diff options
Diffstat (limited to 'hw/block/virtio-blk.c')
| -rw-r--r-- | hw/block/virtio-blk.c | 732 |
1 files changed, 732 insertions, 0 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c new file mode 100644 index 0000000000..6efb2f063d --- /dev/null +++ b/hw/block/virtio-blk.c @@ -0,0 +1,732 @@ +/* + * Virtio Block Device + * + * Copyright IBM, Corp. 2007 + * + * Authors: + * Anthony Liguori <aliguori@us.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + */ + +#include "qemu-common.h" +#include "qemu/error-report.h" +#include "trace.h" +#include "hw/block/block.h" +#include "sysemu/blockdev.h" +#include "hw/virtio/virtio-blk.h" +#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE +# include "dataplane/virtio-blk.h" +#endif +#include "block/scsi.h" +#ifdef __linux__ +# include <scsi/sg.h> +#endif +#include "hw/virtio/virtio-bus.h" + +typedef struct VirtIOBlockReq +{ + VirtIOBlock *dev; + VirtQueueElement elem; + struct virtio_blk_inhdr *in; + struct virtio_blk_outhdr *out; + struct virtio_scsi_inhdr *scsi; + QEMUIOVector qiov; + struct VirtIOBlockReq *next; + BlockAcctCookie acct; +} VirtIOBlockReq; + +static void virtio_blk_req_complete(VirtIOBlockReq *req, int status) +{ + VirtIOBlock *s = req->dev; + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + trace_virtio_blk_req_complete(req, status); + + stb_p(&req->in->status, status); + virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in)); + virtio_notify(vdev, s->vq); +} + +static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, + bool is_read) +{ + BlockErrorAction action = bdrv_get_error_action(req->dev->bs, is_read, error); + VirtIOBlock *s = req->dev; + + if (action == BDRV_ACTION_STOP) { + req->next = s->rq; + s->rq = req; + } else if (action == BDRV_ACTION_REPORT) { + virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); + bdrv_acct_done(s->bs, &req->acct); + g_free(req); + } + + bdrv_error_action(s->bs, action, is_read, error); + return action != BDRV_ACTION_IGNORE; +} + +static void virtio_blk_rw_complete(void *opaque, int ret) +{ + VirtIOBlockReq *req = opaque; + + trace_virtio_blk_rw_complete(req, ret); + + if (ret) { + bool is_read = !(ldl_p(&req->out->type) & VIRTIO_BLK_T_OUT); + if (virtio_blk_handle_rw_error(req, -ret, is_read)) + return; + } + + virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); + bdrv_acct_done(req->dev->bs, &req->acct); + g_free(req); +} + +static void virtio_blk_flush_complete(void *opaque, int ret) +{ + VirtIOBlockReq *req = opaque; + + if (ret) { + if (virtio_blk_handle_rw_error(req, -ret, 0)) { + return; + } + } + + virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); + bdrv_acct_done(req->dev->bs, &req->acct); + g_free(req); +} + +static VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s) +{ + VirtIOBlockReq *req = g_malloc(sizeof(*req)); + req->dev = s; + req->qiov.size = 0; + req->next = NULL; + return req; +} + +static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s) +{ + VirtIOBlockReq *req = virtio_blk_alloc_request(s); + + if (req != NULL) { + if (!virtqueue_pop(s->vq, &req->elem)) { + g_free(req); + return NULL; + } + } + + return req; +} + +static void virtio_blk_handle_scsi(VirtIOBlockReq *req) +{ +#ifdef __linux__ + int ret; + int i; +#endif + int status = VIRTIO_BLK_S_OK; + + /* + * We require at least one output segment each for the virtio_blk_outhdr + * and the SCSI command block. + * + * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr + * and the sense buffer pointer in the input segments. + */ + if (req->elem.out_num < 2 || req->elem.in_num < 3) { + virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); + g_free(req); + return; + } + + /* + * The scsi inhdr is placed in the second-to-last input segment, just + * before the regular inhdr. + */ + req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base; + + if (!req->dev->blk.scsi) { + status = VIRTIO_BLK_S_UNSUPP; + goto fail; + } + + /* + * No support for bidirection commands yet. + */ + if (req->elem.out_num > 2 && req->elem.in_num > 3) { + status = VIRTIO_BLK_S_UNSUPP; + goto fail; + } + +#ifdef __linux__ + struct sg_io_hdr hdr; + memset(&hdr, 0, sizeof(struct sg_io_hdr)); + hdr.interface_id = 'S'; + hdr.cmd_len = req->elem.out_sg[1].iov_len; + hdr.cmdp = req->elem.out_sg[1].iov_base; + hdr.dxfer_len = 0; + + if (req->elem.out_num > 2) { + /* + * If there are more than the minimally required 2 output segments + * there is write payload starting from the third iovec. + */ + hdr.dxfer_direction = SG_DXFER_TO_DEV; + hdr.iovec_count = req->elem.out_num - 2; + + for (i = 0; i < hdr.iovec_count; i++) + hdr.dxfer_len += req->elem.out_sg[i + 2].iov_len; + + hdr.dxferp = req->elem.out_sg + 2; + + } else if (req->elem.in_num > 3) { + /* + * If we have more than 3 input segments the guest wants to actually + * read data. + */ + hdr.dxfer_direction = SG_DXFER_FROM_DEV; + hdr.iovec_count = req->elem.in_num - 3; + for (i = 0; i < hdr.iovec_count; i++) + hdr.dxfer_len += req->elem.in_sg[i].iov_len; + + hdr.dxferp = req->elem.in_sg; + } else { + /* + * Some SCSI commands don't actually transfer any data. + */ + hdr.dxfer_direction = SG_DXFER_NONE; + } + + hdr.sbp = req->elem.in_sg[req->elem.in_num - 3].iov_base; + hdr.mx_sb_len = req->elem.in_sg[req->elem.in_num - 3].iov_len; + + ret = bdrv_ioctl(req->dev->bs, SG_IO, &hdr); + if (ret) { + status = VIRTIO_BLK_S_UNSUPP; + goto fail; + } + + /* + * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi) + * clear the masked_status field [hence status gets cleared too, see + * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED + * status has occurred. However they do set DRIVER_SENSE in driver_status + * field. Also a (sb_len_wr > 0) indicates there is a sense buffer. + */ + if (hdr.status == 0 && hdr.sb_len_wr > 0) { + hdr.status = CHECK_CONDITION; + } + + stl_p(&req->scsi->errors, + hdr.status | (hdr.msg_status << 8) | + (hdr.host_status << 16) | (hdr.driver_status << 24)); + stl_p(&req->scsi->residual, hdr.resid); + stl_p(&req->scsi->sense_len, hdr.sb_len_wr); + stl_p(&req->scsi->data_len, hdr.dxfer_len); + + virtio_blk_req_complete(req, status); + g_free(req); + return; +#else + abort(); +#endif + +fail: + /* Just put anything nonzero so that the ioctl fails in the guest. */ + stl_p(&req->scsi->errors, 255); + virtio_blk_req_complete(req, status); + g_free(req); +} + +typedef struct MultiReqBuffer { + BlockRequest blkreq[32]; + unsigned int num_writes; +} MultiReqBuffer; + +static void virtio_submit_multiwrite(BlockDriverState *bs, MultiReqBuffer *mrb) +{ + int i, ret; + + if (!mrb->num_writes) { + return; + } + + ret = bdrv_aio_multiwrite(bs, mrb->blkreq, mrb->num_writes); + if (ret != 0) { + for (i = 0; i < mrb->num_writes; i++) { + if (mrb->blkreq[i].error) { + virtio_blk_rw_complete(mrb->blkreq[i].opaque, -EIO); + } + } + } + + mrb->num_writes = 0; +} + +static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb) +{ + bdrv_acct_start(req->dev->bs, &req->acct, 0, BDRV_ACCT_FLUSH); + + /* + * Make sure all outstanding writes are posted to the backing device. + */ + virtio_submit_multiwrite(req->dev->bs, mrb); + bdrv_aio_flush(req->dev->bs, virtio_blk_flush_complete, req); +} + +static void virtio_blk_handle_write(VirtIOBlockReq *req, MultiReqBuffer *mrb) +{ + BlockRequest *blkreq; + uint64_t sector; + + sector = ldq_p(&req->out->sector); + + bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_WRITE); + + trace_virtio_blk_handle_write(req, sector, req->qiov.size / 512); + + if (sector & req->dev->sector_mask) { + virtio_blk_rw_complete(req, -EIO); + return; + } + if (req->qiov.size % req->dev->conf->logical_block_size) { + virtio_blk_rw_complete(req, -EIO); + return; + } + + if (mrb->num_writes == 