From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9CF4C11F67 for ; Tue, 29 Jun 2021 20:45:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A45F861D8C for ; Tue, 29 Jun 2021 20:45:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235524AbhF2Urt (ORCPT ); Tue, 29 Jun 2021 16:47:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45318 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234054AbhF2Urs (ORCPT ); Tue, 29 Jun 2021 16:47:48 -0400 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F383C061760; Tue, 29 Jun 2021 13:45:20 -0700 (PDT) Received: by mail-ed1-x532.google.com with SMTP id t3so11539305edt.12; Tue, 29 Jun 2021 13:45:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=SfMnQm3DtGao5johrNoU9SWdQ2/7b5T5k6f5X84peDg=; b=nT0oPGuFsx2cLJfwatPNWWDUD0EnREXVQeiXG1xY+yHFL8XlZJaiahus85/VvfUOFR F3TzgxxUsHjtf0IE55RhEJiJJQXdy0c8xHosgEe6ePKJU6TuydjobgvaOuN4SB1meFHw O0bXVyUfDkGGmDnufQnKuB2EPJJO0kO5l2TRrqk637g6fVseU/ghRsOO6sqS+IYjR2SN mNPkv4jkBwCVxaOgFG6zBBrLgJ14j2wxRENTo0h4ycmh2lcXCQyd6vQo17ltHozrVRci 5rN3IQwws6DyUrksw87u876mQgWMyIBs0uoQ/deDkem4mQONjQtU7Gvs+dSj641PaEz4 +oxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=SfMnQm3DtGao5johrNoU9SWdQ2/7b5T5k6f5X84peDg=; b=aoJXte0rdsrgWuUEEq6SnfKL5PpFf/VDw7CEU/wW0dqmZdpoVlJNcF2jQPOWCG+ObH LzbiNbCPhvmHXp0lNx1dNw4jcTRL9HtYbLM6Rg2drjXkt7Ovqa7PUJqijbSGjEczzTRi x1DUFRlWkz/JE7btDuVyN5LWNssUNBkNNY4c9HCbxIDUO/zhsnSI4FH4pX/fDO/NSO81 7B72dP6ssZG1GqRb91zvS9RRUYaECmrqynFhFDwzR9DHWVTpYYQdI0ujgtwkyV3Gcjzb b+nOOtJmkKZoKzfGmNDXDs078T9+DLg5vIWrz7mGvn090pPB69/UWzB7vOmEc6utI/L3 G4LQ== X-Gm-Message-State: AOAM530RHPRaNtR2hR2KxdPYun1w81XlE1Vsw7tsjbLZzKToJVEFtoxq ea1YLjI5MWDb/4uRrPTbyfiEh4NWhquJKV7jx2s= X-Google-Smtp-Source: ABdhPJyUFvDUrS4PvSOg5KKaFX12uA65uQ9gu89JatIa37/P3l1l6uKGEqJVyiBPIKMmsTZwCietIsIvVIzmBMKaRJg= X-Received: by 2002:a05:6402:358:: with SMTP id r24mr42850846edw.69.1624999518939; Tue, 29 Jun 2021 13:45:18 -0700 (PDT) MIME-Version: 1.0 References: <8ad0d38259a678fb42245368f974f1a5cf47d68d.1623674025.git.lorenzo@kernel.org> <20210629100852.56d995a6@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20210629113714.6d8e2445@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: From: Alexander Duyck Date: Tue, 29 Jun 2021 13:45:07 -0700 Message-ID: Subject: Re: [PATCH v9 bpf-next 01/14] net: skbuff: add data_len field to skb_shared_info To: Lorenzo Bianconi Cc: Jesper Dangaard Brouer , Jakub Kicinski , Lorenzo Bianconi , bpf , Netdev , David Miller , Alexei Starovoitov , Daniel Borkmann , shayagr@amazon.com, "Jubran, Samih" , John Fastabend , David Ahern , Jesper Dangaard Brouer , Eelco Chaudron , Jason Wang , Saeed Mahameed , Maciej Fijalkowski , "Karlsson, Magnus" , Tirthendu Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Tue, Jun 29, 2021 at 12:18 PM Lorenzo Bianconi wrote: > > > > > On 29/06/2021 20.37, Jakub Kicinski wrote: > > > On Tue, 29 Jun 2021 11:18:38 -0700 Alexander Duyck wrote: > > > > On Tue, Jun 29, 2021 at 10:08 AM Jakub Kicinski wrote: > > > > > > ack, I agree. I will fix it in v10. > > > > > Why is XDP mb incompatible with LRO? I thought that was one of the use > > > > > cases (mentioned by Willem IIRC). > > > > XDP is meant to be a per packet operation with support for TX and > > > > REDIRECT, and LRO isn't routable. So we could put together a large LRO > > > > frame but we wouldn't be able to break it apart again. If we allow > > > > that then we are going to need a ton more exception handling added to > > > > the XDP paths. > > > > > > > > As far as GSO it would require setting many more fields in order to > > > > actually make it offloadable by any hardware. > > > It would require more work, but TSO seems to be explicitly stated > > > as what the series builds towards (in the cover letter). It's fine > > > to make choices we'd need to redo later, I guess, I'm just trying > > > to understand the why. > > > > This is also my understanding that LRO and TSO is what this patchset is > > working towards. > > > > Sorry, I don't agree or understand this requested change. > > > > > > My understanding here is to use gso_size to store paged length of the > xdp multi-buffer. When converting the xdp_frame to a skb we will need > to overwrite it to support gro/lro. Is my understanding correct? Yes, I was thinking just of the xdp_buff, not the xdp_frame. My focus for right now is mostly around the Rx side of things, xdp_buff to skb, and around the XDP_TX path. If we want to drop/move where we keep the data length when doing the conversion I would be fine with that.