def _get_sysfs_netdev_path(pci_addr, vf_interface=False):
    """Get the sysfs path based on the PCI address of the device.
    Assumes a networking device - will not check for the existence of the path.
    :param pci_addr: the pci addresee of the device(PF or VF).
    :param vf_interface: True if the pci_addr is a VF,
        False if the pci_addr is a PF.
    :returns: the sysfs path corresponds to the pci_addr.
    """
    if vf_interface:
        return "/sys/bus/pci/devices/%s/physfn/net" % pci_addr
    return "/sys/bus/pci/devices/%s/net" % pci_addr