From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5871639C62B; Wed, 14 Jan 2026 13:30:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768397411; cv=none; b=ECjTLbDxcSiw5PR8t8TvCKi269MnSEYJnwzRuDQAfLNyx08RSbabqeu2Xft9INPkbCdCKMymdDSUPkjAs+WFGv1KfdADhaNadccrHYfRyueLbElfqhRk/oKhmKSNHsCufhLthS2ooWesgJiHYgqYh1v9R9yK9XCeM/10t6UVsdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768397411; c=relaxed/simple; bh=srG/rp6SiZUedgMQAF1TOxtf22RrWkjNu0gLUr/eMZY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tfInS/0NR6lNqxv+0/hyn1mdwf0w4xEweXiP9k+Ysp+wEf1Ub20Gf6u+BHkijBjcT5r9qWpTYm6XTlX+cAm1YptLRaKdWeJM4zsJ38dPCdqUbxQooNk4gYMLBqbwftJsXG+JoCWVZkb5pfrJykOE0hyDKdms8TWLkvqhms7DWy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=diUPluS8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="diUPluS8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E59D6C4CEF7; Wed, 14 Jan 2026 13:30:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768397410; bh=srG/rp6SiZUedgMQAF1TOxtf22RrWkjNu0gLUr/eMZY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=diUPluS8kWVPcYzmKDdzumuE4Y3MysN5Sp0CRPdgXV1pEwQ2Gc25NigfXI9vYD16a 9qVZdKazh3NC+rXloSecyx5oEs3mqa5BLWVnX6BFWfqGgD24t1KpMUYTl/V6j52IfO OhdqgsghUcxdmcz8+utpVqUWAvGoCMqEMJjhmknxE3Z58K2lG2xIjPlMvHOSypGWQv Wof8DetL630oloipW8g+P/cHL0ysTMk2ESPeP5ni2miVXEZyia9IERgYkE+QNAhYZB dcwiKOCD4zOivmMvJSiLq469qm/90QOhAg9Ope+9bwQazwdmEqqnEYSuRHd4fp50P0 C0GFtcpjFu9NQ== Message-ID: Date: Wed, 14 Jan 2026 14:30:07 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [bpf-next,v3] bpf: cpumap: report queue_index to xdp_rxq_info To: =?UTF-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Sai Aung Hlyan Htet Cc: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , John Fastabend , netdev@vger.kernel.org, Lorenzo Bianconi References: <20260114060430.1287640-1-saiaunghlyanhtet2003@gmail.com> <87h5so1n49.fsf@toke.dk> <87bjiw1l0v.fsf@toke.dk> <87zf6gz83v.fsf@toke.dk> Content-Language: en-US From: Jesper Dangaard Brouer In-Reply-To: <87zf6gz83v.fsf@toke.dk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 14/01/2026 13.33, Toke Høiland-Jørgensen wrote: > Sai Aung Hlyan Htet writes: > >> On Wed, Jan 14, 2026 at 8:39 PM Toke Høiland-Jørgensen wrote: >> >>> Yeah, this has been discussed as well :) >>> >>> See: >>> https://netdevconf.info/0x19/sessions/talk/traits-rich-packet-metadata.html >>> >>> Which has since evolved a bit to these series: >>> >>> https://lore.kernel.org/r/20260105-skb-meta-safeproof-netdevs-rx-only-v2-0-a21e679b5afa@cloudflare.com >>> >>> https://lore.kernel.org/r/20260110-skb-meta-fixup-skb_metadata_set-calls-v1-0-1047878ed1b0@cloudflare.com >>> Above links are about 100% user defined metadata, that the kernel itself have no structural knowledge about. The RX queue_index (as you wrote in desc[1]) is something that gets lost when XDP-redirecting. The series in [0] is about transferring properties/info that got lost due to XDP-redirect. Lost info that the SKB could be populated with. [0] https://lore.kernel.org/all/175146824674.1421237.18351246421763677468.stgit@firesoul/ - Subj: "[V2 0/7] xdp: Allow BPF to set RX hints for XDP_REDIRECTed packets" [1] https://lore.kernel.org/all/20260114060430.1287640-1-saiaunghlyanhtet2003@gmail.com/ >>> (Also, please don't top-post on the mailing lists) >>> Please read Networking subsystem (netdev) process[2]: [2] https://kernel.org/doc/html/latest/process/maintainer-netdev.html >> Thanks for the pointers. It is really great to see this series. One >> question: Would adding queue_index to the packet traits KV store be >> a useful follow-up once the core infrastructure lands? > > Possibly? Depends on where things land, I suppose. I'd advise following > the discussion on the list until it does :) > Hmm, the "original" RX queue_index isn't super interesting to CPUMAP. You patch doesn't transfer this lost information to the SKB. Information that got lost in the XDP-redirect and which is needed for the SKB is RX-hash, hardware VLAN (not inlined in pkts) and RX- timestamp. As implemented in [0]. --Jesper