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 <scsi/scsi_host.h>
26 #include <scsi/scsi_device.h>
27 #include <scsi/scsi_cmnd.h>
28 #include <scsi/scsi_tcq.h>
29 #include <scsi/scsi_devinfo.h>
30 #include <linux/seqlock.h>
31 #include <linux/blk-mq-virtio.h>
32
33 #include "sd.h"
34
35 #define VIRTIO_SCSI_MEMPOOL_SZ 64
36 #define VIRTIO_SCSI_EVENT_LEN 8
37 #define VIRTIO_SCSI_VQ_BASE 2
38
39 /* Command queue element */
40 struct virtio_scsi_cmd {
41 struct scsi_cmnd *sc;
42 struct completion *comp;
43 union {
44 struct virtio_scsi_cmd_req cmd;
45 struct virtio_scsi_cmd_req_pi cmd_pi;
46 struct virtio_scsi_ctrl_tmf_req tmf;
47 struct virtio_scsi_ctrl_an_req an;
48 } req;
49 union {
50 struct virtio_scsi_cmd_resp cmd;
51 struct virtio_scsi_ctrl_tmf_resp tmf;
52 struct virtio_scsi_ctrl_an_resp an;
53 struct virtio_scsi_event evt;
54 } resp;
55 } ____cacheline_aligned_in_smp;
56
57 struct virtio_scsi_event_node {
58 struct virtio_scsi *vscsi;
59 struct virtio_scsi_event event;
60 struct work_struct work;
61 };
62
63 struct virtio_scsi_vq {
64 /* Protects vq */
65 spinlock_t vq_lock;
66
67 struct virtqueue *vq;
68 };
69
70 /* Driver instance state */
71 struct virtio_scsi {
72 struct virtio_device *vdev;
73
74 /* Get some buffers ready for event vq */
75 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
76
77 u32 num_queues;
78
79 struct hlist_node node;
80
81 /* Protected by event_vq lock */
82 bool stop_events;
83
84 struct virtio_scsi_vq ctrl_vq;
85 struct virtio_scsi_vq event_vq;
86 struct virtio_scsi_vq req_vqs[];
87 };
88
89 static struct kmem_cache *virtscsi_cmd_cache;
90 static mempool_t *virtscsi_cmd_pool;
91
virtio_scsi_host(struct virtio_device * vdev)92 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
93 {
94 return vdev->priv;
95 }
96
virtscsi_compute_resid(struct scsi_cmnd * sc,u32 resid)97 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
98 {
99 if (resid)
100 scsi_set_resid(sc, min(resid, scsi_bufflen(sc)));
101 }
102
103 /*
104 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
105 *
106 * Called with vq_lock held.
107 */
virtscsi_complete_cmd(struct virtio_scsi * vscsi,void * buf)108 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
109 {
110 struct virtio_scsi_cmd *cmd = buf;
111 struct scsi_cmnd *sc = cmd->sc;
112 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
113
114 dev_dbg(&sc->device->sdev_gendev,
115 "cmd %p response %u status %#02x sense_len %u\n",
116 sc, resp->response, resp->status, resp->sense_len);
117
118 sc->result = resp->status;
119 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid));
120 switch (resp->response) {
121 case VIRTIO_SCSI_S_OK:
122 set_host_byte(sc, DID_OK);
123 break;
124 case VIRTIO_SCSI_S_OVERRUN:
125 set_host_byte(sc, DID_ERROR);
126 break;
127 case VIRTIO_SCSI_S_ABORTED:
128 set_host_byte(sc, DID_ABORT);
129 break;
130 case VIRTIO_SCSI_S_BAD_TARGET:
131 set_host_byte(sc, DID_BAD_TARGET);
132 break;
133 case VIRTIO_SCSI_S_RESET:
134 set_host_byte(sc, DID_RESET);
135 break;
136 case VIRTIO_SCSI_S_BUSY:
137 set_host_byte(sc, DID_BUS_BUSY);
138 break;
139 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
140 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
141 break;
142 case VIRTIO_SCSI_S_TARGET_FAILURE:
143 set_host_byte(sc, DID_TARGET_FAILURE);
144 break;
145 case VIRTIO_SCSI_S_NEXUS_FAILURE:
146 set_host_byte(sc, DID_NEXUS_FAILURE);
147 break;
148 default:
149 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
150 resp->response);
151 fallthrough;
152 case VIRTIO_SCSI_S_FAILURE:
153 set_host_byte(sc, DID_ERROR);
154 break;
155 }
156
157 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
158 VIRTIO_SCSI_SENSE_SIZE);
159 if (resp->sense_len) {
160 memcpy(sc->sense_buffer, resp->sense,
161 min_t(u32,
162 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
