Ejemplo n.º 1
0
static int execute_command(BlockBackend *blk,
                           SCSIGenericReq *r, int direction,
                           BlockCompletionFunc *complete)
{
    r->io_header.interface_id = 'S';
    r->io_header.dxfer_direction = direction;
    r->io_header.dxferp = r->buf;
    r->io_header.dxfer_len = r->buflen;
    r->io_header.cmdp = r->req.cmd.buf;
    r->io_header.cmd_len = r->req.cmd.len;
    r->io_header.mx_sb_len = sizeof(r->req.sense);
    r->io_header.sbp = r->req.sense;
    r->io_header.timeout = MAX_UINT;
    r->io_header.usr_ptr = r;
    r->io_header.flags |= SG_FLAG_DIRECT_IO;

    r->req.aiocb = blk_aio_ioctl(blk, SG_IO, &r->io_header, complete, r);
    if (r->req.aiocb == NULL) {
        return -EIO;
    }

    return 0;
}
Ejemplo n.º 2
0
static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req)
{
    int status = VIRTIO_BLK_S_OK;
    struct virtio_scsi_inhdr *scsi = NULL;
    VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
    VirtQueueElement *elem = &req->elem;
    VirtIOBlock *blk = req->dev;

#ifdef __linux__
    int i;
    VirtIOBlockIoctlReq *ioctl_req;
    BlockAIOCB *acb;
#endif

    /*
     * 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 (elem->out_num < 2 || elem->in_num < 3) {
        status = VIRTIO_BLK_S_IOERR;
        goto fail;
    }

    /*
     * The scsi inhdr is placed in the second-to-last input segment, just
     * before the regular inhdr.
     */
    scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;

    if (!blk->conf.scsi) {
        status = VIRTIO_BLK_S_UNSUPP;
        goto fail;
    }

    /*
     * No support for bidirection commands yet.
     */
    if (elem->out_num > 2 && elem->in_num > 3) {
        status = VIRTIO_BLK_S_UNSUPP;
        goto fail;
    }

#ifdef __linux__
    ioctl_req = g_new0(VirtIOBlockIoctlReq, 1);
    ioctl_req->req = req;
    ioctl_req->hdr.interface_id = 'S';
    ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len;
    ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base;
    ioctl_req->hdr.dxfer_len = 0;

    if (elem->out_num > 2) {
        /*
         * If there are more than the minimally required 2 output segments
         * there is write payload starting from the third iovec.
         */
        ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV;
        ioctl_req->hdr.iovec_count = elem->out_num - 2;

        for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
            ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len;
        }

        ioctl_req->hdr.dxferp = elem->out_sg + 2;

    } else if (elem->in_num > 3) {
        /*
         * If we have more than 3 input segments the guest wants to actually
         * read data.
         */
        ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV;
        ioctl_req->hdr.iovec_count = elem->in_num - 3;
        for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
            ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len;
        }

        ioctl_req->hdr.dxferp = elem->in_sg;
    } else {
        /*
         * Some SCSI commands don't actually transfer any data.
         */
        ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE;
    }

    ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base;
    ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len;

    acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr,
                        virtio_blk_ioctl_complete, ioctl_req);
    if (!acb) {
        g_free(ioctl_req);
        status = VIRTIO_BLK_S_UNSUPP;
        goto fail;
    }
    return -EINPROGRESS;
#else
    abort();
#endif

fail:
    /* Just put anything nonzero so that the ioctl fails in the guest.  */
    if (scsi) {
        virtio_stl_p(vdev, &scsi->errors, 255);
    }
    return status;
}