Commit 2930b313 authored by john cooper's avatar john cooper Committed by Kevin Wolf
Browse files

Add virtio disk identification support 



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 retrieval of the id from guest userland.

Signed-off-by: default avatarjohn cooper <john.cooper@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 9ac228e0

hw/virtio-blk.c

+14 −0
Original line number Diff line number Diff line
@@ -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);
@@ -481,6 +488,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf) 
    VirtIOBlock *s;

    int cylinders, heads, secs;

    static int virtio_blk_id;

    DriveInfo *dinfo;



    s = (VirtIOBlock *)virtio_common_init("virtio-blk", VIRTIO_ID_BLOCK,

                                          sizeof(struct virtio_blk_config),
@@ -495,6 +503,12 @@ 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 the string is terminated

     * by '\0' only when less than sizeof (s->sn)

     */

    dinfo = drive_get_by_blockdev(s->bs);

    strncpy(s->sn, dinfo->serial, 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);

hw/virtio-blk.h

+3 −0
Original line number Diff line number Diff line
@@ -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