1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Virtio SCSI HBA driver
4 *
5 * Copyright IBM Corp. 2010
6 * Copyright Red Hat, Inc. 2011
7 *
8 * Authors:
9 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
10 * Paolo Bonzini <pbonzini@redhat.com>
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
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>
33
34#include "sd.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 struct hlist_node node;
81
82 /* Protected by event_vq lock */
83 bool stop_events;
84
85 struct virtio_scsi_vq ctrl_vq;
86 struct virtio_scsi_vq event_vq;
87 struct virtio_scsi_vq req_vqs[];
88};
89
90static struct kmem_cache *virtscsi_cmd_cache;
91static mempool_t *virtscsi_cmd_pool;
92
93static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
94{
95 return vdev->priv;
96}
97
98static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
99{
100 if (resid)
101 scsi_set_resid(cmd: sc, min(resid, scsi_bufflen(sc)));
102}
103
104/*
105 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
106 *
107 * Called with vq_lock held.
108 */
109static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
110{
111 struct virtio_scsi_cmd *cmd = buf;
112 struct scsi_cmnd *sc = cmd->sc;
113 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
114
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);
118
119 sc->result = resp->status;
120 virtscsi_compute_resid(sc, resid: virtio32_to_cpu(vdev: vscsi->vdev, val: resp->resid));
121 switch (resp->response) {
122 case VIRTIO_SCSI_S_OK:
123 set_host_byte(cmd: sc, status: DID_OK);
124 break;
125 case VIRTIO_SCSI_S_OVERRUN:
126 set_host_byte(cmd: sc, status: DID_ERROR);
127 break;
128 case VIRTIO_SCSI_S_ABORTED:
129 set_host_byte(cmd: sc, status: DID_ABORT);
130 break;
131 case VIRTIO_SCSI_S_BAD_TARGET:
132 set_host_byte(cmd: sc, status: DID_BAD_TARGET);
133 break;
134 case VIRTIO_SCSI_S_RESET:
135 set_host_byte(cmd: sc, status: DID_RESET);
136 break;
137 case VIRTIO_SCSI_S_BUSY:
138 set_host_byte(cmd: sc, status: DID_BUS_BUSY);
139 break;
140 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
141 set_host_byte(cmd: sc, status: DID_TRANSPORT_DISRUPTED);
142 break;
143 case VIRTIO_SCSI_S_TARGET_FAILURE:
144 set_host_byte(cmd: sc, status: DID_BAD_TARGET);
145 break;
146 case VIRTIO_SCSI_S_NEXUS_FAILURE:
147 set_status_byte(cmd: sc, status: SAM_STAT_RESERVATION_CONFLICT);
148 break;
149 default:
150 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
151 resp->response);
152 fallthrough;
153 case VIRTIO_SCSI_S_FAILURE:
154 set_host_byte(cmd: sc, status: DID_ERROR);
155 break;
156 }
157
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,
162 min_t(u32,
163 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
164 VIRTIO_SCSI_SENSE_SIZE));
165 }
166
167 scsi_done(cmd: sc);
168}
169
170static void virtscsi_vq_done(struct virtio_scsi *vscsi,
171 struct virtio_scsi_vq *virtscsi_vq,
172 void (*fn)(struct virtio_scsi *vscsi, void *buf))
173{
174 void *buf;
175 unsigned int len;
176 unsigned long flags;
177 struct virtqueue *vq = virtscsi_vq->vq;
178
179 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
180 do {
181 virtqueue_disable_cb(vq);
182 while ((buf = virtqueue_get_buf(vq, len: &len)) != NULL)
183 fn(vscsi, buf);
184
185 if (unlikely(virtqueue_is_broken(vq)))
186 break;
187 } while (!virtqueue_enable_cb(vq));
188 spin_unlock_irqrestore(lock: &virtscsi_vq->vq_lock, flags);
189}
190
191static void virtscsi_req_done(struct virtqueue *vq)
192{
193 struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev);
194 struct virtio_scsi *vscsi = shost_priv(shost: sh);
195 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
196 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
197
198 virtscsi_vq_done(vscsi, virtscsi_vq: req_vq, fn: virtscsi_complete_cmd);
199};
200
201static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
202{
203 int i, num_vqs;
204
205 num_vqs = vscsi->num_queues;
206 for (i = 0; i < num_vqs; i++)
207 virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->req_vqs[i],
208 fn: virtscsi_complete_cmd);
