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);
129 __rq_for_each_bio(bio, req) {
130 u64 sector = bio->bi_iter.bi_sector;
131 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
133 range[n].flags = cpu_to_le32(flags);
134 range[n].num_sectors = cpu_to_le32(num_sectors);
135 range[n].sector = cpu_to_le64(sector);
139 req->special_vec.bv_page = virt_to_page(range);
140 req->special_vec.bv_offset = offset_in_page(range);
141 req->special_vec.bv_len = sizeof(*range) * segments;
142 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
147 static inline void virtblk_request_done(struct request *req)
149 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
151 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
152 kfree(page_address(req->special_vec.bv_page) +
153 req->special_vec.bv_offset);
156 blk_mq_end_request(req, virtblk_result(vbr));
159 static void virtblk_done(struct virtqueue *vq)
161 struct virtio_blk *vblk = vq->vdev->priv;
162 bool req_done = false;
164 struct virtblk_req *vbr;
168 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
170 virtqueue_disable_cb(vq);
171 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
172 struct request *req = blk_mq_rq_from_pdu(vbr);
174 if (likely(!blk_should_fake_timeout(req->q)))
175 blk_mq_complete_request(req);
178 if (unlikely(virtqueue_is_broken(vq)))
180 } while (!virtqueue_enable_cb(vq));
182 /* In case queue is stopped waiting for more buffers. */
184 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
185 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
188 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
190 struct virtio_blk *vblk = hctx->queue->queuedata;
191 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
194 spin_lock_irq(&vq->lock);
195 kick = virtqueue_kick_prepare(vq->vq);
196 spin_unlock_irq(&vq->lock);
199 virtqueue_notify(vq->vq);
202 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
203 const struct blk_mq_queue_data *bd)
205 struct virtio_blk *vblk = hctx->queue->queuedata;
206 struct request *req = bd->rq;
207 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
210 int qid = hctx->queue_num;
216 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
218 switch (req_op(req)) {
224 type = VIRTIO_BLK_T_FLUSH;
227 type = VIRTIO_BLK_T_DISCARD;
229 case REQ_OP_WRITE_ZEROES:
230 type = VIRTIO_BLK_T_WRITE_ZEROES;
231 unmap = !(req->cmd_flags & REQ_NOUNMAP);
234 type = VIRTIO_BLK_T_GET_ID;
238 return BLK_STS_IOERR;
241 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type);
242 vbr->out_hdr.sector = type ?
243 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req));
244 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req));
246 blk_mq_start_request(req);
248 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
249 err = virtblk_setup_discard_write_zeroes(req, unmap);
251 return BLK_STS_RESOURCE;
254 num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
256 if (rq_data_dir(req) == WRITE)
257 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
259 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
262 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
263 err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
265 virtqueue_kick(vblk->vqs[qid].vq);
266 /* Don't stop the queue if -ENOMEM: we may have failed to
267 * bounce the buffer due to global resource outage.
270 blk_mq_stop_hw_queue(hctx);
271 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
274 return BLK_STS_DEV_RESOURCE;
276 return BLK_STS_RESOURCE;
278 return BLK_STS_IOERR;
282 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
284 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
287 virtqueue_notify(vblk->vqs[qid].vq);
291 /* return id (s/n) string for *disk to *id_str
293 static int virtblk_get_id(struct gendisk *disk, char *id_str)
295 struct virtio_blk *vblk = disk->private_data;
296 struct request_queue *q = vblk->disk->queue;
300 req = blk_get_request(q, REQ_OP_DRV_IN, 0);
304 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
308 blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
309 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
311 blk_put_request(req);
315 static void virtblk_get(struct virtio_blk *vblk)
317 refcount_inc(&vblk->refs);
320 static void virtblk_put(struct virtio_blk *vblk)
322 if (refcount_dec_and_test(&vblk->refs)) {
323 ida_simple_remove(&vd_index_ida, vblk->index);
324 mutex_destroy(&vblk->vdev_mutex);
329 static int virtblk_open(struct block_device *bd, fmode_t mode)
331 struct virtio_blk *vblk = bd->bd_disk->private_data;
334 mutex_lock(&vblk->vdev_mutex);
341 mutex_unlock(&vblk->vdev_mutex);
345 static void virtblk_release(struct gendisk *disk, fmode_t mode)
347 struct virtio_blk *vblk = disk->private_data;
352 /* We provide getgeo only to please some old bootloader/partitioning tools */
