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1//#define DEBUG
2#include <linux/spinlock.h>
3#include <linux/slab.h>
4#include <linux/blkdev.h>
5#include <linux/hdreg.h>
6#include <linux/virtio.h>
7#include <linux/virtio_blk.h>
8#include <linux/scatterlist.h>
9#include <linux/string_helpers.h>
10#include <scsi/scsi_cmnd.h>
11
12#define PART_BITS 4
13
14static int major, index;
15struct workqueue_struct *virtblk_wq;
16
17struct virtio_blk
18{
19 spinlock_t lock;
20
21 struct virtio_device *vdev;
22 struct virtqueue *vq;
23
24 /* The disk structure for the kernel. */
25 struct gendisk *disk;
26
27 /* Request tracking. */
28 struct list_head reqs;
29
30 mempool_t *pool;
31
32 /* Process context for config space updates */
33 struct work_struct config_work;
34
35 /* What host tells us, plus 2 for header & tailer. */
36 unsigned int sg_elems;
37
38 /* Scatterlist: can be too big for stack. */
39 struct scatterlist sg[/*sg_elems*/];
40};
41
42struct virtblk_req
43{
44 struct list_head list;
45 struct request *req;
46 struct virtio_blk_outhdr out_hdr;
47 struct virtio_scsi_inhdr in_hdr;
48 u8 status;
49};
50
51static void blk_done(struct virtqueue *vq)
52{
53 struct virtio_blk *vblk = vq->vdev->priv;
54 struct virtblk_req *vbr;
55 unsigned int len;
56 unsigned long flags;
57
58 spin_lock_irqsave(&vblk->lock, flags);
59 while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) {
60 int error;
61
62 switch (vbr->status) {
63 case VIRTIO_BLK_S_OK:
64 error = 0;
65 break;
66 case VIRTIO_BLK_S_UNSUPP:
67 error = -ENOTTY;
68 break;
69 default:
70 error = -EIO;
71 break;
72 }
73
74 switch (vbr->req->cmd_type) {
75 case REQ_TYPE_BLOCK_PC:
76 vbr->req->resid_len = vbr->in_hdr.residual;
77 vbr->req->sense_len = vbr->in_hdr.sense_len;
78 vbr->req->errors = vbr->in_hdr.errors;
79 break;
80 case REQ_TYPE_SPECIAL:
81 vbr->req->errors = (error != 0);
82 break;
83 default:
84 break;
85 }
86
87 __blk_end_request_all(vbr->req, error);
88 list_del(&vbr->list);
89 mempool_free(vbr, vblk->pool);
90 }
91 /* In case queue is stopped waiting for more buffers. */
92 blk_start_queue(vblk->disk->queue);
93 spin_unlock_irqrestore(&vblk->lock, flags);
94}
95
96static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
97 struct request *req)
98{
99 unsigned long num, out = 0, in = 0;
100 struct virtblk_req *vbr;
101
102 vbr = mempool_alloc(vblk->pool, GFP_ATOMIC);
103 if (!vbr)
104 /* When another request finishes we'll try again. */
105 return false;
106
107 vbr->req = req;
108
109 if (req->cmd_flags & REQ_FLUSH) {
110 vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
111 vbr->out_hdr.sector = 0;
112 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
113 } else {
114 switch (req->cmd_type) {
115 case REQ_TYPE_FS:
116 vbr->out_hdr.type = 0;
117 vbr->out_hdr.sector = blk_rq_pos(vbr->req);
118 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
119 break;
120 case REQ_TYPE_BLOCK_PC:
121 vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
122 vbr->out_hdr.sector = 0;
123 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
124 break;
125 case REQ_TYPE_SPECIAL:
126 vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;
127 vbr->out_hdr.sector = 0;
128 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
129 break;
130 default:
131 /* We don't put anything else in the queue. */
132 BUG();
133 }
134 }
135
136 sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
137
138 /*
139 * If this is a packet command we need a couple of additional headers.
140 * Behind the normal outhdr we put a segment with the scsi command
141 * block, and before the normal inhdr we put the sense data and the
142 * inhdr with additional status information before the normal inhdr.
143 */
144 if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC)
145 sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len);
146
147 num = blk_rq_map_sg(q, vbr->req, vblk->sg + out);
148
149 if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) {
150 sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
151 sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr,
152 sizeof(vbr->in_hdr));
153 }
154
155 sg_set_buf(&vblk->sg[num + out + in++], &vbr->status,
156 sizeof(vbr->status));
157
158 if (num) {
159 if (rq_data_dir(vbr->req) == WRITE) {
160 vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
161 out += num;
162 } else {
163 vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
164 in += num;
165 }
166 }
167
168 if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr) < 0) {
169 mempool_free(vbr, vblk->pool);
170 return false;
171 }
172
173 list_add_tail(&vbr->list, &vblk->reqs);
174 return true;
175}
176
177static void do_virtblk_request(struct request_queue *q)
178{
179 struct virtio_blk *vblk = q->queuedata;
180 struct request *req;
181 unsigned int issued = 0;
182
183 while ((req = blk_peek_request(q)) != NULL) {
184 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
185
186 /* If this request fails, stop queue and wait for something to
187 finish to restart it. */
188 if (!do_req(q, vblk, req)) {
189 blk_stop_queue(q);
190 break;
191 }
192 blk_start_request(req);
193 issued++;
194 }
195
196 if (issued)
197 virtqueue_kick(vblk->vq);
198}
199
200/* return id (s/n) string for *disk to *id_str
201 */
202static int virtblk_get_id(struct gendisk *disk, char *id_str)
203{
204 struct virtio_blk *vblk = disk->private_data;
205 struct request *req;
206 struct bio *bio;
207 int err;
208
209 bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
210 GFP_KERNEL);
211 if (IS_ERR(bio))
212 return PTR_ERR(bio);
213
214 req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
215 if (IS_ERR(req)) {
216 bio_put(bio);
217 return PTR_ERR(req);
218 }
219
220 req->cmd_type = REQ_TYPE_SPECIAL;
221 err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
222 blk_put_request(req);
223
224 return err;
225}
226
227static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
228 unsigned int cmd, unsigned long data)
229{
230 struct gendisk *disk = bdev->bd_disk;
231 struct virtio_blk *vblk = disk->private_data;
232
233 /*
234 * Only allow the generic SCSI ioctls if the host can support it.