209}
210
211static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
212{
213 struct virtio_scsi_cmd *cmd = buf;
214
215 if (cmd->comp)
216 complete(cmd->comp);
217}
218
219static void virtscsi_ctrl_done(struct virtqueue *vq)
220{
221 struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev);
222 struct virtio_scsi *vscsi = shost_priv(shost: sh);
223
224 virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->ctrl_vq, fn: virtscsi_complete_free);
225};
226
227static void virtscsi_handle_event(struct work_struct *work);
228
229static int virtscsi_kick_event(struct virtio_scsi *vscsi,
230 struct virtio_scsi_event_node *event_node)
231{
232 int err;
233 struct scatterlist sg;
234 unsigned long flags;
235
236 INIT_WORK(&event_node->work, virtscsi_handle_event);
237 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
238
239 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
240
241 err = virtqueue_add_inbuf(vq: vscsi->event_vq.vq, sg: &sg, num: 1, data: event_node,
242 GFP_ATOMIC);
243 if (!err)
244 virtqueue_kick(vq: vscsi->event_vq.vq);
245
246 spin_unlock_irqrestore(lock: &vscsi->event_vq.vq_lock, flags);
247
248 return err;
249}
250
251static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
252{
253 int i;
254
255 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
256 vscsi->event_list[i].vscsi = vscsi;
257 virtscsi_kick_event(vscsi, event_node: &vscsi->event_list[i]);
258 }
259
260 return 0;
261}
262
263static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
264{
265 int i;
266
267 /* Stop scheduling work before calling cancel_work_sync. */
268 spin_lock_irq(lock: &vscsi->event_vq.vq_lock);
269 vscsi->stop_events = true;
270 spin_unlock_irq(lock: &vscsi->event_vq.vq_lock);
271
272 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
273 cancel_work_sync(work: &vscsi->event_list[i].work);
274}
275
276static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
277 struct virtio_scsi_event *event)
278{
279 struct scsi_device *sdev;
280 struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev);
281 unsigned int target = event->lun[1];
282 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
283
284 switch (virtio32_to_cpu(vdev: vscsi->vdev, val: event->reason)) {
285 case VIRTIO_SCSI_EVT_RESET_RESCAN:
286 if (lun == 0) {
287 scsi_scan_target(parent: &shost->shost_gendev, channel: 0, id: target,
288 SCAN_WILD_CARD, rescan: SCSI_SCAN_INITIAL);
289 } else {
290 scsi_add_device(host: shost, channel: 0, target, lun);
291 }
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("Unsupported 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(vdev: 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(vdev: vscsi->vdev, val: event->reason) & 255;
316 u8 ascq = virtio32_to_cpu(vdev: vscsi->vdev, val: 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);
329
330 scsi_device_put(sdev);
331}
332
333static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
334{
335 struct scsi_device *sdev;
336 struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev);
337 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
338 int result, inquiry_len, inq_result_len = 256;
339 char *inq_result = kmalloc(size: inq_result_len, GFP_KERNEL);
340
341 if (!inq_result)
342 return -ENOMEM;
343
344 shost_for_each_device(sdev, shost) {
345 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
346
347 memset(scsi_cmd, 0, sizeof(scsi_cmd));
348 scsi_cmd[0] = INQUIRY;
349 scsi_cmd[4] = (unsigned char) inquiry_len;
350
351 memset(inq_result, 0, inq_result_len);
352
353 result = scsi_execute_cmd(sdev, cmd: scsi_cmd, opf: REQ_OP_DRV_IN,
354 buffer: inq_result, bufflen: inquiry_len,
355 SD_TIMEOUT, SD_MAX_RETRIES, NULL);
356
357 if (result == 0 && inq_result[0] >> 5) {
358 /* PQ indicates the LUN is not attached */
359 scsi_remove_device(sdev);
360 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) {
361 /*
362 * If all LUNs of a virtio-scsi device are unplugged
363 * it will respond with BAD TARGET on any INQUIRY
364 * command.
365 * Remove the device in this case as well.
