| //#define DEBUG |
| #include <linux/spinlock.h> |
| #include <linux/slab.h> |
| #include <linux/blkdev.h> |
| #include <linux/hdreg.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/virtio.h> |
| #include <linux/virtio_blk.h> |
| #include <linux/scatterlist.h> |
| #include <linux/string_helpers.h> |
| #include <scsi/scsi_cmnd.h> |
| #include <linux/idr.h> |
| #include <linux/blk-mq.h> |
| #include <linux/numa.h> |
| |
| #define PART_BITS 4 |
| #define VQ_NAME_LEN 16 |
| |
| 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 |
| { |
| 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; |
| |
| /* 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 request *req; |
| struct virtio_blk_outhdr out_hdr; |
| struct virtio_scsi_inhdr in_hdr; |
| u8 status; |
| struct scatterlist sg[]; |
| }; |
| |
| static inline int virtblk_result(struct virtblk_req *vbr) |
| { |
| switch (vbr->status) { |
| case VIRTIO_BLK_S_OK: |
| return 0; |
| case VIRTIO_BLK_S_UNSUPP: |
| return -ENOTTY; |
| default: |
| return -EIO; |
| } |
| } |
| |
| static int __virtblk_add_req(struct virtqueue *vq, |
| struct virtblk_req *vbr, |
| struct scatterlist *data_sg, |
| bool have_data) |
| { |
| struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6]; |
| unsigned int num_out = 0, num_in = 0; |
| __virtio32 type = vbr->out_hdr.type & ~cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT); |
| |
| sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); |
| sgs[num_out++] = &hdr; |
| |
| /* |
| * If this is a packet command we need a couple of additional headers. |
| * Behind the normal outhdr we put a segment with the scsi command |
| * block, and before the normal inhdr we put the sense data and the |
| * inhdr with additional status information. |
| */ |
| if (type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_SCSI_CMD)) { |
| sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len); |
| sgs[num_out++] = &cmd; |
| } |
| |
| 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; |
| } |
| |
| if (type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_SCSI_CMD)) { |
| sg_init_one(&sense, vbr->req->sense, SCSI_SENSE_BUFFERSIZE); |
| sgs[num_out + num_in++] = &sense; |
| sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr)); |
| sgs[num_out + num_in++] = &inhdr; |
| } |
| |
| 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 inline void virtblk_request_done(struct request *req) |
| { |
| struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); |
| struct virtio_blk *vblk = req->q->queuedata; |
| int error = virtblk_result(vbr); |
| |
| if (req->cmd_type == REQ_TYPE_BLOCK_PC) { |
| req->resid_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.residual); |
| req->sense_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.sense_len); |
| req->errors = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors); |
| } else if (req->cmd_type == REQ_TYPE_SPECIAL) { |
| req->errors = (error != 0); |
| } |
| |
| blk_mq_end_request(req, error); |
| } |
| |
| 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) { |
| blk_mq_complete_request(vbr->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 int 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; |
| |
| BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); |
| |
| vbr->req = req; |
| if (req->cmd_flags & REQ_FLUSH) { |
| vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_FLUSH); |
| vbr->out_hdr.sector = 0; |
| vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req)); |
| } else { |
| switch (req->cmd_type) { |
| case REQ_TYPE_FS: |
| vbr->out_hdr.type = 0; |
| vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, blk_rq_pos(vbr->req)); |
| vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req)); |
| break; |
| case REQ_TYPE_BLOCK_PC: |
| vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_SCSI_CMD); |
| vbr->out_hdr.sector = 0; |
| vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req)); |
| break; |
| case REQ_TYPE_SPECIAL: |
| vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); |
| vbr->out_hdr.sector = 0; |
| vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req)); |
| break; |
| default: |
| /* We don't put anything else in the queue. */ |
| BUG(); |
| } |
| } |
| |
| blk_mq_start_request(req); |
| |
| num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg); |
| if (num) { |
| if (rq_data_dir(vbr->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); |