163 VIRTIO_SCSI_SENSE_SIZE));
164 }
165
166 sc->scsi_done(sc);
167 }
168
virtscsi_vq_done(struct virtio_scsi * vscsi,struct virtio_scsi_vq * virtscsi_vq,void (* fn)(struct virtio_scsi * vscsi,void * buf))169 static void virtscsi_vq_done(struct virtio_scsi *vscsi,
170 struct virtio_scsi_vq *virtscsi_vq,
171 void (*fn)(struct virtio_scsi *vscsi, void *buf))
172 {
173 void *buf;
174 unsigned int len;
175 unsigned long flags;
176 struct virtqueue *vq = virtscsi_vq->vq;
177
178 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
179 do {
180 virtqueue_disable_cb(vq);
181 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
182 fn(vscsi, buf);
183
184 if (unlikely(virtqueue_is_broken(vq)))
185 break;
186 } while (!virtqueue_enable_cb(vq));
187 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
188 }
189
virtscsi_req_done(struct virtqueue * vq)190 static void virtscsi_req_done(struct virtqueue *vq)
191 {
192 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
193 struct virtio_scsi *vscsi = shost_priv(sh);
194 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
195 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
196
197 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
198 };
199
virtscsi_poll_requests(struct virtio_scsi * vscsi)200 static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
201 {
202 int i, num_vqs;
203
204 num_vqs = vscsi->num_queues;
205 for (i = 0; i < num_vqs; i++)
206 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
207 virtscsi_complete_cmd);
208 }
209
virtscsi_complete_free(struct virtio_scsi * vscsi,void * buf)210 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
211 {
212 struct virtio_scsi_cmd *cmd = buf;
213
214 if (cmd->comp)
215 complete(cmd->comp);
216 }
217
virtscsi_ctrl_done(struct virtqueue * vq)218 static void virtscsi_ctrl_done(struct virtqueue *vq)
219 {
220 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
221 struct virtio_scsi *vscsi = shost_priv(sh);
222
223 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
224 };
225
226 static void virtscsi_handle_event(struct work_struct *work);
227
virtscsi_kick_event(struct virtio_scsi * vscsi,struct virtio_scsi_event_node * event_node)228 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
229 struct virtio_scsi_event_node *event_node)
230 {
231 int err;
232 struct scatterlist sg;
233 unsigned long flags;
234
235 INIT_WORK(&event_node->work, virtscsi_handle_event);
236 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
237
238 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
239
240 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
241 GFP_ATOMIC);
242 if (!err)
243 virtqueue_kick(vscsi->event_vq.vq);
244
245 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
246
247 return err;
248 }
249
virtscsi_kick_event_all(struct virtio_scsi * vscsi)250 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
251 {
252 int i;
253
254 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
255 vscsi->event_list[i].vscsi = vscsi;
256 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
257 }
258
259 return 0;
260 }
261
virtscsi_cancel_event_work(struct virtio_scsi * vscsi)262 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
263 {
264 int i;
265
266 /* Stop scheduling work before calling cancel_work_sync. */
267 spin_lock_irq(&vscsi->event_vq.vq_lock);
268 vscsi->stop_events = true;
269 spin_unlock_irq(&vscsi->event_vq.vq_lock);
270
271 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
272 cancel_work_sync(&vscsi->event_list[i].work);
273 }
274
virtscsi_handle_transport_reset(struct virtio_scsi * vscsi,struct virtio_scsi_event * event)275 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
276 struct virtio_scsi_event *event)
277 {
278 struct scsi_device *sdev;
279 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
280 unsigned int target = event->lun[1];