366 */
367 scsi_remove_device(sdev);
368 }
369 }
370
371 kfree(objp: inq_result);
372 return 0;
373}
374
375static void virtscsi_handle_event(struct work_struct *work)
376{
377 struct virtio_scsi_event_node *event_node =
378 container_of(work, struct virtio_scsi_event_node, work);
379 struct virtio_scsi *vscsi = event_node->vscsi;
380 struct virtio_scsi_event *event = &event_node->event;
381
382 if (event->event &
383 cpu_to_virtio32(vdev: vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
384 int ret;
385
386 event->event &= ~cpu_to_virtio32(vdev: vscsi->vdev,
387 VIRTIO_SCSI_T_EVENTS_MISSED);
388 ret = virtscsi_rescan_hotunplug(vscsi);
389 if (ret)
390 return;
391 scsi_scan_host(virtio_scsi_host(vdev: vscsi->vdev));
392 }
393
394 switch (virtio32_to_cpu(vdev: vscsi->vdev, val: event->event)) {
395 case VIRTIO_SCSI_T_NO_EVENT:
396 break;
397 case VIRTIO_SCSI_T_TRANSPORT_RESET:
398 virtscsi_handle_transport_reset(vscsi, event);
399 break;
400 case VIRTIO_SCSI_T_PARAM_CHANGE:
401 virtscsi_handle_param_change(vscsi, event);
402 break;
403 default:
404 pr_err("Unsupported virtio scsi event %x\n", event->event);
405 }
406 virtscsi_kick_event(vscsi, event_node);
407}
408
409static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
410{
411 struct virtio_scsi_event_node *event_node = buf;
412
413 if (!vscsi->stop_events)
414 queue_work(wq: system_freezable_wq, work: &event_node->work);
415}
416
417static void virtscsi_event_done(struct virtqueue *vq)
418{
419 struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev);
420 struct virtio_scsi *vscsi = shost_priv(shost: sh);
421
422 virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->event_vq, fn: virtscsi_complete_event);
423};
424
425static int __virtscsi_add_cmd(struct virtqueue *vq,
426 struct virtio_scsi_cmd *cmd,
427 size_t req_size, size_t resp_size)
428{
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;
433
434 out = in = NULL;
435
436 if (sc && sc->sc_data_direction != DMA_NONE) {
437 if (sc->sc_data_direction != DMA_FROM_DEVICE)
438 out = &sc->sdb.table;
439 if (sc->sc_data_direction != DMA_TO_DEVICE)
440 in = &sc->sdb.table;
441 }
442
443 /* Request header. */
444 sg_init_one(&req, &cmd->req, req_size);
445 sgs[out_num++] = &req;
446
447 /* Data-out buffer. */
448 if (out) {
449 /* Place WRITE protection SGLs before Data OUT payload */
450 if (scsi_prot_sg_count(cmd: sc))
451 sgs[out_num++] = scsi_prot_sglist(cmd: sc);
452 sgs[out_num++] = out->sgl;
453 }
454
455 /* Response header. */
456 sg_init_one(&resp, &cmd->resp, resp_size);
457 sgs[out_num + in_num++] = &resp;
458
459 /* Data-in buffer */
460 if (in) {
461 /* Place READ protection SGLs before Data IN payload */
462 if (scsi_prot_sg_count(cmd: sc))
463 sgs[out_num + in_num++] = scsi_prot_sglist(cmd: sc);
464 sgs[out_num + in_num++] = in->sgl;
465 }
466
467 return virtqueue_add_sgs(vq, sgs, out_sgs: out_num, in_sgs: in_num, data: cmd, GFP_ATOMIC);
468}
469
470static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
471{
472 bool needs_kick;
473 unsigned long flags;
474
475 spin_lock_irqsave(&vq->vq_lock, flags);
476 needs_kick = virtqueue_kick_prepare(vq: vq->vq);
477 spin_unlock_irqrestore(lock: &vq->vq_lock, flags);
478
479 if (needs_kick)
480 virtqueue_notify(vq: vq->vq);
481}
482
483/**
484 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
485 * @vq : the struct virtqueue we're talking about
486 * @cmd : command structure
487 * @req_size : size of the request buffer
488 * @resp_size : size of the response buffer
489 * @kick : whether to kick the virtqueue immediately
490 */
491static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
492 struct virtio_scsi_cmd *cmd,
493 size_t req_size, size_t resp_size,
494 bool kick)
495{
496 unsigned long flags;
497 int err;
498 bool needs_kick = false;
499
500 spin_lock_irqsave(&vq->vq_lock, flags);
501 err = __virtscsi_add_cmd(vq: vq->vq, cmd, req_size, resp_size);
502 if (!err && kick)
503 needs_kick = virtqueue_kick_prepare(vq: vq->vq);
504
505 spin_unlock_irqrestore(lock: &vq->vq_lock, flags);
