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
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
39static unsigned int virtscsi_poll_queues;
40module_param(virtscsi_poll_queues, uint, 0644);
41MODULE_PARM_DESC(virtscsi_poll_queues,
42 "The number of dedicated virtqueues for polling I/O");
43
44/* Command queue element */
45struct virtio_scsi_cmd {
46 struct scsi_cmnd *sc;
47 struct completion *comp;
48 union {
49 struct virtio_scsi_cmd_req cmd;
50 struct virtio_scsi_cmd_req_pi cmd_pi;
51 struct virtio_scsi_ctrl_tmf_req tmf;
52 struct virtio_scsi_ctrl_an_req an;
53 } req;
54 union {
55 struct virtio_scsi_cmd_resp cmd;
56 struct virtio_scsi_ctrl_tmf_resp tmf;
57 struct virtio_scsi_ctrl_an_resp an;
58 struct virtio_scsi_event evt;
59 } resp;
60} ____cacheline_aligned_in_smp;
61
62struct virtio_scsi_event_node {
63 struct virtio_scsi *vscsi;
64 struct virtio_scsi_event event;
65 struct work_struct work;
66};
67
68struct virtio_scsi_vq {
69 /* Protects vq */
70 spinlock_t vq_lock;
71
72 struct virtqueue *vq;
73};
74
75/* Driver instance state */
76struct virtio_scsi {
77 struct virtio_device *vdev;
78
79 /* Get some buffers ready for event vq */
80 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
81
82 u32 num_queues;
83 int io_queues[HCTX_MAX_TYPES];
84
85 struct hlist_node node;
86
87 /* Protected by event_vq lock */
88 bool stop_events;
89
90 struct virtio_scsi_vq ctrl_vq;
91 struct virtio_scsi_vq event_vq;
92 struct virtio_scsi_vq req_vqs[];
93};
94
95static struct kmem_cache *virtscsi_cmd_cache;
96static mempool_t *virtscsi_cmd_pool;
97
98static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
99{
100 return vdev->priv;
101}
102
103static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
104{
105 if (resid)
106 scsi_set_resid(cmd: sc, min(resid, scsi_bufflen(sc)));
107}
108
109/*
110 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
111 *
112 * Called with vq_lock held.
113 */
114static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
115{
116 struct virtio_scsi_cmd *cmd = buf;
117 struct scsi_cmnd *sc = cmd->sc;
118 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
119
120 dev_dbg(&sc->device->sdev_gendev,
121 "cmd %p response %u status %#02x sense_len %u\n",
122 sc, resp->response, resp->status, resp->sense_len);
123
124 sc->result = resp->status;
125 virtscsi_compute_resid(sc, resid: virtio32_to_cpu(vdev: vscsi->vdev, val: resp->resid));
126 switch (resp->response) {
127 case VIRTIO_SCSI_S_OK:
128 set_host_byte(cmd: sc, status: DID_OK);
129 break;
130 case VIRTIO_SCSI_S_OVERRUN:
131 set_host_byte(cmd: sc, status: DID_ERROR);
132 break;
133 case VIRTIO_SCSI_S_ABORTED:
134 set_host_byte(cmd: sc, status: DID_ABORT);
135 break;
136 case VIRTIO_SCSI_S_BAD_TARGET:
137 set_host_byte(cmd: sc, status: DID_BAD_TARGET);
138 break;
139 case VIRTIO_SCSI_S_RESET:
140 set_host_byte(cmd: sc, status: DID_RESET);
141 break;
142 case VIRTIO_SCSI_S_BUSY:
143 set_host_byte(cmd: sc, status: DID_BUS_BUSY);
144 break;
145 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
146 set_host_byte(cmd: sc, status: DID_TRANSPORT_DISRUPTED);
147 break;
148 case VIRTIO_SCSI_S_TARGET_FAILURE:
149 set_host_byte(cmd: sc, status: DID_BAD_TARGET);
150 break;
151 case VIRTIO_SCSI_S_NEXUS_FAILURE:
152 set_status_byte(cmd: sc, status: SAM_STAT_RESERVATION_CONFLICT);
153 break;
154 default:
155 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
156 resp->response);
157 fallthrough;
158 case VIRTIO_SCSI_S_FAILURE:
159 set_host_byte(cmd: sc, status: DID_ERROR);
160 break;
161 }
162
163 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
164 VIRTIO_SCSI_SENSE_SIZE);
165 if (resp->sense_len) {
166 memcpy(sc->sense_buffer, resp->sense,
167 min_t(u32,
168 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
169 VIRTIO_SCSI_SENSE_SIZE));
170 }
171
172 scsi_done(cmd: sc);
173}
174
175static void virtscsi_vq_done(struct virtio_scsi *vscsi,
176 struct virtio_scsi_vq *virtscsi_vq,
