Hi,
How many VLANs you have on the VM? is it one VLAN or two?
Do you work in VGT mode? (VLAN Guest Tagging ) or VST (VLAN switching tagging)?
You can review the OFED UM on the SR-IOV chapter (4.15.6.3)
Do you run RoCE?
The VST mode is the default mode, which means, that the hypervisor will enforce (override) the tagging (no matter what the guest will use).
You can also configure two VFs for the VM, one for each VLAN (working in VST mode).
Ophir.