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drm/panthor: Don't add write fences to the shared BOs
[drm/drm-misc.git] / drivers / block / virtio_blk.c
blob194417abc1053c0c73a8efdfe45b13c24534eec0
1 // SPDX-License-Identifier: GPL-2.0-only
2 //#define DEBUG
3 #include <linux/spinlock.h>
4 #include <linux/slab.h>
5 #include <linux/blkdev.h>
6 #include <linux/hdreg.h>
7 #include <linux/module.h>
8 #include <linux/mutex.h>
9 #include <linux/interrupt.h>
10 #include <linux/virtio.h>
11 #include <linux/virtio_blk.h>
12 #include <linux/scatterlist.h>
13 #include <linux/string_helpers.h>
14 #include <linux/idr.h>
15 #include <linux/blk-mq.h>
16 #include <linux/blk-mq-virtio.h>
17 #include <linux/numa.h>
18 #include <linux/vmalloc.h>
19 #include <uapi/linux/virtio_ring.h>
20
21 #define PART_BITS 4
22 #define VQ_NAME_LEN 16
23 #define MAX_DISCARD_SEGMENTS 256u
24
25 /* The maximum number of sg elements that fit into a virtqueue */
26 #define VIRTIO_BLK_MAX_SG_ELEMS 32768
27
28 #ifdef CONFIG_ARCH_NO_SG_CHAIN
29 #define VIRTIO_BLK_INLINE_SG_CNT 0
30 #else
31 #define VIRTIO_BLK_INLINE_SG_CNT 2
32 #endif
33
34 static unsigned int num_request_queues;
35 module_param(num_request_queues, uint, 0644);
36 MODULE_PARM_DESC(num_request_queues,
37 "Limit the number of request queues to use for blk device. "
38 "0 for no limit. "
39 "Values > nr_cpu_ids truncated to nr_cpu_ids.");
40
41 static unsigned int poll_queues;
42 module_param(poll_queues, uint, 0644);
43 MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O");
44
45 static int major;
46 static DEFINE_IDA(vd_index_ida);
47
48 static struct workqueue_struct *virtblk_wq;
49
50 struct virtio_blk_vq {
51 struct virtqueue *vq;
52 spinlock_t lock;
53 char name[VQ_NAME_LEN];
54 } ____cacheline_aligned_in_smp;
55
56 struct virtio_blk {
57 /*
58 * This mutex must be held by anything that may run after
59 * virtblk_remove() sets vblk->vdev to NULL.
60 *
61 * blk-mq, virtqueue processing, and sysfs attribute code paths are
62 * shut down before vblk->vdev is set to NULL and therefore do not need
63 * to hold this mutex.
64 */
65 struct mutex vdev_mutex;
66 struct virtio_device *vdev;
67
68 /* The disk structure for the kernel. */
69 struct gendisk *disk;
70
71 /* Block layer tags. */
72 struct blk_mq_tag_set tag_set;
73
74 /* Process context for config space updates */
75 struct work_struct config_work;
76
77 /* Ida index - used to track minor number allocations. */
78 int index;
79
80 /* num of vqs */
81 int num_vqs;
82 int io_queues[HCTX_MAX_TYPES];
83 struct virtio_blk_vq *vqs;
84
85 /* For zoned device */
86 unsigned int zone_sectors;
87 };
88
89 struct virtblk_req {
90 /* Out header */
91 struct virtio_blk_outhdr out_hdr;
92
93 /* In header */
94 union {
95 u8 status;
96
97 /*
98 * The zone append command has an extended in header.
99 * The status field in zone_append_in_hdr must always
100 * be the last byte.
101 */
102 struct {
103 __virtio64 sector;
104 u8 status;
105 } zone_append;
106 } in_hdr;
107
108 size_t in_hdr_len;
109
110 struct sg_table sg_table;
111 struct scatterlist sg[];
112 };
113
114 static inline blk_status_t virtblk_result(u8 status)
115 {
116 switch (status) {
117 case VIRTIO_BLK_S_OK:
118 return BLK_STS_OK;
119 case VIRTIO_BLK_S_UNSUPP:
120 return BLK_STS_NOTSUPP;
121 case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE:
122 return BLK_STS_ZONE_OPEN_RESOURCE;
123 case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE:
124 return BLK_STS_ZONE_ACTIVE_RESOURCE;
125 case VIRTIO_BLK_S_IOERR:
126 case VIRTIO_BLK_S_ZONE_UNALIGNED_WP:
127 default:
128 return BLK_STS_IOERR;
129 }
130 }
131
132 static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx)
133 {
134 struct virtio_blk *vblk = hctx->queue->queuedata;
135 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
136
137 return vq;
138 }
139
140 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr)
141 {
142 struct scatterlist out_hdr, in_hdr, *sgs[3];
143 unsigned int num_out = 0, num_in = 0;
144
145 sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
146 sgs[num_out++] = &out_hdr;
147
148 if (vbr->sg_table.nents) {
149 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
150 sgs[num_out++] = vbr->sg_table.sgl;
151 else
152 sgs[num_out + num_in++] = vbr->sg_table.sgl;
153 }
154
155 sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len);
156 sgs[num_out + num_in++] = &in_hdr;
157
158 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
159 }
160
161 static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap)
162 {
163 unsigned short segments = blk_rq_nr_discard_segments(req);
164 unsigned short n = 0;
165 struct virtio_blk_discard_write_zeroes *range;
166 struct bio *bio;
167 u32 flags = 0;
168
169 if (unmap)
170 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
171
172 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
173 if (!range)
174 return -ENOMEM;
175
176 /*
177 * Single max discard segment means multi-range discard isn't
178 * supported, and block layer only runs contiguity merge like
179 * normal RW request. So we can't reply on bio for retrieving
180 * each range info.