281 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
282
283 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
284 case VIRTIO_SCSI_EVT_RESET_RESCAN:
285 if (lun == 0) {
286 scsi_scan_target(&shost->shost_gendev, 0, target,
287 SCAN_WILD_CARD, SCSI_SCAN_INITIAL);
288 } else {
289 scsi_add_device(shost, 0, target, lun);
290 }
291 break;
292 case VIRTIO_SCSI_EVT_RESET_REMOVED:
293 sdev = scsi_device_lookup(shost, 0, target, lun);
294 if (sdev) {
295 scsi_remove_device(sdev);
296 scsi_device_put(sdev);
297 } else {
298 pr_err("SCSI device %d 0 %d %d not found\n",
299 shost->host_no, target, lun);
300 }
301 break;
302 default:
303 pr_info("Unsupported virtio scsi event reason %x\n", event->reason);
304 }
305 }
306
virtscsi_handle_param_change(struct virtio_scsi * vscsi,struct virtio_scsi_event * event)307 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
308 struct virtio_scsi_event *event)
309 {
310 struct scsi_device *sdev;
311 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
312 unsigned int target = event->lun[1];
313 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
314 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255;
315 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8;
316
317 sdev = scsi_device_lookup(shost, 0, target, lun);
318 if (!sdev) {
319 pr_err("SCSI device %d 0 %d %d not found\n",
320 shost->host_no, target, lun);
321 return;
322 }
323
324 /* Handle "Parameters changed", "Mode parameters changed", and
325 "Capacity data has changed". */
326 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
327 scsi_rescan_device(&sdev->sdev_gendev);
328
329 scsi_device_put(sdev);
330 }
331
virtscsi_rescan_hotunplug(struct virtio_scsi * vscsi)332 static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
333 {
334 struct scsi_device *sdev;
335 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
336 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
337 int result, inquiry_len, inq_result_len = 256;
338 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
339
340 shost_for_each_device(sdev, shost) {
341 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
342
343 memset(scsi_cmd, 0, sizeof(scsi_cmd));
344 scsi_cmd[0] = INQUIRY;
345 scsi_cmd[4] = (unsigned char) inquiry_len;
346
347 memset(inq_result, 0, inq_result_len);
348
349 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
350 inq_result, inquiry_len, NULL,
351 SD_TIMEOUT, SD_MAX_RETRIES, NULL);
352
353 if (result == 0 && inq_result[0] >> 5) {
354 /* PQ indicates the LUN is not attached */
355 scsi_remove_device(sdev);
356 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) {
357 /*
358 * If all LUNs of a virtio-scsi device are unplugged
359 * it will respond with BAD TARGET on any INQUIRY
360 * command.
361 * Remove the device in this case as well.
362 */
363 scsi_remove_device(sdev);
364 }
365 }
366
367 kfree(inq_result);
368 }
369
virtscsi_handle_event(struct work_struct * work)370 static void virtscsi_handle_event(struct work_struct *work)
371 {
372 struct virtio_scsi_event_node *event_node =
373 container_of(work, struct virtio_scsi_event_node, work);
374 struct virtio_scsi *vscsi = event_node->vscsi;
375 struct virtio_scsi_event *event = &event_node->event;
376
377 if (event->event &
378 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
379 event->event &= ~cpu_to_virtio32(vscsi->vdev,
380 VIRTIO_SCSI_T_EVENTS_MISSED);
381 virtscsi_rescan_hotunplug(vscsi);
382 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
383 }
384
385 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
386 case VIRTIO_SCSI_T_NO_EVENT:
387 break;
388 case VIRTIO_SCSI_T_TRANSPORT_RESET:
389 virtscsi_handle_transport_reset(vscsi, event);
390 break;
391 case VIRTIO_SCSI_T_PARAM_CHANGE:
392 virtscsi_handle_param_change(vscsi, event);
393 break;
394 default:
395 pr_err("Unsupported virtio scsi event %x\n", event->event);
396 }
397 virtscsi_kick_event(vscsi, event_node);
398 }
399
virtscsi_complete_event(struct virtio_scsi * vscsi,void * buf)400 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
401 {
402 struct virtio_scsi_event_node *event_node = buf;
403
404 if (!vscsi->stop_events)
405 queue_work(system_freezable_wq, &event_node->work);
406 }
407
virtscsi_event_done(struct virtqueue * vq)408 static void virtscsi_event_done(struct virtqueue *vq)
409 {
410 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
411 struct virtio_scsi *vscsi = shost_priv(sh);
412
413 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
414 };
415
__virtscsi_add_cmd(struct virtqueue * vq,struct virtio_scsi_cmd * cmd,size_t req_size,size_t resp_size)416 static int __virtscsi_add_cmd(struct virtqueue *vq,
417 struct virtio_scsi_cmd *cmd,
418 size_t req_size, size_t resp_size)
419 {
420 struct scsi_cmnd *sc = cmd->sc;
421 struct scatterlist *sgs[6], req, resp;
422 struct sg_table *out, *in;
423 unsigned out_num = 0, in_num = 0;
424
425 out = in = NULL;
426
427 if (sc && sc->sc_data_direction != DMA_NONE) {
428 if (sc->sc_data_direction != DMA_FROM_DEVICE)
429 out = &sc->sdb.table;
430 if (sc->sc_data_direction != DMA_TO_DEVICE)
431 in = &sc->sdb.table;
432 }
433
434 /* Request header. */
435 sg_init_one(&req, &cmd->req, req_size);
436 sgs[out_num++] = &req;
437
438 /* Data-out buffer. */
439 if (out) {
440 /* Place WRITE protection SGLs before Data OUT payload */
441 if (scsi_prot_sg_count(sc))
442 sgs[out_num++] = scsi_prot_sglist(sc);
443 sgs[out_num++] = out->sgl;
444 }
445
446 /* Response header. */
447 sg_init_one(&resp, &cmd->resp, resp_size);
448 sgs[out_num + in_num++] = &resp;
449
450 /* Data-in buffer */
451 if (in) {
452 /* Place READ protection SGLs before Data IN payload */
453 if (scsi_prot_sg_count(sc))
454 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
455 sgs[out_num + in_num++] = in->sgl;
456 }
457
458 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
459 }
460
virtscsi_kick_vq(struct virtio_scsi_vq * vq)461 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
462 {
463 bool needs_kick;
464 unsigned long flags;
465
466 spin_lock_irqsave(&vq->vq_lock, flags);
467 needs_kick = virtqueue_kick_prepare(vq->vq);
468 spin_unlock_irqrestore(&vq->vq_lock, flags);
469
470 if (needs_kick)
471 virtqueue_notify(vq->vq);
472 }
473
474 /**
475 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
476 * @vq : the struct virtqueue we're talking about
477 * @cmd : command structure
478 * @req_size : size of the request buffer
479 * @resp_size : size of the response buffer
480 * @kick : whether to kick the virtqueue immediately
481 */
virtscsi_add_cmd(struct virtio_scsi_vq * vq,struct virtio_scsi_cmd * cmd,size_t req_size,size_t resp_size,bool kick)482 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
483 struct virtio_scsi_cmd *cmd,
484 size_t req_size, size_t resp_size,
485 bool kick)
486 {
487 unsigned long flags;
488 int err;
489 bool needs_kick = false;
490
491 spin_lock_irqsave(&vq->vq_lock, flags);
492 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
493 if (!err && kick)
494 needs_kick = virtqueue_kick_prepare(vq->vq);
495
496 spin_unlock_irqrestore(&vq->vq_lock, flags);
497
498 if (needs_kick)
499 virtqueue_notify(vq->vq);
500 return err;
501 }
502
virtio_scsi_init_hdr(struct virtio_device * vdev,struct virtio_scsi_cmd_req * cmd,struct scsi_cmnd * sc)503 static void virtio_scsi_init_hdr(struct virtio_device *vdev,
504 struct virtio_scsi_cmd_req *cmd,
505 struct scsi_cmnd *sc)
506 {
507 cmd->lun[0] = 1;
508 cmd->lun[1] = sc->device->id;
509 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
510 cmd->lun[3] = sc->device->lun & 0xff;
511 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
