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>
18 #define VQ_NAME_LEN 16
21 static DEFINE_IDA(vd_index_ida);
23 static struct workqueue_struct *virtblk_wq;
25 struct virtio_blk_vq {
28 char name[VQ_NAME_LEN];
29 } ____cacheline_aligned_in_smp;
33 struct virtio_device *vdev;
35 /* The disk structure for the kernel. */
38 /* Block layer tags. */
39 struct blk_mq_tag_set tag_set;
41 /* Process context for config space updates */
42 struct work_struct config_work;
44 /* What host tells us, plus 2 for header & tailer. */
45 unsigned int sg_elems;
47 /* Ida index - used to track minor number allocations. */
52 struct virtio_blk_vq *vqs;
58 struct virtio_blk_outhdr out_hdr;
59 struct virtio_scsi_inhdr in_hdr;
61 struct scatterlist sg[];
64 static inline int virtblk_result(struct virtblk_req *vbr)
66 switch (vbr->status) {
69 case VIRTIO_BLK_S_UNSUPP:
76 static int __virtblk_add_req(struct virtqueue *vq,
77 struct virtblk_req *vbr,
78 struct scatterlist *data_sg,
81 struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
82 unsigned int num_out = 0, num_in = 0;
83 int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT;
85 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
86 sgs[num_out++] = &hdr;
89 * If this is a packet command we need a couple of additional headers.
90 * Behind the normal outhdr we put a segment with the scsi command
91 * block, and before the normal inhdr we put the sense data and the
92 * inhdr with additional status information.
94 if (type == VIRTIO_BLK_T_SCSI_CMD) {
95 sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len);
96 sgs[num_out++] = &cmd;
100 if (vbr->out_hdr.type & VIRTIO_BLK_T_OUT)
101 sgs[num_out++] = data_sg;
103 sgs[num_out + num_in++] = data_sg;
106 if (type == VIRTIO_BLK_T_SCSI_CMD) {
107 sg_init_one(&sense, vbr->req->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;
113 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
114 sgs[num_out + num_in++] = &status;
116 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
119 static inline void virtblk_request_done(struct request *req)
121 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
122 int error = virtblk_result(vbr);
124 if (req->cmd_type == REQ_TYPE_BLOCK_PC) {
125 req->resid_len = vbr->in_hdr.residual;
126 req->sense_len = vbr->in_hdr.sense_len;
127 req->errors = vbr->in_hdr.errors;
128 } else if (req->cmd_type == REQ_TYPE_SPECIAL) {
129 req->errors = (error != 0);
132 blk_mq_end_request(req, error);
135 static void virtblk_done(struct virtqueue *vq)
137 struct virtio_blk *vblk = vq->vdev->priv;
138 bool req_done = false;
140 struct virtblk_req *vbr;
144 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
146 virtqueue_disable_cb(vq);
147 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
148 blk_mq_complete_request(vbr->req);
151 if (unlikely(virtqueue_is_broken(vq)))
153 } while (!virtqueue_enable_cb(vq));
155 /* In case queue is stopped waiting for more buffers. */
157 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
158 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
161 static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
164 struct virtio_blk *vblk = hctx->queue->queuedata;
165 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
168 int qid = hctx->queue_num;
172 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
175 if (req->cmd_flags & REQ_FLUSH) {
176 vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
177 vbr->out_hdr.sector = 0;
178 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
180 switch (req->cmd_type) {
182 vbr->out_hdr.type = 0;
183 vbr->out_hdr.sector = blk_rq_pos(vbr->req);
184 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
186 case REQ_TYPE_BLOCK_PC:
187 vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
188 vbr->out_hdr.sector = 0;
189 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
191 case REQ_TYPE_SPECIAL:
192 vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;
193 vbr->out_hdr.sector = 0;
194 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
197 /* We don't put anything else in the queue. */
202 blk_mq_start_request(req);
204 num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg);
206 if (rq_data_dir(vbr->req) == WRITE)
207 vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
209 vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
212 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
213 err = __virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
215 virtqueue_kick(vblk->vqs[qid].vq);
216 blk_mq_stop_hw_queue(hctx);
217 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
218 /* Out of mem doesn't actually happen, since we fall back
219 * to direct descriptors */
220 if (err == -ENOMEM || err == -ENOSPC)
221 return BLK_MQ_RQ_QUEUE_BUSY;
222 return BLK_MQ_RQ_QUEUE_ERROR;
225 if (last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
227 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
230 virtqueue_notify(vblk->vqs[qid].vq);
231 return BLK_MQ_RQ_QUEUE_OK;
234 /* return id (s/n) string for *disk to *id_str
236 static int virtblk_get_id(struct gendisk *disk, char *id_str)
238 struct virtio_blk *vblk = disk->private_data;
243 bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
248 req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
254 req->cmd_type = REQ_TYPE_SPECIAL;
255 err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
256 blk_put_request(req);
261 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
262 unsigned int cmd, unsigned long data)
264 struct gendisk *disk = bdev->bd_disk;
265 struct virtio_blk *vblk = disk->private_data;
268 * Only allow the generic SCSI ioctls if the host can support it.
