this is what i was able to learn:
For ConnectX3, VF promiscuous mode is supported and for ConnectX4 CQE have timestamping however, the timestamping netdev/IB is not supported in VF.
On ConnectX4 timestamping Ethernet timestamping should also work in VF.
Of course, i suggest you evaluate this before you start your actual work to make sure it will integrate properly with your app.
Good luck.
VF promiscuous mode is supported