506
507 if (needs_kick)
508 virtqueue_notify(vq: vq->vq);
509 return err;
510}
511
512static void virtio_scsi_init_hdr(struct virtio_device *vdev,
513 struct virtio_scsi_cmd_req *cmd,
514 struct scsi_cmnd *sc)
515{
516 cmd->lun[0] = 1;
517 cmd->lun[1] = sc->device->id;
518 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
519 cmd->lun[3] = sc->device->lun & 0xff;
520 cmd->tag = cpu_to_virtio64(vdev, val: (unsigned long)sc);
521 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
522 cmd->prio = 0;
523 cmd->crn = 0;
524}
525
526#ifdef CONFIG_BLK_DEV_INTEGRITY
527static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
528 struct virtio_scsi_cmd_req_pi *cmd_pi,
529 struct scsi_cmnd *sc)
530{
531 struct request *rq = scsi_cmd_to_rq(scmd: sc);
532 struct blk_integrity *bi;
533
534 virtio_scsi_init_hdr(vdev, cmd: (struct virtio_scsi_cmd_req *)cmd_pi, sc);
535
536 if (!rq || !scsi_prot_sg_count(cmd: sc))
537 return;
538
539 bi = blk_get_integrity(disk: rq->q->disk);
540
541 if (sc->sc_data_direction == DMA_TO_DEVICE)
542 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
543 val: bio_integrity_bytes(bi,
544 sectors: blk_rq_sectors(rq)));
545 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
546 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
547 val: bio_integrity_bytes(bi,
548 sectors: blk_rq_sectors(rq)));
549}
550#endif
551
552static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
553 struct scsi_cmnd *sc)
554{
555 u32 tag = blk_mq_unique_tag(rq: scsi_cmd_to_rq(scmd: sc));
556 u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag: tag);
557
558 return &vscsi->req_vqs[hwq];
559}
560
561static int virtscsi_queuecommand(struct Scsi_Host *shost,
562 struct scsi_cmnd *sc)
563{
564 struct virtio_scsi *vscsi = shost_priv(shost);
565 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
566 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(cmd: sc);
567 bool kick;
568 unsigned long flags;
569 int req_size;
570 int ret;
571
572 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
573
574 /* TODO: check feature bit and fail if unsupported? */
575 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
576
577 dev_dbg(&sc->device->sdev_gendev,
578 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
579
580 cmd->sc = sc;
581
582 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
583
584#ifdef CONFIG_BLK_DEV_INTEGRITY
585 if (virtio_has_feature(vdev: vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
586 virtio_scsi_init_hdr_pi(vdev: vscsi->vdev, cmd_pi: &cmd->req.cmd_pi, sc);
587 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
588 req_size = sizeof(cmd->req.cmd_pi);
589 } else
590#endif
591 {
592 virtio_scsi_init_hdr(vdev: vscsi->vdev, cmd: &cmd->req.cmd, sc);
593 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
594 req_size = sizeof(cmd->req.cmd);
595 }
596
597 kick = (sc->flags & SCMD_LAST) != 0;
598 ret = virtscsi_add_cmd(vq: req_vq, cmd, req_size, resp_size: sizeof(cmd->resp.cmd), kick);
599 if (ret == -EIO) {
600 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
601 spin_lock_irqsave(&req_vq->vq_lock, flags);
602 virtscsi_complete_cmd(vscsi, buf: cmd);
603 spin_unlock_irqrestore(lock: &req_vq->vq_lock, flags);
604 } else if (ret != 0) {
605 return SCSI_MLQUEUE_HOST_BUSY;
606 }
607 return 0;
608}
609
610static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
611{
612 DECLARE_COMPLETION_ONSTACK(comp);
613 int ret = FAILED;
614
615 cmd->comp = &comp;
616 if (virtscsi_add_cmd(vq: &vscsi->ctrl_vq, cmd,
617 req_size: sizeof cmd->req.tmf, resp_size: sizeof cmd->resp.tmf, kick: true) < 0)
618 goto out;
619
620 wait_for_completion(&comp);
621 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
622 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
623 ret = SUCCESS;
624
625 /*
626 * The spec guarantees that all requests related to the TMF have
627 * been completed, but the callback might not have run yet if
628 * we're using independent interrupts (e.g. MSI). Poll the
629 * virtqueues once.