270 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
273 return scsi_cmd_blk_ioctl(bdev, mode, cmd,
274 (void __user *)data);
277 /* We provide getgeo only to please some old bootloader/partitioning tools */
278 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
280 struct virtio_blk *vblk = bd->bd_disk->private_data;
282 /* see if the host passed in geometry config */
283 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
284 virtio_cread(vblk->vdev, struct virtio_blk_config,
285 geometry.cylinders, &geo->cylinders);
286 virtio_cread(vblk->vdev, struct virtio_blk_config,
287 geometry.heads, &geo->heads);
288 virtio_cread(vblk->vdev, struct virtio_blk_config,
289 geometry.sectors, &geo->sectors);
291 /* some standard values, similar to sd */
293 geo->sectors = 1 << 5;
294 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
299 static const struct block_device_operations virtblk_fops = {
300 .ioctl = virtblk_ioctl,
301 .owner = THIS_MODULE,
302 .getgeo = virtblk_getgeo,
305 static int index_to_minor(int index)
307 return index << PART_BITS;
310 static int minor_to_index(int minor)
312 return minor >> PART_BITS;
315 static ssize_t virtblk_serial_show(struct device *dev,
316 struct device_attribute *attr, char *buf)
318 struct gendisk *disk = dev_to_disk(dev);
321 /* sysfs gives us a PAGE_SIZE buffer */
322 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
324 buf[VIRTIO_BLK_ID_BYTES] = '\0';
325 err = virtblk_get_id(disk, buf);
329 if (err == -EIO) /* Unsupported? Make it empty. */
334 DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
336 static void virtblk_config_changed_work(struct work_struct *work)
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 };
346 /* Host must always specify the capacity. */
347 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
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;
356 size = capacity * queue_logical_block_size(q);
357 string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
358 string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
360 dev_notice(&vdev->dev,
361 "new size: %llu %d-byte logical blocks (%s/%s)\n",
362 (unsigned long long)capacity,
363 queue_logical_block_size(q),
364 cap_str_10, cap_str_2);
366 set_capacity(vblk->disk, capacity);
367 revalidate_disk(vblk->disk);
368 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
371 static void virtblk_config_changed(struct virtio_device *vdev)
373 struct virtio_blk *vblk = vdev->priv;
375 queue_work(virtblk_wq, &vblk->config_work);
378 static int init_vq(struct virtio_blk *vblk)
382 vq_callback_t **callbacks;
384 struct virtqueue **vqs;
385 unsigned short num_vqs;
386 struct virtio_device *vdev = vblk->vdev;
388 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
389 struct virtio_blk_config, num_queues,
394 vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL);
400 names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL);
404 callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL);
408 vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL);
412 for (i = 0; i < num_vqs; i++) {
413 callbacks[i] = virtblk_done;
414 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
415 names[i] = vblk->vqs[i].name;
418 /* Discover virtqueues and write information to configuration. */
419 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
423 for (i = 0; i < num_vqs; i++) {
424 spin_lock_init(&vblk->vqs[i].lock);
425 vblk->vqs[i].vq = vqs[i];
427 vblk->num_vqs = num_vqs;
443 * Legacy naming scheme used for virtio devices. We are stuck with it for
444 * virtio blk but don't ever use it for any new driver.
