def _is_virtio_blk(device_path):
    """
    Check whether the supplied device path is a virtio_blk device.

    We assume that virtio_blk device name always begin with `vd` whereas
    Xen devices begin with `xvd`.
    See https://www.kernel.org/doc/Documentation/devices.txt

    :param FilePath device_path: The device path returned by the Cinder API.
    :returns: ``True`` if it's a ``virtio_blk`` device, else ``False``.
    """
    return device_path.basename().startswith('vd')