| blk_mq_stop_hw_queue(hctx); |
| spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); |
| /* Out of mem doesn't actually happen, since we fall back |
| * to direct descriptors */ |
| if (err == -ENOMEM || err == -ENOSPC) |
| return BLK_MQ_RQ_QUEUE_BUSY; |
| return BLK_MQ_RQ_QUEUE_ERROR; |
| } |
| |
| 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_MQ_RQ_QUEUE_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 *req; |
| struct bio *bio; |
| int err; |
| |
| bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES, |
| GFP_KERNEL); |
| if (IS_ERR(bio)) |
| return PTR_ERR(bio); |
| |
| req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL); |
| if (IS_ERR(req)) { |
| bio_put(bio); |
| return PTR_ERR(req); |
| } |
| |
| req->cmd_type = REQ_TYPE_SPECIAL; |
| err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false); |
| blk_put_request(req); |
| |
| return err; |
| } |
| |
| static int virtblk_ioctl(struct block_device *bdev, fmode_t mode, |
| unsigned int cmd, unsigned long data) |
| { |
| struct gendisk *disk = bdev->bd_disk; |
| struct virtio_blk *vblk = disk->private_data; |
| |
| /* |
| * Only allow the generic SCSI ioctls if the host can support it. |
| */ |
| if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI)) |
| return -ENOTTY; |
| |
| return scsi_cmd_blk_ioctl(bdev, mode, cmd, |
| (void __user *)data); |
| } |
| |
| /* 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; |
| |
| /* 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; |
| } |
| return 0; |
| } |
| |
| static const struct block_device_operations virtblk_fops = { |
| .ioctl = virtblk_ioctl, |
| .owner = THIS_MODULE, |
| .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 virtblk_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(serial, S_IRUGO, virtblk_serial_show, NULL); |
| |
| static void virtblk_config_changed_work(struct work_struct *work) |
| { |
| struct virtio_blk *vblk = |
| container_of(work, struct virtio_blk, config_work); |
| struct virtio_device *vdev = vblk->vdev; |
| struct request_queue *q = vblk->disk->queue; |
| char cap_str_2[10], cap_str_10[10]; |
| char *envp[] = { "RESIZE=1", NULL }; |
| u64 capacity, size; |
| |
| /* 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; |
| } |
| |
| size = capacity * queue_logical_block_size(q); |
| string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); |
| string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); |
| |
| dev_notice(&vdev->dev, |
| "new size: %llu %d-byte logical blocks (%s/%s)\n", |
| (unsigned long long)capacity, |
| queue_logical_block_size(q), |
| cap_str_10, cap_str_2); |
| |
| set_capacity(vblk->disk, capacity); |
| revalidate_disk(vblk->disk); |
| kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp); |
| } |
| |
| 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 = 0; |
| int i; |
| vq_callback_t **callbacks; |
| const char **names; |
| struct virtqueue **vqs; |
| unsigned short num_vqs; |
| struct virtio_device *vdev = vblk->vdev; |
| |
| err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, |
| struct virtio_blk_config, num_queues, |
| &num_vqs); |
| if (err) |
| num_vqs = 1; |
| |
| vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL); |
| if (!vblk->vqs) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL); |
| if (!names) |
| goto err_names; |
| |
| callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL); |
| if (!callbacks) |
| goto err_callbacks; |
| |
| vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL); |
| if (!vqs) |
| goto err_vqs; |
| |
| 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 = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); |
| if (err) |
| goto err_find_vqs; |
| |
| 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; |
| |
| err_find_vqs: |
| kfree(vqs); |
| err_vqs: |
| kfree(callbacks); |
| err_callbacks: |
| kfree(names); |
| err_names: |
| if (err) |
| kfree(vblk->vqs); |
| out: |
| 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 (err) |
| writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE) || |
| virtio_has_feature(vdev, VIRTIO_F_VERSION_1); |
| |
| 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; |
| |
| if (writeback) |
| blk_queue_flush(vblk->disk->queue, REQ_FLUSH); |
| else |
| blk_queue_flush(vblk->disk->queue, 0); |
| |
| revalidate_disk(vblk->disk); |
| } |
| |
| static const char *const virtblk_cache_types[] = { |
| "write through", "write back" |
