1 // SPDX-License-Identifier: GPL-2.0-only
3 #include <linux/spinlock.h>
4 #include <linux/slab.h>
5 #include <linux/blkdev.h>
6 #include <linux/hdreg.h>
7 #include <linux/module.h>
8 #include <linux/mutex.h>
9 #include <linux/interrupt.h>
10 #include <linux/virtio.h>
11 #include <linux/virtio_blk.h>
12 #include <linux/scatterlist.h>
13 #include <linux/string_helpers.h>
14 #include <linux/idr.h>
15 #include <linux/blk-mq.h>
16 #include <linux/blk-mq-virtio.h>
17 #include <linux/numa.h>
20 #define VQ_NAME_LEN 16
21 #define MAX_DISCARD_SEGMENTS 256u
24 static DEFINE_IDA(vd_index_ida);
26 static struct workqueue_struct *virtblk_wq;
28 struct virtio_blk_vq {
31 char name[VQ_NAME_LEN];
32 } ____cacheline_aligned_in_smp;
35 struct virtio_device *vdev;
37 /* The disk structure for the kernel. */
40 /* Block layer tags. */
41 struct blk_mq_tag_set tag_set;
43 /* Process context for config space updates */
44 struct work_struct config_work;
46 /* What host tells us, plus 2 for header & tailer. */
47 unsigned int sg_elems;
49 /* Ida index - used to track minor number allocations. */
54 struct virtio_blk_vq *vqs;
58 struct virtio_blk_outhdr out_hdr;
60 struct scatterlist sg[];
63 static inline blk_status_t virtblk_result(struct virtblk_req *vbr)
65 switch (vbr->status) {
68 case VIRTIO_BLK_S_UNSUPP:
69 return BLK_STS_NOTSUPP;
75 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
76 struct scatterlist *data_sg, bool have_data)
78 struct scatterlist hdr, status, *sgs[3];
79 unsigned int num_out = 0, num_in = 0;
81 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
82 sgs[num_out++] = &hdr;
85 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
86 sgs[num_out++] = data_sg;
88 sgs[num_out + num_in++] = data_sg;
91 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
92 sgs[num_out + num_in++] = &status;
94 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
97 static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap)
99 unsigned short segments = blk_rq_nr_discard_segments(req);
100 unsigned short n = 0;
101 struct virtio_blk_discard_write_zeroes *range;
106 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
108 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
112 __rq_for_each_bio(bio, req) {
113 u64 sector = bio->bi_iter.bi_sector;
114 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
116 range[n].flags = cpu_to_le32(flags);
117 range[n].num_sectors = cpu_to_le32(num_sectors);
118 range[n].sector = cpu_to_le64(sector);
122 req->special_vec.bv_page = virt_to_page(range);
123 req->special_vec.bv_offset = offset_in_page(range);
124 req->special_vec.bv_len = sizeof(*range) * segments;
125 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
130 static inline void virtblk_request_done(struct request *req)
132 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
134 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
135 kfree(page_address(req->special_vec.bv_page) +
136 req->special_vec.bv_offset);
139 blk_mq_end_request(req, virtblk_result(vbr));
142 static void virtblk_done(struct virtqueue *vq)
144 struct virtio_blk *vblk = vq->vdev->priv;
145 bool req_done = false;
147 struct virtblk_req *vbr;
151 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
153 virtqueue_disable_cb(vq);
154 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
155 struct request *req = blk_mq_rq_from_pdu(vbr);
157 blk_mq_complete_request(req);
160 if (unlikely(virtqueue_is_broken(vq)))
162 } while (!virtqueue_enable_cb(vq));
164 /* In case queue is stopped waiting for more buffers. */
166 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
167 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
170 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
172 struct virtio_blk *vblk = hctx->queue->queuedata;
173 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
176 spin_lock_irq(&vq->lock);
177 kick = virtqueue_kick_prepare(vq->vq);
178 spin_unlock_irq(&vq->lock);
181 virtqueue_notify(vq->vq);
184 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
185 const struct blk_mq_queue_data *bd)
187 struct virtio_blk *vblk = hctx->queue->queuedata;
188 struct request *req = bd->rq;
189 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
192 int qid = hctx->queue_num;
198 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
200 switch (req_op(req)) {
206 type = VIRTIO_BLK_T_FLUSH;
209 type = VIRTIO_BLK_T_DISCARD;
211 case REQ_OP_WRITE_ZEROES:
212 type = VIRTIO_BLK_T_WRITE_ZEROES;
213 unmap = !(req->cmd_flags & REQ_NOUNMAP);
216 type = VIRTIO_BLK_T_GET_ID;
220 return BLK_STS_IOERR;
223 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type);
224 vbr->out_hdr.sector = type ?