181 */
182 if (queue_max_discard_segments(req->q) == 1) {
183 range[0].flags = cpu_to_le32(flags);
184 range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req));
185 range[0].sector = cpu_to_le64(blk_rq_pos(req));
186 n = 1;
187 } else {
188 __rq_for_each_bio(bio, req) {
189 u64 sector = bio->bi_iter.bi_sector;
190 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
191
192 range[n].flags = cpu_to_le32(flags);
193 range[n].num_sectors = cpu_to_le32(num_sectors);
194 range[n].sector = cpu_to_le64(sector);
195 n++;
196 }
197 }
198
199 WARN_ON_ONCE(n != segments);
200
201 bvec_set_virt(&req->special_vec, range, sizeof(*range) * segments);
202 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
203
204 return 0;
205 }
206
207 static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr)
208 {
209 if (blk_rq_nr_phys_segments(req))
210 sg_free_table_chained(&vbr->sg_table,
211 VIRTIO_BLK_INLINE_SG_CNT);
212 }
213
214 static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req,
215 struct virtblk_req *vbr)
216 {
217 int err;
218
219 if (!blk_rq_nr_phys_segments(req))
220 return 0;
221
222 vbr->sg_table.sgl = vbr->sg;
223 err = sg_alloc_table_chained(&vbr->sg_table,
224 blk_rq_nr_phys_segments(req),
225 vbr->sg_table.sgl,
226 VIRTIO_BLK_INLINE_SG_CNT);
227 if (unlikely(err))
228 return -ENOMEM;
229
230 return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl);
231 }
232
233 static void virtblk_cleanup_cmd(struct request *req)
234 {
235 if (req->rq_flags & RQF_SPECIAL_PAYLOAD)
236 kfree(bvec_virt(&req->special_vec));
237 }
238
239 static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
240 struct request *req,
241 struct virtblk_req *vbr)
242 {
243 size_t in_hdr_len = sizeof(vbr->in_hdr.status);
244 bool unmap = false;
245 u32 type;
246 u64 sector = 0;
247
248 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(req_op(req)))
249 return BLK_STS_NOTSUPP;
250
251 /* Set fields for all request types */
252 vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));
253
254 switch (req_op(req)) {
255 case REQ_OP_READ:
256 type = VIRTIO_BLK_T_IN;
257 sector = blk_rq_pos(req);
258 break;
259 case REQ_OP_WRITE:
260 type = VIRTIO_BLK_T_OUT;
261 sector = blk_rq_pos(req);
262 break;
263 case REQ_OP_FLUSH:
264 type = VIRTIO_BLK_T_FLUSH;
265 break;
266 case REQ_OP_DISCARD:
267 type = VIRTIO_BLK_T_DISCARD;
268 break;
269 case REQ_OP_WRITE_ZEROES:
270 type = VIRTIO_BLK_T_WRITE_ZEROES;
271 unmap = !(req->cmd_flags & REQ_NOUNMAP);
272 break;
273 case REQ_OP_SECURE_ERASE:
274 type = VIRTIO_BLK_T_SECURE_ERASE;
275 break;
276 case REQ_OP_ZONE_OPEN:
277 type = VIRTIO_BLK_T_ZONE_OPEN;
278 sector = blk_rq_pos(req);
279 break;
280 case REQ_OP_ZONE_CLOSE:
281 type = VIRTIO_BLK_T_ZONE_CLOSE;
282 sector = blk_rq_pos(req);
283 break;
284 case REQ_OP_ZONE_FINISH:
285 type = VIRTIO_BLK_T_ZONE_FINISH;
286 sector = blk_rq_pos(req);
287 break;
288 case REQ_OP_ZONE_APPEND:
289 type = VIRTIO_BLK_T_ZONE_APPEND;
290 sector = blk_rq_pos(req);
291 in_hdr_len = sizeof(vbr->in_hdr.zone_append);
292 break;
293 case REQ_OP_ZONE_RESET:
294 type = VIRTIO_BLK_T_ZONE_RESET;
295 sector = blk_rq_pos(req);
296 break;
297 case REQ_OP_ZONE_RESET_ALL:
298 type = VIRTIO_BLK_T_ZONE_RESET_ALL;
299 break;
300 case REQ_OP_DRV_IN:
301 /*
302 * Out header has already been prepared by the caller (virtblk_get_id()
303 * or virtblk_submit_zone_report()), nothing to do here.
304 */
305 return 0;
306 default:
307 WARN_ON_ONCE(1);
308 return BLK_STS_IOERR;
309 }
310
311 /* Set fields for non-REQ_OP_DRV_IN request types */
312 vbr->in_hdr_len = in_hdr_len;
313 vbr->out_hdr.type = cpu_to_virtio32(vdev, type);
314 vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector);
315
316 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES ||
317 type == VIRTIO_BLK_T_SECURE_ERASE) {
318 if (virtblk_setup_discard_write_zeroes_erase(req, unmap))
319 return BLK_STS_RESOURCE;
320 }
321
322 return 0;
323 }
324
325 /*
326 * The status byte is always the last byte of the virtblk request
327 * in-header. This helper fetches its value for all in-header formats
328 * that are currently defined.
329 */
330 static inline u8 virtblk_vbr_status(struct virtblk_req *vbr)
331 {
332 return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1);
333 }
334
335 static inline void virtblk_request_done(struct request *req)
336 {
337 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
338 blk_status_t status = virtblk_result(virtblk_vbr_status(vbr));
339 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
340
341 virtblk_unmap_data(req, vbr);
342 virtblk_cleanup_cmd(req);
343
344 if (req_op(req) == REQ_OP_ZONE_APPEND)
345 req->__sector = virtio64_to_cpu(vblk->vdev,
346 vbr->in_hdr.zone_append.sector);
347
348 blk_mq_end_request(req, status);
349 }
350
351 static void virtblk_done(struct virtqueue *vq)
352 {
353 struct virtio_blk *vblk = vq->vdev->priv;
354 bool req_done = false;
355 int qid = vq->index;
356 struct virtblk_req *vbr;
357 unsigned long flags;
358 unsigned int len;
359
360 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
361 do {
362 virtqueue_disable_cb(vq);
363 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
364 struct request *req = blk_mq_rq_from_pdu(vbr);
365
366 if (likely(!blk_should_fake_timeout(req->q)))
367 blk_mq_complete_request(req);
368 req_done = true;
369 }
370 } while (!virtqueue_enable_cb(vq));
371
372 /* In case queue is stopped waiting for more buffers. */
373 if (req_done)
374 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
375 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
376 }
377
378 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
379 {
380 struct virtio_blk *vblk = hctx->queue->queuedata;
381 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
382 bool kick;
383
384 spin_lock_irq(&vq->lock);
385 kick = virtqueue_kick_prepare(vq->vq);
386 spin_unlock_irq(&vq->lock);
387
388 if (kick)
389 virtqueue_notify(vq->vq);
390 }
391
392 static blk_status_t virtblk_fail_to_queue(struct request *req, int rc)
393 {
394 virtblk_cleanup_cmd(req);
395 switch (rc) {
396 case -ENOSPC:
397 return BLK_STS_DEV_RESOURCE;
398 case -ENOMEM:
399 return BLK_STS_RESOURCE;
400 default:
401 return BLK_STS_IOERR;
402 }
403 }
404
405 static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx,
406 struct virtio_blk *vblk,
407 struct request *req,
408 struct virtblk_req *vbr)
409 {
410 blk_status_t status;
411 int num;
412
413 status = virtblk_setup_cmd(vblk->vdev, req, vbr);
414 if (unlikely(status))
415 return status;
416
417 num = virtblk_map_data(hctx, req, vbr);
418 if (unlikely(num < 0))
419 return virtblk_fail_to_queue(req, -ENOMEM);
420 vbr->sg_table.nents = num;
421
422 blk_mq_start_request(req);
423
424 return BLK_STS_OK;
425 }
426
427 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
428 const struct blk_mq_queue_data *bd)
429 {
430 struct virtio_blk *vblk = hctx->queue->queuedata;
431 struct request *req = bd->rq;
432 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
433 unsigned long flags;
434 int qid = hctx->queue_num;
435 bool notify = false;
436 blk_status_t status;
437 int err;
438
439 status = virtblk_prep_rq(hctx, vblk, req, vbr);
440 if (unlikely(status))
441 return status;
442
443 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
444 err = virtblk_add_req(vblk->vqs[qid].vq, vbr);
445 if (err) {
446 virtqueue_kick(vblk->vqs[qid].vq);
447 /* Don't stop the queue if -ENOMEM: we may have failed to
448 * bounce the buffer due to global resource outage.
