'Add the updated MAC address value to the update_port request body.
Currently this is done only for PF passthrough.'

@staticmethod
def _populate_pci_mac_address(instance, pci_request_id, port_req_body):

    if (pci_request_id is not None):
        pci_devs = pci_manager.get_instance_pci_devs(instance, pci_request_id)
        if (len(pci_devs) != 1):
            LOG.error(_LE('PCI    request    %s    does    not    have    a    unique    device    associated    with    it.    Unable    to    determine    MAC    address'), pci_request, instance=instance)
            return
        pci_dev = pci_devs[0]
        if (pci_dev.dev_type == obj_fields.PciDeviceType.SRIOV_PF):
            try:
                mac = pci_utils.get_mac_by_pci_address(pci_dev.address)
            except exception.PciDeviceNotFoundById as e:
                LOG.error(_LE('Could    not    determine    MAC    address    for    %(addr)s,    error:    %(e)s'), {'addr': pci_dev.address, 'e': e}, instance=instance)
            else:
                port_req_body['port']['mac_address'] = mac