225 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req));
226 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req));
228 blk_mq_start_request(req);
230 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
231 err = virtblk_setup_discard_write_zeroes(req, unmap);
233 return BLK_STS_RESOURCE;
236 num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
238 if (rq_data_dir(req) == WRITE)
239 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
241 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
244 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
245 err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
247 virtqueue_kick(vblk->vqs[qid].vq);
248 /* Don't stop the queue if -ENOMEM: we may have failed to
249 * bounce the buffer due to global resource outage.
252 blk_mq_stop_hw_queue(hctx);
253 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
256 return BLK_STS_DEV_RESOURCE;
258 return BLK_STS_RESOURCE;
260 return BLK_STS_IOERR;
264 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
266 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
269 virtqueue_notify(vblk->vqs[qid].vq);
273 /* return id (s/n) string for *disk to *id_str
275 static int virtblk_get_id(struct gendisk *disk, char *id_str)
277 struct virtio_blk *vblk = disk->private_data;
278 struct request_queue *q = vblk->disk->queue;
282 req = blk_get_request(q, REQ_OP_DRV_IN, 0);
286 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
290 blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
291 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
293 blk_put_request(req);
297 /* We provide getgeo only to please some old bootloader/partitioning tools */
298 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
300 struct virtio_blk *vblk = bd->bd_disk->private_data;
302 /* see if the host passed in geometry config */
303 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
304 virtio_cread(vblk->vdev, struct virtio_blk_config,
305 geometry.cylinders, &geo->cylinders);
306 virtio_cread(vblk->vdev, struct virtio_blk_config,
307 geometry.heads, &geo->heads);
308 virtio_cread(vblk->vdev, struct virtio_blk_config,
309 geometry.sectors, &geo->sectors);
311 /* some standard values, similar to sd */
313 geo->sectors = 1 << 5;
314 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
319 static const struct block_device_operations virtblk_fops = {
320 .owner = THIS_MODULE,
321 .getgeo = virtblk_getgeo,
324 static int index_to_minor(int index)
326 return index << PART_BITS;
329 static int minor_to_index(int minor)
331 return minor >> PART_BITS;
334 static ssize_t serial_show(struct device *dev,
335 struct device_attribute *attr, char *buf)
337 struct gendisk *disk = dev_to_disk(dev);
340 /* sysfs gives us a PAGE_SIZE buffer */
341 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
343 buf[VIRTIO_BLK_ID_BYTES] = '\0';
344 err = virtblk_get_id(disk, buf);
348 if (err == -EIO) /* Unsupported? Make it empty. */
354 static DEVICE_ATTR_RO(serial);
356 /* The queue's logical block size must be set before calling this */
357 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
359 struct virtio_device *vdev = vblk->vdev;
360 struct request_queue *q = vblk->disk->queue;
361 char cap_str_2[10], cap_str_10[10];
362 unsigned long long nblocks;
365 /* Host must always specify the capacity. */
366 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
368 /* If capacity is too big, truncate with warning. */
369 if ((sector_t)capacity != capacity) {
370 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
371 (unsigned long long)capacity);
372 capacity = (sector_t)-1;
375 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
377 string_get_size(nblocks, queue_logical_block_size(q),
378 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
379 string_get_size(nblocks, queue_logical_block_size(q),
380 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
382 dev_notice(&vdev->dev,
383 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
384 vblk->disk->disk_name,
385 resize ? "new size: " : "",
387 queue_logical_block_size(q),
391 set_capacity_revalidate_and_notify(vblk->disk, capacity, true);
394 static void virtblk_config_changed_work(struct work_struct *work)
396 struct virtio_blk *vblk =
