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>
18 #include <uapi/linux/virtio_ring.h>
21 #define VQ_NAME_LEN 16
22 #define MAX_DISCARD_SEGMENTS 256u
25 static DEFINE_IDA(vd_index_ida);
27 static struct workqueue_struct *virtblk_wq;
29 struct virtio_blk_vq {
32 char name[VQ_NAME_LEN];
33 } ____cacheline_aligned_in_smp;
37 * This mutex must be held by anything that may run after
38 * virtblk_remove() sets vblk->vdev to NULL.
40 * blk-mq, virtqueue processing, and sysfs attribute code paths are
41 * shut down before vblk->vdev is set to NULL and therefore do not need
44 struct mutex vdev_mutex;
45 struct virtio_device *vdev;
47 /* The disk structure for the kernel. */
50 /* Block layer tags. */
51 struct blk_mq_tag_set tag_set;
53 /* Process context for config space updates */
54 struct work_struct config_work;
57 * Tracks references from block_device_operations open/release and
58 * virtio_driver probe/remove so this object can be freed once no
63 /* What host tells us, plus 2 for header & tailer. */
64 unsigned int sg_elems;
66 /* Ida index - used to track minor number allocations. */
71 struct virtio_blk_vq *vqs;
75 struct virtio_blk_outhdr out_hdr;
77 struct scatterlist sg[];
80 static inline blk_status_t virtblk_result(struct virtblk_req *vbr)
82 switch (vbr->status) {
85 case VIRTIO_BLK_S_UNSUPP:
86 return BLK_STS_NOTSUPP;
92 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
93 struct scatterlist *data_sg, bool have_data)
95 struct scatterlist hdr, status, *sgs[3];
96 unsigned int num_out = 0, num_in = 0;
98 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
99 sgs[num_out++] = &hdr;
102 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
103 sgs[num_out++] = data_sg;
105 sgs[num_out + num_in++] = data_sg;
108 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
109 sgs[num_out + num_in++] = &status;
111 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
114 static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap)
116 unsigned short segments = blk_rq_nr_discard_segments(req);
117 unsigned short n = 0;
118 struct virtio_blk_discard_write_zeroes *range;
123 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
125 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
130 * Single max discard segment means multi-range discard isn't
131 * supported, and block layer only runs contiguity merge like
132 * normal RW request. So we can't reply on bio for retrieving
135 if (queue_max_discard_segments(req->q) == 1) {
136 range[0].flags = cpu_to_le32(flags);
137 range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req));
138 range[0].sector = cpu_to_le64(blk_rq_pos(req));
141 __rq_for_each_bio(bio, req) {
142 u64 sector = bio->bi_iter.bi_sector;
143 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
145 range[n].flags = cpu_to_le32(flags);
146 range[n].num_sectors = cpu_to_le32(num_sectors);
147 range[n].sector = cpu_to_le64(sector);
152 WARN_ON_ONCE(n != segments);
154 req->special_vec.bv_page = virt_to_page(range);
155 req->special_vec.bv_offset = offset_in_page(range);
156 req->special_vec.bv_len = sizeof(*range) * segments;
157 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
162 static inline void virtblk_request_done(struct request *req)
164 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
166 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
167 kfree(page_address(req->special_vec.bv_page) +
168 req->special_vec.bv_offset);
171 blk_mq_end_request(req, virtblk_result(vbr));
174 static void virtblk_done(struct virtqueue *vq)
176 struct virtio_blk *vblk = vq->vdev->priv;
177 bool req_done = false;
179 struct virtblk_req *vbr;
183 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
185 virtqueue_disable_cb(vq);
186 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
187 struct request *req = blk_mq_rq_from_pdu(vbr);
189 if (likely(!blk_should_fake_timeout(req->q)))
190 blk_mq_complete_request(req);
193 if (unlikely(virtqueue_is_broken(vq)))
195 } while (!virtqueue_enable_cb(vq));
197 /* In case queue is stopped waiting for more buffers. */
199 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
200 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
203 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
205 struct virtio_blk *vblk = hctx->queue->queuedata;
206 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
209 spin_lock_irq(&vq->lock);
210 kick = virtqueue_kick_prepare(vq->vq);
211 spin_unlock_irq(&vq->lock);
214 virtqueue_notify(vq->vq);
217 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
218 const struct blk_mq_queue_data *bd)
220 struct virtio_blk *vblk = hctx->queue->queuedata;
221 struct request *req = bd->rq;
222 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
225 int qid = hctx->queue_num;
231 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
233 switch (req_op(req)) {
239 type = VIRTIO_BLK_T_FLUSH;
242 type = VIRTIO_BLK_T_DISCARD;
244 case REQ_OP_WRITE_ZEROES:
245 type = VIRTIO_BLK_T_WRITE_ZEROES;
246 unmap = !(req->cmd_flags & REQ_NOUNMAP);
249 type = VIRTIO_BLK_T_GET_ID;
253 return BLK_STS_IOERR;
256 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type);
257 vbr->out_hdr.sector = type ?
