1/*
2 * Virtio SCSI HBA driver
3 *
4 * Copyright IBM Corp. 2010
5 * Copyright Red Hat, Inc. 2011
6 *
7 * Authors:
8 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
9 * Paolo Bonzini <pbonzini@redhat.com>
10 *
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.
13 *
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
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>
35
36#define VIRTIO_SCSI_MEMPOOL_SZ 64
37#define VIRTIO_SCSI_EVENT_LEN 8
38#define VIRTIO_SCSI_VQ_BASE 2
39
40/* Command queue element */
41struct virtio_scsi_cmd {
42 struct scsi_cmnd *sc;
43 struct completion *comp;
44 union {
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;
49 } req;
50 union {
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;
55 } resp;
56} ____cacheline_aligned_in_smp;
57
58struct virtio_scsi_event_node {
59 struct virtio_scsi *vscsi;
60 struct virtio_scsi_event event;
61 struct work_struct work;
62};
63
64struct virtio_scsi_vq {
65 /* Protects vq */
66 spinlock_t vq_lock;
67
68 struct virtqueue *vq;
69};
70
71/* Driver instance state */
72struct virtio_scsi {
73 struct virtio_device *vdev;
74
75 /* Get some buffers ready for event vq */
76 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
77
78 u32 num_queues;
79
80 /* If the affinity hint is set for virtqueues */
81 bool affinity_hint_set;
82
83 struct hlist_node node;
84
85 /* Protected by event_vq lock */
86 bool stop_events;
87
88 struct virtio_scsi_vq ctrl_vq;
89 struct virtio_scsi_vq event_vq;
90 struct virtio_scsi_vq req_vqs[];
91};
92
93static struct kmem_cache *virtscsi_cmd_cache;
94static mempool_t *virtscsi_cmd_pool;
95
96static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
97{
98 return vdev->priv;
99}
100
101static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
102{
103 if (resid)
104 scsi_set_resid(sc, resid);
105}
106
107/**
108 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
109 *
110 * Called with vq_lock held.
111 */
112static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
113{
114 struct virtio_scsi_cmd *cmd = buf;
115 struct scsi_cmnd *sc = cmd->sc;
116 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
117
118 dev_dbg(&sc->device->sdev_gendev,
119 "cmd %p response %u status %#02x sense_len %u\n",
120 sc, resp->response, resp->status, resp->sense_len);
121
122 sc->result = resp->status;
123 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid));
124 switch (resp->response) {
125 case VIRTIO_SCSI_S_OK:
126 set_host_byte(sc, DID_OK);
127 break;
128 case VIRTIO_SCSI_S_OVERRUN:
129 set_host_byte(sc, DID_ERROR);
130 break;
131 case VIRTIO_SCSI_S_ABORTED:
132 set_host_byte(sc, DID_ABORT);
133 break;
134 case VIRTIO_SCSI_S_BAD_TARGET:
135 set_host_byte(sc, DID_BAD_TARGET);
136 break;
137 case VIRTIO_SCSI_S_RESET:
138 set_host_byte(sc, DID_RESET);
139 break;
140 case VIRTIO_SCSI_S_BUSY:
141 set_host_byte(sc, DID_BUS_BUSY);
142 break;
143 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
144 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
145 break;
146 case VIRTIO_SCSI_S_TARGET_FAILURE:
147 set_host_byte(sc, DID_TARGET_FAILURE);
148 break;
149 case VIRTIO_SCSI_S_NEXUS_FAILURE:
150 set_host_byte(sc, DID_NEXUS_FAILURE);
151 break;
152 default:
153 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
154 resp->response);
155 /* fall through */
156 case VIRTIO_SCSI_S_FAILURE:
157 set_host_byte(sc, DID_ERROR);
158 break;
159 }
160
161 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
162 VIRTIO_SCSI_SENSE_SIZE);
163 if (sc->sense_buffer) {
164 memcpy(sc->sense_buffer, resp->sense,
165 min_t(u32,
166 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
167 VIRTIO_SCSI_SENSE_SIZE));
168 if (resp->sense_len)
169 set_driver_byte(sc, DRIVER_SENSE);
170 }
171
172 sc->scsi_done(sc);
173}
174
175static void virtscsi_vq_done(struct virtio_scsi *vscsi,
176 struct virtio_scsi_vq *virtscsi_vq,
177 void (*fn)(struct virtio_scsi *vscsi, void *buf))
178{
179 void *buf;
180 unsigned int len;
181 unsigned long flags;
182 struct virtqueue *vq = virtscsi_vq->vq;
183
184 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
185 do {
186 virtqueue_disable_cb(vq);
187 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
188 fn(vscsi, buf);
189
190 if (unlikely(virtqueue_is_broken(vq)))
191 break;
192 } while (!virtqueue_enable_cb(vq));
193 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
194}
195
196static void virtscsi_req_done(struct virtqueue *vq)
197{
198 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
199 struct virtio_scsi *vscsi = shost_priv(sh);
200 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
