RE: [PATCH] public/io/netif.h: add a new extra type for XDP

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: Jürgen Groß <jgross@xxxxxxxx>
> Sent: 18 May 2020 11:28
> To: Denis Kirjanov <kda@xxxxxxxxxxxxxxxxx>
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx; paul@xxxxxxx
> Subject: Re: [PATCH] public/io/netif.h: add a new extra type for XDP
> 
> On 18.05.20 11:52, Denis Kirjanov wrote:
> > On 5/18/20, Jürgen Groß <jgross@xxxxxxxx> wrote:
> >> On 18.05.20 10:24, Denis Kirjanov wrote:
> >>> The patch adds a new extra type to be able to diffirentiate
> >>> between RX responses on xen-netfront side with the adjusted offset
> >>> required for XDP processing.
> >>>
> >>> For Linux the offset value is going to be passed via xenstore.
> >>
> >> Why? I can only see disadvantages by using a different communication
> >> mechanism.
> > I see it like other features passed through xenstore and it requires
> > less changes to
> > other structures with the same final result.
> 
> This is okay as long there is no Xenstore interaction required when the
> interface has been setup completely (i.e. only defining the needed
> offset for XDP is fine, enabling/disabling XDP at runtime should not be
> done via Xenstore IMO).

FWIW it is for this kind of thing that I introduced the control ring, but that 
may be overkill for this.

  Paul

> 
> And please, no guest type special casing. Please replace "Linux" by e.g.
> "The guest" (with additional tweaking of the following sentence).
> 
> 
> Juergen