235 */
236 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
237 return -ENOTTY;
238
239 return scsi_cmd_ioctl(disk->queue, disk, mode, cmd,
240 (void __user *)data);
241}
242
243/* We provide getgeo only to please some old bootloader/partitioning tools */
244static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
245{
246 struct virtio_blk *vblk = bd->bd_disk->private_data;
247 struct virtio_blk_geometry vgeo;
248 int err;
249
250 /* see if the host passed in geometry config */
251 err = virtio_config_val(vblk->vdev, VIRTIO_BLK_F_GEOMETRY,
252 offsetof(struct virtio_blk_config, geometry),
253 &vgeo);
254
255 if (!err) {
256 geo->heads = vgeo.heads;
257 geo->sectors = vgeo.sectors;
258 geo->cylinders = vgeo.cylinders;
259 } else {
260 /* some standard values, similar to sd */
261 geo->heads = 1 << 6;
262 geo->sectors = 1 << 5;
263 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
264 }
265 return 0;
266}
267
268static const struct block_device_operations virtblk_fops = {
269 .ioctl = virtblk_ioctl,
270 .owner = THIS_MODULE,
271 .getgeo = virtblk_getgeo,
272};
273
274static int index_to_minor(int index)
275{
276 return index << PART_BITS;
277}
278
279static ssize_t virtblk_serial_show(struct device *dev,
280 struct device_attribute *attr, char *buf)
281{
282 struct gendisk *disk = dev_to_disk(dev);
283 int err;
284
285 /* sysfs gives us a PAGE_SIZE buffer */
286 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
287
288 buf[VIRTIO_BLK_ID_BYTES] = '\0';
289 err = virtblk_get_id(disk, buf);
290 if (!err)
291 return strlen(buf);
292
293 if (err == -EIO) /* Unsupported? Make it empty. */
294 return 0;
295
296 return err;
297}
298DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
299
300static void virtblk_config_changed_work(struct work_struct *work)
301{
302 struct virtio_blk *vblk =
303 container_of(work, struct virtio_blk, config_work);
304 struct virtio_device *vdev = vblk->vdev;
305 struct request_queue *q = vblk->disk->queue;
306 char cap_str_2[10], cap_str_10[10];
307 u64 capacity, size;
308
309 /* Host must always specify the capacity. */
310 vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
311 &capacity, sizeof(capacity));
312
313 /* If capacity is too big, truncate with warning. */
314 if ((sector_t)capacity != capacity) {
315 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
316 (unsigned long long)capacity);
317 capacity = (sector_t)-1;
318 }
319
320 size = capacity * queue_logical_block_size(q);
321 string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
322 string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
323
324 dev_notice(&vdev->dev,
325 "new size: %llu %d-byte logical blocks (%s/%s)\n",
326 (unsigned long long)capacity,
327 queue_logical_block_size(q),
328 cap_str_10, cap_str_2);
329
330 set_capacity(vblk->disk, capacity);
331}
332
333static void virtblk_config_changed(struct virtio_device *vdev)
334{
335 struct virtio_blk *vblk = vdev->priv;
336
337 queue_work(virtblk_wq, &vblk->config_work);
338}
339
340static int __devinit virtblk_probe(struct virtio_device *vdev)
341{
342 struct virtio_blk *vblk;
343 struct request_queue *q;
344 int err;
345 u64 cap;
346 u32 v, blk_size, sg_elems, opt_io_size;
347 u16 min_io_size;
348 u8 physical_block_exp, alignment_offset;
349
350 if (index_to_minor(index) >= 1 << MINORBITS)
351 return -ENOSPC;
352
353 /* We need to know how many segments before we allocate. */
354 err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
355 offsetof(struct virtio_blk_config, seg_max),
356 &sg_elems);
357
358 /* We need at least one SG element, whatever they say. */
359 if (err || !sg_elems)
360 sg_elems = 1;
361
362 /* We need an extra sg elements at head and tail. */
363 sg_elems += 2;
364 vdev->priv = vblk = kmalloc(sizeof(*vblk) +
365 sizeof(vblk->sg[0]) * sg_elems, GFP_KERNEL);
366 if (!vblk) {
367 err = -ENOMEM;
368 goto out;
369 }
370
371 INIT_LIST_HEAD(&vblk->reqs);
372 spin_lock_init(&vblk->lock);
373 vblk->vdev = vdev;
374 vblk->sg_elems = sg_elems;
375 sg_init_table(vblk->sg, vblk->sg_elems);
376 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
377
378 /* We expect one virtqueue, for output. */
379 vblk->vq = virtio_find_single_vq(vdev, blk_done, "requests");
380 if (IS_ERR(vblk->vq)) {
381 err = PTR_ERR(vblk->vq);
382 goto out_free_vblk;
383 }
384
385 vblk->pool = mempool_create_kmalloc_pool(1,sizeof(struct virtblk_req));
386 if (!vblk->pool) {
387 err = -ENOMEM;
388 goto out_free_vq;
389 }
390
391 /* FIXME: How many partitions? How long is a piece of string? */
392 vblk->disk = alloc_disk(1 << PART_BITS);
393 if (!vblk->disk) {
394 err = -ENOMEM;
395 goto out_mempool;
396 }
397
398 q = vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock);
399 if (!q) {
400 err = -ENOMEM;
