On Wed, 15 Jan 2025 19:53:15 +0800
Guangguan Wang [off-list ref] wrote:

quoted

Imagine the following you have your nice little setup with a PNETID on
a non-leaf and a base_ndev that has no PNETID. Then your HW admin
configures a PNETID to your base_ndev, a different one. Suddenly
your ndev PNETID is ignored for reasons not obvious to you. Yes it is
similar to having a software PNETID on the base_ndev and getting it
overruled by a HW PNETID, but much less obvious IMHO. I am wondering if there are any scenarios that require setting different  

pnetids for different net devices in one netdev hierarchy. If no, maybe
we should limit that only one pnetid can be set to one netdev hierarchy.

I wonder what topologies and changes to topologies are possible. If
changes to a topology are possible then making sure there is only one
PNETID within a netdev hierarchy can be difficult, as we would need
to prevent changing the topology if a device has a not PNETID. (E.g.
we first set a pnetid when the netdev is still not in a hierarchy
and then try to put it into the hierarchy that already has a different
PNETID within). Regarding allowable topologies, using your ASCII-art.

I think you could add 2 Pods with an IPVLAN eth0 (Pod) on top of eth1
(host) each. Those would be in a single hierarchy I guess, but I guess
you would still want to be able to set (most likely the same) PNETID
on each.

Bottom line is, this approach looks tricky to me. Maybe with a crisper
explanation on what are these upper-lower links for. Maybe I am
overgeneralizing here.

Regards,
Halil