[libvirt] [PATCH 0/4 v2] macvtap: Support for sending port profile message for a SRIOV VF to its PF

[Roopa Prabhu]

This patch tries to fix getPhysFn in macvtap.c to get the physical 
function(PF) of the direct attach interface, if the interface is a SR-IOV VF.

It moves some of the sriov pci device handling code from node_device_driver 
to src/util/pci.[ch]. 

This patch series implements the following 
01/3 - pci: Move some pci sriov helper code out of node device driver to util/pci
02/3 - pci: Add helper functions for sriov devices
02/3 - interface: Add functions to get sriov PF/VF relationship of a net interface
03/3 - macvtap: Fix getPhysfn to get the PF of a direct attach network interface

Changelog:
----------
v1: RFC patch introduced new functions to get PF/VF relationship of SRIOV 
net devices by comparing PF/VF sysfs device links. Also mentioned the 
existance of some related code in node_device_driver. The feedback was to
move and use the node_device_driver code 

v2: Moves sriov get_physical_function and get_virtual_functions from 
node_device_driver to src/util/pci*. And reworks the rest of the patches
around the new code. 

Signed-off-by: Roopa Prabhu <roprabhu at cisco.com>
Signed-off-by: Christian Benvenuti <benve at cisco.com>
Signed-off-by: David Wang <dwang2 at cisco.com>