From: Simon Horman <horms@kernel.org>
To: Dimitri Daskalakis <dimitri.daskalakis1@gmail.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Alexander Duyck <alexanderduyck@fb.com>,
Jakub Kicinski <kuba@kernel.org>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
Stanislav Fomichev <sdf@fomichev.me>,
Mohsin Bashir <mohsin.bashr@gmail.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kselftest@vger.kernel.org
Subject: Re: [PATCH net] eth: fbnic: Add validation for MTU changes
Date: Mon, 16 Feb 2026 12:18:51 +0000 [thread overview]
Message-ID: <aZMLK7CVV6hSbUOg@horms.kernel.org> (raw)
In-Reply-To: <20260214171949.772493-1-dimitri.daskalakis1@gmail.com>
On Sat, Feb 14, 2026 at 09:19:49AM -0800, Dimitri Daskalakis wrote:
> Increasing the MTU beyond the HDS threshold causes the hardware to
> fragment packets across multiple buffers. If a single-buffer XDP program
> is attached, the driver will drop all multi-frag frames. While we can't
> prevent a remote sender from sending non-TCP packets larger than the MTU,
> this will prevent users from inadvertently breaking new TCP streams.
>
> Traditionally, drivers supported XDP with MTU less than 4Kb
> (packet per page). Fbnic currently prevents attaching XDP when MTU is too high.
> But it does not prevent increasing MTU after XDP is attached.
>
> Fixes: 1b0a3950dbd4 ("eth: fbnic: Add XDP pass, drop, abort support")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: Dimitri Daskalakis <dimitri.daskalakis1@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
next prev parent reply other threads:[~2026-02-16 12:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-14 17:19 [PATCH net] eth: fbnic: Add validation for MTU changes Dimitri Daskalakis
2026-02-16 12:18 ` Simon Horman [this message]
2026-02-18 6:33 ` patchwork-bot+netdevbpf
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=aZMLK7CVV6hSbUOg@horms.kernel.org \
--to=horms@kernel.org \
--cc=alexanderduyck@fb.com \
--cc=andrew+netdev@lunn.ch \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=dimitri.daskalakis1@gmail.com \
--cc=edumazet@google.com \
--cc=hawk@kernel.org \
--cc=john.fastabend@gmail.com \
--cc=kuba@kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=mohsin.bashr@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sdf@fomichev.me \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox