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