449 */
450 if (err == -ENOSPC)
451 blk_mq_stop_hw_queue(hctx);
452 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
453 virtblk_unmap_data(req, vbr);
454 return virtblk_fail_to_queue(req, err);
455 }
456
457 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
458 notify = true;
459 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
460
461 if (notify)
462 virtqueue_notify(vblk->vqs[qid].vq);
463 return BLK_STS_OK;
464 }
465
466 static bool virtblk_prep_rq_batch(struct request *req)
467 {
468 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
469 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
470
471 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK;
472 }
473
474 static bool virtblk_add_req_batch(struct virtio_blk_vq *vq,
475 struct request **rqlist)
476 {
477 unsigned long flags;
478 int err;
479 bool kick;
480
481 spin_lock_irqsave(&vq->lock, flags);
482
483 while (!rq_list_empty(*rqlist)) {
484 struct request *req = rq_list_pop(rqlist);
485 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
486
487 err = virtblk_add_req(vq->vq, vbr);
488 if (err) {
489 virtblk_unmap_data(req, vbr);
490 virtblk_cleanup_cmd(req);
491 blk_mq_requeue_request(req, true);
492 }
493 }
494
495 kick = virtqueue_kick_prepare(vq->vq);
496 spin_unlock_irqrestore(&vq->lock, flags);
497
498 return kick;
499 }
500
501 static void virtio_queue_rqs(struct request **rqlist)
502 {
503 struct request *req, *next, *prev = NULL;
504 struct request *requeue_list = NULL;
505
506 rq_list_for_each_safe(rqlist, req, next) {
507 struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx);
508 bool kick;
509
510 if (!virtblk_prep_rq_batch(req)) {
511 rq_list_move(rqlist, &requeue_list, req, prev);
512 req = prev;
513 if (!req)
514 continue;
515 }
516
517 if (!next || req->mq_hctx != next->mq_hctx) {
518 req->rq_next = NULL;
519 kick = virtblk_add_req_batch(vq, rqlist);
520 if (kick)
521 virtqueue_notify(vq->vq);
522
523 *rqlist = next;
524 prev = NULL;
525 } else
526 prev = req;
527 }
528
529 *rqlist = requeue_list;
530 }
531
532 #ifdef CONFIG_BLK_DEV_ZONED
533 static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk,
534 unsigned int nr_zones,
535 size_t *buflen)
536 {
537 struct request_queue *q = vblk->disk->queue;
538 size_t bufsize;
539 void *buf;
540
541 nr_zones = min_t(unsigned int, nr_zones,
542 get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors));
543
544 bufsize = sizeof(struct virtio_blk_zone_report) +
545 nr_zones * sizeof(struct virtio_blk_zone_descriptor);
546 bufsize = min_t(size_t, bufsize,
547 queue_max_hw_sectors(q) << SECTOR_SHIFT);
548 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
549
550 while (bufsize >= sizeof(struct virtio_blk_zone_report)) {
551 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
552 if (buf) {
553 *buflen = bufsize;
554 return buf;
555 }
556 bufsize >>= 1;
557 }
558
559 return NULL;
560 }
561
562 static int virtblk_submit_zone_report(struct virtio_blk *vblk,
563 char *report_buf, size_t report_len,
564 sector_t sector)
565 {
566 struct request_queue *q = vblk->disk->queue;
567 struct request *req;
568 struct virtblk_req *vbr;
569 int err;
570
571 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
572 if (IS_ERR(req))
573 return PTR_ERR(req);
574
575 vbr = blk_mq_rq_to_pdu(req);
576 vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
577 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT);
578 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector);
579
580 err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL);
581 if (err)
582 goto out;
583
584 blk_execute_rq(req, false);
585 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status));
586 out:
587 blk_mq_free_request(req);
588 return err;
589 }
590
591 static int virtblk_parse_zone(struct virtio_blk *vblk,
592 struct virtio_blk_zone_descriptor *entry,
593 unsigned int idx, report_zones_cb cb, void *data)
594 {
595 struct blk_zone zone = { };
596
597 zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start);
598 if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk))
599 zone.len = vblk->zone_sectors;
600 else
601 zone.len = get_capacity(vblk->disk) - zone.start;
602 zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap);
603 zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp);
604
605 switch (entry->z_type) {
606 case VIRTIO_BLK_ZT_SWR:
607 zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ;
608 break;
609 case VIRTIO_BLK_ZT_SWP:
610 zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF;
611 break;
612 case VIRTIO_BLK_ZT_CONV:
613 zone.type = BLK_ZONE_TYPE_CONVENTIONAL;
614 break;
615 default:
616 dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n",
617 zone.start, entry->z_type);
618 return -EIO;
619 }
620
621 switch (entry->z_state) {
622 case VIRTIO_BLK_ZS_EMPTY:
623 zone.cond = BLK_ZONE_COND_EMPTY;
624 break;
625 case VIRTIO_BLK_ZS_CLOSED:
626 zone.cond = BLK_ZONE_COND_CLOSED;
627 break;
628 case VIRTIO_BLK_ZS_FULL:
629 zone.cond = BLK_ZONE_COND_FULL;
630 zone.wp = zone.start + zone.len;
631 break;
632 case VIRTIO_BLK_ZS_EOPEN:
633 zone.cond = BLK_ZONE_COND_EXP_OPEN;
634 break;
635 case VIRTIO_BLK_ZS_IOPEN:
636 zone.cond = BLK_ZONE_COND_IMP_OPEN;
637 break;
638 case VIRTIO_BLK_ZS_NOT_WP:
639 zone.cond = BLK_ZONE_COND_NOT_WP;
640 break;
641 case VIRTIO_BLK_ZS_RDONLY:
642 zone.cond = BLK_ZONE_COND_READONLY;
643 zone.wp = ULONG_MAX;
644 break;
645 case VIRTIO_BLK_ZS_OFFLINE:
646 zone.cond = BLK_ZONE_COND_OFFLINE;
647 zone.wp = ULONG_MAX;
648 break;
649 default:
650 dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n",
651 zone.start, entry->z_state);
652 return -EIO;
653 }
654
655 /*
656 * The callback below checks the validity of the reported
657 * entry data, no need to further validate it here.