201 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
202
203 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
204};
205
206static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
207{
208 int i, num_vqs;
209
210 num_vqs = vscsi->num_queues;
211 for (i = 0; i < num_vqs; i++)
212 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
213 virtscsi_complete_cmd);
214}
215
216static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
217{
218 struct virtio_scsi_cmd *cmd = buf;
219
220 if (cmd->comp)
221 complete(cmd->comp);
222}
223
224static void virtscsi_ctrl_done(struct virtqueue *vq)
225{
226 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
227 struct virtio_scsi *vscsi = shost_priv(sh);
228
229 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
230};
231
232static void virtscsi_handle_event(struct work_struct *work);
233
234static int virtscsi_kick_event(struct virtio_scsi *vscsi,
235 struct virtio_scsi_event_node *event_node)
236{
237 int err;
238 struct scatterlist sg;
239 unsigned long flags;
240
241 INIT_WORK(&event_node->work, virtscsi_handle_event);
242 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
243
244 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
245
246 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
247 GFP_ATOMIC);
248 if (!err)
249 virtqueue_kick(vscsi->event_vq.vq);
250
251 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
252
253 return err;
254}
255
256static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
257{
258 int i;
259
260 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
261 vscsi->event_list[i].vscsi = vscsi;
262 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
263 }
264
265 return 0;
266}
267
268static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
269{
270 int i;
271
272 /* Stop scheduling work before calling cancel_work_sync. */
273 spin_lock_irq(&vscsi->event_vq.vq_lock);
274 vscsi->stop_events = true;
275 spin_unlock_irq(&vscsi->event_vq.vq_lock);
276
277 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
278 cancel_work_sync(&vscsi->event_list[i].work);
279}
280
281static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
282 struct virtio_scsi_event *event)
283{
284 struct scsi_device *sdev;
285 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
286 unsigned int target = event->lun[1];
287 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
288
289 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
290 case VIRTIO_SCSI_EVT_RESET_RESCAN:
291 scsi_add_device(shost, 0, target, lun);
292 break;
293 case VIRTIO_SCSI_EVT_RESET_REMOVED:
294 sdev = scsi_device_lookup(shost, 0, target, lun);
295 if (sdev) {
296 scsi_remove_device(sdev);
297 scsi_device_put(sdev);
298 } else {
299 pr_err("SCSI device %d 0 %d %d not found\n",
300 shost->host_no, target, lun);
301 }
302 break;
303 default:
304 pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
305 }
306}
307
308static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
309 struct virtio_scsi_event *event)
310{
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;
317
318 sdev = scsi_device_lookup(shost, 0, target, lun);
319 if (!sdev) {
320 pr_err("SCSI device %d 0 %d %d not found\n",
321 shost->host_no, target, lun);
322 return;
323 }
324
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);
329
330 scsi_device_put(sdev);
331}
332
333static void virtscsi_handle_event(struct work_struct *work)
334{
335 struct virtio_scsi_event_node *event_node =
336 container_of(work, struct virtio_scsi_event_node, work);
337 struct virtio_scsi *vscsi = event_node->vscsi;
338 struct virtio_scsi_event *event = &event_node->event;
339
340 if (event->event &
341 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
342 event->event &= ~cpu_to_virtio32(vscsi->vdev,
343 VIRTIO_SCSI_T_EVENTS_MISSED);
344 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
345 }
346
347 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
348 case VIRTIO_SCSI_T_NO_EVENT:
349 break;
350 case VIRTIO_SCSI_T_TRANSPORT_RESET:
351 virtscsi_handle_transport_reset(vscsi, event);
352 break;
353 case VIRTIO_SCSI_T_PARAM_CHANGE:
354 virtscsi_handle_param_change(vscsi, event);
355 break;
356 default:
357 pr_err("Unsupport virtio scsi event %x\n", event->event);
358 }
359 virtscsi_kick_event(vscsi, event_node);
360}
361
362static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
363{
364 struct virtio_scsi_event_node *event_node = buf;
365
366 if (!vscsi->stop_events)
367 queue_work(system_freezable_wq, &event_node->work);
368}
369
370static void virtscsi_event_done(struct virtqueue *vq)