177 void (*fn)(struct virtio_scsi *vscsi, void *buf))
178{
179 void *buf;
180 unsigned int len;
181 unsigned long flags;
182 struct virtqueue *vq = virtscsi_vq->vq;
183
184 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
185 do {
186 virtqueue_disable_cb(vq);
187 while ((buf = virtqueue_get_buf(vq, len: &len)) != NULL)
188 fn(vscsi, buf);
189
190 } while (!virtqueue_enable_cb(vq));
191 spin_unlock_irqrestore(lock: &virtscsi_vq->vq_lock, flags);
192}
193
194static void virtscsi_req_done(struct virtqueue *vq)
195{
196 struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev);
197 struct virtio_scsi *vscsi = shost_priv(shost: sh);
198 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
199 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
200
201 virtscsi_vq_done(vscsi, virtscsi_vq: req_vq, fn: virtscsi_complete_cmd);
202};
203
204static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
205{
206 int i, num_vqs;
207
208 num_vqs = vscsi->num_queues;
209 for (i = 0; i < num_vqs; i++)
210 virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->req_vqs[i],
211 fn: virtscsi_complete_cmd);
212}
213
214static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
215{
216 struct virtio_scsi_cmd *cmd = buf;
217
218 if (cmd->comp)
219 complete(cmd->comp);
220}
221
222static void virtscsi_ctrl_done(struct virtqueue *vq)
223{
224 struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev);
225 struct virtio_scsi *vscsi = shost_priv(shost: sh);
226
227 virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->ctrl_vq, fn: virtscsi_complete_free);
228};
229
230static void virtscsi_handle_event(struct work_struct *work);
231
232static int virtscsi_kick_event(struct virtio_scsi *vscsi,
233 struct virtio_scsi_event_node *event_node)
234{
235 int err;
236 struct scatterlist sg;
237 unsigned long flags;
238
239 INIT_WORK(&event_node->work, virtscsi_handle_event);
240 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
241
242 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
243
244 err = virtqueue_add_inbuf(vq: vscsi->event_vq.vq, sg: &sg, num: 1, data: event_node,
245 GFP_ATOMIC);
246 if (!err)
247 virtqueue_kick(vq: vscsi->event_vq.vq);
248
249 spin_unlock_irqrestore(lock: &vscsi->event_vq.vq_lock, flags);
250
251 return err;
252}
253
254static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
255{
256 int i;
257
258 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
259 vscsi->event_list[i].vscsi = vscsi;
260 virtscsi_kick_event(vscsi, event_node: &vscsi->event_list[i]);
261 }
262
263 return 0;
264}
265
266static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
267{
268 int i;
269
270 /* Stop scheduling work before calling cancel_work_sync. */
271 spin_lock_irq(lock: &vscsi->event_vq.vq_lock);
272 vscsi->stop_events = true;
273 spin_unlock_irq(lock: &vscsi->event_vq.vq_lock);
274
275 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
276 cancel_work_sync(work: &vscsi->event_list[i].work);
277}
278
279static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
280 struct virtio_scsi_event *event)
281{
282 struct scsi_device *sdev;
283 struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev);
284 unsigned int target = event->lun[1];
285 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
286
287 switch (virtio32_to_cpu(vdev: vscsi->vdev, val: event->reason)) {
288 case VIRTIO_SCSI_EVT_RESET_RESCAN:
289 if (lun == 0) {
290 scsi_scan_target(parent: &shost->shost_gendev, channel: 0, id: target,
291 SCAN_WILD_CARD, rescan: SCSI_SCAN_INITIAL);
292 } else {
293 scsi_add_device(host: shost, channel: 0, target, lun);
294 }
295 break;
296 case VIRTIO_SCSI_EVT_RESET_REMOVED:
297 sdev = scsi_device_lookup(shost, 0, target, lun);
298 if (sdev) {
299 scsi_remove_device(sdev);
300 scsi_device_put(sdev);
301 } else {
302 pr_err("SCSI device %d 0 %d %d not found\n",
303 shost->host_no, target, lun);
304 }
305 break;
306 default:
307 pr_info("Unsupported virtio scsi event reason %x\n", event->reason);
