On Sat, 28 Feb 2026 14:46:28 -0500 Willem de Bruijn wrote:

Jakub Kicinski wrote:

quoted

On Thu, 26 Feb 2026 10:46:53 -0800 Kiran Kella wrote:  

quoted

This is achieved by propagating the psp_dev from the lower device
to the upper devices in the device stack via a netdevice notifier.
The lowest device owns the psp_dev pointer while the upper devices
just borrow the pointer. When the lower device is unlinked, the
borrowed pointer is cleared in the upper device.
Assumption being that psp_dev is set on the lowest device before
any upper devices are stacked on that lowest device.  

As I mentioned in the other thread I'd like to establish some clear
expectation on where psd propagates automatically and where it doesn't.
I don't want to see a stream of patches that say "fix propagating PSP
onto X upper". And conversely report saying "PSP got propagated but
it doesn't actually work" (macvlan in bridge mode etc).

Hence my preference was to require the user who created the device
to propagate PSP. Willem, WDYT?  

Can you give a bit more detail what you have in mind?

An explicit user (netlink) API to associate a psp_dev with a
net_device?

Yes:
https://lore.kernel.org/all/20260224002410.1553838-7-weibunny@fb.com/ (local)