512 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
513 cmd->prio = 0;
514 cmd->crn = 0;
515 }
516
517 #ifdef CONFIG_BLK_DEV_INTEGRITY
virtio_scsi_init_hdr_pi(struct virtio_device * vdev,struct virtio_scsi_cmd_req_pi * cmd_pi,struct scsi_cmnd * sc)518 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
519 struct virtio_scsi_cmd_req_pi *cmd_pi,
520 struct scsi_cmnd *sc)
521 {
522 struct request *rq = scsi_cmd_to_rq(sc);
523 struct blk_integrity *bi;
524
525 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
526
527 if (!rq || !scsi_prot_sg_count(sc))
528 return;
529
530 bi = blk_get_integrity(rq->rq_disk);
531
532 if (sc->sc_data_direction == DMA_TO_DEVICE)
533 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
534 bio_integrity_bytes(bi,
535 blk_rq_sectors(rq)));
536 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
537 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
538 bio_integrity_bytes(bi,
539 blk_rq_sectors(rq)));
540 }
541 #endif
542
virtscsi_pick_vq_mq(struct virtio_scsi * vscsi,struct scsi_cmnd * sc)543 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
544 struct scsi_cmnd *sc)
545 {
546 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc));
547 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
548
549 return &vscsi->req_vqs[hwq];
550 }
551
virtscsi_queuecommand(struct Scsi_Host * shost,struct scsi_cmnd * sc)552 static int virtscsi_queuecommand(struct Scsi_Host *shost,
553 struct scsi_cmnd *sc)
554 {
555 struct virtio_scsi *vscsi = shost_priv(shost);
556 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
557 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
558 bool kick;
559 unsigned long flags;
560 int req_size;
561 int ret;
562
563 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
564
565 /* TODO: check feature bit and fail if unsupported? */
566 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
567
568 dev_dbg(&sc->device->sdev_gendev,
569 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
570
571 cmd->sc = sc;
572
573 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
574
575 #ifdef CONFIG_BLK_DEV_INTEGRITY
576 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
577 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
578 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
579 req_size = sizeof(cmd->req.cmd_pi);
580 } else
581 #endif
582 {
583 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
584 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
585 req_size = sizeof(cmd->req.cmd);
586 }
587
588 kick = (sc->flags & SCMD_LAST) != 0;
589 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick);
590 if (ret == -EIO) {
591 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
592 spin_lock_irqsave(&req_vq->vq_lock, flags);
593 virtscsi_complete_cmd(vscsi, cmd);
594 spin_unlock_irqrestore(&req_vq->vq_lock, flags);
595 } else if (ret != 0) {
596 return SCSI_MLQUEUE_HOST_BUSY;
597 }
598 return 0;
599 }
600
virtscsi_tmf(struct virtio_scsi * vscsi,struct virtio_scsi_cmd * cmd)601 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
602 {
603 DECLARE_COMPLETION_ONSTACK(comp);
604 int ret = FAILED;
605
606 cmd->comp = ∁
607 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd,
608 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0)
609 goto out;
610
611 wait_for_completion(&comp);
612 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
613 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
614 ret = SUCCESS;
615
616 /*
617 * The spec guarantees that all requests related to the TMF have
618 * been completed, but the callback might not have run yet if
619 * we're using independent interrupts (e.g. MSI). Poll the
620 * virtqueues once.
621 *
622 * In the abort case, sc->scsi_done will do nothing, because
623 * the block layer must have detected a timeout and as a result
624 * REQ_ATOM_COMPLETE has been set.