308 }
309}
310
311static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
312 struct virtio_scsi_event *event)
313{
314 struct scsi_device *sdev;
315 struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev);
316 unsigned int target = event->lun[1];
317 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
318 u8 asc = virtio32_to_cpu(vdev: vscsi->vdev, val: event->reason) & 255;
319 u8 ascq = virtio32_to_cpu(vdev: vscsi->vdev, val: event->reason) >> 8;
320
321 sdev = scsi_device_lookup(shost, 0, target, lun);
322 if (!sdev) {
323 pr_err("SCSI device %d 0 %d %d not found\n",
324 shost->host_no, target, lun);
325 return;
326 }
327
328 /* Handle "Parameters changed", "Mode parameters changed", and
329 "Capacity data has changed". */
330 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
331 scsi_rescan_device(sdev);
332
333 scsi_device_put(sdev);
334}
335
336static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
337{
338 struct scsi_device *sdev;
339 struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev);
340 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
341 int result, inquiry_len, inq_result_len = 256;
342 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
343
344 if (!inq_result)
345 return -ENOMEM;
346
347 shost_for_each_device(sdev, shost) {
348 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
349
350 memset(scsi_cmd, 0, sizeof(scsi_cmd));
351 scsi_cmd[0] = INQUIRY;
352 scsi_cmd[4] = (unsigned char) inquiry_len;
353
354 memset(inq_result, 0, inq_result_len);
355
356 result = scsi_execute_cmd(sdev, cmd: scsi_cmd, opf: REQ_OP_DRV_IN,
357 buffer: inq_result, bufflen: inquiry_len,
358 SD_TIMEOUT, SD_MAX_RETRIES, NULL);
359
360 if (result == 0 && inq_result[0] >> 5) {
361 /* PQ indicates the LUN is not attached */
362 scsi_remove_device(sdev);
363 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) {
364 /*
365 * If all LUNs of a virtio-scsi device are unplugged
366 * it will respond with BAD TARGET on any INQUIRY
367 * command.
368 * Remove the device in this case as well.
369 */
370 scsi_remove_device(sdev);
371 }
372 }
373
374 kfree(objp: inq_result);
375 return 0;
376}
377
378static void virtscsi_handle_event(struct work_struct *work)
379{
380 struct virtio_scsi_event_node *event_node =
381 container_of(work, struct virtio_scsi_event_node, work);
382 struct virtio_scsi *vscsi = event_node->vscsi;
383 struct virtio_scsi_event *event = &event_node->event;
384
385 if (event->event &
386 cpu_to_virtio32(vdev: vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
387 int ret;
388
389 event->event &= ~cpu_to_virtio32(vdev: vscsi->vdev,
390 VIRTIO_SCSI_T_EVENTS_MISSED);
391 ret = virtscsi_rescan_hotunplug(vscsi);
392 if (ret)
393 return;
394 scsi_scan_host(virtio_scsi_host(vdev: vscsi->vdev));
395 }
396
397 switch (virtio32_to_cpu(vdev: vscsi->vdev, val: event->event)) {
398 case VIRTIO_SCSI_T_NO_EVENT:
399 break;
400 case VIRTIO_SCSI_T_TRANSPORT_RESET:
401 virtscsi_handle_transport_reset(vscsi, event);
402 break;
403 case VIRTIO_SCSI_T_PARAM_CHANGE:
404 virtscsi_handle_param_change(vscsi, event);
405 break;
406 default:
407 pr_err("Unsupported virtio scsi event %x\n", event->event);
408 }
409 virtscsi_kick_event(vscsi, event_node);
410}
411
412static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
413{
414 struct virtio_scsi_event_node *event_node = buf;
415
416 if (!vscsi->stop_events)
417 queue_work(wq: system_freezable_wq, work: &event_node->work);
418}
419
420static void virtscsi_event_done(struct virtqueue *vq)
421{
422 struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev);
423 struct virtio_scsi *vscsi = shost_priv(shost: sh);
424
425 virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->event_vq, fn: virtscsi_complete_event);
426};
427
428static int __virtscsi_add_cmd(struct virtqueue *vq,
429 struct virtio_scsi_cmd *cmd,
430 size_t req_size, size_t resp_size)
431{
432 struct scsi_cmnd *sc = cmd->sc;
