I tried to use SRIOV to virtualize mellanox nics with vlans on redhat Linux. Long story short it did not work. Per Nvidia the os has to also run open switch. This work was on an already complex setup in finance ... so adding open switch was considered too much additionally complexity. This requirement is not something I run across in the docs.
The situation in networking is a lot different than graphics. I don't know much other than that it depends on what specific protocol, card, firmware, and network topology you're using and there's not really generic advice. If the question is setting up Ethernet switching inside the card so VFs can talk to the network, then I think the Linux switchdev tools can configure that on their own without Open vSwitch but you probably need to find someone who understands your specific type of deployment for better advice.
Depending what you're doing AMD's support for VirtIO Native Context might be a useful alternative (I think it gives less isolation which could be good or bad depending on use).
Anybody know better?