'Discover which Virtual functions to manage.
Discover devices, and create embedded switch object for network device
@param device_mappings: device mapping physical_network:device_name
@param exclude_devices: excluded devices mapping device_name: pci slots'

def discover_devices(self, device_mappings, exclude_devices):

    if (exclude_devices is None):
        exclude_devices = {}
    for (phys_net, dev_names) in device_mappings.items():
        for dev_name in dev_names:
            self._process_emb_switch_map(phys_net, dev_name, exclude_devices)