625 */
626 virtscsi_poll_requests(vscsi);
627
628 out:
629 mempool_free(cmd, virtscsi_cmd_pool);
630 return ret;
631 }
632
virtscsi_device_reset(struct scsi_cmnd * sc)633 static int virtscsi_device_reset(struct scsi_cmnd *sc)
634 {
635 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
636 struct virtio_scsi_cmd *cmd;
637
638 sdev_printk(KERN_INFO, sc->device, "device reset\n");
639 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
640 if (!cmd)
641 return FAILED;
642
643 memset(cmd, 0, sizeof(*cmd));
644 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
645 .type = VIRTIO_SCSI_T_TMF,
646 .subtype = cpu_to_virtio32(vscsi->vdev,
647 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
648 .lun[0] = 1,
649 .lun[1] = sc->device->id,
650 .lun[2] = (sc->device->lun >> 8) | 0x40,
651 .lun[3] = sc->device->lun & 0xff,
652 };
653 return virtscsi_tmf(vscsi, cmd);
654 }
655
virtscsi_device_alloc(struct scsi_device * sdevice)656 static int virtscsi_device_alloc(struct scsi_device *sdevice)
657 {
658 /*
659 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
660 * may have transfer limits which come from the host SCSI
661 * controller or something on the host side other than the
662 * target itself.
663 *
664 * To make this work properly, the hypervisor can adjust the
665 * target's VPD information to advertise these limits. But
666 * for that to work, the guest has to look at the VPD pages,
667 * which we won't do by default if it is an SPC-2 device, even
668 * if it does actually support it.
669 *
670 * So, set the blist to always try to read the VPD pages.
671 */
672 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
673
674 return 0;
675 }
676
677
678 /**
679 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
680 * @sdev: Virtscsi target whose queue depth to change
681 * @qdepth: New queue depth
682 */
virtscsi_change_queue_depth(struct scsi_device * sdev,int qdepth)683 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
684 {
685 struct Scsi_Host *shost = sdev->host;
686 int max_depth = shost->cmd_per_lun;
687
688 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
689 }
690
virtscsi_abort(struct scsi_cmnd * sc)691 static int virtscsi_abort(struct scsi_cmnd *sc)
692 {
693 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
694 struct virtio_scsi_cmd *cmd;
695
696 scmd_printk(KERN_INFO, sc, "abort\n");
697 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
698 if (!cmd)
699 return FAILED;
700
701 memset(cmd, 0, sizeof(*cmd));
702 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
703 .type = VIRTIO_SCSI_T_TMF,
704 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
705 .lun[0] = 1,
706 .lun[1] = sc->device->id,
707 .lun[2] = (sc->device->lun >> 8) | 0x40,
708 .lun[3] = sc->device->lun & 0xff,
709 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
710 };
711 return virtscsi_tmf(vscsi, cmd);
712 }
713
virtscsi_map_queues(struct Scsi_Host * shost)714 static int virtscsi_map_queues(struct Scsi_Host *shost)
715 {
716 struct virtio_scsi *vscsi = shost_priv(shost);
717 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
718
719 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2);
720 }
721
virtscsi_commit_rqs(struct Scsi_Host * shost,u16 hwq)722 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
723 {
724 struct virtio_scsi *vscsi = shost_priv(shost);
725
726 virtscsi_kick_vq(&vscsi->req_vqs[hwq]);
727 }
728
729 /*
730 * The host guarantees to respond to each command, although I/O
731 * latencies might be higher than on bare metal. Reset the timer
732 * unconditionally to give the host a chance to perform EH.