401 goto out_put_disk;
402 }
403
404 q->queuedata = vblk;
405
406 if (index < 26) {
407 sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);
408 } else if (index < (26 + 1) * 26) {
409 sprintf(vblk->disk->disk_name, "vd%c%c",
410 'a' + index / 26 - 1, 'a' + index % 26);
411 } else {
412 const unsigned int m1 = (index / 26 - 1) / 26 - 1;
413 const unsigned int m2 = (index / 26 - 1) % 26;
414 const unsigned int m3 = index % 26;
415 sprintf(vblk->disk->disk_name, "vd%c%c%c",
416 'a' + m1, 'a' + m2, 'a' + m3);
417 }
418
419 vblk->disk->major = major;
420 vblk->disk->first_minor = index_to_minor(index);
421 vblk->disk->private_data = vblk;
422 vblk->disk->fops = &virtblk_fops;
423 vblk->disk->driverfs_dev = &vdev->dev;
424 index++;
425
426 /* configure queue flush support */
427 if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
428 blk_queue_flush(q, REQ_FLUSH);
429
430 /* If disk is read-only in the host, the guest should obey */
431 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
432 set_disk_ro(vblk->disk, 1);
433
434 /* Host must always specify the capacity. */
435 vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
436 &cap, sizeof(cap));
437
438 /* If capacity is too big, truncate with warning. */
439 if ((sector_t)cap != cap) {
440 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
441 (unsigned long long)cap);
442 cap = (sector_t)-1;
443 }
444 set_capacity(vblk->disk, cap);
445
446 /* We can handle whatever the host told us to handle. */
447 blk_queue_max_segments(q, vblk->sg_elems-2);
448
449 /* No need to bounce any requests */
450 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
451
452 /* No real sector limit. */
453 blk_queue_max_hw_sectors(q, -1U);
454
455 /* Host can optionally specify maximum segment size and number of
456 * segments. */
457 err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
458 offsetof(struct virtio_blk_config, size_max),
459 &v);
460 if (!err)
461 blk_queue_max_segment_size(q, v);
462 else
463 blk_queue_max_segment_size(q, -1U);
464
465 /* Host can optionally specify the block size of the device */
466 err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE,
467 offsetof(struct virtio_blk_config, blk_size),
468 &blk_size);
469 if (!err)
470 blk_queue_logical_block_size(q, blk_size);
471 else
472 blk_size = queue_logical_block_size(q);
473
474 /* Use topology information if available */
475 err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
476 offsetof(struct virtio_blk_config, physical_block_exp),
477 &physical_block_exp);
478 if (!err && physical_block_exp)
479 blk_queue_physical_block_size(q,
480 blk_size * (1 << physical_block_exp));
481
482 err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
483 offsetof(struct virtio_blk_config, alignment_offset),
484 &alignment_offset);
485 if (!err && alignment_offset)
486 blk_queue_alignment_offset(q, blk_size * alignment_offset);
487
488 err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
489 offsetof(struct virtio_blk_config, min_io_size),
490 &min_io_size);
491 if (!err && min_io_size)
492 blk_queue_io_min(q, blk_size * min_io_size);
493
494 err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
495 offsetof(struct virtio_blk_config, opt_io_size),
496 &opt_io_size);
497 if (!err && opt_io_size)
498 blk_queue_io_opt(q, blk_size * opt_io_size);
499
500
501 add_disk(vblk->disk);
502 err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
503 if (err)
504 goto out_del_disk;
505
506 return 0;
507
508out_del_disk:
509 del_gendisk(vblk->disk);
510 blk_cleanup_queue(vblk->disk->queue);
511out_put_disk:
512 put_disk(vblk->disk);
513out_mempool:
514 mempool_destroy(vblk->pool);
515out_free_vq:
516 vdev->config->del_vqs(vdev);
517out_free_vblk:
518 kfree(vblk);
519out:
520 return err;
521}
522
523static void __devexit virtblk_remove(struct virtio_device *vdev)
524{
525 struct virtio_blk *vblk = vdev->priv;
526
527 flush_work(&vblk->config_work);
528
529 /* Nothing should be pending. */
530 BUG_ON(!list_empty(&vblk->reqs));
531
532 /* Stop all the virtqueues. */
533 vdev->config->reset(vdev);
534
535 del_gendisk(vblk->disk);
536 blk_cleanup_queue(vblk->disk->queue);
537 put_disk(vblk->disk);
538 mempool_destroy(vblk->pool);
539 vdev->config->del_vqs(vdev);
540 kfree(vblk);
541}
542
543static const struct virtio_device_id id_table[] = {
544 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
545 { 0 },
546};
547
548static unsigned int features[] = {
549 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
550 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
551 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
552};
553
554/*
555 * virtio_blk causes spurious section mismatch warning by
556 * simultaneously referring to a __devinit and a __devexit function.
