can't move mellanox interface to switchdev when SR-IOV disable

[Moshe Levi]

I am looking on the netplan implementation of switchdev [1]. The current code assume that we can move to switchdev only if SR-IOV enabled.
This assumption is incorrect, as we can move to switchdev even if SR-IOV is disabled.

There 2 use-case come to mind:

1. VF Lag with Subfunction (you don't need SR-IOV to enable Subfunction)
2. VF Lag creation. It better to first move the PF (physicals function) to switchdev mode before creating the SR-IOV VF. In this case you don't need to unbind and bind the VFs, which mean you save time at boot.

Who will be the best person at canonical side so help use fix this issues?

[1] - https://github.com/canonical/netplan/blob/3279c57e8b1745be0d19119b4ad1a061c327593e/netplan/cli/sriov.py#L373-L459

[Moshe Levi (moshele)]

Some Nvidia docs on use-cases to move to switchdev mode without SR-IOV

[1] - https://github.com/Mellanox/scalablefunctions/wiki/Upstream-step-by-step-guide
[2] - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/device_drivers/ethernet/mellanox/mlx5.rst?h=v5.12-rc3#n186

[Lukas Märdian (slyon)]

Could this be related to? https://bugs.launchpad.net/ubuntu/+source/netplan.io/+bug/1988018

[Lukas Märdian (slyon)]

https://github.com/canonical/netplan/pull/454