sriov vdsm hook
===============
hook is getting VF via its os nic names, i.e. sriov=eth5
and get its pci address, dettach it from the os, create xml
representation of the device for libvirt domain and adding
it to the guest xml

syntax:
sr-iov: sriov=eth10,eth11
    attach 2 sr-iov VF to vm
    notes at sr-iov/README



RHEL6 sr-iov notes:
===================
o Enable IOMME:
    o Intel CPU, pass intel_iommu=on to the kernel command line
        (dmesg | grep "Intel-IOMMU: enabled" # make sure that iommu is enabled)
    o AMD CPU

o Load sr-iov PF and VF
    o Intel Corporation 82576 Gigabit Network Connection:
        modprobe igb max_vfs=7 # 7 is max for 82576 card
o RHEV-M:
    Add 'sriov=.*' to option_name' to UserDefinedVMProperties (';' is the seperator)
