pub fn generate_pci_topology(
    parent_bus: Arc<Mutex<PciBus>>,
    resources: &mut SystemAllocator,
    io_ranges: &mut BTreeMap<usize, Vec<BarRange>>,
    device_ranges: &mut BTreeMap<usize, Vec<BarRange>>,
    device_addrs: &[PciAddress],
    devices: &mut Vec<(Box<dyn PciDevice>, Option<Minijail>)>
) -> Result<(Vec<BarRange>, u8), DeviceRegistrationError>