Re: [net-next, v3 1/2] psp: Support for transmit on logical device when the underlying transport device supports PSP.

[Jakub Kicinski]

On Sat, 28 Feb 2026 14:46:28 -0500 Willem de Bruijn wrote:
> Jakub Kicinski wrote:
> > On Thu, 26 Feb 2026 10:46:53 -0800 Kiran Kella wrote:  
> > > 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@xxxxxx/