433 struct scatterlist *sgs[6], req, resp;
434 struct sg_table *out, *in;
435 unsigned out_num = 0, in_num = 0;
436
437 out = in = NULL;
438
439 if (sc && sc->sc_data_direction != DMA_NONE) {
440 if (sc->sc_data_direction != DMA_FROM_DEVICE)
441 out = &sc->sdb.table;
442 if (sc->sc_data_direction != DMA_TO_DEVICE)
443 in = &sc->sdb.table;
444 }
445
446 /* Request header. */
447 sg_init_one(&req, &cmd->req, req_size);
448 sgs[out_num++] = &req;
449
450 /* Data-out buffer. */
451 if (out) {
452 /* Place WRITE protection SGLs before Data OUT payload */
453 if (scsi_prot_sg_count(cmd: sc))
454 sgs[out_num++] = scsi_prot_sglist(cmd: sc);
455 sgs[out_num++] = out->sgl;
456 }
457
458 /* Response header. */
459 sg_init_one(&resp, &cmd->resp, resp_size);
460 sgs[out_num + in_num++] = &resp;
461
462 /* Data-in buffer */
463 if (in) {
464 /* Place READ protection SGLs before Data IN payload */
465 if (scsi_prot_sg_count(cmd: sc))
466 sgs[out_num + in_num++] = scsi_prot_sglist(cmd: sc);
467 sgs[out_num + in_num++] = in->sgl;
468 }
469
470 return virtqueue_add_sgs(vq, sgs, out_sgs: out_num, in_sgs: in_num, data: cmd, GFP_ATOMIC);
471}
472
473static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
474{
475 bool needs_kick;
476 unsigned long flags;
477
478 spin_lock_irqsave(&vq->vq_lock, flags);
479 needs_kick = virtqueue_kick_prepare(vq: vq->vq);
480 spin_unlock_irqrestore(lock: &vq->vq_lock, flags);
481
482 if (needs_kick)
483 virtqueue_notify(vq: vq->vq);
484}
485
486/**
487 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
488 * @vq : the struct virtqueue we're talking about
489 * @cmd : command structure
490 * @req_size : size of the request buffer
491 * @resp_size : size of the response buffer
492 * @kick : whether to kick the virtqueue immediately
493 */
494static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
495 struct virtio_scsi_cmd *cmd,
496 size_t req_size, size_t resp_size,
497 bool kick)
498{
499 unsigned long flags;
500 int err;
501 bool needs_kick = false;
502
503 spin_lock_irqsave(&vq->vq_lock, flags);
504 err = __virtscsi_add_cmd(vq: vq->vq, cmd, req_size, resp_size);
505 if (!err && kick)
506 needs_kick = virtqueue_kick_prepare(vq: vq->vq);
507
508 spin_unlock_irqrestore(lock: &vq->vq_lock, flags);
509
510 if (needs_kick)
511 virtqueue_notify(vq: vq->vq);
512 return err;
513}
514
515static void virtio_scsi_init_hdr(struct virtio_device *vdev,
516 struct virtio_scsi_cmd_req *cmd,
517 struct scsi_cmnd *sc)
518{
519 cmd->lun[0] = 1;
520 cmd->lun[1] = sc->device->id;
521 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
522 cmd->lun[3] = sc->device->lun & 0xff;
523 cmd->tag = cpu_to_virtio64(vdev, val: (unsigned long)sc);
524 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
525 cmd->prio = 0;
526 cmd->crn = 0;
527}
528
529#ifdef CONFIG_BLK_DEV_INTEGRITY
530static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
531 struct virtio_scsi_cmd_req_pi *cmd_pi,
532 struct scsi_cmnd *sc)
533{
534 struct request *rq = scsi_cmd_to_rq(scmd: sc);
535 struct blk_integrity *bi;
536
537 virtio_scsi_init_hdr(vdev, cmd: (struct virtio_scsi_cmd_req *)cmd_pi, sc);
538
539 if (!rq || !scsi_prot_sg_count(cmd: sc))
540 return;
541
542 bi = blk_get_integrity(disk: rq->q->disk);
543
544 if (sc->sc_data_direction == DMA_TO_DEVICE)
545 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
546 val: bio_integrity_bytes(bi,
547 sectors: blk_rq_sectors(rq)));
548 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
549 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
550 val: bio_integrity_bytes(bi,
551 sectors: blk_rq_sectors(rq)));
552}
553#endif
554
555static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
556 struct scsi_cmnd *sc)
557{
558 u32 tag = blk_mq_unique_tag(rq: scsi_cmd_to_rq(scmd: sc));
559 u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag: tag);
560
561 return &vscsi->req_vqs[hwq];
562}
563
564static int virtscsi_queuecommand(struct Scsi_Host *shost,
565 struct scsi_cmnd *sc)
