'Get `LibvirtConfigGuestDisk` filled for this image.
:disk_dev: Disk bus device name
:disk_bus: Disk bus type
:device_type: Device type for this image.
:cache_mode: Caching mode for this image
:extra_specs: Instance type extra specs dict.
:hypervisor_version: the hypervisor version
:boot_order: Disk device boot order'

def libvirt_info(self, disk_bus, disk_dev, device_type, cache_mode, extra_specs, hypervisor_version, boot_order=None, disk_unit=None):

    info = vconfig.LibvirtConfigGuestDisk()
    info.source_type = self.source_type
    info.source_device = device_type
    info.target_bus = disk_bus
    info.target_dev = disk_dev
    info.driver_cache = cache_mode
    info.driver_discard = self.discard_mode
    info.driver_io = self.driver_io
    info.driver_format = self.driver_format
    driver_name = libvirt_utils.pick_disk_driver_name(hypervisor_version, self.is_block_dev)
    info.driver_name = driver_name
    info.source_path = self.path
    info.boot_order = boot_order
    if (disk_bus == 'scsi'):
        self.disk_scsi(info, disk_unit)
    self.disk_qos(info, extra_specs)
    return info
