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Subject: Re: Does skb_metadata_differs really need to stop GRO aggregation?
To: =?UTF-8?Q?Toke_H=c3=b8iland-J=c3=b8rgensen?= <toke@redhat.com>,
 Daniel Borkmann <daniel@iogearbox.net>,
 Jesper Dangaard Brouer <hawk@kernel.org>
Cc: Yan Zhai <yan@cloudflare.com>, Stanislav Fomichev <sdf@google.com>,
 Netdev <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
 Alexei Starovoitov <ast@kernel.org>, kernel-team
 <kernel-team@cloudflare.com>, Jakub Kicinski <kuba@kernel.org>,
 Paolo Abeni <pabeni@redhat.com>, Eric Dumazet <edumazet@google.com>,
 "David S. Miller" <davem@davemloft.net>,
 Jakub Sitnicki <jakub@cloudflare.com>
References: <92a355bd-7105-4a17-9543-ba2d8ae36a37@kernel.org>
 <21d05784-3cd7-4050-b66f-bad3eab73f4e@kernel.org>
 <7f48dc04-080d-f7e1-5e01-598a1ace2d37@iogearbox.net> <87fs0qj61x.fsf@toke.dk>
From: Edward Cree <ecree.xilinx@gmail.com>
Message-ID: <0b0c6538-92a5-3041-bc48-d7286f1b873b@gmail.com>
Date: Wed, 29 Nov 2023 18:04:38 +0000
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On 28/11/2023 14:39, Toke Høiland-Jørgensen wrote:
> I'm not quite sure what should be the semantics of that, though. I.e.,
> if you are trying to aggregate two packets that have the flag set, which
> packet do you take the value from? What if only one packet has the flag
> set? Or should we instead have a "metadata_xdp_only" flag that just
> prevents the skb metadata field from being set entirely? Or would both
> be useful?

Sounds like what's actually needed is bpf progs inside the GRO engine
 to implement the metadata "protocol" prepare and coalesce callbacks?

-ed