From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 4E3E1A0096 for ; Thu, 14 Mar 2019 23:04:45 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 761E92C28; Thu, 14 Mar 2019 23:04:44 +0100 (CET) Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by dpdk.org (Postfix) with ESMTP id 95AE31E2F for ; Thu, 14 Mar 2019 23:04:42 +0100 (CET) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id E7D3021C0F; Thu, 14 Mar 2019 18:04:41 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Thu, 14 Mar 2019 18:04:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=mesmtp; bh=5sCVCPFSE93vzYYgYaaMVkduGQmg7ERmOGlOaIqcucI=; b=EkJDsFx/WGTA JbdFzDyi/lO1Nlm83Qgdk4cLOtsGp6hBIm7/2KK96acNuzxbuRsqnZuVlGCF3Ede MHTFpxJ+kfq9HH/52i5t/aWgBT94vch51YG6TvAoca6Peypj2rL64cQ59GtItroX jd/LnrvwN7BF9RhX4uNw80kkznr/AG0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; bh=5sCVCPFSE93vzYYgYaaMVkduGQmg7ERmOGlOaIqcu cI=; b=1IxclPdu0I96KxgEUdtteBrb4yfYIJ382/iTHBEakPFZGQvAkZbjLHlKU NlKgFETuGqB9NOaL3gYY++P5Othm9uZuJ+qgqSq7al0ypo0S0jcIQ7ZNWcWx23jg 02KK3uo7CSvrZC/GDR0kvTikMSWdhPzFEUNk7+Pjl7U0jZzSpNe/GcyW/1unxK64 ICvYFCgJKJjyb0Yu14ZzVNjQLuQKmTINZNyKODKAoIcUW0ooSeMmBePB9zpGc7K3 mWb6t4N+Q+Hjk7byjAzV2MiUD4C3u5j6DiCgNryWvTPNBQltCluRSkQrLPTSQeMF VVsV/+EzMvA4hypQUY5oT4CY3ynEQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedutddrheefgdeihecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkjghfggfgtgesthfuredttddtvdenucfhrhhomhepvfhhohhmrghs ucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtqeenucfkph epjeejrddufeegrddvtdefrddukeegnecurfgrrhgrmhepmhgrihhlfhhrohhmpehthhho mhgrshesmhhonhhjrghlohhnrdhnvghtnecuvehluhhsthgvrhfuihiivgeptd X-ME-Proxy: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id F258010312; Thu, 14 Mar 2019 18:04:38 -0400 (EDT) From: Thomas Monjalon To: Hyong Youb Kim Cc: "John Daley (johndale)" , Ferruh Yigit , Andrew Rybchenko , Qi Zhang , "dev@dpdk.org" , Shahaf Shuler , Jerin Jacob , David Marchand , Maxime Coquelin , Konstantin Ananyev , Hemant Agrawal , Stephen Hemminger , gaetan.rivet@6wind.com Date: Thu, 14 Mar 2019 23:04:37 +0100 Message-ID: <50100234.Q8zoU6jCWW@xps> In-Reply-To: <20190314025800.GA24620@HYONKIM-7R0DR.cisco.com> References: <20190305055659.3095-1-hyonkim@cisco.com> <119440374.MxkLxCl2uq@xps> <20190314025800.GA24620@HYONKIM-7R0DR.cisco.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="UTF-8" Subject: Re: [dpdk-dev] [PATCH v2] net/enic: add private API to set ingress VLAN rewrite mode X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Message-ID: <20190314220437.0tf1WmnZgi7Xd77r7d3Cht_c26mG_9wXfTz0NDVLKbU@z> 14/03/2019 03:58, Hyong Youb Kim: > On Wed, Mar 13, 2019 at 10:29:53PM +0100, Thomas Monjalon wrote: > > 13/03/2019 22:11, John Daley (johndale): > > > From: Thomas Monjalon > > > > 13/03/2019 19:32, Ferruh Yigit: > > > > > On 3/5/2019 7:11 AM, Hyong Youb Kim wrote: > > > > > > The driver currently has a devarg to set the rewrite mode during > > > > > > init. Some apps want to programatically set it after running > > > > > > rte_eal_init() and finding that ports are VIC. Add a private > > > > > > function to support such applications. > > > > > > > > > > It is not good idea to have PMD specific APIs (although we already have > > > > some). > > > > > > > > > > Specific to this case, as far as I can see it is to pass a config > > > > > value and do the action related to it, what would you think having a > > > > > generic key/value set/get API in ethdev for this? Similar to rawdev > > > > get_attr/set_attr [1]? > > > > > > > > > > My concern is it may turn into something like ioctl with many things > > > > > pushed to it, and cause possible duplication ... > > > > > > > > Yes, it is clearly ioctl style. > > > > > > > > Please could you explain more what is the rewrite mode? > > > > Does it apply to the port or the queue? > > > > > > > It applies to a port. By default the Cisco VIC VLAN tags every packet on ingress even if they were untagged coming in on the wire. They are tagged with VLAN 0 or a VLAN id programmed into the NIC depending on the configuration. Its part of the original design, to maintain priority bits, ancient history. > > > > > > Some apps don't like this (VPP) or take a slower path (OVS). Hyong added a ig-vlan-rewrite=untag devarg to disable this (leave untagged/default vlan packets untagged) during rte_eal_init and this is helpful for OVS, but VPP likes to set the rewrite mode after rte_eal_init() and finding the ports are VIC ports. So that is the reasoning behind the private API call. > > > > It looks like an application will always set this flag or never. > > So I don't see the need for an API function. > > Why VPP prefers set this flag later? > > Would it be better to have some driver-specific flags, no matter the ports? > > As is, there seem to be two ways apps deal with NIC-specific tweaks/quirks. > > 1. Leave everything to the user. > > Let the human user specify NIC-specific settings (e.g. devarg, > not-so-standard MTU/MRU, offloads with not-so-uniform behavior). The > app simply passes these to DPDK and does nothing else. Devargs are > passed to rte_eal_init. Other settings are applied during the > configure phase after rte_eal_init. > > For example, OVS seems to go for a smallest common denominator that > works with most NICs out of the box. Otherwiese, it kinda falls into > this camp. > > For a problematic NIC that needs user intervention, troubleshooting > goes like this :-) > - Install app. > - Run with settings that worked on a previous machine. > - Some features suddenly do not work. > - Google search this and that ("why this does not work on this server?"). > - Contact vendors. > - Find out this NIC has unexpected behavior. > - Set devarg, tweak MTU/MRU, ... ("Oh need to set this for .."). > - Now the features work. > > 2. Hide ugly tweaks from the user. > > VPP falls into this camp. The user specifies BDFs in the config (no > devargs). The app calls rte_eal_init(BDFs), iterates through the > discovered ports, applies whatever NIC-specific settings necessary > during the configure phase (i.e. do this for vendor A NIC, do that for > vendor B NIC), and then start the ports. > > The ingress vlan rewrite mode is devarg now, so is not usable in this > model. One way around it is a private API. Driver specific flags > during the configure phase would also work fine. Though, enic might be > the only user of those flags. I think DPDK needs some driver configuration. Currently the config is done per device with devargs. The next devargs format allow this: driver=enic,rewrite=on and it can be passed to rte_eal_init(). We did not progress on the implementation of this format in recent months, but you are welcome to help! Instead of passing devargs in the whitelist/blacklist options, we should introduce a new option, like --dev.