Have ixgbe 3.178.3.
Somehow, libvirt cant set MAC & VLAN to correct VF channel.
Example : trying to set AC to VF 0: checked and "ip link show shown, the setting was in channel VF 21.
I bet this is some ordering issue like, but can't point exact quilty.
Everything works fine with igb v4.3.
As tracked this one through linux/libvirt, and the odd behavior is tied together with just ixgbe -driver, and amount of VF -channels. When channel count increases over 10, indexing failed, which been explained in question sent to libvirt mailing list :
https://www.redhat.com/archives/libvir-list/2013-October/msg00799.html [libvirt] libvirt VF indexing issue