658 */
659 return cb(&zone, idx, data);
660 }
661
662 static int virtblk_report_zones(struct gendisk *disk, sector_t sector,
663 unsigned int nr_zones, report_zones_cb cb,
664 void *data)
665 {
666 struct virtio_blk *vblk = disk->private_data;
667 struct virtio_blk_zone_report *report;
668 unsigned long long nz, i;
669 size_t buflen;
670 unsigned int zone_idx = 0;
671 int ret;
672
673 if (WARN_ON_ONCE(!vblk->zone_sectors))
674 return -EOPNOTSUPP;
675
676 report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen);
677 if (!report)
678 return -ENOMEM;
679
680 mutex_lock(&vblk->vdev_mutex);
681
682 if (!vblk->vdev) {
683 ret = -ENXIO;
684 goto fail_report;
685 }
686
687 while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) {
688 memset(report, 0, buflen);
689
690 ret = virtblk_submit_zone_report(vblk, (char *)report,
691 buflen, sector);
692 if (ret)
693 goto fail_report;
694
695 nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones),
696 nr_zones);
697 if (!nz)
698 break;
699
700 for (i = 0; i < nz && zone_idx < nr_zones; i++) {
701 ret = virtblk_parse_zone(vblk, &report->zones[i],
702 zone_idx, cb, data);
703 if (ret)
704 goto fail_report;
705
706 sector = virtio64_to_cpu(vblk->vdev,
707 report->zones[i].z_start) +
708 vblk->zone_sectors;
709 zone_idx++;
710 }
711 }
712
713 if (zone_idx > 0)
714 ret = zone_idx;
715 else
716 ret = -EINVAL;
717 fail_report:
718 mutex_unlock(&vblk->vdev_mutex);
719 kvfree(report);
720 return ret;
721 }
722
723 static int virtblk_read_zoned_limits(struct virtio_blk *vblk,
724 struct queue_limits *lim)
725 {
726 struct virtio_device *vdev = vblk->vdev;
727 u32 v, wg;
728
729 dev_dbg(&vdev->dev, "probing host-managed zoned device\n");
730
731 lim->features |= BLK_FEAT_ZONED;
732
733 virtio_cread(vdev, struct virtio_blk_config,
734 zoned.max_open_zones, &v);
735 lim->max_open_zones = v;
736 dev_dbg(&vdev->dev, "max open zones = %u\n", v);
737
738 virtio_cread(vdev, struct virtio_blk_config,
739 zoned.max_active_zones, &v);
740 lim->max_active_zones = v;
741 dev_dbg(&vdev->dev, "max active zones = %u\n", v);
742
743 virtio_cread(vdev, struct virtio_blk_config,
744 zoned.write_granularity, &wg);
745 if (!wg) {
746 dev_warn(&vdev->dev, "zero write granularity reported\n");
747 return -ENODEV;
748 }
749 lim->physical_block_size = wg;
750 lim->io_min = wg;
751
752 dev_dbg(&vdev->dev, "write granularity = %u\n", wg);
753
754 /*
755 * virtio ZBD specification doesn't require zones to be a power of
756 * two sectors in size, but the code in this driver expects that.
757 */
758 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors,
759 &vblk->zone_sectors);
760 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) {
761 dev_err(&vdev->dev,
762 "zoned device with non power of two zone size %u\n",
763 vblk->zone_sectors);
764 return -ENODEV;
765 }
766 lim->chunk_sectors = vblk->zone_sectors;
767 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors);
768
769 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
770 dev_warn(&vblk->vdev->dev,
771 "ignoring negotiated F_DISCARD for zoned device\n");
772 lim->max_hw_discard_sectors = 0;
773 }
774
775 virtio_cread(vdev, struct virtio_blk_config,
776 zoned.max_append_sectors, &v);
777 if (!v) {
778 dev_warn(&vdev->dev, "zero max_append_sectors reported\n");
779 return -ENODEV;
780 }
781 if ((v << SECTOR_SHIFT) < wg) {
782 dev_err(&vdev->dev,
783 "write granularity %u exceeds max_append_sectors %u limit\n",
784 wg, v);
785 return -ENODEV;
786 }
787 lim->max_zone_append_sectors = v;
788 dev_dbg(&vdev->dev, "max append sectors = %u\n", v);
789
790 return 0;
791 }
792 #else
793 /*
794 * Zoned block device support is not configured in this kernel, host-managed
795 * zoned devices can't be supported.
