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 C7651EB64DD for ; Mon, 24 Jul 2023 21:36:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231132AbjGXVg5 (ORCPT ); Mon, 24 Jul 2023 17:36:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229553AbjGXVgy (ORCPT ); Mon, 24 Jul 2023 17:36:54 -0400 Received: from mail-lj1-x229.google.com (mail-lj1-x229.google.com [IPv6:2a00:1450:4864:20::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 368F3126 for ; Mon, 24 Jul 2023 14:36:53 -0700 (PDT) Received: by mail-lj1-x229.google.com with SMTP id 38308e7fff4ca-2b95efb9d89so70385691fa.0 for ; Mon, 24 Jul 2023 14:36:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastly.com; s=google; t=1690234611; x=1690839411; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=Cl41eJ1WC6ILldSjNqzW1R/MpU0yZbIUTyos3W/vR0o=; b=J4CUcw3+5oLla8TJKoKYSVEPfeoBbb8HGbt1EaSjZ5ZYN0cwUeijDPUg754M8TWgKq i9EBAjICG+W2jNI6eXpwG/Co/CfB4nPkXtHKfV4vAXs8zs1d+e47Twh+4/O1k8ZQGPKb i0GyJMUdcXrSAuHZLaWZ2UC9hk2OSsDLE84BE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690234611; x=1690839411; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Cl41eJ1WC6ILldSjNqzW1R/MpU0yZbIUTyos3W/vR0o=; b=A/YhTUWP2/rzqueuVQaETTU0EQbBJhLS9y6H+ANz6rZt139QWSdoQVcu45tc5QcxeU eu5xPIRMhN3fd0GeN3UmRVui8QtxTu1Tp6Psa8km9deoJecjzzzTNqyHC/cG68PgEQJV o9feyJm3csltKUfBmMaKzJqIlFPhQAMgopO6E8KHAjwq/J+tlTWU/1+vnpW11F8c2IUl Sh+NWxaup5yTSHop2KlX6/JgEppTJAgZNZupkGxkqYTsnxIGBBnrgo+MOTX1eeNsP7yX w4jctN/PRDqi7FlzcKZ9CG+Z5ktjhvyb8soIei6bhO3/2fg/ZpmRdpt/cCbJp7kZbSOL pAlw== X-Gm-Message-State: ABy/qLZ1kcQJGxBtnsjEdpHbJUFYPqT2/FdpEZSg5L9uHmw5AaMzS/LG UnH2ymjv+jgvbZtEe67NWsbbSQ== X-Google-Smtp-Source: APBJJlEIBhBaRS5nkCMsUEUORF8/eFhcX7G26UgE+SkpTlX6AirHvLESoYGQK4lOK9BQqV+Y87oGoQ== X-Received: by 2002:a2e:80cd:0:b0:2b6:d790:d1a3 with SMTP id r13-20020a2e80cd000000b002b6d790d1a3mr6457024ljg.11.1690234611479; Mon, 24 Jul 2023 14:36:51 -0700 (PDT) Received: from fastly.com ([188.225.251.141]) by smtp.gmail.com with ESMTPSA id hn32-20020a05600ca3a000b003f9bd9e3226sm11447112wmb.7.2023.07.24.14.36.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 24 Jul 2023 14:36:51 -0700 (PDT) Date: Mon, 24 Jul 2023 14:36:48 -0700 From: Joe Damato To: Edward Cree Cc: netdev@vger.kernel.org, saeedm@nvidia.com, tariqt@nvidia.com, ecree@solarflare.com, andrew@lunn.ch, kuba@kernel.org, davem@davemloft.net, leon@kernel.org, pabeni@redhat.com, arnd@arndb.de, linux-kernel@vger.kernel.org Subject: Re: [net 0/2] rxfh with custom RSS fixes Message-ID: <20230724213647.GA48335@fastly.com> References: <20230723150658.241597-1-jdamato@fastly.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 24, 2023 at 08:27:43PM +0100, Edward Cree wrote: > On 23/07/2023 16:06, Joe Damato wrote: > > Greetings: > > > > While attempting to get the RX flow hash key for a custom RSS context on > > my mlx5 NIC, I got an error: > > > > $ sudo ethtool -u eth1 rx-flow-hash tcp4 context 1 > > Cannot get RX network flow hashing options: Invalid argument > > > > I dug into this a bit and noticed two things: > > > > 1. ETHTOOL_GRXFH supports custom RSS contexts, but ETHTOOL_SRXFH does > > not. I moved the copy logic out of ETHTOOL_GRXFH and into a helper so > > that both ETHTOOL_{G,S}RXFH now call it, which fixes ETHTOOL_SRXFH. This > > is patch 1/2. > > As I see it, this is a new feature, not a fix, so belongs on net-next. > (No existing driver accepts FLOW_RSS in ETHTOOL_SRXFH's cmd->flow_type, > which is just as well as if they did this would be a uABI break.) > > Going forward, ETHTOOL_SRXFH will hopefully be integrated into the new > RSS context kAPI I'm working on[1], so that we can have a new netlink > uAPI for RSS configuration that's all in one place instead of the > piecemeal-grown ethtool API with its backwards-compatible hacks. > But that will take a while, so I think this should go in even though > it's technically an extension to legacy ethtool; it was part of the > documented uAPI and userland implements it, it just never got > implemented on the kernel side (because the initial driver with > context support, sfc, didn't support SRXFH). > > > 2. mlx5 defaulted to RSS context 0 for both ETHTOOL_{G,S}RXFH paths. I > > have modified the driver to support custom contexts for both paths. It > > is now possible to get and set the flow hash key for custom RSS contexts > > with mlx5. This is patch 2/2. > > My feeling would be that this isn't a Fix either, but not my place to say. Thanks for the context above; I'll let the Mellanox folks weigh in on what they think about the code in the second patch before I proceed. I suspect that you are probably right and that net-next might be a more appropriate place for this. If the code is ack'd by Mellanox (and they agree re: net-next), I can re-send this series to net-next with the Fixes removed and the Ack's added.