// SPDX-License-Identifier: GPL-2.0-only //#define DEBUG #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define PART_BITS 4 #define VQ_NAME_LEN 16 #define MAX_DISCARD_SEGMENTS 256u static int major; static DEFINE_IDA(vd_index_ida); static struct workqueue_struct *virtblk_wq; struct virtio_blk_vq { struct virtqueue *vq; spinlock_t lock; char name[VQ_NAME_LEN]; } ____cacheline_aligned_in_smp; struct virtio_blk { /* * This mutex must be held by anything that may run after * virtblk_remove() sets vblk->vdev to NULL. * * blk-mq, virtqueue processing, and sysfs attribute code paths are * shut down before vblk->vdev is set to NULL and therefore do not need * to hold this mutex. */ struct mutex vdev_mutex; struct virtio_device *vdev; /* The disk structure for the kernel. */ struct gendisk *disk; /* Block layer tags. */ struct blk_mq_tag_set tag_set; /* Process context for config space updates */ struct work_struct config_work; /* * Tracks references from block_device_operations open/release and * virtio_driver probe/remove so this object can be freed once no * longer in use. */ refcount_t refs; /* What host tells us, plus 2 for header & tailer. */ unsigned int sg_elems; /* Ida index - used to track minor number allocations. */ int index; /* num of vqs */ int num_vqs; struct virtio_blk_vq *vqs; }; struct virtblk_req { struct virtio_blk_outhdr out_hdr; u8 status; struct scatterlist sg[]; }; static inline blk_status_t virtblk_result(struct virtblk_req *vbr) { switch (vbr->status) { case VIRTIO_BLK_S_OK: return BLK_STS_OK; case VIRTIO_BLK_S_UNSUPP: return BLK_STS_NOTSUPP; default: return BLK_STS_IOERR; } } static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr, struct scatterlist *data_sg, bool have_data) { struct scatterlist hdr, status, *sgs[3]; unsigned int num_out = 0, num_in = 0; sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); sgs[num_out++] = &hdr; if (have_data) { if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) sgs[num_out++] = data_sg; else sgs[num_out + num_in++] = data_sg; } sg_init_one(&status, &vbr->status, sizeof(vbr->status)); sgs[num_out + num_in++] = &status; return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); } static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap) { unsigned short segments = blk_rq_nr_discard_segments(req); unsigned short n = 0; struct virtio_blk_discard_write_zeroes *range; struct bio *bio; u32 flags = 0; if (unmap) flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); if (!range) return -ENOMEM; __rq_for_each_bio(bio, req) { u64 sector = bio->bi_iter.bi_sector; u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; range[n].flags = cpu_to_le32(flags); range[n].num_sectors = cpu_to_le32(num_sectors); range[n].sector = cpu_to_le64(sector); n++; } req->special_vec.bv_page = virt_to_page(range); req->special_vec.bv_offset = offset_in_page(range); req->special_vec.bv_len = sizeof(*range) * segments; req->rq_flags |= RQF_SPECIAL_PAYLOAD; return 0; } static inline void virtblk_request_done(struct request *req) { struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); if (req->rq_flags & RQF_SPECIAL_PAYLOAD) { kfree(page_address(req->special_vec.bv_page) + req->special_vec.bv_offset); } blk_mq_end_request(req, virtblk_result(vbr)); } static void virtblk_done(struct virtqueue *vq) { struct virtio_blk *vblk = vq->vdev->priv; bool req_done = false; int qid = vq->index; struct virtblk_req *vbr; unsigned long flags; unsigned int len; spin_lock_irqsave(&vblk->vqs[qid].lock, flags); do { virtqueue_disable_cb(vq); while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { struct request *req = blk_mq_rq_from_pdu(vbr); blk_mq_complete_request(req); req_done = true; } if (unlikely(virtqueue_is_broken(vq))) break; } while (!virtqueue_enable_cb(vq)); /* In case queue is stopped waiting for more buffers. */ if (req_done) blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); } static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) { struct virtio_blk *vblk = hctx->queue->queuedata; struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; bool kick; spin_lock_irq(&vq->lock); kick = virtqueue_kick_prepare(vq->vq); spin_unlock_irq(&vq->lock); if (kick) virtqueue_notify(vq->vq); } static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { struct virtio_blk *vblk = hctx->queue->queuedata; struct request *req = bd->rq; struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); unsigned long flags; unsigned int num; int qid = hctx->queue_num; int err; bool notify = false; bool unmap = false; u32 type; BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); switch (req_op(req)) { case REQ_OP_READ: case REQ_OP_WRITE: type = 0; break; case REQ_OP_FLUSH: type = VIRTIO_BLK_T_FLUSH; break; case REQ_OP_DISCARD: type = VIRTIO_BLK_T_DISCARD; break; case REQ_OP_WRITE_ZEROES: type = VIRTIO_BLK_T_WRITE_ZEROES; unmap = !