397 container_of(work, struct virtio_blk, config_work);
399 virtblk_update_capacity(vblk, true);
402 static void virtblk_config_changed(struct virtio_device *vdev)
404 struct virtio_blk *vblk = vdev->priv;
406 queue_work(virtblk_wq, &vblk->config_work);
409 static int init_vq(struct virtio_blk *vblk)
413 vq_callback_t **callbacks;
415 struct virtqueue **vqs;
416 unsigned short num_vqs;
417 struct virtio_device *vdev = vblk->vdev;
418 struct irq_affinity desc = { 0, };
420 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
421 struct virtio_blk_config, num_queues,
426 num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
428 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
432 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
433 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
434 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
435 if (!names || !callbacks || !vqs) {
440 for (i = 0; i < num_vqs; i++) {
441 callbacks[i] = virtblk_done;
442 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
443 names[i] = vblk->vqs[i].name;
446 /* Discover virtqueues and write information to configuration. */
447 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
451 for (i = 0; i < num_vqs; i++) {
452 spin_lock_init(&vblk->vqs[i].lock);
453 vblk->vqs[i].vq = vqs[i];
455 vblk->num_vqs = num_vqs;
467 * Legacy naming scheme used for virtio devices. We are stuck with it for
468 * virtio blk but don't ever use it for any new driver.
470 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
472 const int base = 'z' - 'a' + 1;
473 char *begin = buf + strlen(prefix);
474 char *end = buf + buflen;
484 *--p = 'a' + (index % unit);
485 index = (index / unit) - 1;
486 } while (index >= 0);
488 memmove(begin, p, end - p);
489 memcpy(buf, prefix, strlen(prefix));
494 static int virtblk_get_cache_mode(struct virtio_device *vdev)
499 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
500 struct virtio_blk_config, wce,
504 * If WCE is not configurable and flush is not available,
505 * assume no writeback cache is in use.
508 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
513 static void virtblk_update_cache_mode(struct virtio_device *vdev)
515 u8 writeback = virtblk_get_cache_mode(vdev);
516 struct virtio_blk *vblk = vdev->priv;
518 blk_queue_write_cache(vblk->disk->queue, writeback, false);
519 revalidate_disk(vblk->disk);
522 static const char *const virtblk_cache_types[] = {
523 "write through", "write back"
527 cache_type_store(struct device *dev, struct device_attribute *attr,
528 const char *buf, size_t count)
530 struct gendisk *disk = dev_to_disk(dev);
531 struct virtio_blk *vblk = disk->private_data;
532 struct virtio_device *vdev = vblk->vdev;
535 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
536 i = sysfs_match_string(virtblk_cache_types, buf);
540 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
541 virtblk_update_cache_mode(vdev);
546 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
548 struct gendisk *disk = dev_to_disk(dev);
549 struct virtio_blk *vblk = disk->private_data;
550 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
552 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
553 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
556 static DEVICE_ATTR_RW(cache_type);
558 static struct attribute *virtblk_attrs[] = {
559 &dev_attr_serial.attr,
560 &dev_attr_cache_type.attr,
564 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
565 struct attribute *a, int n)
567 struct device *dev = container_of(kobj, struct device, kobj);
568 struct gendisk *disk = dev_to_disk(dev);
569 struct virtio_blk *vblk = disk->private_data;
570 struct virtio_device *vdev = vblk->vdev;
572 if (a == &dev_attr_cache_type.attr &&
573 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
579 static const struct attribute_group virtblk_attr_group = {
580 .attrs = virtblk_attrs,
581 .is_visible = virtblk_attrs_are_visible,
584 static const struct attribute_group *virtblk_attr_groups[] = {
589 static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
590 unsigned int hctx_idx, unsigned int numa_node)
592 struct virtio_blk *vblk = set->driver_data;
593 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
595 sg_init_table(vbr->sg, vblk->sg_elems);
