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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B771C4332F for ; Wed, 23 Nov 2022 14:35:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238107AbiKWOe7 (ORCPT ); Wed, 23 Nov 2022 09:34:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238592AbiKWOeu (ORCPT ); Wed, 23 Nov 2022 09:34:50 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 997FE18B28 for ; Wed, 23 Nov 2022 06:33:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669214031; 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=VEC/ljsECl0xwOwNuuFj4J2VWL3DFQIVZWJ6dvR2khs=; b=C9vFwQEbkehORiQkhkuDd6jbj1pJJD5GTz1hlCK4houkRU0hjw/p+GBLHz0jh/Q0mvcK5B ffMtksegjZjM70KD/hnYcwmctRsEhcBLBBKP3ZWE7ZMfDgdqyq6XKLR7pVdWJ3WSQTpyyl liBiuuf9jVo5yOx0goFrS/kPxJTV9fY= Received: from mail-ej1-f72.google.com (mail-ej1-f72.google.com [209.85.218.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-570-Ft1aI_j6M_Ca9gdsI1F23w-1; Wed, 23 Nov 2022 09:33:50 -0500 X-MC-Unique: Ft1aI_j6M_Ca9gdsI1F23w-1 Received: by mail-ej1-f72.google.com with SMTP id xc12-20020a170907074c00b007416699ea14so10050678ejb.19 for ; Wed, 23 Nov 2022 06:33:50 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=VEC/ljsECl0xwOwNuuFj4J2VWL3DFQIVZWJ6dvR2khs=; b=DqVc+OKKMjxFFbDtNIsiIv1txuMWj7mRJl67HOFFIJ8BrwHAu8Z2pku3UjvGPteUcZ KMTU/YIliOL/fTACTy7XFVbPB3oAFlEGAEdejHkc4tWRobB62S6ZvQbCD0oht77Dm++Z zHqW1nvCt0Iyk31NKRLoBIm0RsaBkC21z9usp7zqnb2+Jj2erwfuKuwplX4z19ChDW2J yQ29pkA7ToLHS7Lw3seTefE0zJRJ27w0cRepqajpOIusnBcYkFFcViGs3kJhaijQdoQm R8jE2PzLYrikg9/vDKY41Mc0BuvhKFBpUikgb2oIOe3Iy2lOjZBEJxcJO7/DiNONej+E fkeg== X-Gm-Message-State: ANoB5plCmfpmq3y28eDBCu2I/dq2d1vCrbAQdWiFH9Ax97NSMeIzB+V1 b97HHEutCq4b7AMcA676NXjKgEIFXhzeqNUzIsuDiZE9+Qx7X3UasZP3o4qO7g8Yzc/7SYnENiv cemW6g1yoHYv9 X-Received: by 2002:a17:906:ce35:b0:7ae:215:2dd5 with SMTP id sd21-20020a170906ce3500b007ae02152dd5mr8205308ejb.208.1669214029128; Wed, 23 Nov 2022 06:33:49 -0800 (PST) X-Google-Smtp-Source: AA0mqf6Br7EfMXN8zzJJucIbAC1NA/3UEE3+EzuxBZef9EsnddC7aq3JapzaQq+3gcmcLf6jmsIGvw== X-Received: by 2002:a17:906:ce35:b0:7ae:215:2dd5 with SMTP id sd21-20020a170906ce3500b007ae02152dd5mr8205265ejb.208.1669214028772; Wed, 23 Nov 2022 06:33:48 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id es8-20020a056402380800b00459148fbb3csm7642794edb.86.2022.11.23.06.33.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Nov 2022 06:33:48 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 63FC87D511B; Wed, 23 Nov 2022 15:33:47 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Stanislav Fomichev , bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, Tariq Toukan , David Ahern , Jakub Kicinski , Willem de Bruijn , Jesper Dangaard Brouer , Anatoly Burakov , Alexander Lobakin , Magnus Karlsson , Maryam Tahhan , xdp-hints@xdp-project.net, netdev@vger.kernel.org Subject: Re: [xdp-hints] [PATCH bpf-next v2 6/8] mlx4: Introduce mlx4_xdp_buff wrapper for xdp_buff In-Reply-To: <20221121182552.2152891-7-sdf@google.com> References: <20221121182552.2152891-1-sdf@google.com> <20221121182552.2152891-7-sdf@google.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 23 Nov 2022 15:33:47 +0100 Message-ID: <874jupviyc.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Stanislav Fomichev writes: > No functional changes. Boilerplate to allow stuffing more data after xdp_buff. > > Cc: Tariq Toukan > Cc: John Fastabend > Cc: David Ahern > Cc: Martin KaFai Lau > Cc: Jakub Kicinski > Cc: Willem de Bruijn > Cc: Jesper Dangaard Brouer > Cc: Anatoly Burakov > Cc: Alexander Lobakin > Cc: Magnus Karlsson > Cc: Maryam Tahhan > Cc: xdp-hints@xdp-project.net > Cc: netdev@vger.kernel.org > Signed-off-by: Stanislav Fomichev > --- > drivers/net/ethernet/mellanox/mlx4/en_rx.c | 26 +++++++++++++--------- > 1 file changed, 15 insertions(+), 11 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c > index 8f762fc170b3..467356633172 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c > +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c > @@ -661,17 +661,21 @@ static int check_csum(struct mlx4_cqe *cqe, struct sk_buff *skb, void *va, > #define MLX4_CQE_STATUS_IP_ANY (MLX4_CQE_STATUS_IPV4) > #endif > > +struct mlx4_xdp_buff { > + struct xdp_buff xdp; > +}; This embedding trick works for drivers that put xdp_buff on the stack, but mlx5 supports XSK zerocopy, which uses the xsk_buff_pool for allocating them. This makes it a bit awkward to do the same thing there; and since it's probably going to be fairly common to do something like this, how about we just add a 'void *drv_priv' pointer to struct xdp_buff that the drivers can use? The xdp_buff already takes up a full cache line anyway, so any data stuffed after it will spill over to a new one; so I don't think there's much difference performance-wise. I'll send my patch to add support to mlx5 (using the drv_priv pointer approach) separately. -Toke