd);
605 spin_unlock_irqrestore(&req_vq->vq_lock, flags);
606 } else if (ret != 0) {
607 return SCSI_MLQUEUE_HOST_BUSY;
612 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
614 DECLARE_COMPLETION_ONSTACK(comp);
618 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd,
619 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0)
622 wait_for_completion(&comp);
623 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
624 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
628 * The spec guarantees that all requests related to the TMF have
629 * been completed, but the callback might not have run yet if
630 * we're using independent interrupts (e.g. MSI). Poll the
633 * In the abort case, scsi_done() will do nothing, because the
634 * command timed out and hence SCMD_STATE_COMPLETE has been set.
636 virtscsi_poll_requests(vscsi);
639 mempool_free(cmd, virtscsi_cmd_pool);
643 static int virtscsi_device_reset(struct scsi_cmnd *sc)
645 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
646 struct virtio_scsi_cmd *cmd;
648 sdev_printk(KERN_INFO, sc->device, "device reset\n");
649 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
653 memset(cmd, 0, sizeof(*cmd));
654 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
655 .type = VIRTIO_SCSI_T_TMF,
656 .subtype = cpu_to_virtio32(vscsi->vdev,
657 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
659 .lun[1] = sc->device->id,
660 .lun[2] = (sc->device->lun >> 8) | 0x40,
661 .lun[3] = sc->device->lun & 0xff,
663 return virtscsi_tmf(vscsi, cmd);
666 static int virtscsi_device_alloc(struct scsi_device *sdevice)
669 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
670 * may have transfer limits which come from the host SCSI
671 * controller or something on the host side other than the
674 * To make this work properly, the hypervisor can adjust the
675 * target's VPD information to advertise these limits. But
676 * for that to work, the guest has to look at the VPD pages,
677 * which we won't do by default if it is an SPC-2 device, even
678 * if it does actually support it.
680 * So, set the blist to always try to read the VPD pages.
682 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
689 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
690 * @sdev: Virtscsi target whose queue depth to change
691 * @qdepth: New queue depth
693 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
695 struct Scsi_Host *shost = sdev->host;
696 int max_depth = shost->cmd_per_lun;
698 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
701 static int virtscsi_abort(struct scsi_cmnd *sc)
703 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
704 struct virtio_scsi_cmd *cmd;
706 scmd_printk(KERN_INFO, sc, "abort\n");
707 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
711 memset(cmd, 0, sizeof(*cmd));
712 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
713 .type = VIRTIO_SCSI_T_TMF,
714 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
716 .lun[1] = sc->device->id,
717 .lun[2] = (sc->device->lun >> 8) | 0x40,
718 .lun[3] = sc->device->lun & 0xff,
719 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
721 return virtscsi_tmf(vscsi, cmd);
724 static void virtscsi_map_queues(struct Scsi_Host *shost)
726 struct virtio_scsi *vscsi = shost_priv(shost);
727 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
729 blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2);
732 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
734 struct virtio_scsi *vscsi = shost_priv(shost);
736 virtscsi_kick_vq(&vscsi->req_vqs[hwq]);
740 * The host guarantees to respond to each command, although I/O
741 * latencies might be higher than on bare metal. Reset the timer
742 * unconditionally to give the host a chance to perform EH.
744 static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
746 return SCSI_EH_RESET_TIMER;
749 static const struct scsi_host_template virtscsi_host_template = {
750 .module = THIS_MODULE,
751 .name = "Virtio SCSI HBA",
752 .proc_name = "virtio_scsi",
754 .cmd_size = sizeof(struct virtio_scsi_cmd),
755 .queuecommand = virtscsi_queuecommand,
756 .commit_rqs = virtscsi_commit_rqs,
757 .change_queue_depth = virtscsi_change_queue_depth,
758 .eh_abort_handler = virtscsi_abort,
759 .eh_device_reset_handler = virtscsi_device_reset,
760 .eh_timed_out = virtscsi_eh_timed_out,
761 .slave_alloc = virtscsi_device_alloc,
763 .dma_boundary = UINT_MAX,
764 .map_queues = virtscsi_map_queues,
765 .track_queue_depth = 1,
768 #define virtscsi_config_get(vdev, fld) \
770 __virtio_native_type(struct virtio_scsi_config, fld) __val; \
771 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
775 #define virtscsi_config_set(vdev, fld, val) \
777 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \
778 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
781 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
782 struct virtqueue *vq)
784 spin_lock_init(&virtscsi_vq->vq_lock);
785 virtscsi_vq->vq = vq;
788 static void virtscsi_remove_vqs(struct virtio_device *vdev)
790 /* Stop all the virtqueues. */
791 virtio_reset_device(vdev);
792 vdev->config->del_vqs(vdev);
795 static int virtscsi_init(struct virtio_device *vdev,
796 struct virtio_scsi *vscsi)
801 vq_callback_t **callbacks;
803 struct virtqueue **vqs;
804 struct irq_affinity desc = { .pre_vectors = 2 };
806 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