557 * Use __refdata to avoid this warning.
558 */
559static struct virtio_driver __refdata virtio_blk = {
560 .feature_table = features,
561 .feature_table_size = ARRAY_SIZE(features),
562 .driver.name = KBUILD_MODNAME,
563 .driver.owner = THIS_MODULE,
564 .id_table = id_table,
565 .probe = virtblk_probe,
566 .remove = __devexit_p(virtblk_remove),
567 .config_changed = virtblk_config_changed,
568};
569
570static int __init init(void)
571{
572 int error;
573
574 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
575 if (!virtblk_wq)
576 return -ENOMEM;
577
578 major = register_blkdev(0, "virtblk");
579 if (major < 0) {
580 error = major;
581 goto out_destroy_workqueue;
582 }
583
584 error = register_virtio_driver(&virtio_blk);
585 if (error)
586 goto out_unregister_blkdev;
587 return 0;
588
589out_unregister_blkdev:
590 unregister_blkdev(major, "virtblk");
591out_destroy_workqueue:
592 destroy_workqueue(virtblk_wq);
593 return error;
594}
595
596static void __exit fini(void)
597{
598 unregister_blkdev(major, "virtblk");
599 unregister_virtio_driver(&virtio_blk);
600 destroy_workqueue(virtblk_wq);
601}
602module_init(init);
603module_exit(fini);
604
605MODULE_DEVICE_TABLE(virtio, id_table);
606MODULE_DESCRIPTION("Virtio block driver");
607MODULE_LICENSE("GPL");
1//#define DEBUG
2#include <linux/spinlock.h>
3#include <linux/slab.h>
4#include <linux/blkdev.h>
5#include <linux/hdreg.h>
6#include <linux/module.h>
7#include <linux/mutex.h>
8#include <linux/virtio.h>
9#include <linux/virtio_blk.h>
10#include <linux/scatterlist.h>
11#include <linux/string_helpers.h>
12#include <scsi/scsi_cmnd.h>
13#include <linux/idr.h>
14#include <linux/blk-mq.h>
15#include <linux/numa.h>
16
17#define PART_BITS 4
18#define VQ_NAME_LEN 16
19
20static int major;
21static DEFINE_IDA(vd_index_ida);
22
23static struct workqueue_struct *virtblk_wq;
24
25struct virtio_blk_vq {
26 struct virtqueue *vq;
27 spinlock_t lock;
28 char name[VQ_NAME_LEN];
29} ____cacheline_aligned_in_smp;
30
31struct virtio_blk {
32 struct virtio_device *vdev;
33
34 /* The disk structure for the kernel. */
35 struct gendisk *disk;
36
37 /* Block layer tags. */
38 struct blk_mq_tag_set tag_set;
39
40 /* Process context for config space updates */
41 struct work_struct config_work;
42
43 /* What host tells us, plus 2 for header & tailer. */
44 unsigned int sg_elems;
45
46 /* Ida index - used to track minor number allocations. */
47 int index;
48
49 /* num of vqs */
50 int num_vqs;
51 struct virtio_blk_vq *vqs;
52};
53
54struct virtblk_req {
55 struct request *req;
56 struct virtio_blk_outhdr out_hdr;
57 struct virtio_scsi_inhdr in_hdr;
58 u8 status;
59 u8 sense[SCSI_SENSE_BUFFERSIZE];
60 struct scatterlist sg[];
61};
62
63static inline int virtblk_result(struct virtblk_req *vbr)
64{
65 switch (vbr->status) {
66 case VIRTIO_BLK_S_OK:
67 return 0;
68 case VIRTIO_BLK_S_UNSUPP:
69 return -ENOTTY;
70 default:
71 return -EIO;
72 }
73}
74
75static int __virtblk_add_req(struct virtqueue *vq,
76 struct virtblk_req *vbr,
77 struct scatterlist *data_sg,
78 bool have_data)
79{
80 struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
81 unsigned int num_out = 0, num_in = 0;
82 __virtio32 type = vbr->out_hdr.type & ~cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT);
83
84 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
85 sgs[num_out++] = &hdr;
86
87 /*
88 * If this is a packet command we need a couple of additional headers.
89 * Behind the normal outhdr we put a segment with the scsi command
90 * block, and before the normal inhdr we put the sense data and the
91 * inhdr with additional status information.
