DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2548520868
MIME-Version: 1.0
References: <cover.1543343124.git.lorenzo.bianconi@redhat.com>
 <8736rla4ow.fsf@purkki.adurom.net> <20181128104436.GA2298@localhost.localdomain>
 <87bm69v0ol.fsf@toke.dk> <20181128131141.GD2298@localhost.localdomain>
 <875zwhuvta.fsf@toke.dk> <20181128143533.GE2298@localhost.localdomain>
 <87zhtttg8p.fsf@toke.dk> <20181128153508.GG2298@localhost.localdomain>
 <87in0gu78s.fsf@toke.dk> <20181129125929.GB6365@localhost.localdomain>
In-Reply-To: <20181129125929.GB6365@localhost.localdomain>
From:   =?UTF-8?Q?Micha=C5=82_Kazior?= <kazikcz@gmail.com>
Date:   Thu, 29 Nov 2018 14:45:28 +0100
Message-ID: <CABvG-CVpYXpjE9vxsA90qzsGm3n48SBYv-dYWAB8vi9-dvhK4A@mail.gmail.com>
Subject: Re: [RFC 0/5] add XDP support to mt76x2e/mt76x0e drivers
To:     lorenzo.bianconi@redhat.com
Cc:     =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= <toke@toke.dk>,
        kvalo@codeaurora.org,
        linux-wireless <linux-wireless@vger.kernel.org>,
        Felix Fietkau <nbd@nbd.name>, brouer@redhat.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

On Thu, 29 Nov 2018 at 14:00, Lorenzo Bianconi
<lorenzo.bianconi@redhat.com> wrote:
[...]
> > The other direction will probably be more difficult, at least if 802.11
> > frames need to be built in software. It *might* be possible with the XD=
P
> > egress hook we are planning (with a suitable set of helpers, the eBPF
> > program could build the 802.11 frames), but I'm not really sure if that
> > is worth doing as I'm quite sure there are some hairy edge cases
> > there...
>
> The possible issue with XDP_DROP action you are referring to here is A-MP=
DU
> reordering on rx side, right? If so I guess the issue will be fixed by
> tid_agg_rx->reorder_timer. Are you referring to other possible edge cases=
?

What I'm thinking is reordering could be one of possible things to
offload to an XDP program. It would require per-station data structure
to keep track of the frame sequence numbers (among other things). Same
could be said for crypto offloads (would require XDP programs to be
able to use crypto apis I guess?).


Micha=C5=82