258 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req));
259 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req));
261 blk_mq_start_request(req);
263 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
264 err = virtblk_setup_discard_write_zeroes(req, unmap);
266 return BLK_STS_RESOURCE;
269 num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
271 if (rq_data_dir(req) == WRITE)
272 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
274 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
277 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
278 err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
280 virtqueue_kick(vblk->vqs[qid].vq);
281 /* Don't stop the queue if -ENOMEM: we may have failed to
282 * bounce the buffer due to global resource outage.
285 blk_mq_stop_hw_queue(hctx);
286 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
289 return BLK_STS_DEV_RESOURCE;
291 return BLK_STS_RESOURCE;
293 return BLK_STS_IOERR;
297 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
299 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
302 virtqueue_notify(vblk->vqs[qid].vq);
306 /* return id (s/n) string for *disk to *id_str
308 static int virtblk_get_id(struct gendisk *disk, char *id_str)
310 struct virtio_blk *vblk = disk->private_data;
311 struct request_queue *q = vblk->disk->queue;
315 req = blk_get_request(q, REQ_OP_DRV_IN, 0);
319 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
323 blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
324 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
326 blk_put_request(req);
330 static void virtblk_get(struct virtio_blk *vblk)
332 refcount_inc(&vblk->refs);
335 static void virtblk_put(struct virtio_blk *vblk)
337 if (refcount_dec_and_test(&vblk->refs)) {
338 ida_simple_remove(&vd_index_ida, vblk->index);
339 mutex_destroy(&vblk->vdev_mutex);
344 static int virtblk_open(struct block_device *bd, fmode_t mode)
346 struct virtio_blk *vblk = bd->bd_disk->private_data;
349 mutex_lock(&vblk->vdev_mutex);
356 mutex_unlock(&vblk->vdev_mutex);
360 static void virtblk_release(struct gendisk *disk, fmode_t mode)
362 struct virtio_blk *vblk = disk->private_data;
367 /* We provide getgeo only to please some old bootloader/partitioning tools */
368 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
370 struct virtio_blk *vblk = bd->bd_disk->private_data;
373 mutex_lock(&vblk->vdev_mutex);
380 /* see if the host passed in geometry config */
381 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
382 virtio_cread(vblk->vdev, struct virtio_blk_config,
383 geometry.cylinders, &geo->cylinders);
384 virtio_cread(vblk->vdev, struct virtio_blk_config,
385 geometry.heads, &geo->heads);
386 virtio_cread(vblk->vdev, struct virtio_blk_config,
387 geometry.sectors, &geo->sectors);
389 /* some standard values, similar to sd */
391 geo->sectors = 1 << 5;
392 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
395 mutex_unlock(&vblk->vdev_mutex);
399 static const struct block_device_operations virtblk_fops = {
400 .owner = THIS_MODULE,
401 .open = virtblk_open,
402 .release = virtblk_release,
403 .getgeo = virtblk_getgeo,
406 static int index_to_minor(int index)
408 return index << PART_BITS;
411 static int minor_to_index(int minor)
413 return minor >> PART_BITS;
416 static ssize_t serial_show(struct device *dev,
417 struct device_attribute *attr, char *buf)
419 struct gendisk *disk = dev_to_disk(dev);
422 /* sysfs gives us a PAGE_SIZE buffer */
423 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
425 buf[VIRTIO_BLK_ID_BYTES] = '\0';
426 err = virtblk_get_id(disk, buf);
430 if (err == -EIO) /* Unsupported? Make it empty. */
436 static DEVICE_ATTR_RO(serial);
438 /* The queue's logical block size must be set before calling this */
439 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
441 struct virtio_device *vdev = vblk->vdev;
442 struct request_queue *q = vblk->disk->queue;
443 char cap_str_2[10], cap_str_10[10];
444 unsigned long long nblocks;
447 /* Host must always specify the capacity. */
448 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
450 /* If capacity is too big, truncate with warning. */
451 if ((sector_t)capacity != capacity) {
452 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
453 (unsigned long long)capacity);
454 capacity = (sector_t)-1;
457 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
459 string_get_size(nblocks, queue_logical_block_size(q),
460 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