796 */
797 #define virtblk_report_zones NULL
798 static inline int virtblk_read_zoned_limits(struct virtio_blk *vblk,
799 struct queue_limits *lim)
800 {
801 dev_err(&vblk->vdev->dev,
802 "virtio_blk: zoned devices are not supported");
803 return -EOPNOTSUPP;
804 }
805 #endif /* CONFIG_BLK_DEV_ZONED */
806
807 /* return id (s/n) string for *disk to *id_str
808 */
809 static int virtblk_get_id(struct gendisk *disk, char *id_str)
810 {
811 struct virtio_blk *vblk = disk->private_data;
812 struct request_queue *q = vblk->disk->queue;
813 struct request *req;
814 struct virtblk_req *vbr;
815 int err;
816
817 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
818 if (IS_ERR(req))
819 return PTR_ERR(req);
820
821 vbr = blk_mq_rq_to_pdu(req);
822 vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
823 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID);
824 vbr->out_hdr.sector = 0;
825
826 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
827 if (err)
828 goto out;
829
830 blk_execute_rq(req, false);
831 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status));
832 out:
833 blk_mq_free_request(req);
834 return err;
835 }
836
837 /* We provide getgeo only to please some old bootloader/partitioning tools */
838 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
839 {
840 struct virtio_blk *vblk = bd->bd_disk->private_data;
841 int ret = 0;
842
843 mutex_lock(&vblk->vdev_mutex);
844
845 if (!vblk->vdev) {
846 ret = -ENXIO;
847 goto out;
848 }
849
850 /* see if the host passed in geometry config */
851 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
852 virtio_cread(vblk->vdev, struct virtio_blk_config,
853 geometry.cylinders, &geo->cylinders);
854 virtio_cread(vblk->vdev, struct virtio_blk_config,
855 geometry.heads, &geo->heads);
856 virtio_cread(vblk->vdev, struct virtio_blk_config,
857 geometry.sectors, &geo->sectors);
858 } else {
859 /* some standard values, similar to sd */
860 geo->heads = 1 << 6;
861 geo->sectors = 1 << 5;
862 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
863 }
864 out:
865 mutex_unlock(&vblk->vdev_mutex);
866 return ret;
867 }
868
869 static void virtblk_free_disk(struct gendisk *disk)
870 {
871 struct virtio_blk *vblk = disk->private_data;
872
873 ida_free(&vd_index_ida, vblk->index);
874 mutex_destroy(&vblk->vdev_mutex);
875 kfree(vblk);
876 }
877
878 static const struct block_device_operations virtblk_fops = {
879 .owner = THIS_MODULE,
880 .getgeo = virtblk_getgeo,
881 .free_disk = virtblk_free_disk,
882 .report_zones = virtblk_report_zones,
883 };
884
885 static int index_to_minor(int index)
886 {
887 return index << PART_BITS;
888 }
889
890 static int minor_to_index(int minor)
891 {
892 return minor >> PART_BITS;
893 }
894
895 static ssize_t serial_show(struct device *dev,
896 struct device_attribute *attr, char *buf)
897 {
898 struct gendisk *disk = dev_to_disk(dev);
899 int err;
900
901 /* sysfs gives us a PAGE_SIZE buffer */
902 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
903
904 buf[VIRTIO_BLK_ID_BYTES] = '\0';
905 err = virtblk_get_id(disk, buf);
906 if (!err)
907 return strlen(buf);
908
909 if (err == -EIO) /* Unsupported? Make it empty. */
910 return 0;
911
912 return err;
913 }
914
915 static DEVICE_ATTR_RO(serial);
916
917 /* The queue's logical block size must be set before calling this */
918 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
919 {
920 struct virtio_device *vdev = vblk->vdev;
921 struct request_queue *q = vblk->disk->queue;
922 char cap_str_2[10], cap_str_10[10];
923 unsigned long long nblocks;
924 u64 capacity;
925
926 /* Host must always specify the capacity. */
927 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
928
929 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
930
931 string_get_size(nblocks, queue_logical_block_size(q),
932 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
933 string_get_size(nblocks, queue_logical_block_size(q),
934 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
935
936 dev_notice(&vdev->dev,
937 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
938 vblk->disk->disk_name,
939 resize ? "new size: " : "",
940 nblocks,
941 queue_logical_block_size(q),
942 cap_str_10,
943 cap_str_2);
944
945 set_capacity_and_notify(vblk->disk, capacity);
946 }
947
948 static void virtblk_config_changed_work(struct work_struct *work)
949 {
950 struct virtio_blk *vblk =
951 container_of(work, struct virtio_blk, config_work);
952
953 virtblk_update_capacity(vblk, true);
954 }
955
956 static void virtblk_config_changed(struct virtio_device *vdev)
957 {
958 struct virtio_blk *vblk = vdev->priv;
959
960 queue_work(virtblk_wq, &vblk->config_work);
961 }
962
963 static int init_vq(struct virtio_blk *vblk)
964 {
965 int err;
966 unsigned short i;
967 struct virtqueue_info *vqs_info;
968 struct virtqueue **vqs;
969 unsigned short num_vqs;
970 unsigned short num_poll_vqs;
971 struct virtio_device *vdev = vblk->vdev;
972 struct irq_affinity desc = { 0, };
973
974 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
975 struct virtio_blk_config, num_queues,
976 &num_vqs);
977 if (err)
978 num_vqs = 1;
979
980 if (!err && !num_vqs) {
981 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n");
982 return -EINVAL;
983 }
984
985 num_vqs = min_t(unsigned int,
986 min_not_zero(num_request_queues, nr_cpu_ids),
987 num_vqs);
988
989 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1);
990
991 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs;
992 vblk->io_queues[HCTX_TYPE_READ] = 0;
993 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
994
995 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
996 vblk->io_queues[HCTX_TYPE_DEFAULT],
997 vblk->io_queues[HCTX_TYPE_READ],
998 vblk->io_queues[HCTX_TYPE_POLL]);
999
1000 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
1001 if (!vblk->vqs)
1002 return -ENOMEM;
1003
1004 vqs_info = kcalloc(num_vqs, sizeof(*vqs_info), GFP_KERNEL);
1005 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
1006 if (!vqs_info || !vqs) {
1007 err = -ENOMEM;
1008 goto out;
1009 }
1010
1011 for (i = 0; i < num_vqs - num_poll_vqs; i++) {
1012 vqs_info[i].callback = virtblk_done;
1013 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i);
1014 vqs_info[i].name = vblk->vqs[i].name;
1015 }
1016
1017 for (; i < num_vqs; i++) {
1018 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i);
1019 vqs_info[i].name = vblk->vqs[i].name;
1020 }
1021
1022 /* Discover virtqueues and write information to configuration. */
1023 err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, &desc);
1024 if (err)
1025 goto out;
1026
1027 for (i = 0; i < num_vqs; i++) {
1028 spin_lock_init(&vblk->vqs[i].lock);
1029 vblk->vqs[i].vq = vqs[i];
1030 }
1031 vblk->num_vqs = num_vqs;
1032
1033 out:
1034 kfree(vqs);
1035 kfree(vqs_info);
1036 if (err)
1037 kfree(vblk->vqs);
1038 return err;
1039 }
1040
1041 /*
1042 * Legacy naming scheme used for virtio devices. We are stuck with it for
1043 * virtio blk but don't ever use it for any new driver.
1044 */
1045 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
1046 {
1047 const int base = 'z' - 'a' + 1;
1048 char *begin = buf + strlen(prefix);
1049 char *end = buf + buflen;
1050 char *p;
1051 int unit;
1052
1053 p = end - 1;
1054 *p = '\0';
1055 unit = base;
1056 do {
1057 if (p == begin)
1058 return -EINVAL;
1059 *--p = 'a' + (index % unit);
1060 index = (index / unit) - 1;
1061 } while (index >= 0);
1062
1063 memmove(begin, p, end - p);
1064 memcpy(buf, prefix, strlen(prefix));
1065
1066 return 0;
1067 }
1068
1069 static int virtblk_get_cache_mode(struct virtio_device *vdev)
1070 {
1071 u8 writeback;
1072 int err;
1073
1074 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
1075 struct virtio_blk_config, wce,
1076 &writeback);
1077
1078 /*
1079 * If WCE is not configurable and flush is not available,
1080 * assume no writeback cache is in use.
