From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (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 B01863B0AF8 for ; Wed, 27 May 2026 19:52:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779911578; cv=none; b=jrmShKfeJhDTq0I9vIZKwCND8PQXhrWuOR3w3z6MHXuLKrXUh3PKOT1SnQHRsfTELR606b+oopH605gj7kcBtV0H817A3DEsP5Li/rGRud2NGKO2UypLAlkabP7SQb7M37IeD1oy+hrCaUZ2wjcozOA3u3gUjdQxB+NeiLk/qu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779911578; c=relaxed/simple; bh=ESpWEv8U7i/rwZrk159PCTa8esnF553wJdOucCIE2xI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bi1e8gAqpmzTSvxWLqfezjBdMmpZA2MHwHR9NVYenJT1DozLHPSyb5vfx3h2+ad6jtRysHyXBUW+BlAXE88dK1ndONyx94UCYjryrtRwk++9pfo5Akg1EYLe2h+ELAbIWNG1LoR82jGop0cN2vaZRJ6nBcQh/zfIZN0QgFn4nVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=tHo2OWCW; arc=none smtp.client-ip=91.218.175.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="tHo2OWCW" Date: Wed, 27 May 2026 12:52:44 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779911574; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LrC/E5OOEeBssNuQEBba+PXsRMzs7+0VDFGOMKZnl4c=; b=tHo2OWCWF9KY921Ly0Tx/o/TqLfAdgZ8WGqi8CJxjSDuHfRRK2GmbhH1Udzewbv7EHX1k5 /9ehA64Ire+BJpPmSaf5RrS4uJRcus261bYuTxvZcWS8D0RVLlVvs2FQrQcq2hk0MS0mpX /x//OtHMdsV2exINFT61dby6S7MqONQ= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau To: Jason Xing Cc: Kuniyuki Iwashima , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Yonghong Song , John Fastabend , Stanislav Fomichev , Eric Dumazet , Neal Cardwell , Willem de Bruijn , Tenzin Ukyab , Kuniyuki Iwashima , bpf@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH v3 bpf-next 03/11] bpf: tcp: Support bpf_skb_load_bytes() for BPF_SOCK_OPS_RCVQ_CB. Message-ID: <202652719515.aUpT.martin.lau@linux.dev> References: <20260523083001.2911931-1-kuniyu@google.com> <20260523083001.2911931-4-kuniyu@google.com> <202652620632.prOx.martin.lau@linux.dev> <2026526214538.Vhly.martin.lau@linux.dev> <2026527192229.olv9.martin.lau@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2026527192229.olv9.martin.lau@linux.dev> X-Migadu-Flow: FLOW_OUT On Wed, May 27, 2026 at 12:46:25PM -0700, Martin KaFai Lau wrote: > > > > > If this new rcvq callback is added to the 'bpf_tcp_ops' proposal [1], > > > > > all this will go away. 'struct sk_buff *skb' can be directly passed to an > > > > > ops of the 'bpf_tcp_ops'. Supporting '*skb' in a struct_ops has already > > > > > been done in the bpf_qdisc. > > > > > > > > > > [1]: https://lore.kernel.org/bpf/20260519215841.2984970-11-martin.lau@linux.dev/ > > > > > > > > Oh I missed the series, the struct_ops conversion looks nice ! > > > > Since this work isn't urgent, I can wait for your series if mine > > > > churns it. > > > > > > > > Jason's series is adding a new op, and I guess this can be > > > > integrated too ? > > > > https://lore.kernel.org/bpf/20260521135244.40869-5-kerneljasonxing@gmail.com/ > > > > > > imo, a new sock_ops cb should be added as an ops in struct_ops. For example, > > > in patch 4 of that series, bpf_skops_rx_timestamping assigns u64 to 'u32 > > > args[4]', which is adding tech debt to the current sock_ops interface. > > > For the timestamping case, it could be a separate ops for the > > > 'struct sock' instead of 'struct tcp_sock' because it should > > > at least work for both TCP and UDP. > > > > Sorry, I don't get it. What is the tech debt in this? And > > bpf_skops_rx_timestamping() only outputs the timestamps, which has > > nothing to do with either 'sock' or 'tcp_sock'. > > Did I say the tech debt is in bpf_skops_rx_timestamping? > I said the tech debt of the bpf_sock_ops[_kern] interface. > Besides always memzero the whole &sockops, the way that the bpf prog > needs to get a u64 timestamp from u32 is not thrilling in 2026. > args[4] is also not reliable when the earlier cgroup bpf prog > writes to replylong. We had already hit some of these in our rx net > timestamping discussion a few years ago. I suggest you go back > and revisit. > > > > > Could you show me what to do next? Thanks in advance. It sounds like > > the tx side of bpf timestamping should be adjusted accordingly? > > imo, the bpf_tcp_ops can land first. and then add net timestamping > ops (existing tx and the new rx) in bpf_sock_ops. To be clear, for bpf_sock_ops, I meant a struct_ops named bpf_sock_ops (or another better name).