371{
372 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
373 struct virtio_scsi *vscsi = shost_priv(sh);
374
375 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
376};
377
378/**
379 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
380 * @vq : the struct virtqueue we're talking about
381 * @cmd : command structure
382 * @req_size : size of the request buffer
383 * @resp_size : size of the response buffer
384 */
385static int virtscsi_add_cmd(struct virtqueue *vq,
386 struct virtio_scsi_cmd *cmd,
387 size_t req_size, size_t resp_size)
388{
389 struct scsi_cmnd *sc = cmd->sc;
390 struct scatterlist *sgs[6], req, resp;
391 struct sg_table *out, *in;
392 unsigned out_num = 0, in_num = 0;
393
394 out = in = NULL;
395
396 if (sc && sc->sc_data_direction != DMA_NONE) {
397 if (sc->sc_data_direction != DMA_FROM_DEVICE)
398 out = &sc->sdb.table;
399 if (sc->sc_data_direction != DMA_TO_DEVICE)
400 in = &sc->sdb.table;
401 }
402
403 /* Request header. */
404 sg_init_one(&req, &cmd->req, req_size);
405 sgs[out_num++] = &req;
406
407 /* Data-out buffer. */
408 if (out) {
409 /* Place WRITE protection SGLs before Data OUT payload */
410 if (scsi_prot_sg_count(sc))
411 sgs[out_num++] = scsi_prot_sglist(sc);
412 sgs[out_num++] = out->sgl;
413 }
414
415 /* Response header. */
416 sg_init_one(&resp, &cmd->resp, resp_size);
417 sgs[out_num + in_num++] = &resp;
418
419 /* Data-in buffer */
420 if (in) {
421 /* Place READ protection SGLs before Data IN payload */
422 if (scsi_prot_sg_count(sc))
423 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
424 sgs[out_num + in_num++] = in->sgl;
425 }
426
427 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
428}
429
430static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
431 struct virtio_scsi_cmd *cmd,
432 size_t req_size, size_t resp_size)
433{
434 unsigned long flags;
435 int err;
436 bool needs_kick = false;
437
438 spin_lock_irqsave(&vq->vq_lock, flags);
439 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
440 if (!err)
441 needs_kick = virtqueue_kick_prepare(vq->vq);
442
443 spin_unlock_irqrestore(&vq->vq_lock, flags);
444
445 if (needs_kick)
446 virtqueue_notify(vq->vq);
447 return err;
448}
449
450static void virtio_scsi_init_hdr(struct virtio_device *vdev,
451 struct virtio_scsi_cmd_req *cmd,
452 struct scsi_cmnd *sc)
453{
454 cmd->lun[0] = 1;
455 cmd->lun[1] = sc->device->id;
456 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
457 cmd->lun[3] = sc->device->lun & 0xff;
458 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
459 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
460 cmd->prio = 0;
461 cmd->crn = 0;
462}
463
464#ifdef CONFIG_BLK_DEV_INTEGRITY
465static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
466 struct virtio_scsi_cmd_req_pi *cmd_pi,
467 struct scsi_cmnd *sc)
468{
469 struct request *rq = sc->request;
470 struct blk_integrity *bi;
471
472 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
473
474 if (!rq || !scsi_prot_sg_count(sc))
475 return;
476
477 bi = blk_get_integrity(rq->rq_disk);
478
479 if (sc->sc_data_direction == DMA_TO_DEVICE)
480 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
481 bio_integrity_bytes(bi,
482 blk_rq_sectors(rq)));
483 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
484 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
485 bio_integrity_bytes(bi,
486 blk_rq_sectors(rq)));
487}
488#endif
489
490static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
491 struct scsi_cmnd *sc)
492{
493 u32 tag = blk_mq_unique_tag(sc->request);
494 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
495
496 return &vscsi->req_vqs[hwq];
497}
498
499static int virtscsi_queuecommand(struct Scsi_Host *shost,
500 struct scsi_cmnd *sc)
501{
502 struct virtio_scsi *vscsi = shost_priv(shost);
503 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
504 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
505 unsigned long flags;
506 int req_size;
507 int ret;
508
509 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
510
511 /* TODO: check feature bit and fail if unsupported? */
512 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
513
514 dev_dbg(&sc->device->sdev_gendev,
515 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
516
517 cmd->sc = sc;
518
519 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
520
521#ifdef CONFIG_BLK_DEV_INTEGRITY
522 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
523 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
524 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