1081 */
1082 if (err)
1083 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
1084
1085 return writeback;
1086 }
1087
1088 static const char *const virtblk_cache_types[] = {
1089 "write through", "write back"
1090 };
1091
1092 static ssize_t
1093 cache_type_store(struct device *dev, struct device_attribute *attr,
1094 const char *buf, size_t count)
1095 {
1096 struct gendisk *disk = dev_to_disk(dev);
1097 struct virtio_blk *vblk = disk->private_data;
1098 struct virtio_device *vdev = vblk->vdev;
1099 struct queue_limits lim;
1100 int i;
1101
1102 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
1103 i = sysfs_match_string(virtblk_cache_types, buf);
1104 if (i < 0)
1105 return i;
1106
1107 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
1108
1109 lim = queue_limits_start_update(disk->queue);
1110 if (virtblk_get_cache_mode(vdev))
1111 lim.features |= BLK_FEAT_WRITE_CACHE;
1112 else
1113 lim.features &= ~BLK_FEAT_WRITE_CACHE;
1114 blk_mq_freeze_queue(disk->queue);
1115 i = queue_limits_commit_update(disk->queue, &lim);
1116 blk_mq_unfreeze_queue(disk->queue);
1117 if (i)
1118 return i;
1119 return count;
1120 }
1121
1122 static ssize_t
1123 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1124 {
1125 struct gendisk *disk = dev_to_disk(dev);
1126 struct virtio_blk *vblk = disk->private_data;
1127 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
1128
1129 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
1130 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]);
1131 }
1132
1133 static DEVICE_ATTR_RW(cache_type);
1134
1135 static struct attribute *virtblk_attrs[] = {
1136 &dev_attr_serial.attr,
1137 &dev_attr_cache_type.attr,
1138 NULL,
1139 };
1140
1141 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
1142 struct attribute *a, int n)
1143 {
1144 struct device *dev = kobj_to_dev(kobj);
1145 struct gendisk *disk = dev_to_disk(dev);
1146 struct virtio_blk *vblk = disk->private_data;
1147 struct virtio_device *vdev = vblk->vdev;
1148
1149 if (a == &dev_attr_cache_type.attr &&
1150 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
1151 return S_IRUGO;
1152
1153 return a->mode;
1154 }
1155
1156 static const struct attribute_group virtblk_attr_group = {
1157 .attrs = virtblk_attrs,
1158 .is_visible = virtblk_attrs_are_visible,
1159 };
1160
1161 static const struct attribute_group *virtblk_attr_groups[] = {
1162 &virtblk_attr_group,
1163 NULL,
1164 };
1165
1166 static void virtblk_map_queues(struct blk_mq_tag_set *set)
1167 {
1168 struct virtio_blk *vblk = set->driver_data;
1169 int i, qoff;
1170
1171 for (i = 0, qoff = 0; i < set->nr_maps; i++) {
1172 struct blk_mq_queue_map *map = &set->map[i];
1173
1174 map->nr_queues = vblk->io_queues[i];
1175 map->queue_offset = qoff;
1176 qoff += map->nr_queues;
1177
1178 if (map->nr_queues == 0)
1179 continue;
1180
1181 /*
1182 * Regular queues have interrupts and hence CPU affinity is
1183 * defined by the core virtio code, but polling queues have
1184 * no interrupts so we let the block layer assign CPU affinity.
1185 */
1186 if (i == HCTX_TYPE_POLL)
1187 blk_mq_map_queues(&set->map[i]);
1188 else
1189 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0);
1190 }
1191 }
1192
1193 static void virtblk_complete_batch(struct io_comp_batch *iob)
1194 {
1195 struct request *req;
1196
1197 rq_list_for_each(&iob->req_list, req) {
1198 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req));
1199 virtblk_cleanup_cmd(req);
1200 }
1201 blk_mq_end_request_batch(iob);
1202 }
1203
1204 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)
1205 {
1206 struct virtio_blk *vblk = hctx->queue->queuedata;
1207 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx);
1208 struct virtblk_req *vbr;
1209 unsigned long flags;
1210 unsigned int len;
1211 int found = 0;
1212
1213 spin_lock_irqsave(&vq->lock, flags);
1214
1215 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) {
1216 struct request *req = blk_mq_rq_from_pdu(vbr);
1217
1218 found++;
1219 if (!blk_mq_complete_request_remote(req) &&
1220 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr),
1221 virtblk_complete_batch))
1222 virtblk_request_done(req);
1223 }
1224
1225 if (found)
1226 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
1227
1228 spin_unlock_irqrestore(&vq->lock, flags);
1229
1230 return found;
1231 }
1232
1233 static const struct blk_mq_ops virtio_mq_ops = {
1234 .queue_rq = virtio_queue_rq,
1235 .queue_rqs = virtio_queue_rqs,
1236 .commit_rqs = virtio_commit_rqs,
1237 .complete = virtblk_request_done,
1238 .map_queues = virtblk_map_queues,
1239 .poll = virtblk_poll,
1240 };
1241
1242 static unsigned int virtblk_queue_depth;
1243 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
1244
1245 static int virtblk_read_limits(struct virtio_blk *vblk,
1246 struct queue_limits *lim)
1247 {
1248 struct virtio_device *vdev = vblk->vdev;
1249 u32 v, max_size, sg_elems, opt_io_size;
1250 u32 max_discard_segs = 0;
1251 u32 discard_granularity = 0;
1252 u16 min_io_size;
1253 u8 physical_block_exp, alignment_offset;
1254 size_t max_dma_size;
1255 int err;
1256
1257 /* We need to know how many segments before we allocate. */
1258 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
1259 struct virtio_blk_config, seg_max,
1260 &sg_elems);
1261
1262 /* We need at least one SG element, whatever they say. */
1263 if (err || !sg_elems)
1264 sg_elems = 1;
1265
1266 /* Prevent integer overflows and honor max vq size */
1267 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2);
1268
1269 /* We can handle whatever the host told us to handle. */
1270 lim->max_segments = sg_elems;
1271
1272 /* No real sector limit. */
1273 lim->max_hw_sectors = UINT_MAX;
1274
1275 max_dma_size = virtio_max_dma_size(vdev);
1276 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size;
1277
1278 /* Host can optionally specify maximum segment size and number of
1279 * segments. */
1280 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
1281 struct virtio_blk_config, size_max, &v);
1282 if (!err)
1283 max_size = min(max_size, v);
1284
1285 lim->max_segment_size = max_size;
1286
1287 /* Host can optionally specify the block size of the device */
1288 virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
1289 struct virtio_blk_config, blk_size,
1290 &lim->logical_block_size);
1291
1292 /* Use topology information if available */
1293 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1294 struct virtio_blk_config, physical_block_exp,
1295 &physical_block_exp);
1296 if (!err && physical_block_exp)
1297 lim->physical_block_size =
1298 lim->logical_block_size * (1 << physical_block_exp);
1299
1300 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1301 struct virtio_blk_config, alignment_offset,
1302 &alignment_offset);
1303 if (!err && alignment_offset)
1304 lim->alignment_offset =
1305 lim->logical_block_size * alignment_offset;
1306
1307 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1308 struct virtio_blk_config, min_io_size,
1309 &min_io_size);
1310 if (!err && min_io_size)
1311 lim->io_min = lim->logical_block_size * min_io_size;
1312
1313 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1314 struct virtio_blk_config, opt_io_size,
1315 &opt_io_size);
1316 if (!err && opt_io_size)
1317 lim->io_opt = lim->logical_block_size * opt_io_size;
1318
1319 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
1320 virtio_cread(vdev, struct virtio_blk_config,
1321 discard_sector_alignment, &discard_granularity);
1322
1323 virtio_cread(vdev, struct virtio_blk_config,
1324 max_discard_sectors, &v);
1325 lim->max_hw_discard_sectors = v ? v : UINT_MAX;
1326
1327 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
1328 &max_discard_segs);
1329 }
1330
1331 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
1332 virtio_cread(vdev, struct virtio_blk_config,
1333 max_write_zeroes_sectors, &v);
1334 lim->max_write_zeroes_sectors = v ? v : UINT_MAX;
1335 }
1336
1337 /* The discard and secure erase limits are combined since the Linux
1338 * block layer uses the same limit for both commands.