32) { + virtio_submit_multiwrite(req->dev->bs, mrb); + } + + blkreq = &mrb->blkreq[mrb->num_writes]; + blkreq->sector = sector; + blkreq->nb_sectors = req->qiov.size / BDRV_SECTOR_SIZE; + blkreq->qiov = &req->qiov; + blkreq->cb = virtio_blk_rw_complete; + blkreq->opaque = req; + blkreq->error = 0; + + mrb->num_writes++; +} + +static void virtio_blk_handle_read(VirtIOBlockReq *req) +{ + uint64_t sector; + + sector = ldq_p(&req->out->sector); + + bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_READ); + + trace_virtio_blk_handle_read(req, sector, req->qiov.size / 512); + + if (sector & req->dev->sector_mask) { + virtio_blk_rw_complete(req, -EIO); + return; + } + if (req->qiov.size % req->dev->conf->logical_block_size) { + virtio_blk_rw_complete(req, -EIO); + return; + } + bdrv_aio_readv(req->dev->bs, sector, &req->qiov, + req->qiov.size / BDRV_SECTOR_SIZE, + virtio_blk_rw_complete, req); +} + +static void virtio_blk_handle_request(VirtIOBlockReq *req, + MultiReqBuffer *mrb) +{ + uint32_t type; + + if (req->elem.out_num < 1 || req->elem.in_num < 1) { + error_report("virtio-blk missing headers"); + exit(1); + } + + if (req->elem.out_sg[0].iov_len < sizeof(*req->out) || + req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) { + error_report("virtio-blk header not in correct element"); + exit(1); + } + + req->out = (void *)req->elem.out_sg[0].iov_base; + req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base; + + type = ldl_p(&req->out->type); + + if (type & VIRTIO_BLK_T_FLUSH) { + virtio_blk_handle_flush(req, mrb); + } else if (type & VIRTIO_BLK_T_SCSI_CMD) { + virtio_blk_handle_scsi(req); + } else if (type & VIRTIO_BLK_T_GET_ID) { + VirtIOBlock *s = req->dev; + + /* + * NB: per existing s/n string convention the string is + * terminated by '\0' only when shorter than buffer. + */ + strncpy(req->elem.in_sg[0].iov_base, + s->blk.serial ? s->blk.serial : "", + MIN(req->elem.in_sg[0].iov_len, VIRTIO_BLK_ID_BYTES)); + virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); + g_free(req); + } else if (type & VIRTIO_BLK_T_OUT) { + qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1], + req->elem.out_num - 1); + virtio_blk_handle_write(req, mrb); + } else if (type == VIRTIO_BLK_T_IN || type == VIRTIO_BLK_T_BARRIER) { + /* VIRTIO_BLK_T_IN is 0, so we can't just & it. */ + qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0], + req->elem.in_num - 1); + virtio_blk_handle_read(req); + } else { + virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); + g_free(req); + } +} + +static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) +{ + VirtIOBlock *s = VIRTIO_BLK(vdev); + VirtIOBlockReq *req; + MultiReqBuffer mrb = { + .num_writes = 0, + }; + +#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE + /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start + * dataplane here instead of waiting for .set_status(). + */ + if (s->dataplane) { + virtio_blk_data_plane_start(s->dataplane); + return; + } +#endif + + while ((req = virtio_blk_get_request(s))) { + virtio_blk_handle_request(req, &mrb); + } + + virtio_submit_multiwrite(s->bs, &mrb); + + /* + * FIXME: Want to check for completions before returning to guest mode, + * so cached reads and writes are reported as quickly as possible. But + * that should be done in the generic block layer. + */ +} + +static void virtio_blk_dma_restart_bh(void *opaque) +{ + VirtIOBlock *s = opaque; + VirtIOBlockReq *req = s->rq; + MultiReqBuffer mrb = { + .num_writes = 0, + }; + + qemu_bh_delete(s->bh); + s->bh = NULL; + + s->rq = NULL; + + while (req) { + virtio_blk_handle_request(req, &mrb); + req = req->next; + } + + virtio_submit_multiwrite(s->bs, &mrb); +} + +static void virtio_blk_dma_restart_cb(void *opaque, int running, + RunState state) +{ + VirtIOBlock *s = opaque; + + if (!running) { + return; + } + + if (!s->bh) { + s->bh = qemu_bh_new(virtio_blk_dma_restart_bh, s); + qemu_bh_schedule(s->bh); + } +} + +static void virtio_blk_reset(VirtIODevice *vdev) +{ +#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE + VirtIOBlock *s = VIRTIO_BLK(vdev); + + if (s->dataplane) { + virtio_blk_data_plane_stop(s->dataplane); + } +#endif + + /* + * This should cancel pending requests, but can't do nicely until there + * are per-device request lists. + */ + bdrv_drain_all(); +} + +/* coalesce internal state, copy to pci i/o region 0 + */ +static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) +{ + VirtIOBlock *s = VIRTIO_BLK(vdev); + struct virtio_blk_config blkcfg; + uint64_t capacity; + int blk_size = s->conf->logical_block_size; + + bdrv_get_geometry(s->bs, &capacity); + memset(&blkcfg, 0, sizeof(blkcfg)); + stq_raw(&blkcfg.capacity, capacity); + stl_raw(&blkcfg.seg_max, 128 - 2); + stw_raw(&blkcfg.cylinders, s->conf->cyls); + stl_raw(&blkcfg.blk_size, blk_size); + stw_raw(&blkcfg.min_io_size, s->conf->min_io_size / blk_size); + stw_raw(&blkcfg.opt_io_size, s->conf->opt_io_size / blk_size); + blkcfg.heads = s->conf->heads; + /* + * We must ensure that the block device capacity is a multiple of + * the logical block size. If that is not the case, lets use + * sector_mask to adopt the geometry to have a correct picture. + * For those devices where the capacity is ok for the given geometry + * we dont touch the sector value of the geometry, since some devices + * (like s390 dasd) need a specific value. Here the capacity is already + * cyls*heads*secs*blk_size and the sector value is not block size + * divided by 512 - instead it is the amount of blk_size blocks + * per track (cylinder). + */ + if (bdrv_getlength(s->bs) / s->conf->heads / s->conf->secs % blk_size) { + blkcfg.sectors = s->conf->secs & ~s->sector_mask; + } else { + blkcfg.sectors = s->conf->secs; + } + blkcfg.size_max = 0; + blkcfg.physical_block_exp = get_physical_block_exp(s->conf); + blkcfg.alignment_offset = 0; + blkcfg.wce = bdrv_enable_write_cache(s->bs); + memcpy(config, &blkcfg, sizeof(struct virtio_blk_config)); +} + +static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) +{ + VirtIOBlock *s = VIRTIO_BLK(vdev); + struct virtio_blk_config blkcfg; + + memcpy(&blkcfg, config, sizeof(blkcfg)); + bdrv_set_enable_write_cache(s->bs, blkcfg.wce != 0); +} + +static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features) +{ + VirtIOBlock *s = VIRTIO_BLK(vdev); + + features |= (1 << VIRTIO_BLK_F_SEG_MAX); + features |= (1 << VIRTIO_BLK_F_GEOMETRY); + features |= (1 << VIRTIO_BLK_F_TOPOLOGY); + features |= (1 << VIRTIO_BLK_F_BLK_SIZE); + features |= (1 << VIRTIO_BLK_F_SCSI); + + if (s->blk.config_wce) { + features |= (1 << VIRTIO_BLK_F_CONFIG_WCE); + } + if (bdrv_enable_write_cache(s->bs)) + features |= (1 << VIRTIO_BLK_F_WCE); + + if (bdrv_is_read_only(s->bs)) + features |= 1 << VIRTIO_BLK_F_RO; + + return features; +} + +static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) +{ + VirtIOBlock *s = VIRTIO_BLK(vdev); + uint32_t features; + +#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE + if (s->dataplane && !(status & (VIRTIO_CONFIG_S_DRIVER | + VIRTIO_CONFIG_S_DRIVER_OK))) { + virtio_blk_data_plane_stop(s->dataplane); + } +#endif + + if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) { + return; + } + + features = vdev->guest_features; + bdrv_set_enable_write_cache(s->bs, !!