461 string_get_size(nblocks, queue_logical_block_size(q),
462 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
464 dev_notice(&vdev->dev,
465 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
466 vblk->disk->disk_name,
467 resize ? "new size: " : "",
469 queue_logical_block_size(q),
473 set_capacity_revalidate_and_notify(vblk->disk, capacity, true);
476 static void virtblk_config_changed_work(struct work_struct *work)
478 struct virtio_blk *vblk =
479 container_of(work, struct virtio_blk, config_work);
481 virtblk_update_capacity(vblk, true);
484 static void virtblk_config_changed(struct virtio_device *vdev)
486 struct virtio_blk *vblk = vdev->priv;
488 queue_work(virtblk_wq, &vblk->config_work);
491 static int init_vq(struct virtio_blk *vblk)
495 vq_callback_t **callbacks;
497 struct virtqueue **vqs;
498 unsigned short num_vqs;
499 struct virtio_device *vdev = vblk->vdev;
500 struct irq_affinity desc = { 0, };
502 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
503 struct virtio_blk_config, num_queues,
508 num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
510 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
514 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
515 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
516 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
517 if (!names || !callbacks || !vqs) {
522 for (i = 0; i < num_vqs; i++) {
523 callbacks[i] = virtblk_done;
524 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
525 names[i] = vblk->vqs[i].name;
528 /* Discover virtqueues and write information to configuration. */
529 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
533 for (i = 0; i < num_vqs; i++) {
534 spin_lock_init(&vblk->vqs[i].lock);
535 vblk->vqs[i].vq = vqs[i];
537 vblk->num_vqs = num_vqs;
549 * Legacy naming scheme used for virtio devices. We are stuck with it for
550 * virtio blk but don't ever use it for any new driver.
552 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
554 const int base = 'z' - 'a' + 1;
555 char *begin = buf + strlen(prefix);
556 char *end = buf + buflen;
566 *--p = 'a' + (index % unit);
567 index = (index / unit) - 1;
568 } while (index >= 0);
570 memmove(begin, p, end - p);
571 memcpy(buf, prefix, strlen(prefix));
576 static int virtblk_get_cache_mode(struct virtio_device *vdev)
581 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
582 struct virtio_blk_config, wce,
586 * If WCE is not configurable and flush is not available,
587 * assume no writeback cache is in use.
590 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
595 static void virtblk_update_cache_mode(struct virtio_device *vdev)
597 u8 writeback = virtblk_get_cache_mode(vdev);
598 struct virtio_blk *vblk = vdev->priv;
600 blk_queue_write_cache(vblk->disk->queue, writeback, false);
601 revalidate_disk_size(vblk->disk, true);
604 static const char *const virtblk_cache_types[] = {
605 "write through", "write back"
609 cache_type_store(struct device *dev, struct device_attribute *attr,
610 const char *buf, size_t count)
612 struct gendisk *disk = dev_to_disk(dev);
613 struct virtio_blk *vblk = disk->private_data;
614 struct virtio_device *vdev = vblk->vdev;
617 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
618 i = sysfs_match_string(virtblk_cache_types, buf);
622 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
623 virtblk_update_cache_mode(vdev);
628 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
630 struct gendisk *disk = dev_to_disk(dev);
631 struct virtio_blk *vblk = disk->private_data;
632 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
634 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
635 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
638 static DEVICE_ATTR_RW(cache_type);
640 static struct attribute *virtblk_attrs[] = {
641 &dev_attr_serial.attr,
642 &dev_attr_cache_type.attr,
646 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
647 struct attribute *a, int n)
649 struct device *dev = kobj_to_dev(kobj);
650 struct gendisk *disk = dev_to_disk(dev);
651 struct virtio_blk *vblk = disk->private_data;
652 struct virtio_device *vdev = vblk->vdev;
654 if (a == &dev_attr_cache_type.attr &&
655 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
661 static const struct attribute_group virtblk_attr_group = {
662 .attrs = virtblk_attrs,
663 .is_visible = virtblk_attrs_are_visible,
666 static const struct attribute_group *virtblk_attr_groups[] = {
671 static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
