Re: [PATCH v5 bpf-next 8/8] selftests/bpf: introduce XDP compliance test tool

From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Lorenzo Bianconi <lorenzo@kernel.org>
Cc: bpf <bpf@vger.kernel.org>,
	"Network Development" <netdev@vger.kernel.org>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Paolo Abeni" <pabeni@redhat.com>,
	"Eric Dumazet" <edumazet@google.com>,
	"Jesper Dangaard Brouer" <hawk@kernel.org>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Kumar Kartikeya Dwivedi" <memxor@gmail.com>,
	"Marek Majtyka" <alardam@gmail.com>,
	"Saeed Mahameed" <saeedm@nvidia.com>,
	anthony.l.nguyen@intel.com,
	"Andy Gospodarek" <gospo@broadcom.com>,
	vladimir.oltean@nxp.com, "Felix Fietkau" <nbd@nbd.name>,
	john@phrozen.org, "Leon Romanovsky" <leon@kernel.org>,
	"Simon Horman" <simon.horman@corigine.com>,
	"Ariel Elior" <aelior@marvell.com>,
	christophe.jaillet@wanadoo.fr, ecree.xilinx@gmail.com,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Björn Töpel" <bjorn@kernel.org>,
	"Karlsson, Magnus" <magnus.karlsson@intel.com>,
	"Fijalkowski, Maciej" <maciej.fijalkowski@intel.com>,
	intel-wired-lan <intel-wired-lan@lists.osuosl.org>,
	"Lorenzo Bianconi" <lorenzo.bianconi@redhat.com>,
	"Martin KaFai Lau" <martin.lau@linux.dev>,
	"Stanislav Fomichev" <sdf@google.com>,
	gerhard@engleder-embedded.com
Subject: Re: [PATCH v5 bpf-next 8/8] selftests/bpf: introduce XDP compliance test tool
Date: Fri, 3 Feb 2023 15:50:30 -0800	[thread overview]
Message-ID: <CAADnVQKnTzfDuZL0BD9sONeR2jEnQr=mD8kwWHqdaz9dv8VQRA@mail.gmail.com> (raw)
In-Reply-To: <Y91GLP4LCqsGE8kX@localhost.localdomain>

On Fri, Feb 3, 2023 at 9:35 AM Lorenzo Bianconi <lorenzo@kernel.org> wrote:
>
> > On Wed, Feb 1, 2023 at 2:25 AM Lorenzo Bianconi <lorenzo@kernel.org> wrote:
> > >
> > > Introduce xdp_features tool in order to test XDP features supported by
> > > the NIC and match them against advertised ones.
> > > In order to test supported/advertised XDP features, xdp_features must
> > > run on the Device Under Test (DUT) and on a Tester device.
> > > xdp_features opens a control TCP channel between DUT and Tester devices
> > > to send control commands from Tester to the DUT and a UDP data channel
> > > where the Tester sends UDP 'echo' packets and the DUT is expected to
> > > reply back with the same packet. DUT installs multiple XDP programs on the
> > > NIC to test XDP capabilities and reports back to the Tester some XDP stats.
> >
> >
> > 'DUT installs...'? what? The device installs XDP programs ?
>
> Hi Alexei,
>
> DUT stands for Device Under Test, I was thinking it is quite a common term.
> Sorry for that.

It was clear from the commit log.
My point was not questioning whether abbreviation is common or not.
It's this:
"device under test installs...". device installs? No. device doesn't
install anything. It's xdp_features tool attaches a prog to the
device.

and more:
"device under test socket"... what does it even mean?

> >
> > > +
> > > +       ctrl_sockfd = accept(*sockfd, (struct sockaddr *)&ctrl_addr, &addrlen);
> > > +       if (ctrl_sockfd < 0) {
> > > +               fprintf(stderr, "Failed to accept connection on DUT socket\n");
> >
> > Applied, but overuse of the word 'DUT' is incorrect and confusing.
> >
> > 'DUT socket' ? what is that?
> > 'Invalid DUT address' ? what address?
> > The UX in general is not user friendly.
> >
> > ./xdp_features
> > Invalid ifindex
> >
> > This is not a helpful message.
> >
> > ./xdp_features eth0
> > Starting DUT on device 3
> > Failed to accept connection on DUT socket
> >
> > 'Starting DUT' ? What did it start?
>
> I will post a follow-up patch to clarify them.
>
> Regards,
> Lorenzo