This patch adds the final missing bits for support of passing a serial/id string to a virtio-blk guest driver.
The guest-side component already exists in the virtio driver, and has recently been reworked by Ryan to export a /sys interface for retrival of the id from guest userland. Signed-off-by: john cooper<john.coo...@redhat.com> --- diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 0bf929a..bd6b896 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -26,6 +26,7 @@ typedef struct VirtIOBlock QEMUBH *bh; BlockConf *conf; unsigned short sector_mask; + char sn[BLOCK_SERIAL_STRLEN]; } VirtIOBlock; static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev) @@ -324,6 +325,12 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req, virtio_blk_handle_flush(req, mrb); } else if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) { virtio_blk_handle_scsi(req); + } else if (req->out->type & VIRTIO_BLK_T_GET_ID) { + VirtIOBlock *s = req->dev; + + memcpy(req->elem.in_sg[0].iov_base, s->sn, + MIN(req->elem.in_sg[0].iov_len, sizeof(s->sn))); + virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); } else if (req->out->type & VIRTIO_BLK_T_OUT) { qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1], req->elem.out_num - 1); @@ -495,6 +502,12 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf) s->sector_mask = (s->conf->logical_block_size / BDRV_SECTOR_SIZE) - 1; bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs); + /* NB: per existing s/n string convention we really intend to hard-limit + * the copy length to sizeof (s->sn) even in the case we're left without + * a trailing '\0' + */ + strncpy(s->sn, drive_get_serial(s->bs), sizeof (s->sn)); + s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output); qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h index 7a7ece3..fff46da 100644 --- a/hw/virtio-blk.h +++ b/hw/virtio-blk.h @@ -59,6 +59,9 @@ struct virtio_blk_config /* Flush the volatile write cache */ #define VIRTIO_BLK_T_FLUSH 4 +/* return the device ID string */ +#define VIRTIO_BLK_T_GET_ID 8 + /* Barrier before this op. */ #define VIRTIO_BLK_T_BARRIER 0x80000000 -- john.coo...@redhat.com