1339 *
1340 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features
1341 * are negotiated, we will use the minimum between the limits.
1342 *
1343 * discard sector alignment is set to the minimum between discard_sector_alignment
1344 * and secure_erase_sector_alignment.
1345 *
1346 * max discard sectors is set to the minimum between max_discard_seg and
1347 * max_secure_erase_seg.
1348 */
1349 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1350
1351 virtio_cread(vdev, struct virtio_blk_config,
1352 secure_erase_sector_alignment, &v);
1353
1354 /* secure_erase_sector_alignment should not be zero, the device should set a
1355 * valid number of sectors.
1356 */
1357 if (!v) {
1358 dev_err(&vdev->dev,
1359 "virtio_blk: secure_erase_sector_alignment can't be 0\n");
1360 return -EINVAL;
1361 }
1362
1363 discard_granularity = min_not_zero(discard_granularity, v);
1364
1365 virtio_cread(vdev, struct virtio_blk_config,
1366 max_secure_erase_sectors, &v);
1367
1368 /* max_secure_erase_sectors should not be zero, the device should set a
1369 * valid number of sectors.
1370 */
1371 if (!v) {
1372 dev_err(&vdev->dev,
1373 "virtio_blk: max_secure_erase_sectors can't be 0\n");
1374 return -EINVAL;
1375 }
1376
1377 lim->max_secure_erase_sectors = v;
1378
1379 virtio_cread(vdev, struct virtio_blk_config,
1380 max_secure_erase_seg, &v);
1381
1382 /* max_secure_erase_seg should not be zero, the device should set a
1383 * valid number of segments
1384 */
1385 if (!v) {
1386 dev_err(&vdev->dev,
1387 "virtio_blk: max_secure_erase_seg can't be 0\n");
1388 return -EINVAL;
1389 }
1390
1391 max_discard_segs = min_not_zero(max_discard_segs, v);
1392 }
1393
1394 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) ||
1395 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1396 /* max_discard_seg and discard_granularity will be 0 only
1397 * if max_discard_seg and discard_sector_alignment fields in the virtio
1398 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated.
1399 * In this case, we use default values.
1400 */
1401 if (!max_discard_segs)
1402 max_discard_segs = sg_elems;
1403
1404 lim->max_discard_segments =
1405 min(max_discard_segs, MAX_DISCARD_SEGMENTS);
1406
1407 if (discard_granularity)
1408 lim->discard_granularity =
1409 discard_granularity << SECTOR_SHIFT;
1410 else
1411 lim->discard_granularity = lim->logical_block_size;
1412 }
1413
1414 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) {
1415 u8 model;
1416
1417 virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model);
1418 switch (model) {
1419 case VIRTIO_BLK_Z_NONE:
1420 case VIRTIO_BLK_Z_HA:
1421 /* treat host-aware devices as non-zoned */
1422 return 0;
1423 case VIRTIO_BLK_Z_HM:
1424 err = virtblk_read_zoned_limits(vblk, lim);
1425 if (err)
1426 return err;
1427 break;
1428 default:
1429 dev_err(&vdev->dev, "unsupported zone model %d\n", model);
1430 return -EINVAL;
1431 }
1432 }
1433
1434 return 0;
1435 }
1436
1437 static int virtblk_probe(struct virtio_device *vdev)
1438 {
1439 struct virtio_blk *vblk;
1440 struct queue_limits lim = {
1441 .features = BLK_FEAT_ROTATIONAL,
1442 .logical_block_size = SECTOR_SIZE,
1443 };
1444 int err, index;
1445 unsigned int queue_depth;
1446
1447 if (!vdev->config->get) {
1448 dev_err(&vdev->dev, "%s failure: config access disabled\n",
1449 __func__);
1450 return -EINVAL;
1451 }
1452
1453 err = ida_alloc_range(&vd_index_ida, 0,
1454 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL);
1455 if (err < 0)
1456 goto out;
1457 index = err;
1458
1459 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
1460 if (!vblk) {
1461 err = -ENOMEM;
1462 goto out_free_index;
1463 }
1464
1465 mutex_init(&vblk->vdev_mutex);
1466
1467 vblk->vdev = vdev;
1468
1469 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
1470
1471 err = init_vq(vblk);
1472 if (err)
1473 goto out_free_vblk;
1474
1475 /* Default queue sizing is to fill the ring. */
1476 if (!virtblk_queue_depth) {
1477 queue_depth = vblk->vqs[0].vq->num_free;
1478 /* ... but without indirect descs, we use 2 descs per req */
1479 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
1480 queue_depth /= 2;
1481 } else {
1482 queue_depth = virtblk_queue_depth;
1483 }
1484
1485 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
1486 vblk->tag_set.ops = &virtio_mq_ops;
1487 vblk->tag_set.queue_depth = queue_depth;
1488 vblk->tag_set.numa_node = NUMA_NO_NODE;
1489 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
1490 vblk->tag_set.cmd_size =
1491 sizeof(struct virtblk_req) +
1492 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT;
1493 vblk->tag_set.driver_data = vblk;
1494 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
1495 vblk->tag_set.nr_maps = 1;
1496 if (vblk->io_queues[HCTX_TYPE_POLL])
1497 vblk->tag_set.nr_maps = 3;
1498
1499 err = blk_mq_alloc_tag_set(&vblk->tag_set);
1500 if (err)
1501 goto out_free_vq;
1502
1503 err = virtblk_read_limits(vblk, &lim);
1504 if (err)
1505 goto out_free_tags;
1506
1507 if (virtblk_get_cache_mode(vdev))
1508 lim.features |= BLK_FEAT_WRITE_CACHE;
1509
1510 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk);
1511 if (IS_ERR(vblk->disk)) {
1512 err = PTR_ERR(vblk->disk);
1513 goto out_free_tags;
1514 }
1515
1516 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
1517
1518 vblk->disk->major = major;
1519 vblk->disk->first_minor = index_to_minor(index);
1520 vblk->disk->minors = 1 << PART_BITS;
1521 vblk->disk->private_data = vblk;
1522 vblk->disk->fops = &virtblk_fops;
1523 vblk->index = index;
1524
1525 /* If disk is read-only in the host, the guest should obey */
1526 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
1527 set_disk_ro(vblk->disk, 1);
1528
1529 virtblk_update_capacity(vblk, false);
1530 virtio_device_ready(vdev);
1531
1532 /*
1533 * All steps that follow use the VQs therefore they need to be
1534 * placed after the virtio_device_ready() call above.