630 *
631 * In the abort case, scsi_done() will do nothing, because the
632 * command timed out and hence SCMD_STATE_COMPLETE has been set.
633 */
634 virtscsi_poll_requests(vscsi);
635
636out:
637 mempool_free(element: cmd, pool: virtscsi_cmd_pool);
638 return ret;
639}
640
641static int virtscsi_device_reset(struct scsi_cmnd *sc)
642{
643 struct virtio_scsi *vscsi = shost_priv(shost: sc->device->host);
644 struct virtio_scsi_cmd *cmd;
645
646 sdev_printk(KERN_INFO, sc->device, "device reset\n");
647 cmd = mempool_alloc(pool: virtscsi_cmd_pool, GFP_NOIO);
648 if (!cmd)
649 return FAILED;
650
651 memset(cmd, 0, sizeof(*cmd));
652 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
653 .type = VIRTIO_SCSI_T_TMF,
654 .subtype = cpu_to_virtio32(vdev: vscsi->vdev,
655 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
656 .lun[0] = 1,
657 .lun[1] = sc->device->id,
658 .lun[2] = (sc->device->lun >> 8) | 0x40,
659 .lun[3] = sc->device->lun & 0xff,
660 };
661 return virtscsi_tmf(vscsi, cmd);
662}
663
664static int virtscsi_device_alloc(struct scsi_device *sdevice)
665{
666 /*
667 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
668 * may have transfer limits which come from the host SCSI
669 * controller or something on the host side other than the
670 * target itself.
671 *
672 * To make this work properly, the hypervisor can adjust the
673 * target's VPD information to advertise these limits. But
674 * for that to work, the guest has to look at the VPD pages,
675 * which we won't do by default if it is an SPC-2 device, even
676 * if it does actually support it.
677 *
678 * So, set the blist to always try to read the VPD pages.
679 */
680 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
681
682 return 0;
683}
684
685
686/**
687 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
688 * @sdev: Virtscsi target whose queue depth to change
689 * @qdepth: New queue depth
690 */
691static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
692{
693 struct Scsi_Host *shost = sdev->host;
694 int max_depth = shost->cmd_per_lun;
695
696 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
697}
698
699static int virtscsi_abort(struct scsi_cmnd *sc)
700{
701 struct virtio_scsi *vscsi = shost_priv(shost: sc->device->host);
702 struct virtio_scsi_cmd *cmd;
703
704 scmd_printk(KERN_INFO, sc, "abort\n");
705 cmd = mempool_alloc(pool: virtscsi_cmd_pool, GFP_NOIO);
706 if (!cmd)
707 return FAILED;
708
709 memset(cmd, 0, sizeof(*cmd));
710 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
711 .type = VIRTIO_SCSI_T_TMF,
712 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
713 .lun[0] = 1,
714 .lun[1] = sc->device->id,
715 .lun[2] = (sc->device->lun >> 8) | 0x40,
716 .lun[3] = sc->device->lun & 0xff,
717 .tag = cpu_to_virtio64(vdev: vscsi->vdev, val: (unsigned long)sc),
718 };
719 return virtscsi_tmf(vscsi, cmd);
720}
721
722static void virtscsi_map_queues(struct Scsi_Host *shost)
723{
724 struct virtio_scsi *vscsi = shost_priv(shost);
725 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
726
727 blk_mq_virtio_map_queues(qmap, vdev: vscsi->vdev, first_vec: 2);
728}
729
730static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
731{
732 struct virtio_scsi *vscsi = shost_priv(shost);
733
734 virtscsi_kick_vq(vq: &vscsi->req_vqs[hwq]);
735}
736
737/*
738 * The host guarantees to respond to each command, although I/O
739 * latencies might be higher than on bare metal. Reset the timer
740 * unconditionally to give the host a chance to perform EH.