| }; |
| |
| static ssize_t |
| virtblk_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)); |
| for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; ) |
| if (sysfs_streq(buf, virtblk_cache_types[i])) |
| break; |
| |
| if (i < 0) |
| return -EINVAL; |
| |
| virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); |
| virtblk_update_cache_mode(vdev); |
| return count; |
| } |
| |
| static ssize_t |
| virtblk_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 const struct device_attribute dev_attr_cache_type_ro = |
| __ATTR(cache_type, S_IRUGO, |
| virtblk_cache_type_show, NULL); |
| static const struct device_attribute dev_attr_cache_type_rw = |
| __ATTR(cache_type, S_IRUGO|S_IWUSR, |
| virtblk_cache_type_show, virtblk_cache_type_store); |
| |
| static int virtblk_init_request(void *data, struct request *rq, |
| unsigned int hctx_idx, unsigned int request_idx, |
| unsigned int numa_node) |
| { |
| struct virtio_blk *vblk = data; |
| struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq); |
| |
| sg_init_table(vbr->sg, vblk->sg_elems); |
| return 0; |
| } |
| |
| static struct blk_mq_ops virtio_mq_ops = { |
| .queue_rq = virtio_queue_rq, |
| .map_queue = blk_mq_map_queue, |
| .complete = virtblk_request_done, |
| .init_request = virtblk_init_request, |
| }; |
| |
| 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; |
| |
| u64 cap; |
| u32 v, blk_size, sg_elems, opt_io_size; |
| u16 min_io_size; |
| u8 physical_block_exp, alignment_offset; |
| |
| 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; |
| } |
| |
| 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 = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set); |
| if (!q) { |
| err = -ENOMEM; |
| goto out_free_tags; |
| } |
| |
| 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->driverfs_dev = &vdev->dev; |
| 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); |
| |
| /* Host must always specify the capacity. */ |
| virtio_cread(vdev, struct virtio_blk_config, capacity, &cap); |
| |
| /* If capacity is too big, truncate with warning. */ |
| if ((sector_t)cap != cap) { |
| dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n", |
| (unsigned long long)cap); |
| cap = (sector_t)-1; |
| } |
| set_capacity(vblk->disk, cap); |
| |
| /* We can handle whatever the host told us to handle. */ |
| blk_queue_max_segments(q, vblk->sg_elems-2); |
| |
| /* No need to bounce any requests */ |
| blk_queue_bounce_limit(q, BLK_BOUNCE_ANY); |
| |
| /* No real sector limit. */ |
| blk_queue_max_hw_sectors(q, -1U); |
| |
| /* 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) |
| blk_queue_max_segment_size(q, v); |
| else |
| blk_queue_max_segment_size(q, -1U); |
| |
| /* 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); |
| |
| virtio_device_ready(vdev); |
| |
| add_disk(vblk->disk); |
| err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial); |
| if (err) |
| goto out_del_disk; |
| |
| if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) |
| err = device_create_file(disk_to_dev(vblk->disk), |
| &dev_attr_cache_type_rw); |
| else |
| err = device_create_file(disk_to_dev(vblk->disk), |
| &dev_attr_cache_type_ro); |
| if (err) |
| goto out_del_disk; |
| return 0; |
| |
| out_del_disk: |
| del_gendisk(vblk->disk); |
| blk_cleanup_queue(vblk->disk->queue); |
| 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); |
| 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; |
| int index = vblk->index; |
| int refc; |
| |
| /* 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); |
| |
| /* Stop all the virtqueues. */ |
| vdev->config->reset(vdev); |
| |
| refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount); |
| put_disk(vblk->disk); |
| vdev->config->del_vqs(vdev); |
| kfree(vblk->vqs); |
| kfree(vblk); |
| |
| /* Only free device id if we don't have any users */ |
| if (refc == 1) |
| ida_simple_remove(&vd_index_ida, index); |
| } |
| |
| #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_stop_hw_queues(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_start_stopped_hw_queues(vblk->disk->queue, true); |
| 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_SCSI, |
| VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, |
| VIRTIO_BLK_F_MQ, |
| } |
| ; |
| 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_TOPOLOGY, |
| VIRTIO_BLK_F_MQ, |
| }; |
| |
| 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"); |