566{
567 struct virtio_scsi *vscsi = shost_priv(shost);
568 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
569 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(cmd: sc);
570 bool kick;
571 unsigned long flags;
572 int req_size;
573 int ret;
574
575 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
576
577 /* TODO: check feature bit and fail if unsupported? */
578 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
579
580 dev_dbg(&sc->device->sdev_gendev,
581 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
582
583 cmd->sc = sc;
584
585 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
586
587#ifdef CONFIG_BLK_DEV_INTEGRITY
588 if (virtio_has_feature(vdev: vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
589 virtio_scsi_init_hdr_pi(vdev: vscsi->vdev, cmd_pi: &cmd->req.cmd_pi, sc);
590 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
591 req_size = sizeof(cmd->req.cmd_pi);
592 } else
593#endif
594 {
595 virtio_scsi_init_hdr(vdev: vscsi->vdev, cmd: &cmd->req.cmd, sc);
596 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
597 req_size = sizeof(cmd->req.cmd);
598 }
599
600 kick = (sc->flags & SCMD_LAST) != 0;
601 ret = virtscsi_add_cmd(vq: req_vq, cmd, req_size, resp_size: sizeof(cmd->resp.cmd), kick);
602 if (ret == -EIO) {
603 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
604 spin_lock_irqsave(&req_vq->vq_lock, flags);
605 virtscsi_complete_cmd(vscsi, buf: cmd);
606 spin_unlock_irqrestore(lock: &req_vq->vq_lock, flags);
607 } else if (ret != 0) {
608 return SCSI_MLQUEUE_HOST_BUSY;
609 }
610 return 0;
611}
612
613static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
614{
615 DECLARE_COMPLETION_ONSTACK(comp);
616 int ret = FAILED;
617
618 cmd->comp = &comp;
619 if (virtscsi_add_cmd(vq: &vscsi->ctrl_vq, cmd,
620 req_size: sizeof cmd->req.tmf, resp_size: sizeof cmd->resp.tmf, kick: true) < 0)
621 goto out;
622
623 wait_for_completion(&comp);
624 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
625 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
626 ret = SUCCESS;
627
628 /*
629 * The spec guarantees that all requests related to the TMF have
630 * been completed, but the callback might not have run yet if
631 * we're using independent interrupts (e.g. MSI). Poll the
632 * virtqueues once.
633 *
634 * In the abort case, scsi_done() will do nothing, because the
635 * command timed out and hence SCMD_STATE_COMPLETE has been set.
636 */
637 virtscsi_poll_requests(vscsi);
638
639out:
640 mempool_free(element: cmd, pool: virtscsi_cmd_pool);
641 return ret;
642}
643
644static int virtscsi_device_reset(struct scsi_cmnd *sc)
645{
646 struct virtio_scsi *vscsi = shost_priv(shost: sc->device->host);
647 struct virtio_scsi_cmd *cmd;
648
649 sdev_printk(KERN_INFO, sc->device, "device reset\n");
650 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
651 if (!cmd)
652 return FAILED;
653
654 memset(cmd, 0, sizeof(*cmd));
655 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
656 .type = VIRTIO_SCSI_T_TMF,
657 .subtype = cpu_to_virtio32(vdev: vscsi->vdev,
658 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
659 .lun[0] = 1,
660 .lun[1] = sc->device->id,
661 .lun[2] = (sc->device->lun >> 8) | 0x40,
662 .lun[3] = sc->device->lun & 0xff,
663 };
664 return virtscsi_tmf(vscsi, cmd);
665}
666
667static int virtscsi_device_alloc(struct scsi_device *sdevice)
668{
669 /*
670 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
671 * may have transfer limits which come from the host SCSI
672 * controller or something on the host side other than the
673 * target itself.
674 *
675 * To make this work properly, the hypervisor can adjust the
676 * target's VPD information to advertise these limits. But
677 * for that to work, the guest has to look at the VPD pages,
678 * which we won't do by default if it is an SPC-2 device, even
679 * if it does actually support it.
680 *
681 * So, set the blist to always try to read the VPD pages.