599 static int virtblk_map_queues(struct blk_mq_tag_set *set)
601 struct virtio_blk *vblk = set->driver_data;
603 return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT],
607 static const struct blk_mq_ops virtio_mq_ops = {
608 .queue_rq = virtio_queue_rq,
609 .commit_rqs = virtio_commit_rqs,
610 .complete = virtblk_request_done,
611 .init_request = virtblk_init_request,
612 .map_queues = virtblk_map_queues,
615 static unsigned int virtblk_queue_depth;
616 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
618 static int virtblk_probe(struct virtio_device *vdev)
620 struct virtio_blk *vblk;
621 struct request_queue *q;
624 u32 v, blk_size, max_size, sg_elems, opt_io_size;
626 u8 physical_block_exp, alignment_offset;
628 if (!vdev->config->get) {
629 dev_err(&vdev->dev, "%s failure: config access disabled\n",
634 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
640 /* We need to know how many segments before we allocate. */
641 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
642 struct virtio_blk_config, seg_max,
645 /* We need at least one SG element, whatever they say. */
646 if (err || !sg_elems)
649 /* We need an extra sg elements at head and tail. */
651 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
658 vblk->sg_elems = sg_elems;
660 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
666 /* FIXME: How many partitions? How long is a piece of string? */
667 vblk->disk = alloc_disk(1 << PART_BITS);
673 /* Default queue sizing is to fill the ring. */
674 if (!virtblk_queue_depth) {
675 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
676 /* ... but without indirect descs, we use 2 descs per req */
677 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
678 virtblk_queue_depth /= 2;
681 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
682 vblk->tag_set.ops = &virtio_mq_ops;
683 vblk->tag_set.queue_depth = virtblk_queue_depth;
684 vblk->tag_set.numa_node = NUMA_NO_NODE;
685 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
686 vblk->tag_set.cmd_size =
687 sizeof(struct virtblk_req) +
688 sizeof(struct scatterlist) * sg_elems;
689 vblk->tag_set.driver_data = vblk;
690 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
692 err = blk_mq_alloc_tag_set(&vblk->tag_set);
696 q = blk_mq_init_queue(&vblk->tag_set);
701 vblk->disk->queue = q;
705 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
707 vblk->disk->major = major;
708 vblk->disk->first_minor = index_to_minor(index);
709 vblk->disk->private_data = vblk;
710 vblk->disk->fops = &virtblk_fops;
711 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
714 /* configure queue flush support */
715 virtblk_update_cache_mode(vdev);
717 /* If disk is read-only in the host, the guest should obey */
718 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
719 set_disk_ro(vblk->disk, 1);
721 /* We can handle whatever the host told us to handle. */
722 blk_queue_max_segments(q, vblk->sg_elems-2);
724 /* No real sector limit. */
725 blk_queue_max_hw_sectors(q, -1U);
727 max_size = virtio_max_dma_size(vdev);
729 /* Host can optionally specify maximum segment size and number of
731 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
732 struct virtio_blk_config, size_max, &v);
734 max_size = min(max_size, v);
736 blk_queue_max_segment_size(q, max_size);
738 /* Host can optionally specify the block size of the device */
739 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
740 struct virtio_blk_config, blk_size,
743 blk_queue_logical_block_size(q, blk_size);
745 blk_size = queue_logical_block_size(q);
747 /* Use topology information if available */
748 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
749 struct virtio_blk_config, physical_block_exp,
750 &physical_block_exp);
751 if (!err && physical_block_exp)
752 blk_queue_physical_block_size(q,
753 blk_size * (1 << physical_block_exp));
755 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
756 struct virtio_blk_config, alignment_offset,
758 if (!err && alignment_offset)
759 blk_queue_alignment_offset(q, blk_size * alignment_offset);
761 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
762 struct virtio_blk_config, min_io_size,
764 if (!err && min_io_size)
765 blk_queue_io_min(q, blk_size * min_io_size);
