fn create_virtio_devices(
    cfg: &Config,
    vm: &mut impl VmArch,
    resources: &mut SystemAllocator,
    add_control_tube: &mut impl FnMut(AnyControlTube),
    vm_evt_wrtube: &SendTube,
    balloon_inflate_tube: Option<Tube>,
    worker_process_pids: &mut BTreeSet<Pid>,
    render_server_fd: Option<SafeDescriptor>,
    has_vfio_gfx_device: bool,
    registered_evt_q: &SendTube
) -> Result<Vec<VirtioDeviceStub>>