682 */
683 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
684
685 return 0;
686}
687
688
689/**
690 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
691 * @sdev: Virtscsi target whose queue depth to change
692 * @qdepth: New queue depth
693 */
694static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
695{
696 struct Scsi_Host *shost = sdev->host;
697 int max_depth = shost->cmd_per_lun;
698
699 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
700}
701
702static int virtscsi_abort(struct scsi_cmnd *sc)
703{
704 struct virtio_scsi *vscsi = shost_priv(shost: sc->device->host);
705 struct virtio_scsi_cmd *cmd;
706
707 scmd_printk(KERN_INFO, sc, "abort\n");
708 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
709 if (!cmd)
710 return FAILED;
711
712 memset(cmd, 0, sizeof(*cmd));
713 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
714 .type = VIRTIO_SCSI_T_TMF,
715 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
716 .lun[0] = 1,
717 .lun[1] = sc->device->id,
718 .lun[2] = (sc->device->lun >> 8) | 0x40,
719 .lun[3] = sc->device->lun & 0xff,
720 .tag = cpu_to_virtio64(vdev: vscsi->vdev, val: (unsigned long)sc),
721 };
722 return virtscsi_tmf(vscsi, cmd);
723}
724
725static void virtscsi_map_queues(struct Scsi_Host *shost)
726{
727 struct virtio_scsi *vscsi = shost_priv(shost);
728 int i, qoff;
729
730 for (i = 0, qoff = 0; i < shost->nr_maps; i++) {
731 struct blk_mq_queue_map *map = &shost->tag_set.map[i];
732
733 map->nr_queues = vscsi->io_queues[i];
734 map->queue_offset = qoff;
735 qoff += map->nr_queues;
736
737 if (map->nr_queues == 0)
738 continue;
739
740 /*
741 * Regular queues have interrupts and hence CPU affinity is
742 * defined by the core virtio code, but polling queues have
743 * no interrupts so we let the block layer assign CPU affinity.
744 */
745 if (i == HCTX_TYPE_POLL)
746 blk_mq_map_queues(qmap: map);
747 else
748 blk_mq_map_hw_queues(qmap: map, dev: &vscsi->vdev->dev, offset: 2);
749 }
750}
751
752static int virtscsi_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
753{
754 struct virtio_scsi *vscsi = shost_priv(shost);
755 struct virtio_scsi_vq *virtscsi_vq = &vscsi->req_vqs[queue_num];
756 unsigned long flags;
757 unsigned int len;
758 int found = 0;
759 void *buf;
760
761 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
762
763 while ((buf = virtqueue_get_buf(vq: virtscsi_vq->vq, len: &len)) != NULL) {
764 virtscsi_complete_cmd(vscsi, buf);
765 found++;
766 }
767
768 spin_unlock_irqrestore(lock: &virtscsi_vq->vq_lock, flags);
769
770 return found;
771}
772
773static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
774{
775 struct virtio_scsi *vscsi = shost_priv(shost);
776
777 virtscsi_kick_vq(vq: &vscsi->req_vqs[hwq]);
778}
779
780/*
781 * The host guarantees to respond to each command, although I/O
782 * latencies might be higher than on bare metal. Reset the timer
783 * unconditionally to give the host a chance to perform EH.
784 */
785static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
786{
787 return SCSI_EH_RESET_TIMER;
788}
789
790static const struct scsi_host_template virtscsi_host_template = {
791 .module = THIS_MODULE,
792 .name = "Virtio SCSI HBA",
793 .proc_name = "virtio_scsi",
794 .this_id = -1,
795 .cmd_size = sizeof(struct virtio_scsi_cmd),
796 .queuecommand = virtscsi_queuecommand,
797 .mq_poll = virtscsi_mq_poll,
798 .commit_rqs = virtscsi_commit_rqs,
799 .change_queue_depth = virtscsi_change_queue_depth,
800 .eh_abort_handler = virtscsi_abort,
801 .eh_device_reset_handler = virtscsi_device_reset,
802 .eh_timed_out = virtscsi_eh_timed_out,
803 .sdev_init = virtscsi_device_alloc,
804
805 .dma_boundary = UINT_MAX,
806 .map_queues = virtscsi_map_queues,
807 .track_queue_depth = 1,
808};
809
810#define virtscsi_config_get(vdev, fld) \
811 ({ \
812 __virtio_native_type(struct virtio_scsi_config, fld) __val; \
813 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
814 __val; \
815 })
816
817#define virtscsi_config_set(vdev, fld, val) \
818 do { \
819 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \
820 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