(req->cmd_flags & REQ_NOUNMAP); break; case REQ_OP_DRV_IN: type = VIRTIO_BLK_T_GET_ID; break; default: WARN_ON_ONCE(1); return BLK_STS_IOERR; } vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type); vbr->out_hdr.sector = type ? 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req)); vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req)); blk_mq_start_request(req); if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) { err = virtblk_setup_discard_write_zeroes(req, unmap); if (err) return BLK_STS_RESOURCE; } num = blk_rq_map_sg(hctx->queue, req, vbr->sg); if (num) { if (rq_data_dir(req) == WRITE) vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT); else vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN); } spin_lock_irqsave(&vblk->vqs[qid].lock, flags); err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num); if (err) { virtqueue_kick(vblk->vqs[qid].vq); /* Don't stop the queue if -ENOMEM: we may have failed to * bounce the buffer due to global resource outage. */ if (err == -ENOSPC) blk_mq_stop_hw_queue(hctx); spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); switch (err) { case -ENOSPC: return BLK_STS_DEV_RESOURCE; case -ENOMEM: return BLK_STS_RESOURCE; default: return BLK_STS_IOERR; } } if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) notify = true; spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); if (notify) virtqueue_notify(vblk->vqs[qid].vq); return BLK_STS_OK; } /* return id (s/n) string for *disk to *id_str */ static int virtblk_get_id(struct gendisk *disk, char *id_str) { struct virtio_blk *vblk = disk->private_data; struct request_queue *q = vblk->disk->queue; struct request *req; int err; req = blk_get_request(q, REQ_OP_DRV_IN, 0); if (IS_ERR(req)) return PTR_ERR(req); err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); if (err) goto out; blk_execute_rq(vblk->disk->queue, vblk->disk, req, false); err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req))); out: blk_put_request(req); return err; } static void virtblk_get(struct virtio_blk *vblk) { refcount_inc(&vblk->refs); } static void virtblk_put(struct virtio_blk *vblk) { if (refcount_dec_and_test(&vblk->refs)) { ida_simple_remove(&vd_index_ida, vblk->index); mutex_destroy(&vblk->vdev_mutex); kfree(vblk); } } static int virtblk_open(struct block_device *bd, fmode_t mode) { struct virtio_blk *vblk = bd->bd_disk->private_data; int ret = 0; mutex_lock(&vblk->vdev_mutex); if (vblk->vdev) virtblk_get(vblk); else ret = -ENXIO; mutex_unlock(&vblk->vdev_mutex); return ret; } static void virtblk_release(struct gendisk *disk, fmode_t mode) { struct virtio_blk *vblk = disk->private_data; virtblk_put(vblk); } /* We provide getgeo only to please some old bootloader/partitioning tools */ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) { struct virtio_blk *vblk = bd->bd_disk->private_data; int ret = 0; mutex_lock(&vblk->vdev_mutex); if (!vblk->vdev) { ret = -ENXIO; goto out; } /* see if the host passed in geometry config */ if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { virtio_cread(vblk->vdev, struct virtio_blk_config, geometry.cylinders, &geo->cylinders); virtio_cread(vblk->vdev, struct virtio_blk_config, geometry.heads, &geo->heads); virtio_cread(vblk->vdev, struct virtio_blk_config, geometry.sectors, &geo->sectors); } else { /* some standard values, similar to sd */ geo->heads = 1 << 6; geo->sectors = 1 << 5; geo->cylinders = get_capacity(bd->bd_disk) >> 11; } out: mutex_unlock(&vblk->vdev_mutex); return ret; } static const struct block_device_operations virtblk_fops = { .owner = THIS_MODULE, .open = virtblk_open, .release = virtblk_release, .getgeo = virtblk_getgeo, }; static int index_to_minor(int index) { return index << PART_BITS; } static int minor_to_index(int minor) { return minor >> PART_BITS; } static ssize_t serial_show(struct device *dev, struct device_attribute *attr, char *buf) { struct gendisk *disk = dev_to_disk(dev); int err; /* sysfs gives us a PAGE_SIZE buffer */ BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); buf[VIRTIO_BLK_ID_BYTES] = '\0'; err = virtblk_get_id(disk, buf); if (!err) return strlen(buf); if (err == -EIO) /* Unsupported? Make it empty. */ return 0; return err; } static DEVICE_ATTR_RO(serial); /* The queue's logical block size must be set before calling this */ static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) { struct virtio_device *vdev = vblk->vdev; struct request_queue *q = vblk->disk->queue; char cap_str_2[10], cap_str_10[10]; unsigned long long nblocks; u64 capacity; /* Host must always specify the capacity. */ virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); /* If capacity is too big, truncate with warning. */ if ((sector_t)capacity != capacity) { dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n", (unsigned long long)capacity); capacity = (sector_t)-1; } nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); string_get_size(nblocks, queue_logical_block_size(q), STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); string_get_size(nblocks, queue_logical_block_size(q), STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); dev_notice(&vdev->dev, "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", vblk->disk->disk_name, resize ? "new size: " : "", nblocks, queue_logical_block_size(q), cap_str_10, cap_str_2); set_capacity_revalidate_and_notify(vblk->disk, capacity, true); } static void virtblk_config_changed_work(struct work_struct *work) { struct virtio_blk *vblk = container_of(work, struct virtio_blk, config_work); virtblk_update_capacity(vblk, true); } static void virtblk_config_changed(struct virtio_device *vdev) { struct virtio_blk *vblk = vdev->priv; queue_work(virtblk_wq, &vblk->config_work); } static int init_vq(struct virtio_blk *vblk) { int err; int i; vq_callback_t **callbacks; const char **names; struct virtqueue **vqs; unsigned short num_vqs; struct virtio_device *vdev = vblk->vdev; struct irq_affinity desc = { 0, }; err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, struct virtio_blk_config, num_queues, &num_vqs); if (err) num_vqs = 1; num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); if (!vblk->vqs) return -ENOMEM; names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); if (!names || !callbacks || !vqs) { err = -ENOMEM; goto out; } for (i = 0; i < num_vqs; i++) { callbacks[i] = virtblk_done; snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i); names[i] = vblk->vqs[i].name; } /* Discover virtqueues and write information to configuration. */ err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); if (err) goto out; for (i = 0; i < num_vqs; i++) { spin_lock_init(&vblk->vqs[i].lock); vblk->vqs[i].vq = vqs[i]; } vblk->num_vqs = num_vqs; out: kfree(vqs); kfree(callbacks); kfree(names); if (err) kfree(vblk->vqs); return err; } /* * Legacy naming scheme used for virtio devices. We are stuck with it for * virtio blk but don't ever use it for any new driver. */ static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) { const int base = 'z' - 'a' + 1; char *begin = buf + strlen(prefix); char *end = buf + buflen; char *p; int unit; p = end - 1; *p = '\0'; unit = base; do { if (p == begin) return -EINVAL; *--p = 'a' + (index % unit); index = (index / unit) - 1; } while (index >= 0); memmove(begin, p, end - p); memcpy(buf, prefix, strlen(prefix)); return 0; } static int virtblk_get_cache_mode(struct virtio_device *vdev) { u8 writeback; int err; err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, struct virtio_blk_config, wce, &writeback); /* * If WCE is not configurable and flush is not available, * assume no writeback cache is in use. */ if (err) writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); return writeback; } static void virtblk_update_cache_mode(struct virtio_device *vdev) { u8 writeback = virtblk_get_cache_mode(vdev); struct virtio_blk *vblk = vdev->priv; blk_queue_write_cache(vblk->disk->queue, writeback, false); revalidate_disk(vblk->disk); } static const char *const virtblk_cache_types[] = { "write through", "write back" }; static ssize_t cache_type_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct gendisk *disk = dev_to_disk(dev); struct virtio_blk *vblk = disk->private_data; struct virtio_device *vdev = vblk->vdev; int i; BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); i = sysfs_match_string(virtblk_cache_types, buf); if (i < 0) return i; virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); virtblk_update_cache_mode(vdev); return count; } static ssize_t cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct gendisk *disk = dev_to_disk(dev); struct virtio_blk *vblk = disk->private_data; u8 writeback = virtblk_get_cache_mode(vblk->vdev); BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]); } static DEVICE_ATTR_RW(cache_type); static struct attribute *virtblk_attrs[] = { &dev_attr_serial.attr, &dev_attr_cache_type.attr, NULL, }; static umode_t virtblk_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = container_of(kobj, struct device, kobj); struct gendisk *disk = dev_to_disk(dev); struct virtio_blk *vblk = disk->private_data; struct virtio_device *vdev = vblk->vdev; if (a == &dev_attr_cache_type.attr && !