807 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
808 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *),
810 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL);
812 if (!callbacks || !vqs || !names) {
817 callbacks[0] = virtscsi_ctrl_done;
818 callbacks[1] = virtscsi_event_done;
819 names[0] = "control";
821 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
822 callbacks[i] = virtscsi_req_done;
823 names[i] = "request";
826 /* Discover virtqueues and write information to configuration. */
827 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
831 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
832 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
833 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
834 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
837 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
838 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
847 virtscsi_remove_vqs(vdev);
851 static int virtscsi_probe(struct virtio_device *vdev)
853 struct Scsi_Host *shost;
854 struct virtio_scsi *vscsi;
856 u32 sg_elems, num_targets;
860 if (!vdev->config->get) {
861 dev_err(&vdev->dev, "%s failure: config access disabled\n",
866 /* We need to know how many queues before we allocate. */
867 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
868 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
870 num_targets = virtscsi_config_get(vdev, max_target) + 1;
872 shost = scsi_host_alloc(&virtscsi_host_template,
873 struct_size(vscsi, req_vqs, num_queues));
877 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
878 shost->sg_tablesize = sg_elems;
879 vscsi = shost_priv(shost);
881 vscsi->num_queues = num_queues;
884 err = virtscsi_init(vdev, vscsi);
886 goto virtscsi_init_failed;
888 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
890 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
891 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
892 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
894 /* LUNs > 256 are reported with format 1, so they go in the range
897 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
898 shost->max_id = num_targets;
899 shost->max_channel = 0;
900 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
901 shost->nr_hw_queues = num_queues;
903 #ifdef CONFIG_BLK_DEV_INTEGRITY
904 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
907 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
908 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
909 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
911 scsi_host_set_prot(shost, host_prot);
912 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
916 err = scsi_add_host(shost, &vdev->dev);
918 goto scsi_add_host_failed;
920 virtio_device_ready(vdev);
922 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
923 virtscsi_kick_event_all(vscsi);
925 scsi_scan_host(shost);
928 scsi_add_host_failed:
929 vdev->config->del_vqs(vdev);
930 virtscsi_init_failed:
931 scsi_host_put(shost);
935 static void virtscsi_remove(struct virtio_device *vdev)
937 struct Scsi_Host *shost = virtio_scsi_host(vdev);
938 struct virtio_scsi *vscsi = shost_priv(shost);
940 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
941 virtscsi_cancel_event_work(vscsi);
943 scsi_remove_host(shost);
944 virtscsi_remove_vqs(vdev);
945 scsi_host_put(shost);
948 #ifdef CONFIG_PM_SLEEP
949 static int virtscsi_freeze(struct virtio_device *vdev)
951 virtscsi_remove_vqs(vdev);
955 static int virtscsi_restore(struct virtio_device *vdev)
957 struct Scsi_Host *sh = virtio_scsi_host(vdev);
958 struct virtio_scsi *vscsi = shost_priv(sh);
961 err = virtscsi_init(vdev, vscsi);
965 virtio_device_ready(vdev);
967 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
968 virtscsi_kick_event_all(vscsi);
974 static struct virtio_device_id id_table[] = {
975 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
979 static unsigned int features[] = {
980 VIRTIO_SCSI_F_HOTPLUG,
981 VIRTIO_SCSI_F_CHANGE,
982 #ifdef CONFIG_BLK_DEV_INTEGRITY
983 VIRTIO_SCSI_F_T10_PI,
987 static struct virtio_driver virtio_scsi_driver = {
988 .feature_table = features,
989 .feature_table_size = ARRAY_SIZE(features),
990 .driver.name = KBUILD_MODNAME,
991 .driver.owner = THIS_MODULE,
992 .id_table = id_table,
993 .probe = virtscsi_probe,
994 #ifdef CONFIG_PM_SLEEP
995 .freeze = virtscsi_freeze,
996 .restore = virtscsi_restore,
998 .remove = virtscsi_remove,
1001 static int __init virtio_scsi_init(void)
1005 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1006 if (!virtscsi_cmd_cache) {
1007 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1013 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1014 virtscsi_cmd_cache);
1015 if (!virtscsi_cmd_pool) {
1016 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1019 ret = register_virtio_driver(&virtio_scsi_driver);
1026 mempool_destroy(virtscsi_cmd_pool);
1027 virtscsi_cmd_pool = NULL;
1028 kmem_cache_destroy(virtscsi_cmd_cache);
1029 virtscsi_cmd_cache = NULL;
1033 static void __exit virtio_scsi_fini(void)
1035 unregister_virtio_driver(&virtio_scsi_driver);
1036 mempool_destroy(virtscsi_cmd_pool);
1037 kmem_cache_destroy(virtscsi_cmd_cache);
1039 module_init(virtio_scsi_init);
1040 module_exit(virtio_scsi_fini);
1042 MODULE_DEVICE_TABLE(virtio, id_table);
1043 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1044 MODULE_LICENSE("GPL");