672 unsigned int hctx_idx, unsigned int numa_node)
674 struct virtio_blk *vblk = set->driver_data;
675 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
677 sg_init_table(vbr->sg, vblk->sg_elems);
681 static int virtblk_map_queues(struct blk_mq_tag_set *set)
683 struct virtio_blk *vblk = set->driver_data;
685 return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT],
689 static const struct blk_mq_ops virtio_mq_ops = {
690 .queue_rq = virtio_queue_rq,
691 .commit_rqs = virtio_commit_rqs,
692 .complete = virtblk_request_done,
693 .init_request = virtblk_init_request,
694 .map_queues = virtblk_map_queues,
697 static unsigned int virtblk_queue_depth;
698 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
700 static int virtblk_probe(struct virtio_device *vdev)
702 struct virtio_blk *vblk;
703 struct request_queue *q;
706 u32 v, blk_size, max_size, sg_elems, opt_io_size;
708 u8 physical_block_exp, alignment_offset;
710 if (!vdev->config->get) {
711 dev_err(&vdev->dev, "%s failure: config access disabled\n",
716 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
722 /* We need to know how many segments before we allocate. */
723 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
724 struct virtio_blk_config, seg_max,
727 /* We need at least one SG element, whatever they say. */
728 if (err || !sg_elems)
731 /* We need an extra sg elements at head and tail. */
733 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
739 /* This reference is dropped in virtblk_remove(). */
740 refcount_set(&vblk->refs, 1);
741 mutex_init(&vblk->vdev_mutex);
744 vblk->sg_elems = sg_elems;
746 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
752 /* FIXME: How many partitions? How long is a piece of string? */
753 vblk->disk = alloc_disk(1 << PART_BITS);
759 /* Default queue sizing is to fill the ring. */
760 if (!virtblk_queue_depth) {
761 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
762 /* ... but without indirect descs, we use 2 descs per req */
763 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
764 virtblk_queue_depth /= 2;
767 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
768 vblk->tag_set.ops = &virtio_mq_ops;
769 vblk->tag_set.queue_depth = virtblk_queue_depth;
770 vblk->tag_set.numa_node = NUMA_NO_NODE;
771 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
772 vblk->tag_set.cmd_size =
773 sizeof(struct virtblk_req) +
774 sizeof(struct scatterlist) * sg_elems;
775 vblk->tag_set.driver_data = vblk;
776 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
778 err = blk_mq_alloc_tag_set(&vblk->tag_set);
782 q = blk_mq_init_queue(&vblk->tag_set);
787 vblk->disk->queue = q;
791 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
793 vblk->disk->major = major;
794 vblk->disk->first_minor = index_to_minor(index);
795 vblk->disk->private_data = vblk;
796 vblk->disk->fops = &virtblk_fops;
797 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
800 /* configure queue flush support */
801 virtblk_update_cache_mode(vdev);
803 /* If disk is read-only in the host, the guest should obey */
804 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
805 set_disk_ro(vblk->disk, 1);
807 /* We can handle whatever the host told us to handle. */
808 blk_queue_max_segments(q, vblk->sg_elems-2);
810 /* No real sector limit. */
811 blk_queue_max_hw_sectors(q, -1U);
813 max_size = virtio_max_dma_size(vdev);
815 /* Host can optionally specify maximum segment size and number of
817 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
818 struct virtio_blk_config, size_max, &v);
820 max_size = min(max_size, v);
822 blk_queue_max_segment_size(q, max_size);
824 /* Host can optionally specify the block size of the device */
825 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
826 struct virtio_blk_config, blk_size,
829 err = blk_validate_block_size(blk_size);
832 "virtio_blk: invalid block size: 0x%x\n",
837 blk_queue_logical_block_size(q, blk_size);
839 blk_size = queue_logical_block_size(q);
841 /* Use topology information if available */
842 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
843 struct virtio_blk_config, physical_block_exp,
844 &physical_block_exp);
845 if (!err && physical_block_exp)
846 blk_queue_physical_block_size(q,
847 blk_size * (1 << physical_block_exp));
849 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
850 struct virtio_blk_config, alignment_offset,
852 if (!err && alignment_offset)
853 blk_queue_alignment_offset(q, blk_size * alignment_offset);