353 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
355 struct virtio_blk *vblk = bd->bd_disk->private_data;
358 mutex_lock(&vblk->vdev_mutex);
365 /* see if the host passed in geometry config */
366 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
367 virtio_cread(vblk->vdev, struct virtio_blk_config,
368 geometry.cylinders, &geo->cylinders);
369 virtio_cread(vblk->vdev, struct virtio_blk_config,
370 geometry.heads, &geo->heads);
371 virtio_cread(vblk->vdev, struct virtio_blk_config,
372 geometry.sectors, &geo->sectors);
374 /* some standard values, similar to sd */
376 geo->sectors = 1 << 5;
377 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
380 mutex_unlock(&vblk->vdev_mutex);
384 static const struct block_device_operations virtblk_fops = {
385 .owner = THIS_MODULE,
386 .open = virtblk_open,
387 .release = virtblk_release,
388 .getgeo = virtblk_getgeo,
391 static int index_to_minor(int index)
393 return index << PART_BITS;
396 static int minor_to_index(int minor)
398 return minor >> PART_BITS;
401 static ssize_t serial_show(struct device *dev,
402 struct device_attribute *attr, char *buf)
404 struct gendisk *disk = dev_to_disk(dev);
407 /* sysfs gives us a PAGE_SIZE buffer */
408 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
410 buf[VIRTIO_BLK_ID_BYTES] = '\0';
411 err = virtblk_get_id(disk, buf);
415 if (err == -EIO) /* Unsupported? Make it empty. */
421 static DEVICE_ATTR_RO(serial);
423 /* The queue's logical block size must be set before calling this */
424 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
426 struct virtio_device *vdev = vblk->vdev;
427 struct request_queue *q = vblk->disk->queue;
428 char cap_str_2[10], cap_str_10[10];
429 unsigned long long nblocks;
432 /* Host must always specify the capacity. */
433 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
435 /* If capacity is too big, truncate with warning. */
436 if ((sector_t)capacity != capacity) {
437 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
438 (unsigned long long)capacity);
439 capacity = (sector_t)-1;
442 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
444 string_get_size(nblocks, queue_logical_block_size(q),
445 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
446 string_get_size(nblocks, queue_logical_block_size(q),
447 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
449 dev_notice(&vdev->dev,
450 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
451 vblk->disk->disk_name,
452 resize ? "new size: " : "",
454 queue_logical_block_size(q),
458 set_capacity_revalidate_and_notify(vblk->disk, capacity, true);
461 static void virtblk_config_changed_work(struct work_struct *work)
463 struct virtio_blk *vblk =
464 container_of(work, struct virtio_blk, config_work);
466 virtblk_update_capacity(vblk, true);
469 static void virtblk_config_changed(struct virtio_device *vdev)
471 struct virtio_blk *vblk = vdev->priv;
473 queue_work(virtblk_wq, &vblk->config_work);
476 static int init_vq(struct virtio_blk *vblk)
480 vq_callback_t **callbacks;
482 struct virtqueue **vqs;
483 unsigned short num_vqs;
484 struct virtio_device *vdev = vblk->vdev;
485 struct irq_affinity desc = { 0, };
487 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
488 struct virtio_blk_config, num_queues,
493 num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
495 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
499 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
500 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
501 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
502 if (!names || !callbacks || !vqs) {
507 for (i = 0; i < num_vqs; i++) {
508 callbacks[i] = virtblk_done;
509 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
510 names[i] = vblk->vqs[i].name;
513 /* Discover virtqueues and write information to configuration. */
514 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
518 for (i = 0; i < num_vqs; i++) {
519 spin_lock_init(&vblk->vqs[i].lock);
520 vblk->vqs[i].vq = vqs[i];
522 vblk->num_vqs = num_vqs;
534 * Legacy naming scheme used for virtio devices. We are stuck with it for
535 * virtio blk but don't ever use it for any new driver.
537 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
539 const int base = 'z' - 'a' + 1;
540 char *begin = buf + strlen(prefix);
541 char *end = buf + buflen;
551 *--p = 'a' + (index % unit);
552 index = (index / unit) - 1;
553 } while (index >= 0);
555 memmove(begin, p, end - p);
556 memcpy(buf, prefix, strlen(prefix));
561 static int virtblk_get_cache_mode(struct virtio_device *vdev)
566 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
567 struct virtio_blk_config, wce,
571 * If WCE is not configurable and flush is not available,
572 * assume no writeback cache is in use.