92 */
93 if (type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_SCSI_CMD)) {
94 sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len);
95 sgs[num_out++] = &cmd;
96 }
97
98 if (have_data) {
99 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
100 sgs[num_out++] = data_sg;
101 else
102 sgs[num_out + num_in++] = data_sg;
103 }
104
105 if (type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_SCSI_CMD)) {
106 memcpy(vbr->sense, vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
107 sg_init_one(&sense, vbr->sense, SCSI_SENSE_BUFFERSIZE);
108 sgs[num_out + num_in++] = &sense;
109 sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr));
110 sgs[num_out + num_in++] = &inhdr;
111 }
112
113 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
114 sgs[num_out + num_in++] = &status;
115
116 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
117}
118
119static inline void virtblk_request_done(struct request *req)
120{
121 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
122 struct virtio_blk *vblk = req->q->queuedata;
123 int error = virtblk_result(vbr);
124
125 if (req->cmd_type == REQ_TYPE_BLOCK_PC) {
126 req->resid_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.residual);
127 req->sense_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.sense_len);
128 req->errors = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
129 } else if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
130 req->errors = (error != 0);
131 }
132
133 blk_mq_end_request(req, error);
134}
135
136static void virtblk_done(struct virtqueue *vq)
137{
138 struct virtio_blk *vblk = vq->vdev->priv;
139 bool req_done = false;
140 int qid = vq->index;
141 struct virtblk_req *vbr;
142 unsigned long flags;
143 unsigned int len;
144
145 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
146 do {
147 virtqueue_disable_cb(vq);
148 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
149 blk_mq_complete_request(vbr->req, vbr->req->errors);
150 req_done = true;
151 }
152 if (unlikely(virtqueue_is_broken(vq)))
153 break;
154 } while (!virtqueue_enable_cb(vq));
155
156 /* In case queue is stopped waiting for more buffers. */
157 if (req_done)
158 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
159 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
160}
161
162static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
163 const struct blk_mq_queue_data *bd)
164{
165 struct virtio_blk *vblk = hctx->queue->queuedata;
166 struct request *req = bd->rq;
167 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
168 unsigned long flags;
169 unsigned int num;
170 int qid = hctx->queue_num;
171 int err;
172 bool notify = false;
173
174 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
175
176 vbr->req = req;
177 if (req_op(req) == REQ_OP_FLUSH) {
178 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_FLUSH);
179 vbr->out_hdr.sector = 0;
180 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
181 } else {
182 switch (req->cmd_type) {
183 case REQ_TYPE_FS:
184 vbr->out_hdr.type = 0;
185 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, blk_rq_pos(vbr->req));
186 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
187 break;
188 case REQ_TYPE_BLOCK_PC:
189 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_SCSI_CMD);
190 vbr->out_hdr.sector = 0;
191 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
192 break;
193 case REQ_TYPE_DRV_PRIV:
194 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID);
195 vbr->out_hdr.sector = 0;
196 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
197 break;
198 default:
199 /* We don't put anything else in the queue. */
200 BUG();
201 }
202 }
203
204 blk_mq_start_request(req);
205
206 num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg);
207 if (num) {
208 if (rq_data_dir(vbr->req) == WRITE)
209 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
210 else
211 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
212 }
213
214 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
215 err = __virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
216 if (err) {
217 virtqueue_kick(vblk->vqs[qid].vq);
218 blk_mq_stop_hw_queue(hctx);
219 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
220 /* Out of mem doesn't actually happen, since we fall back
221 * to direct descriptors */
222 if (err == -ENOMEM || err == -ENOSPC)
223 return BLK_MQ_RQ_QUEUE_BUSY;
224 return BLK_MQ_RQ_QUEUE_ERROR;
225 }
226
227 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
228 notify = true;
229 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
230
231 if (notify)
232 virtqueue_notify(vblk->vqs[qid].vq);
233 return BLK_MQ_RQ_QUEUE_OK;
234}
235
236/* return id (s/n) string for *disk to *id_str
237 */
238static int virtblk_get_id(struct gendisk *disk, char *id_str)
239{
240 struct virtio_blk *vblk = disk->private_data;
241 struct request_queue *q = vblk->disk->queue;
242 struct request *req;
243 int err;
244
245 req = blk_get_request(q, READ, GFP_KERNEL);
246 if (IS_ERR(req))
247 return PTR_ERR(req);
248 req->cmd_type = REQ_TYPE_DRV_PRIV;
249
250 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
251 if (err)
252 goto out;
253
254 err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
255out:
256 blk_put_request(req);
257 return err;
258}
259
260static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
261 unsigned int cmd, unsigned long data)
262{
263 struct gendisk *disk = bdev->bd_disk;
264 struct virtio_blk *vblk = disk->private_data;
265
266 /*
267 * Only allow the generic SCSI ioctls if the host can support it.