855 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
856 struct virtio_blk_config, min_io_size,
858 if (!err && min_io_size)
859 blk_queue_io_min(q, blk_size * min_io_size);
861 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
862 struct virtio_blk_config, opt_io_size,
864 if (!err && opt_io_size)
865 blk_queue_io_opt(q, blk_size * opt_io_size);
867 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
868 virtio_cread(vdev, struct virtio_blk_config,
869 discard_sector_alignment, &v);
871 q->limits.discard_granularity = v << SECTOR_SHIFT;
873 q->limits.discard_granularity = blk_size;
875 virtio_cread(vdev, struct virtio_blk_config,
876 max_discard_sectors, &v);
877 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
879 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
883 * max_discard_seg == 0 is out of spec but we always
888 blk_queue_max_discard_segments(q,
889 min(v, MAX_DISCARD_SEGMENTS));
891 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
894 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
895 virtio_cread(vdev, struct virtio_blk_config,
896 max_write_zeroes_sectors, &v);
897 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
900 virtblk_update_capacity(vblk, false);
901 virtio_device_ready(vdev);
903 device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
907 blk_mq_free_tag_set(&vblk->tag_set);
909 put_disk(vblk->disk);
911 vdev->config->del_vqs(vdev);
916 ida_simple_remove(&vd_index_ida, index);
921 static void virtblk_remove(struct virtio_device *vdev)
923 struct virtio_blk *vblk = vdev->priv;
925 /* Make sure no work handler is accessing the device. */
926 flush_work(&vblk->config_work);
928 del_gendisk(vblk->disk);
929 blk_cleanup_queue(vblk->disk->queue);
931 blk_mq_free_tag_set(&vblk->tag_set);
933 mutex_lock(&vblk->vdev_mutex);
935 /* Stop all the virtqueues. */
936 vdev->config->reset(vdev);
938 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */
941 put_disk(vblk->disk);
942 vdev->config->del_vqs(vdev);
945 mutex_unlock(&vblk->vdev_mutex);
950 #ifdef CONFIG_PM_SLEEP
951 static int virtblk_freeze(struct virtio_device *vdev)
953 struct virtio_blk *vblk = vdev->priv;
955 /* Ensure we don't receive any more interrupts */
956 vdev->config->reset(vdev);
958 /* Make sure no work handler is accessing the device. */
959 flush_work(&vblk->config_work);
961 blk_mq_quiesce_queue(vblk->disk->queue);
963 vdev->config->del_vqs(vdev);
969 static int virtblk_restore(struct virtio_device *vdev)
971 struct virtio_blk *vblk = vdev->priv;
974 ret = init_vq(vdev->priv);
978 virtio_device_ready(vdev);
980 blk_mq_unquiesce_queue(vblk->disk->queue);
985 static const struct virtio_device_id id_table[] = {
986 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
990 static unsigned int features_legacy[] = {
991 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
992 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
993 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
994 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
997 static unsigned int features[] = {
998 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
999 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1000 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1001 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1004 static struct virtio_driver virtio_blk = {
1005 .feature_table = features,
1006 .feature_table_size = ARRAY_SIZE(features),
1007 .feature_table_legacy = features_legacy,
1008 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
1009 .driver.name = KBUILD_MODNAME,
1010 .driver.owner = THIS_MODULE,
1011 .id_table = id_table,
1012 .probe = virtblk_probe,
1013 .remove = virtblk_remove,
1014 .config_changed = virtblk_config_changed,
1015 #ifdef CONFIG_PM_SLEEP
1016 .freeze = virtblk_freeze,
1017 .restore = virtblk_restore,
1021 static int __init init(void)
1025 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
1029 major = register_blkdev(0, "virtblk");
1032 goto out_destroy_workqueue;
1035 error = register_virtio_driver(&virtio_blk);
1037 goto out_unregister_blkdev;
1040 out_unregister_blkdev:
1041 unregister_blkdev(major, "virtblk");
1042 out_destroy_workqueue:
1043 destroy_workqueue(virtblk_wq);
1047 static void __exit fini(void)
1049 unregister_virtio_driver(&virtio_blk);
1050 unregister_blkdev(major, "virtblk");
1051 destroy_workqueue(virtblk_wq);
1056 MODULE_DEVICE_TABLE(virtio, id_table);
1057 MODULE_DESCRIPTION("Virtio block driver");
1058 MODULE_LICENSE("GPL");