(features & (1 << VIRTIO_BLK_F_WCE))); +} + +static void virtio_blk_save(QEMUFile *f, void *opaque) +{ + VirtIOBlock *s = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(s); + VirtIOBlockReq *req = s->rq; + + virtio_save(vdev, f); + + while (req) { + qemu_put_sbyte(f, 1); + qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem)); + req = req->next; + } + qemu_put_sbyte(f, 0); +} + +static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id) +{ + VirtIOBlock *s = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(s); + int ret; + + if (version_id != 2) + return -EINVAL; + + ret = virtio_load(vdev, f); + if (ret) { + return ret; + } + + while (qemu_get_sbyte(f)) { + VirtIOBlockReq *req = virtio_blk_alloc_request(s); + qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem)); + req->next = s->rq; + s->rq = req; + + virtqueue_map_sg(req->elem.in_sg, req->elem.in_addr, + req->elem.in_num, 1); + virtqueue_map_sg(req->elem.out_sg, req->elem.out_addr, + req->elem.out_num, 0); + } + + return 0; +} + +static void virtio_blk_resize(void *opaque) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + + virtio_notify_config(vdev); +} + +static const BlockDevOps virtio_block_ops = { + .resize_cb = virtio_blk_resize, +}; + +void virtio_blk_set_conf(DeviceState *dev, VirtIOBlkConf *blk) +{ + VirtIOBlock *s = VIRTIO_BLK(dev); + memcpy(&(s->blk), blk, sizeof(struct VirtIOBlkConf)); +} + +static int virtio_blk_device_init(VirtIODevice *vdev) +{ + DeviceState *qdev = DEVICE(vdev); + VirtIOBlock *s = VIRTIO_BLK(vdev); + VirtIOBlkConf *blk = &(s->blk); + static int virtio_blk_id; + + if (!blk->conf.bs) { + error_report("drive property not set"); + return -1; + } + if (!bdrv_is_inserted(blk->conf.bs)) { + error_report("Device needs media, but drive is empty"); + return -1; + } + + blkconf_serial(&blk->conf, &blk->serial); + if (blkconf_geometry(&blk->conf, NULL, 65535, 255, 255) < 0) { + return -1; + } + + virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, + sizeof(struct virtio_blk_config)); + + vdev->get_config = virtio_blk_update_config; + vdev->set_config = virtio_blk_set_config; + vdev->get_features = virtio_blk_get_features; + vdev->set_status = virtio_blk_set_status; + vdev->reset = virtio_blk_reset; + s->bs = blk->conf.bs; + s->conf = &blk->conf; + memcpy(&(s->blk), blk, sizeof(struct VirtIOBlkConf)); + s->rq = NULL; + s->sector_mask = (s->conf->logical_block_size / BDRV_SECTOR_SIZE) - 1; + + s->vq = virtio_add_queue(vdev, 128, virtio_blk_handle_output); +#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE + if (!virtio_blk_data_plane_create(vdev, blk, &s->dataplane)) { + virtio_common_cleanup(vdev); + return -1; + } +#endif + + s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); + register_savevm(qdev, "virtio-blk", virtio_blk_id++, 2, + virtio_blk_save, virtio_blk_load, s); + bdrv_set_dev_ops(s->bs, &virtio_block_ops, s); + bdrv_set_buffer_alignment(s->bs, s->conf->logical_block_size); + + bdrv_iostatus_enable(s->bs); + + add_boot_device_path(s->conf->bootindex, qdev, "/disk@0,0"); + return 0; +} + +static int virtio_blk_device_exit(DeviceState *dev) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + VirtIOBlock *s = VIRTIO_BLK(dev); +#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE + virtio_blk_data_plane_destroy(s->dataplane); + s->dataplane = NULL; +#endif + qemu_del_vm_change_state_handler(s->change); + unregister_savevm(dev, "virtio-blk", s); + blockdev_mark_auto_del(s->bs); + virtio_common_cleanup(vdev); + return 0; +} + +static Property virtio_blk_properties[] = { + DEFINE_VIRTIO_BLK_PROPERTIES(VirtIOBlock, blk), + DEFINE_PROP_END_OF_LIST(), +}; + +static void virtio_blk_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); + dc->exit = virtio_blk_device_exit; + dc->props = virtio_blk_properties; + vdc->init = virtio_blk_device_init; + vdc->get_config = virtio_blk_update_config; + vdc->set_config = virtio_blk_set_config; + vdc->get_features = virtio_blk_get_features; + vdc->set_status = virtio_blk_set_status; + vdc->reset = virtio_blk_reset; +} + +static const TypeInfo virtio_device_info = { + .name = TYPE_VIRTIO_BLK, + .parent = TYPE_VIRTIO_DEVICE, + .instance_size = sizeof(VirtIOBlock), + .class_init = virtio_blk_class_init, +}; + +static void virtio_register_types(void) +{ + type_register_static(&virtio_device_info); +} + +type_init(virtio_register_types) |