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) return S_IRUGO; return a->mode; } static const struct attribute_group virtblk_attr_group = { .attrs = virtblk_attrs, .is_visible = virtblk_attrs_are_visible, }; static const struct attribute_group *virtblk_attr_groups[] = { &virtblk_attr_group, NULL, }; static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq, unsigned int hctx_idx, unsigned int numa_node) { struct virtio_blk *vblk = set->driver_data; struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq); sg_init_table(vbr->sg, vblk->sg_elems); return 0; } static int virtblk_map_queues(struct blk_mq_tag_set *set) { struct virtio_blk *vblk = set->driver_data; return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT], vblk->vdev, 0); } static const struct blk_mq_ops virtio_mq_ops = { .queue_rq = virtio_queue_rq, .commit_rqs = virtio_commit_rqs, .complete = virtblk_request_done, .init_request = virtblk_init_request, .map_queues = virtblk_map_queues, }; static unsigned int virtblk_queue_depth; module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); static int virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; struct request_queue *q; int err, index; u32 v, blk_size, max_size, sg_elems, opt_io_size; u16 min_io_size; u8 physical_block_exp, alignment_offset; if (!vdev->config->get) { dev_err(&vdev->dev, "%s failure: config access disabled\n", __func__); return -EINVAL; } err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS), GFP_KERNEL); if (err < 0) goto out; index = err; /* We need to know how many segments before we allocate. */ err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, struct virtio_blk_config, seg_max, &sg_elems); /* We need at least one SG element, whatever they say. */ if (err || !sg_elems) sg_elems = 1; /* We need an extra sg elements at head and tail. */ sg_elems += 2; vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); if (!vblk) { err = -ENOMEM; goto out_free_index; } /* This reference is dropped in virtblk_remove(). */ refcount_set(&vblk->refs, 1); mutex_init(&vblk->vdev_mutex); vblk->vdev = vdev; vblk->sg_elems = sg_elems; INIT_WORK(&vblk->config_work, virtblk_config_changed_work); err = init_vq(vblk); if (err) goto out_free_vblk; /* FIXME: How many partitions? How long is a piece of string? */ vblk->disk = alloc_disk(1 << PART_BITS); if (!vblk->disk) { err = -ENOMEM; goto out_free_vq; } /* Default queue sizing is to fill the ring. */ if (!virtblk_queue_depth) { virtblk_queue_depth = vblk->vqs[0].vq->num_free; /* ... but without indirect descs, we use 2 descs per req */ if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) virtblk_queue_depth /= 2; } memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); vblk->tag_set.ops = &virtio_mq_ops; vblk->tag_set.queue_depth = virtblk_queue_depth; vblk->tag_set.numa_node = NUMA_NO_NODE; vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; vblk->tag_set.cmd_size = sizeof(struct virtblk_req) + sizeof(struct scatterlist) * sg_elems; vblk->tag_set.driver_data = vblk; vblk->tag_set.nr_hw_queues = vblk->num_vqs; err = blk_mq_alloc_tag_set(&vblk->tag_set); if (err) goto out_put_disk; q = blk_mq_init_queue(&vblk->tag_set); if (IS_ERR(q)) { err = -ENOMEM; goto out_free_tags; } vblk->disk->queue = q; q->queuedata = vblk; virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); vblk->disk->major = major; vblk->disk->first_minor = index_to_minor(index); vblk->disk->private_data = vblk; vblk->disk->fops = &virtblk_fops; vblk->disk->flags |= GENHD_FL_EXT_DEVT; vblk->index = index; /* configure queue flush support */ virtblk_update_cache_mode(vdev); /* If disk is read-only in the host, the guest should obey */ if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) set_disk_ro(vblk->disk, 1); /* We can handle whatever the host told us to handle. */ blk_queue_max_segments(q, vblk->sg_elems-2); /* No real sector limit. */ blk_queue_max_hw_sectors(q, -1U); max_size = virtio_max_dma_size(vdev); /* Host can optionally specify maximum segment size and number of * segments. */ err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, struct virtio_blk_config, size_max, &v); if (!err) max_size = min(max_size, v); blk_queue_max_segment_size(q, max_size); /* Host can optionally specify the block size of the device */ err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, struct virtio_blk_config, blk_size, &blk_size); if (!err) blk_queue_logical_block_size(q, blk_size); else blk_size = queue_logical_block_size(q); /* Use topology information if available */ err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, struct virtio_blk_config, physical_block_exp, &physical_block_exp); if (!err && physical_block_exp) blk_queue_physical_block_size(q, blk_size * (1 << physical_block_exp)); err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, struct virtio_blk_config, alignment_offset, &alignment_offset); if (!err && alignment_offset) blk_queue_alignment_offset(q, blk_size * alignment_offset); err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, struct virtio_blk_config, min_io_size, &min_io_size); if (!err && min_io_size) blk_queue_io_min(q, blk_size * min_io_size); err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, struct virtio_blk_config, opt_io_size, &opt_io_size); if (!err && opt_io_size) blk_queue_io_opt(q, blk_size * opt_io_size); if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { q->limits.discard_granularity = blk_size; virtio_cread(vdev, struct virtio_blk_config, discard_sector_alignment, &v); q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0; virtio_cread(vdev, struct virtio_blk_config, max_discard_sectors, &v); blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, &v); blk_queue_max_discard_segments(q, min_not_zero(v, MAX_DISCARD_SEGMENTS)); blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); } if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { virtio_cread(vdev, struct virtio_blk_config, max_write_zeroes_sectors, &v); blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); } virtblk_update_capacity(vblk, false); virtio_device_ready(vdev); device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); return 0; out_free_tags: blk_mq_free_tag_set(&vblk->tag_set); out_put_disk: put_disk(vblk->disk); out_free_vq: vdev->config->del_vqs(vdev); kfree(vblk->vqs); out_free_vblk: kfree(vblk); out_free_index: ida_simple_remove(&vd_index_ida, index); out: return err; } static void virtblk_remove(struct virtio_device *vdev) { struct virtio_blk *vblk = vdev->priv; /* Make sure no work handler is accessing the device. */ flush_work(&vblk->config_work); del_gendisk(vblk->disk); blk_cleanup_queue(vblk->disk->queue); blk_mq_free_tag_set(&vblk->tag_set); mutex_lock(&vblk->vdev_mutex); /* Stop all the virtqueues. */ vdev->config->reset(vdev); /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ vblk->vdev = NULL; put_disk(vblk->disk); vdev->config->del_vqs(vdev); kfree(vblk->vqs); mutex_unlock(&vblk->vdev_mutex); virtblk_put(vblk); } #ifdef CONFIG_PM_SLEEP static int virtblk_freeze(struct virtio_device *vdev) { struct virtio_blk *vblk = vdev->priv; /* Ensure we don't receive any more interrupts */ vdev->config->reset(vdev); /* Make sure no work handler is accessing the device. */ flush_work(&vblk->config_work); blk_mq_quiesce_queue(vblk->disk->queue); vdev->config->del_vqs(vdev); return 0; } static int virtblk_restore(struct virtio_device *vdev) { struct virtio_blk *vblk = vdev->priv; int ret; ret = init_vq(vdev->priv); if (ret) return ret; virtio_device_ready(vdev); blk_mq_unquiesce_queue(vblk->disk->queue); return 0; } #endif static const struct virtio_device_id id_table[] = { { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, { 0 }, }; static unsigned int features_legacy[] = { VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, } ; static unsigned int features[] = { VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, }; static struct virtio_driver virtio_blk = { .feature_table = features, .feature_table_size = ARRAY_SIZE(features), .feature_table_legacy = features_legacy, .feature_table_size_legacy = ARRAY_SIZE(features_legacy), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, .probe = virtblk_probe, .remove = virtblk_remove, .config_changed = virtblk_config_changed, #ifdef CONFIG_PM_SLEEP .freeze = virtblk_freeze, .restore = virtblk_restore, #endif }; static int __init init(void) { int error; virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); if (!virtblk_wq) return -ENOMEM; major = register_blkdev(0, "virtblk"); if (major < 0) { error = major; goto out_destroy_workqueue; } error = register_virtio_driver(&virtio_blk); if (error) goto out_unregister_blkdev; return 0; out_unregister_blkdev: unregister_blkdev(major, "virtblk"); out_destroy_workqueue: destroy_workqueue(virtblk_wq); return error; } static void __exit fini(void) { unregister_virtio_driver(&virtio_blk); unregister_blkdev(major, "virtblk"); destroy_workqueue(virtblk_wq); } module_init(init); module_exit(fini); MODULE_DEVICE_TABLE(virtio, id_table); MODULE_DESCRIPTION("Virtio block driver"); MODULE_LICENSE("GPL");