525 req_size = sizeof(cmd->req.cmd_pi);
526 } else
527#endif
528 {
529 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
530 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
531 req_size = sizeof(cmd->req.cmd);
532 }
533
534 ret = virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd));
535 if (ret == -EIO) {
536 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
537 spin_lock_irqsave(&req_vq->vq_lock, flags);
538 virtscsi_complete_cmd(vscsi, cmd);
539 spin_unlock_irqrestore(&req_vq->vq_lock, flags);
540 } else if (ret != 0) {
541 return SCSI_MLQUEUE_HOST_BUSY;
542 }
543 return 0;
544}
545
546static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
547{
548 DECLARE_COMPLETION_ONSTACK(comp);
549 int ret = FAILED;
550
551 cmd->comp = &comp;
552 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
553 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
554 goto out;
555
556 wait_for_completion(&comp);
557 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
558 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
559 ret = SUCCESS;
560
561 /*
562 * The spec guarantees that all requests related to the TMF have
563 * been completed, but the callback might not have run yet if
564 * we're using independent interrupts (e.g. MSI). Poll the
565 * virtqueues once.
566 *
567 * In the abort case, sc->scsi_done will do nothing, because
568 * the block layer must have detected a timeout and as a result
569 * REQ_ATOM_COMPLETE has been set.
570 */
571 virtscsi_poll_requests(vscsi);
572
573out:
574 mempool_free(cmd, virtscsi_cmd_pool);
575 return ret;
576}
577
578static int virtscsi_device_reset(struct scsi_cmnd *sc)
579{
580 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
581 struct virtio_scsi_cmd *cmd;
582
583 sdev_printk(KERN_INFO, sc->device, "device reset\n");
584 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
585 if (!cmd)
586 return FAILED;
587
588 memset(cmd, 0, sizeof(*cmd));
589 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
590 .type = VIRTIO_SCSI_T_TMF,
591 .subtype = cpu_to_virtio32(vscsi->vdev,
592 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
593 .lun[0] = 1,
594 .lun[1] = sc->device->id,
595 .lun[2] = (sc->device->lun >> 8) | 0x40,
596 .lun[3] = sc->device->lun & 0xff,
597 };
598 return virtscsi_tmf(vscsi, cmd);
599}
600
601static int virtscsi_device_alloc(struct scsi_device *sdevice)
602{
603 /*
604 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
605 * may have transfer limits which come from the host SCSI
606 * controller or something on the host side other than the
607 * target itself.
608 *
609 * To make this work properly, the hypervisor can adjust the
610 * target's VPD information to advertise these limits. But
611 * for that to work, the guest has to look at the VPD pages,
612 * which we won't do by default if it is an SPC-2 device, even
613 * if it does actually support it.
614 *
615 * So, set the blist to always try to read the VPD pages.
616 */
617 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
618
619 return 0;
620}
621
622
623/**
624 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
625 * @sdev: Virtscsi target whose queue depth to change
626 * @qdepth: New queue depth
627 */
628static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
629{
630 struct Scsi_Host *shost = sdev->host;
631 int max_depth = shost->cmd_per_lun;
632
633 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
634}
635
636static int virtscsi_abort(struct scsi_cmnd *sc)
637{
638 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
639 struct virtio_scsi_cmd *cmd;
640
641 scmd_printk(KERN_INFO, sc, "abort\n");
642 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
643 if (!cmd)
644 return FAILED;
645
646 memset(cmd, 0, sizeof(*cmd));
647 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
648 .type = VIRTIO_SCSI_T_TMF,
649 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
650 .lun[0] = 1,
651 .lun[1] = sc->device->id,
652 .lun[2] = (sc->device->lun >> 8) | 0x40,
653 .lun[3] = sc->device->lun & 0xff,
654 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
655 };
656 return virtscsi_tmf(vscsi, cmd);
657}
658
659static int virtscsi_map_queues(struct Scsi_Host *shost)
660{
661 struct virtio_scsi *vscsi = shost_priv(shost);
662 struct blk_mq_queue_map *qmap = &shost->tag_set.map[0];
663
664 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2);
665}
666
667/*
668 * The host guarantees to respond to each command, although I/O
669 * latencies might be higher than on bare metal. Reset the timer
670 * unconditionally to give the host a chance to perform EH.