821 } while(0)
822
823static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
824 struct virtqueue *vq)
825{
826 spin_lock_init(&virtscsi_vq->vq_lock);
827 virtscsi_vq->vq = vq;
828}
829
830static void virtscsi_remove_vqs(struct virtio_device *vdev)
831{
832 /* Stop all the virtqueues. */
833 virtio_reset_device(dev: vdev);
834 vdev->config->del_vqs(vdev);
835}
836
837static int virtscsi_init(struct virtio_device *vdev,
838 struct virtio_scsi *vscsi)
839{
840 int err;
841 u32 i;
842 u32 num_vqs, num_poll_vqs, num_req_vqs;
843 struct virtqueue_info *vqs_info;
844 struct virtqueue **vqs;
845 struct irq_affinity desc = { .pre_vectors = 2 };
846
847 num_req_vqs = vscsi->num_queues;
848 num_vqs = num_req_vqs + VIRTIO_SCSI_VQ_BASE;
849 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
850 vqs_info = kcalloc(num_vqs, sizeof(*vqs_info), GFP_KERNEL);
851
852 if (!vqs || !vqs_info) {
853 err = -ENOMEM;
854 goto out;
855 }
856
857 num_poll_vqs = min_t(unsigned int, virtscsi_poll_queues,
858 num_req_vqs - 1);
859 vscsi->io_queues[HCTX_TYPE_DEFAULT] = num_req_vqs - num_poll_vqs;
860 vscsi->io_queues[HCTX_TYPE_READ] = 0;
861 vscsi->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
862
863 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
864 vscsi->io_queues[HCTX_TYPE_DEFAULT],
865 vscsi->io_queues[HCTX_TYPE_READ],
866 vscsi->io_queues[HCTX_TYPE_POLL]);
867
868 vqs_info[0].callback = virtscsi_ctrl_done;
869 vqs_info[0].name = "control";
870 vqs_info[1].callback = virtscsi_event_done;
871 vqs_info[1].name = "event";
872 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs - num_poll_vqs; i++) {
873 vqs_info[i].callback = virtscsi_req_done;
874 vqs_info[i].name = "request";
875 }
876
877 for (; i < num_vqs; i++)
878 vqs_info[i].name = "request_poll";
879
880 /* Discover virtqueues and write information to configuration. */
881 err = virtio_find_vqs(vdev, nvqs: num_vqs, vqs, vqs_info, desc: &desc);
882 if (err)
883 goto out;
884
885 virtscsi_init_vq(virtscsi_vq: &vscsi->ctrl_vq, vq: vqs[0]);
886 virtscsi_init_vq(virtscsi_vq: &vscsi->event_vq, vq: vqs[1]);
887 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
888 virtscsi_init_vq(virtscsi_vq: &vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
889 vq: vqs[i]);
890
891 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
892 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
893
894 err = 0;
895
896out:
897 kfree(objp: vqs_info);
898 kfree(objp: vqs);
899 if (err)
900 virtscsi_remove_vqs(vdev);
901 return err;
902}
903
904static int virtscsi_probe(struct virtio_device *vdev)
905{
906 struct Scsi_Host *shost;
907 struct virtio_scsi *vscsi;
908 int err;
909 u32 sg_elems, num_targets;
910 u32 cmd_per_lun;
911 u32 num_queues;
912
913 if (!vdev->config->get) {
914 dev_err(&vdev->dev, "%s failure: config access disabled\n",
915 __func__);
916 return -EINVAL;
917 }
918
919 /* We need to know how many queues before we allocate. */
920 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
921 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
922 num_queues = blk_mq_num_possible_queues(max_queues: num_queues);
923
924 num_targets = virtscsi_config_get(vdev, max_target) + 1;
925
926 shost = scsi_host_alloc(&virtscsi_host_template,
927 struct_size(vscsi, req_vqs, num_queues));
928 if (!shost)
929 return -ENOMEM;
930
931 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
932 shost->sg_tablesize = sg_elems;
933 shost->nr_maps = 1;
934 vscsi = shost_priv(shost);
935 vscsi->vdev = vdev;
936 vscsi->num_queues = num_queues;
937 vdev->priv = shost;
938
939 err = virtscsi_init(vdev, vscsi);
940 if (err)
941 goto virtscsi_init_failed;
942
943 if (vscsi->io_queues[HCTX_TYPE_POLL])
944 shost->nr_maps = HCTX_TYPE_POLL + 1;
945
946 shost->can_queue = virtqueue_get_vring_size(vq: vscsi->req_vqs[0].vq);
947
948 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
949 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
950 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
951
952 /* LUNs > 256 are reported with format 1, so they go in the range
953 * 16640-32767.
