From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Jakub Kicinski <kuba@kernel.org>, David Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@kernel.org>,
netdev@vger.kernel.org, prashantbhole.linux@gmail.com,
jasowang@redhat.com, davem@davemloft.net, jbrouer@redhat.com,
mst@redhat.com, toshiaki.makita1@gmail.com, daniel@iogearbox.net,
john.fastabend@gmail.com, ast@kernel.org, kafai@fb.com,
songliubraving@fb.com, yhs@fb.com, andriin@fb.com,
David Ahern <dahern@digitalocean.com>
Subject: Re: [PATCH bpf-next 03/12] net: Add IFLA_XDP_EGRESS for XDP programs in the egress path
Date: Fri, 24 Jan 2020 16:36:58 +0100 [thread overview]
Message-ID: <87o8usg92d.fsf@toke.dk> (raw)
In-Reply-To: <20200124072128.4fcb4bd1@cakuba>
Jakub Kicinski <kuba@kernel.org> writes:
> On Thu, 23 Jan 2020 14:33:42 -0700, David Ahern wrote:
>> On 1/23/20 4:35 AM, Toke Høiland-Jørgensen wrote:
>> > David Ahern <dsahern@kernel.org> writes:
>> >> From: David Ahern <dahern@digitalocean.com>
>> >>
>> >> Add IFLA_XDP_EGRESS to if_link.h uapi to handle an XDP program attached
>> >> to the egress path of a device. Add rtnl_xdp_egress_fill and helpers as
>> >> the egress counterpart to the existing rtnl_xdp_fill. The expectation
>> >> is that going forward egress path will acquire the various levels of
>> >> attach - generic, driver and hardware.
>> >
>> > How would a 'hardware' attach work for this? As I said in my reply to
>> > the previous patch, isn't this explicitly for emulating XDP on the other
>> > end of a point-to-point link? How would that work with offloaded
>> > programs?
>>
>> Nothing about this patch set is limited to point-to-point links.
>
> I struggle to understand of what the expected semantics of this new
> hook are. Is this going to be run on all frames sent to the device
> from the stack? All frames from the stack and from XDP_REDIRECT?
>
> A little hard to figure out the semantics when we start from a funky
> device like tun :S
Yes, that is also why I found this a bit weird. We have discussed plans
for an XDP TX hook before:
https://github.com/xdp-project/xdp-project/blob/master/xdp-project.org#xdp-hook-at-tx
That TX hook would run for everything at TX, but it would be a separate
program type with its own metadata access. Whereas the idea with this
series (seemed to me) to be just to be able to "emulate" run a regular
RX-side XDP program on egress for devices where this makes sense.
If this series is not meant to implement that "emulation", but rather be
usable for all devices, I really think we should go straight for the
full TX hook as discussed earlier...
-Toke
next prev parent reply other threads:[~2020-01-24 15:37 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-23 1:41 [PATCH bpf-next 00/12] Add support for XDP in egress path David Ahern
2020-01-23 1:41 ` [PATCH bpf-next 01/12] net: Add new XDP setup and query commands David Ahern
2020-01-23 1:42 ` [PATCH bpf-next 02/12] net: Add BPF_XDP_EGRESS as a bpf_attach_type David Ahern
2020-01-23 11:34 ` Toke Høiland-Jørgensen
2020-01-23 21:32 ` David Ahern
2020-01-24 9:49 ` Toke Høiland-Jørgensen
2020-01-24 7:33 ` Martin Lau
2020-01-23 1:42 ` [PATCH bpf-next 03/12] net: Add IFLA_XDP_EGRESS for XDP programs in the egress path David Ahern
2020-01-23 11:35 ` Toke Høiland-Jørgensen
2020-01-23 21:33 ` David Ahern
2020-01-24 15:21 ` Jakub Kicinski
2020-01-24 15:36 ` Toke Høiland-Jørgensen [this message]
2020-01-26 1:43 ` David Ahern
2020-01-26 4:54 ` Alexei Starovoitov
2020-02-02 17:59 ` David Ahern
2020-01-26 12:49 ` Jesper Dangaard Brouer
2020-01-26 16:38 ` David Ahern
2020-01-26 22:17 ` Jakub Kicinski
2020-01-28 14:13 ` Jesper Dangaard Brouer
2020-01-30 14:45 ` Jakub Kicinski
2020-02-01 16:03 ` Toke Høiland-Jørgensen
2020-02-02 17:48 ` David Ahern
2020-01-26 22:11 ` Jakub Kicinski
2020-01-27 4:03 ` David Ahern
2020-01-27 14:16 ` Jakub Kicinski
2020-01-28 3:43 ` David Ahern
2020-01-28 13:57 ` Jakub Kicinski
2020-02-01 16:24 ` Toke Høiland-Jørgensen
2020-02-01 17:08 ` Jakub Kicinski
2020-02-01 20:05 ` Toke Høiland-Jørgensen
2020-02-02 4:15 ` Jakub Kicinski
2020-02-03 19:56 ` Toke Høiland-Jørgensen
2020-02-03 20:13 ` Toke Høiland-Jørgensen
2020-02-03 22:15 ` Jesper Dangaard Brouer
2020-02-04 11:00 ` Toke Høiland-Jørgensen
2020-02-04 17:09 ` Jakub Kicinski
2020-02-05 15:30 ` Toke Høiland-Jørgensen
2020-02-02 17:45 ` David Ahern
2020-02-02 19:12 ` Jakub Kicinski
2020-02-02 17:43 ` David Ahern
2020-02-02 19:31 ` Jakub Kicinski
2020-02-02 21:51 ` David Ahern
2020-02-01 15:59 ` Toke Høiland-Jørgensen
2020-02-02 17:54 ` David Ahern
2020-02-03 20:09 ` Toke Høiland-Jørgensen
2020-01-23 1:42 ` [PATCH bpf-next 04/12] net: core: rename netif_receive_generic_xdp() to do_generic_xdp_core() David Ahern
2020-01-23 1:42 ` [PATCH bpf-next 05/12] tuntap: check tun_msg_ctl type at necessary places David Ahern
2020-01-23 1:42 ` [PATCH bpf-next 06/12] tun: move shared functions to if_tun.h David Ahern
2020-01-23 1:42 ` [PATCH bpf-next 07/12] vhost_net: user tap recvmsg api to access ptr ring David Ahern
2020-01-23 8:26 ` Michael S. Tsirkin
2020-01-23 1:42 ` [PATCH bpf-next 08/12] tuntap: remove usage of ptr ring in vhost_net David Ahern
2020-01-23 1:42 ` [PATCH bpf-next 09/12] tun: set egress XDP program David Ahern
2020-01-23 1:42 ` [PATCH bpf-next 10/12] tun: run XDP program in tx path David Ahern
2020-01-23 8:23 ` Michael S. Tsirkin
2020-01-24 13:36 ` Prashant Bhole
2020-01-24 13:44 ` Prashant Bhole
2020-01-23 1:42 ` [PATCH bpf-next 11/12] libbpf: Add egress XDP support David Ahern
2020-01-23 1:42 ` [PATCH bpf-next 12/12] samples/bpf: xdp1, add " David Ahern
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87o8usg92d.fsf@toke.dk \
--to=toke@redhat.com \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=dahern@digitalocean.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=dsahern@gmail.com \
--cc=dsahern@kernel.org \
--cc=jasowang@redhat.com \
--cc=jbrouer@redhat.com \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=kuba@kernel.org \
--cc=mst@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=prashantbhole.linux@gmail.com \
--cc=songliubraving@fb.com \
--cc=toshiaki.makita1@gmail.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.