671 */
672static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
673{
674 return BLK_EH_RESET_TIMER;
675}
676
677static struct scsi_host_template virtscsi_host_template = {
678 .module = THIS_MODULE,
679 .name = "Virtio SCSI HBA",
680 .proc_name = "virtio_scsi",
681 .this_id = -1,
682 .cmd_size = sizeof(struct virtio_scsi_cmd),
683 .queuecommand = virtscsi_queuecommand,
684 .change_queue_depth = virtscsi_change_queue_depth,
685 .eh_abort_handler = virtscsi_abort,
686 .eh_device_reset_handler = virtscsi_device_reset,
687 .eh_timed_out = virtscsi_eh_timed_out,
688 .slave_alloc = virtscsi_device_alloc,
689
690 .dma_boundary = UINT_MAX,
691 .map_queues = virtscsi_map_queues,
692 .track_queue_depth = 1,
693 .force_blk_mq = 1,
694};
695
696#define virtscsi_config_get(vdev, fld) \
697 ({ \
698 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
699 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
700 __val; \
701 })
702
703#define virtscsi_config_set(vdev, fld, val) \
704 do { \
705 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
706 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
707 } while(0)
708
709static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
710 struct virtqueue *vq)
711{
712 spin_lock_init(&virtscsi_vq->vq_lock);
713 virtscsi_vq->vq = vq;
714}
715
716static void virtscsi_remove_vqs(struct virtio_device *vdev)
717{
718 /* Stop all the virtqueues. */
719 vdev->config->reset(vdev);
720 vdev->config->del_vqs(vdev);
721}
722
723static int virtscsi_init(struct virtio_device *vdev,
724 struct virtio_scsi *vscsi)
725{
726 int err;
727 u32 i;
728 u32 num_vqs;
729 vq_callback_t **callbacks;
730 const char **names;
731 struct virtqueue **vqs;
732 struct irq_affinity desc = { .pre_vectors = 2 };
733
734 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
735 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
736 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *),
737 GFP_KERNEL);
738 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL);
739
740 if (!callbacks || !vqs || !names) {
741 err = -ENOMEM;
742 goto out;
743 }
744
745 callbacks[0] = virtscsi_ctrl_done;
746 callbacks[1] = virtscsi_event_done;
747 names[0] = "control";
748 names[1] = "event";
749 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
750 callbacks[i] = virtscsi_req_done;
751 names[i] = "request";
752 }
753
754 /* Discover virtqueues and write information to configuration. */
755 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
756 if (err)
757 goto out;
758
759 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
760 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
761 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
762 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
763 vqs[i]);
764
765 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
766 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
767
768 err = 0;
769
770out:
771 kfree(names);
772 kfree(callbacks);
773 kfree(vqs);
774 if (err)
775 virtscsi_remove_vqs(vdev);
776 return err;
777}
778
779static int virtscsi_probe(struct virtio_device *vdev)
780{
781 struct Scsi_Host *shost;
782 struct virtio_scsi *vscsi;
783 int err;
784 u32 sg_elems, num_targets;
785 u32 cmd_per_lun;
786 u32 num_queues;
787
788 if (!vdev->config->get) {
789 dev_err(&vdev->dev, "%s failure: config access disabled\n",
790 __func__);
791 return -EINVAL;
792 }
793
794 /* We need to know how many queues before we allocate. */
795 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
796
797 num_targets = virtscsi_config_get(vdev, max_target) + 1;
798
799 shost = scsi_host_alloc(&virtscsi_host_template,
800 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
801 if (!shost)
802 return -ENOMEM;
803
804 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
805 shost->sg_tablesize = sg_elems;
806 vscsi = shost_priv(shost);
807 vscsi->vdev = vdev;
808 vscsi->num_queues = num_queues;
809 vdev->priv = shost;
810
811 err = virtscsi_init(vdev, vscsi);
812 if (err)
813 goto virtscsi_init_failed;
814
815 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
816
817 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
818 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
819 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
820
821 /* LUNs > 256 are reported with format 1, so they go in the range
822 * 16640-32767.