733 */
virtscsi_eh_timed_out(struct scsi_cmnd * scmnd)734 static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
735 {
736 return SCSI_EH_RESET_TIMER;
737 }
738
739 static struct scsi_host_template virtscsi_host_template = {
740 .module = THIS_MODULE,
741 .name = "Virtio SCSI HBA",
742 .proc_name = "virtio_scsi",
743 .this_id = -1,
744 .cmd_size = sizeof(struct virtio_scsi_cmd),
745 .queuecommand = virtscsi_queuecommand,
746 .commit_rqs = virtscsi_commit_rqs,
747 .change_queue_depth = virtscsi_change_queue_depth,
748 .eh_abort_handler = virtscsi_abort,
749 .eh_device_reset_handler = virtscsi_device_reset,
750 .eh_timed_out = virtscsi_eh_timed_out,
751 .slave_alloc = virtscsi_device_alloc,
752
753 .dma_boundary = UINT_MAX,
754 .map_queues = virtscsi_map_queues,
755 .track_queue_depth = 1,
756 };
757
758 #define virtscsi_config_get(vdev, fld) \
759 ({ \
760 __virtio_native_type(struct virtio_scsi_config, fld) __val; \
761 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
762 __val; \
763 })
764
765 #define virtscsi_config_set(vdev, fld, val) \
766 do { \
767 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \
768 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
769 } while(0)
770
virtscsi_init_vq(struct virtio_scsi_vq * virtscsi_vq,struct virtqueue * vq)771 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
772 struct virtqueue *vq)
773 {
774 spin_lock_init(&virtscsi_vq->vq_lock);
775 virtscsi_vq->vq = vq;
776 }
777
virtscsi_remove_vqs(struct virtio_device * vdev)778 static void virtscsi_remove_vqs(struct virtio_device *vdev)
779 {
780 /* Stop all the virtqueues. */
781 vdev->config->reset(vdev);
782 vdev->config->del_vqs(vdev);
783 }
784
virtscsi_init(struct virtio_device * vdev,struct virtio_scsi * vscsi)785 static int virtscsi_init(struct virtio_device *vdev,
786 struct virtio_scsi *vscsi)
787 {
788 int err;
789 u32 i;
790 u32 num_vqs;
791 vq_callback_t **callbacks;
792 const char **names;
793 struct virtqueue **vqs;
794 struct irq_affinity desc = { .pre_vectors = 2 };
795
796 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
797 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
798 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *),
799 GFP_KERNEL);
800 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL);
801
802 if (!callbacks || !vqs || !names) {
803 err = -ENOMEM;
804 goto out;
805 }
806
807 callbacks[0] = virtscsi_ctrl_done;
808 callbacks[1] = virtscsi_event_done;
809 names[0] = "control";
810 names[1] = "event";
811 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
812 callbacks[i] = virtscsi_req_done;
813 names[i] = "request";
814 }
815
816 /* Discover virtqueues and write information to configuration. */
817 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
818 if (err)
819 goto out;
820
821 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
822 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
823 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
824 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
825 vqs[i]);
826
827 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
828 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
829
830 err = 0;
831
832 out:
833 kfree(names);
834 kfree(callbacks);
835 kfree(vqs);
836 if (err)
837 virtscsi_remove_vqs(vdev);
838 return err;
839 }
840
virtscsi_probe(struct virtio_device * vdev)841 static int virtscsi_probe(struct virtio_device *vdev)
842 {
843 struct Scsi_Host *shost;
844 struct virtio_scsi *vscsi;
845 int err;
846 u32 sg_elems, num_targets;
847 u32 cmd_per_lun;
848 u32 num_queues;
849
850 if (!vdev->config->get) {
851 dev_err(&vdev->dev, "%s failure: config access disabled\n",
852 __func__);
853 return -EINVAL;
854 }
855
856 /* We need to know how many queues before we allocate. */
857 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
858 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
859
860 num_targets = virtscsi_config_get(vdev, max_target) + 1;
861
862 shost = scsi_host_alloc(&virtscsi_host_template,
863 struct_size(vscsi, req_vqs, num_queues));
864 if (!shost)
865 return -ENOMEM;
866
867 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
868 shost->sg_tablesize = sg_elems;
869 vscsi = shost_priv(shost);
870 vscsi->vdev = vdev;
871 vscsi->num_queues = num_queues;
872 vdev->priv = shost;
873
874 err = virtscsi_init(vdev, vscsi);
875 if (err)
876 goto virtscsi_init_failed;
877
878 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
879
880 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
881 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
882 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
883
884 /* LUNs > 256 are reported with format 1, so they go in the range
885 * 16640-32767.