446 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
448 const int base = 'z' - 'a' + 1;
449 char *begin = buf + strlen(prefix);
450 char *end = buf + buflen;
460 *--p = 'a' + (index % unit);
461 index = (index / unit) - 1;
462 } while (index >= 0);
464 memmove(begin, p, end - p);
465 memcpy(buf, prefix, strlen(prefix));
470 static int virtblk_get_cache_mode(struct virtio_device *vdev)
475 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
476 struct virtio_blk_config, wce,
479 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
484 static void virtblk_update_cache_mode(struct virtio_device *vdev)
486 u8 writeback = virtblk_get_cache_mode(vdev);
487 struct virtio_blk *vblk = vdev->priv;
490 blk_queue_flush(vblk->disk->queue, REQ_FLUSH);
492 blk_queue_flush(vblk->disk->queue, 0);
494 revalidate_disk(vblk->disk);
497 static const char *const virtblk_cache_types[] = {
498 "write through", "write back"
502 virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
503 const char *buf, size_t count)
505 struct gendisk *disk = dev_to_disk(dev);
506 struct virtio_blk *vblk = disk->private_data;
507 struct virtio_device *vdev = vblk->vdev;
510 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
511 for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
512 if (sysfs_streq(buf, virtblk_cache_types[i]))
518 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
519 virtblk_update_cache_mode(vdev);
524 virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
527 struct gendisk *disk = dev_to_disk(dev);
528 struct virtio_blk *vblk = disk->private_data;
529 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
531 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
532 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
535 static const struct device_attribute dev_attr_cache_type_ro =
536 __ATTR(cache_type, S_IRUGO,
537 virtblk_cache_type_show, NULL);
538 static const struct device_attribute dev_attr_cache_type_rw =
539 __ATTR(cache_type, S_IRUGO|S_IWUSR,
540 virtblk_cache_type_show, virtblk_cache_type_store);
542 static int virtblk_init_request(void *data, struct request *rq,
543 unsigned int hctx_idx, unsigned int request_idx,
544 unsigned int numa_node)
546 struct virtio_blk *vblk = data;
547 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
549 sg_init_table(vbr->sg, vblk->sg_elems);
553 static struct blk_mq_ops virtio_mq_ops = {
554 .queue_rq = virtio_queue_rq,
555 .map_queue = blk_mq_map_queue,
556 .complete = virtblk_request_done,
557 .init_request = virtblk_init_request,
560 static unsigned int virtblk_queue_depth;
561 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
563 static int virtblk_probe(struct virtio_device *vdev)
565 struct virtio_blk *vblk;
566 struct request_queue *q;
570 u32 v, blk_size, sg_elems, opt_io_size;
572 u8 physical_block_exp, alignment_offset;
574 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
580 /* We need to know how many segments before we allocate. */
581 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
582 struct virtio_blk_config, seg_max,
585 /* We need at least one SG element, whatever they say. */
586 if (err || !sg_elems)
589 /* We need an extra sg elements at head and tail. */
591 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
598 vblk->sg_elems = sg_elems;
600 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
606 /* FIXME: How many partitions? How long is a piece of string? */
607 vblk->disk = alloc_disk(1 << PART_BITS);
613 /* Default queue sizing is to fill the ring. */
614 if (!virtblk_queue_depth) {
615 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
616 /* ... but without indirect descs, we use 2 descs per req */
617 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
618 virtblk_queue_depth /= 2;
621 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
622 vblk->tag_set.ops = &virtio_mq_ops;
623 vblk->tag_set.queue_depth = virtblk_queue_depth;
624 vblk->tag_set.numa_node = NUMA_NO_NODE;
625 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
626 vblk->tag_set.cmd_size =
627 sizeof(struct virtblk_req) +
628 sizeof(struct scatterlist) * sg_elems;
629 vblk->tag_set.driver_data = vblk;
630 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
632 err = blk_mq_alloc_tag_set(&vblk->tag_set);
636 q = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set);
644 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
646 vblk->disk->major = major;
647 vblk->disk->first_minor = index_to_minor(index);
648 vblk->disk->private_data = vblk;
649 vblk->disk->fops = &virtblk_fops;
650 vblk->disk->driverfs_dev = &vdev->dev;
653 /* configure queue flush support */
654 virtblk_update_cache_mode(vdev);
656 /* If disk is read-only in the host, the guest should obey */
657 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
658 set_disk_ro(vblk->disk, 1);
660 /* Host must always specify the capacity. */
661 virtio_cread(vdev, struct virtio_blk_config, capacity, &cap);
663 /* If capacity is too big, truncate with warning. */