823 */
824 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
825 shost->max_id = num_targets;
826 shost->max_channel = 0;
827 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
828 shost->nr_hw_queues = num_queues;
829
830#ifdef CONFIG_BLK_DEV_INTEGRITY
831 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
832 int host_prot;
833
834 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
835 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
836 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
837
838 scsi_host_set_prot(shost, host_prot);
839 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
840 }
841#endif
842
843 err = scsi_add_host(shost, &vdev->dev);
844 if (err)
845 goto scsi_add_host_failed;
846
847 virtio_device_ready(vdev);
848
849 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
850 virtscsi_kick_event_all(vscsi);
851
852 scsi_scan_host(shost);
853 return 0;
854
855scsi_add_host_failed:
856 vdev->config->del_vqs(vdev);
857virtscsi_init_failed:
858 scsi_host_put(shost);
859 return err;
860}
861
862static void virtscsi_remove(struct virtio_device *vdev)
863{
864 struct Scsi_Host *shost = virtio_scsi_host(vdev);
865 struct virtio_scsi *vscsi = shost_priv(shost);
866
867 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
868 virtscsi_cancel_event_work(vscsi);
869
870 scsi_remove_host(shost);
871 virtscsi_remove_vqs(vdev);
872 scsi_host_put(shost);
873}
874
875#ifdef CONFIG_PM_SLEEP
876static int virtscsi_freeze(struct virtio_device *vdev)
877{
878 virtscsi_remove_vqs(vdev);
879 return 0;
880}
881
882static int virtscsi_restore(struct virtio_device *vdev)
883{
884 struct Scsi_Host *sh = virtio_scsi_host(vdev);
885 struct virtio_scsi *vscsi = shost_priv(sh);
886 int err;
887
888 err = virtscsi_init(vdev, vscsi);
889 if (err)
890 return err;
891
892 virtio_device_ready(vdev);
893
894 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
895 virtscsi_kick_event_all(vscsi);
896
897 return err;
898}
899#endif
900
901static struct virtio_device_id id_table[] = {
902 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
903 { 0 },
904};
905
906static unsigned int features[] = {
907 VIRTIO_SCSI_F_HOTPLUG,
908 VIRTIO_SCSI_F_CHANGE,
909#ifdef CONFIG_BLK_DEV_INTEGRITY
910 VIRTIO_SCSI_F_T10_PI,
911#endif
912};
913
914static struct virtio_driver virtio_scsi_driver = {
915 .feature_table = features,
916 .feature_table_size = ARRAY_SIZE(features),
917 .driver.name = KBUILD_MODNAME,
918 .driver.owner = THIS_MODULE,
919 .id_table = id_table,
920 .probe = virtscsi_probe,
921#ifdef CONFIG_PM_SLEEP
922 .freeze = virtscsi_freeze,
923 .restore = virtscsi_restore,
924#endif
925 .remove = virtscsi_remove,
926};
927
928static int __init init(void)
929{
930 int ret = -ENOMEM;
931
932 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
933 if (!virtscsi_cmd_cache) {
934 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
935 goto error;
936 }
937
938
939 virtscsi_cmd_pool =
940 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
941 virtscsi_cmd_cache);
942 if (!virtscsi_cmd_pool) {
943 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
944 goto error;
945 }
946 ret = register_virtio_driver(&virtio_scsi_driver);
947 if (ret < 0)
948 goto error;
949
950 return 0;
951
952error:
953 if (virtscsi_cmd_pool) {
954 mempool_destroy(virtscsi_cmd_pool);
955 virtscsi_cmd_pool = NULL;
956 }
957 if (virtscsi_cmd_cache) {
958 kmem_cache_destroy(virtscsi_cmd_cache);
959 virtscsi_cmd_cache = NULL;
960 }
961 return ret;
962}
963
964static void __exit fini(void)
965{
966 unregister_virtio_driver(&virtio_scsi_driver);
967 mempool_destroy(virtscsi_cmd_pool);
968 kmem_cache_destroy(virtscsi_cmd_cache);
969}
970module_init(init);
971module_exit(fini);
972
973MODULE_DEVICE_TABLE(virtio, id_table);
974MODULE_DESCRIPTION("Virtio SCSI HBA driver");
975MODULE_LICENSE("GPL");
976