575 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
580 static void virtblk_update_cache_mode(struct virtio_device *vdev)
582 u8 writeback = virtblk_get_cache_mode(vdev);
583 struct virtio_blk *vblk = vdev->priv;
585 blk_queue_write_cache(vblk->disk->queue, writeback, false);
586 revalidate_disk(vblk->disk);
589 static const char *const virtblk_cache_types[] = {
590 "write through", "write back"
594 cache_type_store(struct device *dev, struct device_attribute *attr,
595 const char *buf, size_t count)
597 struct gendisk *disk = dev_to_disk(dev);
598 struct virtio_blk *vblk = disk->private_data;
599 struct virtio_device *vdev = vblk->vdev;
602 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
603 i = sysfs_match_string(virtblk_cache_types, buf);
607 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
608 virtblk_update_cache_mode(vdev);
613 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
615 struct gendisk *disk = dev_to_disk(dev);
616 struct virtio_blk *vblk = disk->private_data;
617 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
619 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
620 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
623 static DEVICE_ATTR_RW(cache_type);
625 static struct attribute *virtblk_attrs[] = {
626 &dev_attr_serial.attr,
627 &dev_attr_cache_type.attr,
631 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
632 struct attribute *a, int n)
634 struct device *dev = container_of(kobj, struct device, kobj);
635 struct gendisk *disk = dev_to_disk(dev);
636 struct virtio_blk *vblk = disk->private_data;
637 struct virtio_device *vdev = vblk->vdev;
639 if (a == &dev_attr_cache_type.attr &&
640 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
646 static const struct attribute_group virtblk_attr_group = {
647 .attrs = virtblk_attrs,
648 .is_visible = virtblk_attrs_are_visible,
651 static const struct attribute_group *virtblk_attr_groups[] = {
656 static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
657 unsigned int hctx_idx, unsigned int numa_node)
659 struct virtio_blk *vblk = set->driver_data;
660 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
662 sg_init_table(vbr->sg, vblk->sg_elems);
666 static int virtblk_map_queues(struct blk_mq_tag_set *set)
668 struct virtio_blk *vblk = set->driver_data;
670 return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT],
674 static const struct blk_mq_ops virtio_mq_ops = {
675 .queue_rq = virtio_queue_rq,
676 .commit_rqs = virtio_commit_rqs,
677 .complete = virtblk_request_done,
678 .init_request = virtblk_init_request,
679 .map_queues = virtblk_map_queues,
682 static unsigned int virtblk_queue_depth;
683 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
685 static int virtblk_probe(struct virtio_device *vdev)
687 struct virtio_blk *vblk;
688 struct request_queue *q;
691 u32 v, blk_size, max_size, sg_elems, opt_io_size;
693 u8 physical_block_exp, alignment_offset;
695 if (!vdev->config->get) {
696 dev_err(&vdev->dev, "%s failure: config access disabled\n",
701 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
707 /* We need to know how many segments before we allocate. */
708 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
709 struct virtio_blk_config, seg_max,
712 /* We need at least one SG element, whatever they say. */
713 if (err || !sg_elems)
716 /* We need an extra sg elements at head and tail. */
718 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
724 /* This reference is dropped in virtblk_remove(). */
725 refcount_set(&vblk->refs, 1);
726 mutex_init(&vblk->vdev_mutex);
729 vblk->sg_elems = sg_elems;
731 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
737 /* FIXME: How many partitions? How long is a piece of string? */
738 vblk->disk = alloc_disk(1 << PART_BITS);
744 /* Default queue sizing is to fill the ring. */
745 if (!virtblk_queue_depth) {
746 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
747 /* ... but without indirect descs, we use 2 descs per req */
748 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
749 virtblk_queue_depth /= 2;
752 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
753 vblk->tag_set.ops = &virtio_mq_ops;
754 vblk->tag_set.queue_depth = virtblk_queue_depth;
755 vblk->tag_set.numa_node = NUMA_NO_NODE;
756 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
757 vblk->tag_set.cmd_size =
758 sizeof(struct virtblk_req) +
759 sizeof(struct scatterlist) * sg_elems;
760 vblk->tag_set.driver_data = vblk;
761 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
763 err = blk_mq_alloc_tag_set(&vblk->tag_set);
767 q = blk_mq_init_queue(&vblk->tag_set);
772 vblk->disk->queue = q;
776 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
778 vblk->disk->major = major;
779 vblk->disk->first_minor = index_to_minor(index);
780 vblk->disk->private_data = vblk;
781 vblk->disk->fops = &virtblk_fops;
782 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
785 /* configure queue flush support */
786 virtblk_update_cache_mode(vdev);
788 /* If disk is read-only in the host, the guest should obey */
789 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
790 set_disk_ro(vblk->disk, 1);
792 /* We can handle whatever the host told us to handle. */
793 blk_queue_max_segments(q, vblk->sg_elems-2);
795 /* No real sector limit. */
796 blk_queue_max_hw_sectors(q, -1U);
798 max_size = virtio_max_dma_size(vdev);