767 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
768 struct virtio_blk_config, opt_io_size,
770 if (!err && opt_io_size)
771 blk_queue_io_opt(q, blk_size * opt_io_size);
773 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
774 q->limits.discard_granularity = blk_size;
776 virtio_cread(vdev, struct virtio_blk_config,
777 discard_sector_alignment, &v);
778 q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
780 virtio_cread(vdev, struct virtio_blk_config,
781 max_discard_sectors, &v);
782 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
784 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
786 blk_queue_max_discard_segments(q,
788 MAX_DISCARD_SEGMENTS));
790 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
793 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
794 virtio_cread(vdev, struct virtio_blk_config,
795 max_write_zeroes_sectors, &v);
796 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
799 virtblk_update_capacity(vblk, false);
800 virtio_device_ready(vdev);
802 device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
806 blk_mq_free_tag_set(&vblk->tag_set);
808 put_disk(vblk->disk);
810 vdev->config->del_vqs(vdev);
814 ida_simple_remove(&vd_index_ida, index);
819 static void virtblk_remove(struct virtio_device *vdev)
821 struct virtio_blk *vblk = vdev->priv;
822 int index = vblk->index;
825 /* Make sure no work handler is accessing the device. */
826 flush_work(&vblk->config_work);
828 del_gendisk(vblk->disk);
829 blk_cleanup_queue(vblk->disk->queue);
831 blk_mq_free_tag_set(&vblk->tag_set);
833 /* Stop all the virtqueues. */
834 vdev->config->reset(vdev);
836 refc = kref_read(&disk_to_dev(vblk->disk)->kobj.kref);
837 put_disk(vblk->disk);
838 vdev->config->del_vqs(vdev);
842 /* Only free device id if we don't have any users */
844 ida_simple_remove(&vd_index_ida, index);
847 #ifdef CONFIG_PM_SLEEP
848 static int virtblk_freeze(struct virtio_device *vdev)
850 struct virtio_blk *vblk = vdev->priv;
852 /* Ensure we don't receive any more interrupts */
853 vdev->config->reset(vdev);
855 /* Make sure no work handler is accessing the device. */
856 flush_work(&vblk->config_work);
858 blk_mq_quiesce_queue(vblk->disk->queue);
860 vdev->config->del_vqs(vdev);
864 static int virtblk_restore(struct virtio_device *vdev)
866 struct virtio_blk *vblk = vdev->priv;
869 ret = init_vq(vdev->priv);
873 virtio_device_ready(vdev);
875 blk_mq_unquiesce_queue(vblk->disk->queue);
880 static const struct virtio_device_id id_table[] = {
881 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
885 static unsigned int features_legacy[] = {
886 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
887 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
888 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
889 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
892 static unsigned int features[] = {
893 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
894 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
895 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
896 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
899 static struct virtio_driver virtio_blk = {
900 .feature_table = features,
901 .feature_table_size = ARRAY_SIZE(features),
902 .feature_table_legacy = features_legacy,
903 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
904 .driver.name = KBUILD_MODNAME,
905 .driver.owner = THIS_MODULE,
906 .id_table = id_table,
907 .probe = virtblk_probe,
908 .remove = virtblk_remove,
909 .config_changed = virtblk_config_changed,
910 #ifdef CONFIG_PM_SLEEP
911 .freeze = virtblk_freeze,
912 .restore = virtblk_restore,
916 static int __init init(void)
920 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
924 major = register_blkdev(0, "virtblk");
927 goto out_destroy_workqueue;
930 error = register_virtio_driver(&virtio_blk);
932 goto out_unregister_blkdev;
935 out_unregister_blkdev:
936 unregister_blkdev(major, "virtblk");
937 out_destroy_workqueue:
938 destroy_workqueue(virtblk_wq);
942 static void __exit fini(void)
944 unregister_virtio_driver(&virtio_blk);
945 unregister_blkdev(major, "virtblk");
946 destroy_workqueue(virtblk_wq);
951 MODULE_DEVICE_TABLE(virtio, id_table);
952 MODULE_DESCRIPTION("Virtio block driver");
953 MODULE_LICENSE("GPL");