741 */
742static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
743{
744 return SCSI_EH_RESET_TIMER;
745}
746
747static const struct scsi_host_template virtscsi_host_template = {
748 .module = THIS_MODULE,
749 .name = "Virtio SCSI HBA",
750 .proc_name = "virtio_scsi",
751 .this_id = -1,
752 .cmd_size = sizeof(struct virtio_scsi_cmd),
753 .queuecommand = virtscsi_queuecommand,
754 .commit_rqs = virtscsi_commit_rqs,
755 .change_queue_depth = virtscsi_change_queue_depth,
756 .eh_abort_handler = virtscsi_abort,
757 .eh_device_reset_handler = virtscsi_device_reset,
758 .eh_timed_out = virtscsi_eh_timed_out,
759 .slave_alloc = virtscsi_device_alloc,
760
761 .dma_boundary = UINT_MAX,
762 .map_queues = virtscsi_map_queues,
763 .track_queue_depth = 1,
764};
765
766#define virtscsi_config_get(vdev, fld) \
767 ({ \
768 __virtio_native_type(struct virtio_scsi_config, fld) __val; \
769 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
770 __val; \
771 })
772
773#define virtscsi_config_set(vdev, fld, val) \
774 do { \
775 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \
776 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
777 } while(0)
778
779static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
780 struct virtqueue *vq)
781{
782 spin_lock_init(&virtscsi_vq->vq_lock);
783 virtscsi_vq->vq = vq;
784}
785
786static void virtscsi_remove_vqs(struct virtio_device *vdev)
787{
788 /* Stop all the virtqueues. */
789 virtio_reset_device(dev: vdev);
790 vdev->config->del_vqs(vdev);
791}
792
793static int virtscsi_init(struct virtio_device *vdev,
794 struct virtio_scsi *vscsi)
795{
796 int err;
797 u32 i;
798 u32 num_vqs;
799 vq_callback_t **callbacks;
800 const char **names;
801 struct virtqueue **vqs;
802 struct irq_affinity desc = { .pre_vectors = 2 };
803
804 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
805 vqs = kmalloc_array(n: num_vqs, size: sizeof(struct virtqueue *), GFP_KERNEL);
806 callbacks = kmalloc_array(n: num_vqs, size: sizeof(vq_callback_t *),
807 GFP_KERNEL);
808 names = kmalloc_array(n: num_vqs, size: sizeof(char *), GFP_KERNEL);
809
810 if (!callbacks || !vqs || !names) {
811 err = -ENOMEM;
812 goto out;
813 }
814
815 callbacks[0] = virtscsi_ctrl_done;
816 callbacks[1] = virtscsi_event_done;
817 names[0] = "control";
818 names[1] = "event";
819 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
820 callbacks[i] = virtscsi_req_done;
821 names[i] = "request";
822 }
823
824 /* Discover virtqueues and write information to configuration. */
825 err = virtio_find_vqs(vdev, nvqs: num_vqs, vqs, callbacks, names, desc: &desc);
826 if (err)
827 goto out;
828
829 virtscsi_init_vq(virtscsi_vq: &vscsi->ctrl_vq, vq: vqs[0]);
830 virtscsi_init_vq(virtscsi_vq: &vscsi->event_vq, vq: vqs[1]);
831 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
832 virtscsi_init_vq(virtscsi_vq: &vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
833 vq: vqs[i]);
834
835 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
836 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
837
838 err = 0;
839
840out:
841 kfree(objp: names);
842 kfree(objp: callbacks);
843 kfree(objp: vqs);
844 if (err)
845 virtscsi_remove_vqs(vdev);
846 return err;
847}
848
849static int virtscsi_probe(struct virtio_device *vdev)
850{
851 struct Scsi_Host *shost;
852 struct virtio_scsi *vscsi;
853 int err;
854 u32 sg_elems, num_targets;
855 u32 cmd_per_lun;
856 u32 num_queues;
857
858 if (!vdev->config->get) {
859 dev_err(&vdev->dev, "%s failure: config access disabled\n",
860 __func__);
861 return -EINVAL;
862 }
863
864 /* We need to know how many queues before we allocate. */
865 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
866 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
867
868 num_targets = virtscsi_config_get(vdev, max_target) + 1;
869
870 shost = scsi_host_alloc(&virtscsi_host_template,
871 struct_size(vscsi, req_vqs, num_queues));
872 if (!shost)
873 return -ENOMEM;
874
875 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
876 shost->sg_tablesize = sg_elems;
877 vscsi = shost_priv(shost);
878 vscsi->vdev = vdev;
879 vscsi->num_queues = num_queues;
880 vdev->priv = shost;
881
882 err = virtscsi_init(vdev, vscsi);
883 if (err)
884 goto virtscsi_init_failed;
885
886 shost->can_queue = virtqueue_get_vring_size(vq: vscsi->req_vqs[0].vq);
887
888 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
889 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
890 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
891
892 /* LUNs > 256 are reported with format 1, so they go in the range
893 * 16640-32767.
