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