From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id 894FA1B19 for ; Tue, 19 Mar 2019 18:29:58 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Mar 2019 10:29:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,245,1549958400"; d="scan'208";a="308552212" Received: from fyigit-mobl.ger.corp.intel.com (HELO [10.237.221.46]) ([10.237.221.46]) by orsmga005.jf.intel.com with ESMTP; 19 Mar 2019 10:29:17 -0700 To: Thomas Monjalon , Hyong Youb Kim Cc: "John Daley (johndale)" , 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 References: <20190305055659.3095-1-hyonkim@cisco.com> <119440374.MxkLxCl2uq@xps> <20190314025800.GA24620@HYONKIM-7R0DR.cisco.com> <50100234.Q8zoU6jCWW@xps> From: Ferruh Yigit Openpgp: preference=signencrypt Autocrypt: addr=ferruh.yigit@intel.com; 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WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 In-Reply-To: <50100234.Q8zoU6jCWW@xps> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit 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: , X-List-Received-Date: Tue, 19 Mar 2019 17:29:59 -0000 On 3/14/2019 10:04 PM, Thomas Monjalon wrote: > 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. But it will be still devarg in new implementation. I guess for this use case, there is a need to pass this information from an API. Options can be: 1- PMD specific API 2- Extend ethdev dev_ops for each usecase 3- Have a generic API, as suggested above 4- Extend configure to accept flags I don't see a winner in above list, each has some problems. Any comment on how to proceed? 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 AD432A00E6 for ; Tue, 19 Mar 2019 18:30:00 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 89D814C96; Tue, 19 Mar 2019 18:30:00 +0100 (CET) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id 894FA1B19 for ; Tue, 19 Mar 2019 18:29:58 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Mar 2019 10:29:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,245,1549958400"; d="scan'208";a="308552212" Received: from fyigit-mobl.ger.corp.intel.com (HELO [10.237.221.46]) ([10.237.221.46]) by orsmga005.jf.intel.com with ESMTP; 19 Mar 2019 10:29:17 -0700 To: Thomas Monjalon , Hyong Youb Kim Cc: "John Daley (johndale)" , 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 References: <20190305055659.3095-1-hyonkim@cisco.com> <119440374.MxkLxCl2uq@xps> <20190314025800.GA24620@HYONKIM-7R0DR.cisco.com> <50100234.Q8zoU6jCWW@xps> From: Ferruh Yigit Openpgp: preference=signencrypt Autocrypt: addr=ferruh.yigit@intel.com; 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WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 In-Reply-To: <50100234.Q8zoU6jCWW@xps> Content-Type: text/plain; charset="UTF-8" Content-Language: en-US Content-Transfer-Encoding: 8bit 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: <20190319172916.nzDN1gW_ryyC7IWG83oWC49ScNxNr_l83Q379pUnBwU@z> On 3/14/2019 10:04 PM, Thomas Monjalon wrote: > 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. But it will be still devarg in new implementation. I guess for this use case, there is a need to pass this information from an API. Options can be: 1- PMD specific API 2- Extend ethdev dev_ops for each usecase 3- Have a generic API, as suggested above 4- Extend configure to accept flags I don't see a winner in above list, each has some problems. Any comment on how to proceed?