Re: [PATCH net-next] tsnep: Link queues to NAPIs

[Jakub Kicinski <kuba@kernel.org>]

On Tue, 14 Jan 2025 21:58:24 +0100 Gerhard Engleder wrote:
> > XDP and AF_XDP are different things. The XDP part of AF_XDP is to some
> > extent for advertising purposes :) If memory serves me well:
> > 
> > XDP Tx -> these are additional queues automatically allocated for
> >            in-kernel XDP, allocated when XDP is attached on Rx.
> >            These should _not_ be listed in netlink queue, or NAPI;
> >            IOW should not be linked to NAPI instances.
> > XDP Rx -> is not a thing, XDP attaches to stack queues, there are no
> >            dedicated XDP Rx queues
> > AF_XDP -> AF_XDP "takes over" stack queues. It's a bit of a gray area.
> >            I don't recall if we made a call on these being linked, but
> >            they could probably be listed like devmem as a queue with
> >            an extra attribute, not a completely separate queue type.  
> 
> For tsnep if have no additional XDP Tx queues, only the netdev queues
> are used. For AF_XDP/XSK I would keep the linking, as the stack queues
> still exist and are operated still with NAPI. Maybe queues taken over
> by AF_XDP/XSK get an extra attribute in the future. So I can keep the
> permanent linking to NAPI while interface is up no matter if XDP or
> AF_XDP/XSK is used or not. Did I understand it right?

I think so.