1535 */
1536 if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
1537 (lim.features & BLK_FEAT_ZONED)) {
1538 err = blk_revalidate_disk_zones(vblk->disk);
1539 if (err)
1540 goto out_cleanup_disk;
1541 }
1542
1543 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
1544 if (err)
1545 goto out_cleanup_disk;
1546
1547 return 0;
1548
1549 out_cleanup_disk:
1550 put_disk(vblk->disk);
1551 out_free_tags:
1552 blk_mq_free_tag_set(&vblk->tag_set);
1553 out_free_vq:
1554 vdev->config->del_vqs(vdev);
1555 kfree(vblk->vqs);
1556 out_free_vblk:
1557 kfree(vblk);
1558 out_free_index:
1559 ida_free(&vd_index_ida, index);
1560 out:
1561 return err;
1562 }
1563
1564 static void virtblk_remove(struct virtio_device *vdev)
1565 {
1566 struct virtio_blk *vblk = vdev->priv;
1567
1568 /* Make sure no work handler is accessing the device. */
1569 flush_work(&vblk->config_work);
1570
1571 del_gendisk(vblk->disk);
1572 blk_mq_free_tag_set(&vblk->tag_set);
1573
1574 mutex_lock(&vblk->vdev_mutex);
1575
1576 /* Stop all the virtqueues. */
1577 virtio_reset_device(vdev);
1578
1579 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */
1580 vblk->vdev = NULL;
1581
1582 vdev->config->del_vqs(vdev);
1583 kfree(vblk->vqs);
1584
1585 mutex_unlock(&vblk->vdev_mutex);
1586
1587 put_disk(vblk->disk);
1588 }
1589
1590 #ifdef CONFIG_PM_SLEEP
1591 static int virtblk_freeze(struct virtio_device *vdev)
1592 {
1593 struct virtio_blk *vblk = vdev->priv;
1594
1595 /* Ensure no requests in virtqueues before deleting vqs. */
1596 blk_mq_freeze_queue(vblk->disk->queue);
1597
1598 /* Ensure we don't receive any more interrupts */
1599 virtio_reset_device(vdev);
1600
1601 /* Make sure no work handler is accessing the device. */
1602 flush_work(&vblk->config_work);
1603
1604 vdev->config->del_vqs(vdev);
1605 kfree(vblk->vqs);
1606
1607 return 0;
1608 }
1609
1610 static int virtblk_restore(struct virtio_device *vdev)
1611 {
1612 struct virtio_blk *vblk = vdev->priv;
1613 int ret;
1614
1615 ret = init_vq(vdev->priv);
1616 if (ret)
1617 return ret;
1618
1619 virtio_device_ready(vdev);
1620
1621 blk_mq_unfreeze_queue(vblk->disk->queue);
1622 return 0;
1623 }
1624 #endif
1625
1626 static const struct virtio_device_id id_table[] = {
1627 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
1628 { 0 },
1629 };
1630
1631 static unsigned int features_legacy[] = {
1632 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1633 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1634 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1635 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1636 VIRTIO_BLK_F_SECURE_ERASE,
1637 }
1638 ;
1639 static unsigned int features[] = {
1640 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1641 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1642 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1643 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1644 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED,
1645 };
1646
1647 static struct virtio_driver virtio_blk = {
1648 .feature_table = features,
1649 .feature_table_size = ARRAY_SIZE(features),
1650 .feature_table_legacy = features_legacy,
1651 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
1652 .driver.name = KBUILD_MODNAME,
1653 .id_table = id_table,
1654 .probe = virtblk_probe,
1655 .remove = virtblk_remove,
1656 .config_changed = virtblk_config_changed,
1657 #ifdef CONFIG_PM_SLEEP
1658 .freeze = virtblk_freeze,
1659 .restore = virtblk_restore,
1660 #endif
1661 };
1662
1663 static int __init virtio_blk_init(void)
1664 {
1665 int error;
1666
1667 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
1668 if (!virtblk_wq)
1669 return -ENOMEM;
1670
1671 major = register_blkdev(0, "virtblk");
1672 if (major < 0) {
1673 error = major;
1674 goto out_destroy_workqueue;
1675 }
1676
1677 error = register_virtio_driver(&virtio_blk);
1678 if (error)
1679 goto out_unregister_blkdev;
1680 return 0;
1681
1682 out_unregister_blkdev:
1683 unregister_blkdev(major, "virtblk");
1684 out_destroy_workqueue:
1685 destroy_workqueue(virtblk_wq);
1686 return error;
1687 }
1688
1689 static void __exit virtio_blk_fini(void)
1690 {
1691 unregister_virtio_driver(&virtio_blk);
1692 unregister_blkdev(major, "virtblk");
1693 destroy_workqueue(virtblk_wq);
1694 }
1695 module_init(virtio_blk_init);
1696 module_exit(virtio_blk_fini);
1697
1698 MODULE_DEVICE_TABLE(virtio, id_table);
1699 MODULE_DESCRIPTION("Virtio block driver");
1700 MODULE_LICENSE("GPL");
Kernel DRM miscellaneous fixes and cross-tree changes