664 if ((sector_t)cap != cap) {
665 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
666 (unsigned long long)cap);
669 set_capacity(vblk->disk, cap);
671 /* We can handle whatever the host told us to handle. */
672 blk_queue_max_segments(q, vblk->sg_elems-2);
674 /* No need to bounce any requests */
675 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
677 /* No real sector limit. */
678 blk_queue_max_hw_sectors(q, -1U);
680 /* Host can optionally specify maximum segment size and number of
682 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
683 struct virtio_blk_config, size_max, &v);
685 blk_queue_max_segment_size(q, v);
687 blk_queue_max_segment_size(q, -1U);
689 /* Host can optionally specify the block size of the device */
690 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
691 struct virtio_blk_config, blk_size,
694 blk_queue_logical_block_size(q, blk_size);
696 blk_size = queue_logical_block_size(q);
698 /* Use topology information if available */
699 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
700 struct virtio_blk_config, physical_block_exp,
701 &physical_block_exp);
702 if (!err && physical_block_exp)
703 blk_queue_physical_block_size(q,
704 blk_size * (1 << physical_block_exp));
706 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
707 struct virtio_blk_config, alignment_offset,
709 if (!err && alignment_offset)
710 blk_queue_alignment_offset(q, blk_size * alignment_offset);
712 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
713 struct virtio_blk_config, min_io_size,
715 if (!err && min_io_size)
716 blk_queue_io_min(q, blk_size * min_io_size);
718 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
719 struct virtio_blk_config, opt_io_size,
721 if (!err && opt_io_size)
722 blk_queue_io_opt(q, blk_size * opt_io_size);
724 virtio_device_ready(vdev);
726 add_disk(vblk->disk);
727 err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
731 if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
732 err = device_create_file(disk_to_dev(vblk->disk),
733 &dev_attr_cache_type_rw);
735 err = device_create_file(disk_to_dev(vblk->disk),
736 &dev_attr_cache_type_ro);
742 del_gendisk(vblk->disk);
743 blk_cleanup_queue(vblk->disk->queue);
745 blk_mq_free_tag_set(&vblk->tag_set);
747 put_disk(vblk->disk);
749 vdev->config->del_vqs(vdev);
753 ida_simple_remove(&vd_index_ida, index);
758 static void virtblk_remove(struct virtio_device *vdev)
760 struct virtio_blk *vblk = vdev->priv;
761 int index = vblk->index;
764 /* Make sure no work handler is accessing the device. */
765 flush_work(&vblk->config_work);
767 del_gendisk(vblk->disk);
768 blk_cleanup_queue(vblk->disk->queue);
770 blk_mq_free_tag_set(&vblk->tag_set);
772 /* Stop all the virtqueues. */
773 vdev->config->reset(vdev);
775 refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
776 put_disk(vblk->disk);
777 vdev->config->del_vqs(vdev);
781 /* Only free device id if we don't have any users */
783 ida_simple_remove(&vd_index_ida, index);
786 #ifdef CONFIG_PM_SLEEP
787 static int virtblk_freeze(struct virtio_device *vdev)
789 struct virtio_blk *vblk = vdev->priv;
791 /* Ensure we don't receive any more interrupts */
792 vdev->config->reset(vdev);
794 /* Make sure no work handler is accessing the device. */
795 flush_work(&vblk->config_work);
797 blk_mq_stop_hw_queues(vblk->disk->queue);
799 vdev->config->del_vqs(vdev);
803 static int virtblk_restore(struct virtio_device *vdev)
805 struct virtio_blk *vblk = vdev->priv;
808 ret = init_vq(vdev->priv);
812 virtio_device_ready(vdev);
814 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
819 static const struct virtio_device_id id_table[] = {
820 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
824 static unsigned int features[] = {
825 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
826 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
827 VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
831 static struct virtio_driver virtio_blk = {
832 .feature_table = features,
833 .feature_table_size = ARRAY_SIZE(features),
834 .driver.name = KBUILD_MODNAME,
835 .driver.owner = THIS_MODULE,
836 .id_table = id_table,
837 .probe = virtblk_probe,
838 .remove = virtblk_remove,
839 .config_changed = virtblk_config_changed,
840 #ifdef CONFIG_PM_SLEEP
841 .freeze = virtblk_freeze,
842 .restore = virtblk_restore,
846 static int __init init(void)
850 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
854 major = register_blkdev(0, "virtblk");
857 goto out_destroy_workqueue;
860 error = register_virtio_driver(&virtio_blk);
862 goto out_unregister_blkdev;
865 out_unregister_blkdev:
866 unregister_blkdev(major, "virtblk");
867 out_destroy_workqueue:
868 destroy_workqueue(virtblk_wq);
872 static void __exit fini(void)
874 unregister_blkdev(major, "virtblk");
875 unregister_virtio_driver(&virtio_blk);
876 destroy_workqueue(virtblk_wq);
881 MODULE_DEVICE_TABLE(virtio, id_table);
882 MODULE_DESCRIPTION("Virtio block driver");
883 MODULE_LICENSE("GPL");