268 */
269 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
270 return -ENOTTY;
271
272 return scsi_cmd_blk_ioctl(bdev, mode, cmd,
273 (void __user *)data);
274}
275
276/* We provide getgeo only to please some old bootloader/partitioning tools */
277static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
278{
279 struct virtio_blk *vblk = bd->bd_disk->private_data;
280
281 /* see if the host passed in geometry config */
282 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
283 virtio_cread(vblk->vdev, struct virtio_blk_config,
284 geometry.cylinders, &geo->cylinders);
285 virtio_cread(vblk->vdev, struct virtio_blk_config,
286 geometry.heads, &geo->heads);
287 virtio_cread(vblk->vdev, struct virtio_blk_config,
288 geometry.sectors, &geo->sectors);
289 } else {
290 /* some standard values, similar to sd */
291 geo->heads = 1 << 6;
292 geo->sectors = 1 << 5;
293 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
294 }
295 return 0;
296}
297
298static const struct block_device_operations virtblk_fops = {
299 .ioctl = virtblk_ioctl,
300 .owner = THIS_MODULE,
301 .getgeo = virtblk_getgeo,
302};
303
304static int index_to_minor(int index)
305{
306 return index << PART_BITS;
307}
308
309static int minor_to_index(int minor)
310{
311 return minor >> PART_BITS;
312}
313
314static ssize_t virtblk_serial_show(struct device *dev,
315 struct device_attribute *attr, char *buf)
316{
317 struct gendisk *disk = dev_to_disk(dev);
318 int err;
319
320 /* sysfs gives us a PAGE_SIZE buffer */
321 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
322
323 buf[VIRTIO_BLK_ID_BYTES] = '\0';
324 err = virtblk_get_id(disk, buf);
325 if (!err)
326 return strlen(buf);
327
328 if (err == -EIO) /* Unsupported? Make it empty. */
329 return 0;
330
331 return err;
332}
333
334static DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
335
336static void virtblk_config_changed_work(struct work_struct *work)
337{
338 struct virtio_blk *vblk =
339 container_of(work, struct virtio_blk, config_work);
340 struct virtio_device *vdev = vblk->vdev;
341 struct request_queue *q = vblk->disk->queue;
342 char cap_str_2[10], cap_str_10[10];
343 char *envp[] = { "RESIZE=1", NULL };
344 u64 capacity;
345
346 /* Host must always specify the capacity. */
347 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
348
349 /* If capacity is too big, truncate with warning. */
350 if ((sector_t)capacity != capacity) {
351 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
352 (unsigned long long)capacity);
353 capacity = (sector_t)-1;
354 }
355
356 string_get_size(capacity, queue_logical_block_size(q),
357 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
358 string_get_size(capacity, queue_logical_block_size(q),
359 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
360
361 dev_notice(&vdev->dev,
362 "new size: %llu %d-byte logical blocks (%s/%s)\n",
363 (unsigned long long)capacity,
364 queue_logical_block_size(q),
365 cap_str_10, cap_str_2);
366
367 set_capacity(vblk->disk, capacity);
368 revalidate_disk(vblk->disk);
369 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
370}
371
372static void virtblk_config_changed(struct virtio_device *vdev)
373{
374 struct virtio_blk *vblk = vdev->priv;
375
376 queue_work(virtblk_wq, &vblk->config_work);
377}
378
379static int init_vq(struct virtio_blk *vblk)
380{
381 int err;
382 int i;
383 vq_callback_t **callbacks;
384 const char **names;
385 struct virtqueue **vqs;
386 unsigned short num_vqs;
387 struct virtio_device *vdev = vblk->vdev;
388
389 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
390 struct virtio_blk_config, num_queues,
391 &num_vqs);
392 if (err)
393 num_vqs = 1;
394
395 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
396 if (!vblk->vqs)
397 return -ENOMEM;
398
399 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
400 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
401 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
402 if (!names || !callbacks || !vqs) {
403 err = -ENOMEM;
404 goto out;
405 }
406
407 for (i = 0; i < num_vqs; i++) {
408 callbacks[i] = virtblk_done;
409 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
410 names[i] = vblk->vqs[i].name;
411 }
412
413 /* Discover virtqueues and write information to configuration. */
414 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
415 if (err)
416 goto out;
417
418 for (i = 0; i < num_vqs; i++) {
419 spin_lock_init(&vblk->vqs[i].lock);
420 vblk->vqs[i].vq = vqs[i];
421 }
422 vblk->num_vqs = num_vqs;
423
424out:
425 kfree(vqs);
426 kfree(callbacks);
427 kfree(names);
428 if (err)
429 kfree(vblk->vqs);
430 return err;
431}
432
433/*
434 * Legacy naming scheme used for virtio devices. We are stuck with it for
435 * virtio blk but don't ever use it for any new driver.
436 */
437static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
438{
439 const int base = 'z' - 'a' + 1;
440 char *begin = buf + strlen(prefix);
441 char *end = buf + buflen;
442 char *p;
443 int unit;
444
445 p = end - 1;
446 *p = '\0';
447 unit = base;
448 do {
449 if (p == begin)
450 return -EINVAL;
451 *--p = 'a' + (index % unit);
452 index = (index / unit) - 1;
453 } while (index >= 0);
454
455 memmove(begin, p, end - p);
456 memcpy(buf, prefix, strlen(prefix));
457
458 return 0;
459}
460
461static int virtblk_get_cache_mode(struct virtio_device *vdev)
462{
463 u8 writeback;
464 int err;
465
466 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
467 struct virtio_blk_config, wce,
468 &writeback);
469
470 /*
471 * If WCE is not configurable and flush is not available,
472 * assume no writeback cache is in use.