800 /* Host can optionally specify maximum segment size and number of
802 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
803 struct virtio_blk_config, size_max, &v);
805 max_size = min(max_size, v);
807 blk_queue_max_segment_size(q, max_size);
809 /* Host can optionally specify the block size of the device */
810 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
811 struct virtio_blk_config, blk_size,
814 blk_queue_logical_block_size(q, blk_size);
816 blk_size = queue_logical_block_size(q);
818 /* Use topology information if available */
819 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
820 struct virtio_blk_config, physical_block_exp,
821 &physical_block_exp);
822 if (!err && physical_block_exp)
823 blk_queue_physical_block_size(q,
824 blk_size * (1 << physical_block_exp));
826 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
827 struct virtio_blk_config, alignment_offset,
829 if (!err && alignment_offset)
830 blk_queue_alignment_offset(q, blk_size * alignment_offset);
832 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
833 struct virtio_blk_config, min_io_size,
835 if (!err && min_io_size)
836 blk_queue_io_min(q, blk_size * min_io_size);
838 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
839 struct virtio_blk_config, opt_io_size,
841 if (!err && opt_io_size)
842 blk_queue_io_opt(q, blk_size * opt_io_size);
844 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
845 q->limits.discard_granularity = blk_size;
847 virtio_cread(vdev, struct virtio_blk_config,
848 discard_sector_alignment, &v);
849 q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
851 virtio_cread(vdev, struct virtio_blk_config,
852 max_discard_sectors, &v);
853 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
855 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
857 blk_queue_max_discard_segments(q,
859 MAX_DISCARD_SEGMENTS));
861 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
864 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
865 virtio_cread(vdev, struct virtio_blk_config,
866 max_write_zeroes_sectors, &v);
867 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
870 virtblk_update_capacity(vblk, false);
871 virtio_device_ready(vdev);
873 device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
877 blk_mq_free_tag_set(&vblk->tag_set);
879 put_disk(vblk->disk);
881 vdev->config->del_vqs(vdev);
886 ida_simple_remove(&vd_index_ida, index);
891 static void virtblk_remove(struct virtio_device *vdev)
893 struct virtio_blk *vblk = vdev->priv;
895 /* Make sure no work handler is accessing the device. */
896 flush_work(&vblk->config_work);
898 del_gendisk(vblk->disk);
899 blk_cleanup_queue(vblk->disk->queue);
901 blk_mq_free_tag_set(&vblk->tag_set);
903 mutex_lock(&vblk->vdev_mutex);
905 /* Stop all the virtqueues. */
906 vdev->config->reset(vdev);
908 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */
911 put_disk(vblk->disk);
912 vdev->config->del_vqs(vdev);
915 mutex_unlock(&vblk->vdev_mutex);
920 #ifdef CONFIG_PM_SLEEP
921 static int virtblk_freeze(struct virtio_device *vdev)
923 struct virtio_blk *vblk = vdev->priv;
925 /* Ensure we don't receive any more interrupts */
926 vdev->config->reset(vdev);
928 /* Make sure no work handler is accessing the device. */
929 flush_work(&vblk->config_work);
931 blk_mq_quiesce_queue(vblk->disk->queue);
933 vdev->config->del_vqs(vdev);
937 static int virtblk_restore(struct virtio_device *vdev)
939 struct virtio_blk *vblk = vdev->priv;
942 ret = init_vq(vdev->priv);
946 virtio_device_ready(vdev);
948 blk_mq_unquiesce_queue(vblk->disk->queue);
953 static const struct virtio_device_id id_table[] = {
954 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
958 static unsigned int features_legacy[] = {
959 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
960 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
961 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
962 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
965 static unsigned int features[] = {
966 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
967 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
968 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
969 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
972 static struct virtio_driver virtio_blk = {
973 .feature_table = features,
974 .feature_table_size = ARRAY_SIZE(features),
975 .feature_table_legacy = features_legacy,
976 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
977 .driver.name = KBUILD_MODNAME,
978 .driver.owner = THIS_MODULE,
979 .id_table = id_table,
980 .probe = virtblk_probe,
981 .remove = virtblk_remove,
982 .config_changed = virtblk_config_changed,
983 #ifdef CONFIG_PM_SLEEP
984 .freeze = virtblk_freeze,
985 .restore = virtblk_restore,
989 static int __init init(void)
993 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
997 major = register_blkdev(0, "virtblk");
1000 goto out_destroy_workqueue;
1003 error = register_virtio_driver(&virtio_blk);
1005 goto out_unregister_blkdev;
1008 out_unregister_blkdev:
1009 unregister_blkdev(major, "virtblk");
1010 out_destroy_workqueue:
1011 destroy_workqueue(virtblk_wq);
1015 static void __exit fini(void)
1017 unregister_virtio_driver(&virtio_blk);
1018 unregister_blkdev(major, "virtblk");
1019 destroy_workqueue(virtblk_wq);
1024 MODULE_DEVICE_TABLE(virtio, id_table);
1025 MODULE_DESCRIPTION("Virtio block driver");
1026 MODULE_LICENSE("GPL");