It is in beta stages, I do not think it is going to be GA on ConnectX-2 adapters or going to be in the support matrix, but things might change.
To enable it you will need to modify your firmware configuration file with SRIOV support - "SRIOV_EN = 1" using the MFT package
How can I enable SRIOV on ConnectX-2 adapters on Centos 7?
I'm trying MFT packages 3.6 - 4.8 versions but got errors
[root@kvm ~]# mlxconfig -d /dev/mst/mt26448_pciconf0 q
Device type: ConnectX2
PCI device: /dev/mst/mt26448_pciconf0
-E- Failed to query device: /dev/mst/mt26448_pciconf0. Device not supported.