On Tue, May 31, 2022 at 11:34:21AM +0200, Hans Schultz wrote:

quoted

Just to give you another data point about how this works in other
devices, I can say that at least in Spectrum this works a bit
differently. Packets that ingress via a locked port and incur an FDB
miss are trapped to the CPU where they should be injected into the Rx
path so that the bridge will create the 'locked' FDB entry and notify it
to user space. The packets are obviously rated limited as the CPU cannot
handle billions of packets per second, unlike the ASIC. The limit is not
per bridge port (or even per bridge), but instead global to the entire
device.

Btw, will the bridge not create a SWITCHDEV_FDB_ADD_TO_DEVICE event
towards the switchcore in the scheme you mention and thus add an entry
that opens up for the specified mac address?

It will, but the driver needs to ignore FDB entries that are notified
with locked flag. I see that you extended 'struct
switchdev_notifier_fdb_info' with the locked flag, but it's not
initialized in br_switchdev_fdb_populate(). Can you add it in the next
version?