Re: Timing of host-joined bridge multicast groups with switchdev

On Tue, Feb 23, 2021 at 07:56:22PM +0200, Ido Schimmel wrote:

For route offload you get a dump of all the existing routes when you
register your notifier. It's a bit different with bridge because you
don't care about existing bridges when you just initialize your driver.

We had a similar issue with VXLAN because its FDB can be populated and
only then attached to a bridge that you offload. Check
vxlan_fdb_replay(). Probably need to introduce something similar for
FDB/MDB entries.

So you would be in favor of a driver-voluntary 'pull' type of approach
at bridge join, instead of the bridge 'pushing' the addresses?

That's all fine, except when we'll have more than 3 switchdev drivers,
how do we expect to manage all this complexity duplicated in many places
in the kernel, instead of having it in a central place? Are there corner
cases I'm missing which make the 'push' approach impractical?