954 */
955 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
956 shost->max_id = num_targets;
957 shost->max_channel = 0;
958 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
959 shost->nr_hw_queues = num_queues;
960
961#ifdef CONFIG_BLK_DEV_INTEGRITY
962 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
963 int host_prot;
964
965 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
966 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
967 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
968
969 scsi_host_set_prot(shost, mask: host_prot);
970 scsi_host_set_guard(shost, type: SHOST_DIX_GUARD_CRC);
971 }
972#endif
973
974 err = scsi_add_host(host: shost, dev: &vdev->dev);
975 if (err)
976 goto scsi_add_host_failed;
977
978 virtio_device_ready(dev: vdev);
979
980 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
981 virtscsi_kick_event_all(vscsi);
982
983 scsi_scan_host(shost);
984 return 0;
985
986scsi_add_host_failed:
987 vdev->config->del_vqs(vdev);
988virtscsi_init_failed:
989 scsi_host_put(t: shost);
990 return err;
991}
992
993static void virtscsi_remove(struct virtio_device *vdev)
994{
995 struct Scsi_Host *shost = virtio_scsi_host(vdev);
996 struct virtio_scsi *vscsi = shost_priv(shost);
997
998 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
999 virtscsi_cancel_event_work(vscsi);
1000
1001 scsi_remove_host(shost);
1002 virtscsi_remove_vqs(vdev);
1003 scsi_host_put(t: shost);
1004}
1005
1006#ifdef CONFIG_PM_SLEEP
1007static int virtscsi_freeze(struct virtio_device *vdev)
1008{
1009 virtscsi_remove_vqs(vdev);
1010 return 0;
1011}
1012
1013static int virtscsi_restore(struct virtio_device *vdev)
1014{
1015 struct Scsi_Host *sh = virtio_scsi_host(vdev);
1016 struct virtio_scsi *vscsi = shost_priv(shost: sh);
1017 int err;
1018
1019 err = virtscsi_init(vdev, vscsi);
1020 if (err)
1021 return err;
1022
1023 virtio_device_ready(dev: vdev);
1024
1025 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
1026 virtscsi_kick_event_all(vscsi);
1027
1028 return err;
1029}
1030#endif
1031
1032static struct virtio_device_id id_table[] = {
1033 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
1034 { 0 },
1035};
1036
1037static unsigned int features[] = {
1038 VIRTIO_SCSI_F_HOTPLUG,
1039 VIRTIO_SCSI_F_CHANGE,
1040#ifdef CONFIG_BLK_DEV_INTEGRITY
1041 VIRTIO_SCSI_F_T10_PI,
1042#endif
1043};
1044
1045static struct virtio_driver virtio_scsi_driver = {
1046 .feature_table = features,
1047 .feature_table_size = ARRAY_SIZE(features),
1048 .driver.name = KBUILD_MODNAME,
1049 .id_table = id_table,
1050 .probe = virtscsi_probe,
1051#ifdef CONFIG_PM_SLEEP
1052 .freeze = virtscsi_freeze,
1053 .restore = virtscsi_restore,
1054#endif
1055 .remove = virtscsi_remove,
1056};
1057
1058static int __init virtio_scsi_init(void)
1059{
1060 int ret = -ENOMEM;
1061
1062 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1063 if (!virtscsi_cmd_cache) {
1064 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1065 goto error;
1066 }
1067
1068
1069 virtscsi_cmd_pool =
1070 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1071 virtscsi_cmd_cache);
1072 if (!virtscsi_cmd_pool) {
1073 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1074 goto error;
1075 }
1076 ret = register_virtio_driver(&virtio_scsi_driver);
1077 if (ret < 0)
1078 goto error;
1079
1080 return 0;
1081
1082error:
1083 mempool_destroy(pool: virtscsi_cmd_pool);
1084 virtscsi_cmd_pool = NULL;
1085 kmem_cache_destroy(s: virtscsi_cmd_cache);
1086 virtscsi_cmd_cache = NULL;
1087 return ret;
1088}
1089
1090static void __exit virtio_scsi_fini(void)
1091{
1092 unregister_virtio_driver(drv: &virtio_scsi_driver);
1093 mempool_destroy(pool: virtscsi_cmd_pool);
1094 kmem_cache_destroy(s: virtscsi_cmd_cache);
1095}
1096module_init(virtio_scsi_init);
1097module_exit(virtio_scsi_fini);
1098
1099MODULE_DEVICE_TABLE(virtio, id_table);
1100MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1101MODULE_LICENSE("GPL");
1102

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