From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 0DBFE41B99; Wed, 1 Feb 2023 07:10:49 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id A2FF240A7A; Wed, 1 Feb 2023 07:10:48 +0100 (CET) Received: from agw.arknetworks.am (agw.arknetworks.am [79.141.165.80]) by mails.dpdk.org (Postfix) with ESMTP id 31F7E4021F for ; Wed, 1 Feb 2023 07:10:47 +0100 (CET) Received: from debian (unknown [78.109.71.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by agw.arknetworks.am (Postfix) with ESMTPSA id D3FCCE0F03; Wed, 1 Feb 2023 10:10:45 +0400 (+04) Date: Wed, 1 Feb 2023 10:10:50 +0400 (+04) From: Ivan Malov To: Thomas Monjalon cc: Ivan Malov , Andrew Rybchenko , Ferruh Yigit , orika@nvidia.com, Jerin Jacob , Nithin Kumar Dabilpuram , Aman Singh , Yuying Zhang , "dev@dpdk.org" , Hanumanth Reddy Pothula , "viacheslavo@nvidia.com" , Jerin Jacob Kollanukkaran , "david.marchand@redhat.com" Subject: Re: [EXT] Re: [PATCH v5 2/2] app/testpmd: add command to process Rx metadata negotiation In-Reply-To: <837604649.0ifERbkFSE@thomas> Message-ID: References: <20221220200250.2413443-1-hpothula@marvell.com> <13375798.lhuNh5TYOU@thomas> <837604649.0ifERbkFSE@thomas> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Hello everyone, Since making automatic, or implicit, offload decisions does not belong in testpmd responsibility domain, it should be safer to avoid calling the "negotiate metadata delivery" API with some default selection unless the user asks to do so explicitly, via internal CLI or app options. With that in mind, port config ... sounds OK. PMDs that support flow primitives which can generate metadata but, if in started state, can't enable its delivery may pass appropriate rte_error messages to the user suggesting they enable delivery of such metadata from NIC to PMD first. This way, if the person operating testpmd enters a flow create command and that fails, they can figure out the inconsistency, stop the port, negotiate, start and try again. As for non-debug applications, their developers shall be properly informed about the problem of enabling delivery of metadata from NIC to PMD. This way, they will invoke the negotiate API by default in their apps, with the feature selection (eg. MARK) as per nature of the app's business. This API should indeed be helpful to some PMDs with regard to collecting upfront knowledge like this. At the same time, should be benign to those PMDs who do not need this knowledge and can enable delivery of metadata right when inserting the flow rules. So I hope the API does not create too much discomfort to vendors not needing it. Thank you. On Wed, 1 Feb 2023, Thomas Monjalon wrote: > 31/01/2023 17:17, Jerin Jacob: >> On Fri, Jan 27, 2023 at 8:31 PM Thomas Monjalon wrote: >>> >>> 27/01/2023 11:42, Nithin Kumar Dabilpuram: >>>> From: Thomas Monjalon >>>>> 27/01/2023 06:02, Nithin Kumar Dabilpuram: >>>>>> From: Thomas Monjalon >>>>>>> Ferruh is proposing to have a command "port config ..." >>>>>>> to configure the flags to negotiate. >>>>>>> Are you OK with this approach? >>>>>> >>>>>> Yes, we are fine to have such command to enable and disable the feature >>>>>> with default being it disabled if supported by PMD. >>>>>> Is default being disabled fine if the feature is supported by a PMD ? >>>>> >>>>> I think the default should be enabled for ease of use. >>>> >>>> Since testpmd is used extensively for benchmarking purposes, we thought it should have minimum features >>>> enabled by default. The default testpmd doesn't have any Rx/Tx offloads enabled(except for FAST FREE), default >>>> fwd mode being "iofwd" and the Rx metadata is only referenced when dumping packets. >>>> >>>> >>>>> Do we have similar features disables by default? >>>>> I mean do we know features in testpmd which require a "double enablement" >>>>> like one configuration command + one rte_flow rule? >>>> >>>> Spec itself is that way i.e "RTE_FLOW_RULE + RX_METADATA_NEGOTIATE(once)" >>>> >>>> Isn't it enough if >>>> >>>> #1 We have enough print when rte_flow is being create without negotiation done and ask user to enable rx metadata using >>>> "port config ..." >>>> #2 Provide testpmd app arg to enable Rx metadata(for example " --rx-metadata") like other features to avoid calling another >>>> command before rte flow create. >>> >>> I'm not sure what is best. >>> I will let others discuss this part. >> >> IMO, enabling something always defeat the purpose to negotiate. IMO, >> someone needs to negotiate >> for a feature if the feature is needed. I think, the double enablement >> is part of the spec itself. In case, The PMD >> drivers won't like double enablement, no need to implement the PMD >> callback. That way, there is no change in the existing flow. >> >> The reason why cnxk driver thought of leveraging negotiate() feature >> so that it helps for optimization. e.s.p >> function template for multiprocess case as we know what features >> needed in fastpath upfront. >> >> If there still concerns with patch we can take up this to TB decide >> one way or another to make forward progress. Let us know. > > Ferruh, Andrew, Ori, Ivan, what is your opinion? > Let's progress with this patch to make it in -rc1. > > >