473 */
474 if (err)
475 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
476
477 return writeback;
478}
479
480static void virtblk_update_cache_mode(struct virtio_device *vdev)
481{
482 u8 writeback = virtblk_get_cache_mode(vdev);
483 struct virtio_blk *vblk = vdev->priv;
484
485 blk_queue_write_cache(vblk->disk->queue, writeback, false);
486 revalidate_disk(vblk->disk);
487}
488
489static const char *const virtblk_cache_types[] = {
490 "write through", "write back"
491};
492
493static ssize_t
494virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
495 const char *buf, size_t count)
496{
497 struct gendisk *disk = dev_to_disk(dev);
498 struct virtio_blk *vblk = disk->private_data;
499 struct virtio_device *vdev = vblk->vdev;
500 int i;
501
502 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
503 for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
504 if (sysfs_streq(buf, virtblk_cache_types[i]))
505 break;
506
507 if (i < 0)
508 return -EINVAL;
509
510 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
511 virtblk_update_cache_mode(vdev);
512 return count;
513}
514
515static ssize_t
516virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
517 char *buf)
518{
519 struct gendisk *disk = dev_to_disk(dev);
520 struct virtio_blk *vblk = disk->private_data;
521 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
522
523 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
524 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
525}
526
527static const struct device_attribute dev_attr_cache_type_ro =
528 __ATTR(cache_type, S_IRUGO,
529 virtblk_cache_type_show, NULL);
530static const struct device_attribute dev_attr_cache_type_rw =
531 __ATTR(cache_type, S_IRUGO|S_IWUSR,
532 virtblk_cache_type_show, virtblk_cache_type_store);
533
534static int virtblk_init_request(void *data, struct request *rq,
535 unsigned int hctx_idx, unsigned int request_idx,
536 unsigned int numa_node)
537{
538 struct virtio_blk *vblk = data;
539 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
540
541 sg_init_table(vbr->sg, vblk->sg_elems);
542 return 0;
543}
544
545static struct blk_mq_ops virtio_mq_ops = {
546 .queue_rq = virtio_queue_rq,
547 .complete = virtblk_request_done,
548 .init_request = virtblk_init_request,
549};
550
551static unsigned int virtblk_queue_depth;
552module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
553
554static int virtblk_probe(struct virtio_device *vdev)
555{
556 struct virtio_blk *vblk;
557 struct request_queue *q;
558 int err, index;
559
560 u64 cap;
561 u32 v, blk_size, sg_elems, opt_io_size;
562 u16 min_io_size;
563 u8 physical_block_exp, alignment_offset;
564
565 if (!vdev->config->get) {
566 dev_err(&vdev->dev, "%s failure: config access disabled\n",
567 __func__);
568 return -EINVAL;
569 }
570
571 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
572 GFP_KERNEL);
573 if (err < 0)
574 goto out;
575 index = err;
576
577 /* We need to know how many segments before we allocate. */
578 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
579 struct virtio_blk_config, seg_max,
580 &sg_elems);
581
582 /* We need at least one SG element, whatever they say. */
583 if (err || !sg_elems)
584 sg_elems = 1;
585
586 /* We need an extra sg elements at head and tail. */
587 sg_elems += 2;
588 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
589 if (!vblk) {
590 err = -ENOMEM;
591 goto out_free_index;
592 }
593
594 vblk->vdev = vdev;
595 vblk->sg_elems = sg_elems;
596
597 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
598
599 err = init_vq(vblk);
600 if (err)
601 goto out_free_vblk;
602
603 /* FIXME: How many partitions? How long is a piece of string? */
604 vblk->disk = alloc_disk(1 << PART_BITS);
605 if (!vblk->disk) {
606 err = -ENOMEM;
607 goto out_free_vq;
608 }
609
610 /* Default queue sizing is to fill the ring. */
611 if (!virtblk_queue_depth) {
612 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
613 /* ... but without indirect descs, we use 2 descs per req */
614 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
615 virtblk_queue_depth /= 2;
616 }
617
618 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
619 vblk->tag_set.ops = &virtio_mq_ops;
620 vblk->tag_set.queue_depth = virtblk_queue_depth;
621 vblk->tag_set.numa_node = NUMA_NO_NODE;
622 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
623 vblk->tag_set.cmd_size =
624 sizeof(struct virtblk_req) +
625 sizeof(struct scatterlist) * sg_elems;
626 vblk->tag_set.driver_data = vblk;
627 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
628
629 err = blk_mq_alloc_tag_set(&vblk->tag_set);
630 if (err)
631 goto out_put_disk;
632
633 q = blk_mq_init_queue(&vblk->tag_set);
634 if (IS_ERR(q)) {
635 err = -ENOMEM;
636 goto out_free_tags;
637 }
638 vblk->disk->queue = q;
639
640 q->queuedata = vblk;
641
642 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
643
644 vblk->disk->major = major;
645 vblk->disk->first_minor = index_to_minor(index);
646 vblk->disk->private_data = vblk;
647 vblk->disk->fops = &virtblk_fops;
648 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
649 vblk->index = index;
650
651 /* configure queue flush support */
652 virtblk_update_cache_mode(vdev);
653
654 /* If disk is read-only in the host, the guest should obey */
655 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
656 set_disk_ro(vblk->disk, 1);
657
658 /* Host must always specify the capacity. */
659 virtio_cread(vdev, struct virtio_blk_config, capacity, &cap);
660
661 /* If capacity is too big, truncate with warning. */
662 if ((sector_t)cap != cap) {
663 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
664 (unsigned long long)cap);
665 cap = (sector_t)-1;
666 }
667 set_capacity(vblk->disk, cap);
668
669 /* We can handle whatever the host told us to handle. */
670 blk_queue_max_segments(q, vblk->sg_elems-2);
671
672 /* No need to bounce any requests */
673 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
674