894 */
895 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
896 shost->max_id = num_targets;
897 shost->max_channel = 0;
898 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
899 shost->nr_hw_queues = num_queues;
900
901#ifdef CONFIG_BLK_DEV_INTEGRITY
902 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
903 int host_prot;
904
905 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
906 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
907 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
908
909 scsi_host_set_prot(shost, mask: host_prot);
910 scsi_host_set_guard(shost, type: SHOST_DIX_GUARD_CRC);
911 }
912#endif
913
914 err = scsi_add_host(host: shost, dev: &vdev->dev);
915 if (err)
916 goto scsi_add_host_failed;
917
918 virtio_device_ready(dev: vdev);
919
920 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
921 virtscsi_kick_event_all(vscsi);
922
923 scsi_scan_host(shost);
924 return 0;
925
926scsi_add_host_failed:
927 vdev->config->del_vqs(vdev);
928virtscsi_init_failed:
929 scsi_host_put(t: shost);
930 return err;
931}
932
933static void virtscsi_remove(struct virtio_device *vdev)
934{
935 struct Scsi_Host *shost = virtio_scsi_host(vdev);
936 struct virtio_scsi *vscsi = shost_priv(shost);
937
938 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
939 virtscsi_cancel_event_work(vscsi);
940
941 scsi_remove_host(shost);
942 virtscsi_remove_vqs(vdev);
943 scsi_host_put(t: shost);
944}
945
946#ifdef CONFIG_PM_SLEEP
947static int virtscsi_freeze(struct virtio_device *vdev)
948{
949 virtscsi_remove_vqs(vdev);
950 return 0;
951}
952
953static int virtscsi_restore(struct virtio_device *vdev)
954{
955 struct Scsi_Host *sh = virtio_scsi_host(vdev);
956 struct virtio_scsi *vscsi = shost_priv(shost: sh);
957 int err;
958
959 err = virtscsi_init(vdev, vscsi);
960 if (err)
961 return err;
962
963 virtio_device_ready(dev: vdev);
964
965 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
966 virtscsi_kick_event_all(vscsi);
967
968 return err;
969}
970#endif
971
972static struct virtio_device_id id_table[] = {
973 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
974 { 0 },
975};
976
977static unsigned int features[] = {
978 VIRTIO_SCSI_F_HOTPLUG,
979 VIRTIO_SCSI_F_CHANGE,
980#ifdef CONFIG_BLK_DEV_INTEGRITY
981 VIRTIO_SCSI_F_T10_PI,
982#endif
983};
984
985static struct virtio_driver virtio_scsi_driver = {
986 .feature_table = features,
987 .feature_table_size = ARRAY_SIZE(features),
988 .driver.name = KBUILD_MODNAME,
989 .driver.owner = THIS_MODULE,
990 .id_table = id_table,
991 .probe = virtscsi_probe,
992#ifdef CONFIG_PM_SLEEP
993 .freeze = virtscsi_freeze,
994 .restore = virtscsi_restore,
995#endif
996 .remove = virtscsi_remove,
997};
998
999static int __init virtio_scsi_init(void)
1000{
1001 int ret = -ENOMEM;
1002
1003 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1004 if (!virtscsi_cmd_cache) {
1005 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1006 goto error;
1007 }
1008
1009
1010 virtscsi_cmd_pool =
1011 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1012 kc: virtscsi_cmd_cache);
1013 if (!virtscsi_cmd_pool) {
1014 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1015 goto error;
1016 }
1017 ret = register_virtio_driver(drv: &virtio_scsi_driver);
1018 if (ret < 0)
1019 goto error;
1020
1021 return 0;
1022
1023error:
1024 mempool_destroy(pool: virtscsi_cmd_pool);
1025 virtscsi_cmd_pool = NULL;
1026 kmem_cache_destroy(s: virtscsi_cmd_cache);
1027 virtscsi_cmd_cache = NULL;
1028 return ret;
1029}
1030
1031static void __exit virtio_scsi_fini(void)
1032{
1033 unregister_virtio_driver(drv: &virtio_scsi_driver);
1034 mempool_destroy(pool: virtscsi_cmd_pool);
1035 kmem_cache_destroy(s: virtscsi_cmd_cache);
1036}
1037module_init(virtio_scsi_init);
1038module_exit(virtio_scsi_fini);
1039
1040MODULE_DEVICE_TABLE(virtio, id_table);
1041MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1042MODULE_LICENSE("GPL");
1043

source code of linux/drivers/scsi/virtio_scsi.c