Re: [PATCH net-next] tun: use xdp_get_frame_len()

[Willem de Bruijn]

Jon Kohler wrote:
> 
> 
> > On May 7, 2025, at 4:56 PM, Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx> wrote:
> > 
> > !-------------------------------------------------------------------|
> >  CAUTION: External Email
> > 
> > |-------------------------------------------------------------------!
> > 
> > Jon Kohler wrote:
> >> Use xdp_get_frame_len helper to ensure xdp frame size is calculated
> >> correctly in both single buffer and multi buffer configurations.
> > 
> > Not necessarily opposed, but multi buffer is not actually possible
> > in this code path, right?
> > 
> > tun_put_user_xdp only copies xdp_frame->data, for one.
> > 
> > Else this would also be fix, not net-next material.
> 
> Correct, this is a prep patch for future multi buffer support,
> I’m not aware of any path that can currently do that thru
> this code.
> 
> The reason for pursuing multi-buffer is to allow vhost/net
> batching to work again for large payloads.

I was not aware of that context. I'd add a comment to that in the
commit message, and send it as part of that series.