675 /* No real sector limit. */
676 blk_queue_max_hw_sectors(q, -1U);
677
678 /* Host can optionally specify maximum segment size and number of
679 * segments. */
680 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
681 struct virtio_blk_config, size_max, &v);
682 if (!err)
683 blk_queue_max_segment_size(q, v);
684 else
685 blk_queue_max_segment_size(q, -1U);
686
687 /* Host can optionally specify the block size of the device */
688 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
689 struct virtio_blk_config, blk_size,
690 &blk_size);
691 if (!err)
692 blk_queue_logical_block_size(q, blk_size);
693 else
694 blk_size = queue_logical_block_size(q);
695
696 /* Use topology information if available */
697 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
698 struct virtio_blk_config, physical_block_exp,
699 &physical_block_exp);
700 if (!err && physical_block_exp)
701 blk_queue_physical_block_size(q,
702 blk_size * (1 << physical_block_exp));
703
704 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
705 struct virtio_blk_config, alignment_offset,
706 &alignment_offset);
707 if (!err && alignment_offset)
708 blk_queue_alignment_offset(q, blk_size * alignment_offset);
709
710 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
711 struct virtio_blk_config, min_io_size,
712 &min_io_size);
713 if (!err && min_io_size)
714 blk_queue_io_min(q, blk_size * min_io_size);
715
716 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
717 struct virtio_blk_config, opt_io_size,
718 &opt_io_size);
719 if (!err && opt_io_size)
720 blk_queue_io_opt(q, blk_size * opt_io_size);
721
722 virtio_device_ready(vdev);
723
724 device_add_disk(&vdev->dev, vblk->disk);
725 err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
726 if (err)
727 goto out_del_disk;
728
729 if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
730 err = device_create_file(disk_to_dev(vblk->disk),
731 &dev_attr_cache_type_rw);
732 else
733 err = device_create_file(disk_to_dev(vblk->disk),
734 &dev_attr_cache_type_ro);
735 if (err)
736 goto out_del_disk;
737 return 0;
738
739out_del_disk:
740 del_gendisk(vblk->disk);
741 blk_cleanup_queue(vblk->disk->queue);
742out_free_tags:
743 blk_mq_free_tag_set(&vblk->tag_set);
744out_put_disk:
745 put_disk(vblk->disk);
746out_free_vq:
747 vdev->config->del_vqs(vdev);
748out_free_vblk:
749 kfree(vblk);
750out_free_index:
751 ida_simple_remove(&vd_index_ida, index);
752out:
753 return err;
754}
755
756static void virtblk_remove(struct virtio_device *vdev)
757{
758 struct virtio_blk *vblk = vdev->priv;
759 int index = vblk->index;
760 int refc;
761
762 /* Make sure no work handler is accessing the device. */
763 flush_work(&vblk->config_work);
764
765 del_gendisk(vblk->disk);
766 blk_cleanup_queue(vblk->disk->queue);
767
768 blk_mq_free_tag_set(&vblk->tag_set);
769
770 /* Stop all the virtqueues. */
771 vdev->config->reset(vdev);
772
773 refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
774 put_disk(vblk->disk);
775 vdev->config->del_vqs(vdev);
776 kfree(vblk->vqs);
777 kfree(vblk);
778
779 /* Only free device id if we don't have any users */
780 if (refc == 1)
781 ida_simple_remove(&vd_index_ida, index);
782}
783
784#ifdef CONFIG_PM_SLEEP
785static int virtblk_freeze(struct virtio_device *vdev)
786{
787 struct virtio_blk *vblk = vdev->priv;
788
789 /* Ensure we don't receive any more interrupts */
790 vdev->config->reset(vdev);
791
792 /* Make sure no work handler is accessing the device. */
793 flush_work(&vblk->config_work);
794
795 blk_mq_stop_hw_queues(vblk->disk->queue);
796
797 vdev->config->del_vqs(vdev);
798 return 0;
799}
800
801static int virtblk_restore(struct virtio_device *vdev)
802{
803 struct virtio_blk *vblk = vdev->priv;
804 int ret;
805
806 ret = init_vq(vdev->priv);
807 if (ret)
808 return ret;
809
810 virtio_device_ready(vdev);
811
812 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
813 return 0;
814}
815#endif
816
817static const struct virtio_device_id id_table[] = {
818 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
819 { 0 },
820};
821
822static unsigned int features_legacy[] = {
823 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
824 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
825 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
826 VIRTIO_BLK_F_MQ,
827}
828;
829static unsigned int features[] = {
830 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
831 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
832 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
833 VIRTIO_BLK_F_MQ,
834};
835
836static struct virtio_driver virtio_blk = {
837 .feature_table = features,
838 .feature_table_size = ARRAY_SIZE(features),
839 .feature_table_legacy = features_legacy,
840 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
841 .driver.name = KBUILD_MODNAME,
842 .driver.owner = THIS_MODULE,
843 .id_table = id_table,
844 .probe = virtblk_probe,
845 .remove = virtblk_remove,
846 .config_changed = virtblk_config_changed,
847#ifdef CONFIG_PM_SLEEP
848 .freeze = virtblk_freeze,
849 .restore = virtblk_restore,
850#endif
851};
852
853static int __init init(void)
854{
855 int error;
856
857 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
858 if (!virtblk_wq)
859 return -ENOMEM;
860
861 major = register_blkdev(0, "virtblk");
862 if (major < 0) {
863 error = major;
864 goto out_destroy_workqueue;
865 }
866
867 error = register_virtio_driver(&virtio_blk);
868 if (error)
869 goto out_unregister_blkdev;
870 return 0;
871
872out_unregister_blkdev:
873 unregister_blkdev(major, "virtblk");
874out_destroy_workqueue:
875 destroy_workqueue(virtblk_wq);
876 return error;
877}
878
879static void __exit fini(void)
880{
881 unregister_virtio_driver(&virtio_blk);
882 unregister_blkdev(major, "virtblk");
883 destroy_workqueue(virtblk_wq);
884}
885module_init(init);
886module_exit(fini);
887
888MODULE_DEVICE_TABLE(virtio, id_table);
889MODULE_DESCRIPTION("Virtio block driver");
890MODULE_LICENSE("GPL");