886 */
887 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
888 shost->max_id = num_targets;
889 shost->max_channel = 0;
890 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
891 shost->nr_hw_queues = num_queues;
892
893 #ifdef CONFIG_BLK_DEV_INTEGRITY
894 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
895 int host_prot;
896
897 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
898 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
899 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
900
901 scsi_host_set_prot(shost, host_prot);
902 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
903 }
904 #endif
905
906 err = scsi_add_host(shost, &vdev->dev);
907 if (err)
908 goto scsi_add_host_failed;
909
910 virtio_device_ready(vdev);
911
912 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
913 virtscsi_kick_event_all(vscsi);
914
915 scsi_scan_host(shost);
916 return 0;
917
918 scsi_add_host_failed:
919 vdev->config->del_vqs(vdev);
920 virtscsi_init_failed:
921 scsi_host_put(shost);
922 return err;
923 }
924
virtscsi_remove(struct virtio_device * vdev)925 static void virtscsi_remove(struct virtio_device *vdev)
926 {
927 struct Scsi_Host *shost = virtio_scsi_host(vdev);
928 struct virtio_scsi *vscsi = shost_priv(shost);
929
930 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
931 virtscsi_cancel_event_work(vscsi);
932
933 scsi_remove_host(shost);
934 virtscsi_remove_vqs(vdev);
935 scsi_host_put(shost);
936 }
937
938 #ifdef CONFIG_PM_SLEEP
virtscsi_freeze(struct virtio_device * vdev)939 static int virtscsi_freeze(struct virtio_device *vdev)
940 {
941 virtscsi_remove_vqs(vdev);
942 return 0;
943 }
944
virtscsi_restore(struct virtio_device * vdev)945 static int virtscsi_restore(struct virtio_device *vdev)
946 {
947 struct Scsi_Host *sh = virtio_scsi_host(vdev);
948 struct virtio_scsi *vscsi = shost_priv(sh);
949 int err;
950
951 err = virtscsi_init(vdev, vscsi);
952 if (err)
953 return err;
954
955 virtio_device_ready(vdev);
956
957 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
958 virtscsi_kick_event_all(vscsi);
959
960 return err;
961 }
962 #endif
963
964 static struct virtio_device_id id_table[] = {
965 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
966 { 0 },
967 };
968
969 static unsigned int features[] = {
970 VIRTIO_SCSI_F_HOTPLUG,
971 VIRTIO_SCSI_F_CHANGE,
972 #ifdef CONFIG_BLK_DEV_INTEGRITY
973 VIRTIO_SCSI_F_T10_PI,
974 #endif
975 };
976
977 static struct virtio_driver virtio_scsi_driver = {
978 .feature_table = features,
979 .feature_table_size = ARRAY_SIZE(features),
980 .driver.name = KBUILD_MODNAME,
981 .driver.owner = THIS_MODULE,
982 .id_table = id_table,
983 .probe = virtscsi_probe,
984 #ifdef CONFIG_PM_SLEEP
985 .freeze = virtscsi_freeze,
986 .restore = virtscsi_restore,
987 #endif
988 .remove = virtscsi_remove,
989 };
990
init(void)991 static int __init init(void)
992 {
993 int ret = -ENOMEM;
994
995 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
996 if (!virtscsi_cmd_cache) {
997 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
998 goto error;
999 }
1000
1001
1002 virtscsi_cmd_pool =
1003 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1004 virtscsi_cmd_cache);
1005 if (!virtscsi_cmd_pool) {
1006 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1007 goto error;
1008 }
1009 ret = register_virtio_driver(&virtio_scsi_driver);
1010 if (ret < 0)
1011 goto error;
1012
1013 return 0;
1014
1015 error:
1016 mempool_destroy(virtscsi_cmd_pool);
1017 virtscsi_cmd_pool = NULL;
1018 kmem_cache_destroy(virtscsi_cmd_cache);
1019 virtscsi_cmd_cache = NULL;
1020 return ret;
1021 }
1022
fini(void)1023 static void __exit fini(void)
1024 {
1025 unregister_virtio_driver(&virtio_scsi_driver);
1026 mempool_destroy(virtscsi_cmd_pool);
1027 kmem_cache_destroy(virtscsi_cmd_cache);
1028 }
1029 module_init(init);
1030 module_exit(fini);
1031
1032 MODULE_DEVICE_TABLE(virtio, id_table);
1033 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1034 MODULE_LICENSE("GPL");
1035