From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 64546A04DD; Tue, 20 Oct 2020 12:02:28 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 4431CBE2F; Tue, 20 Oct 2020 12:02:27 +0200 (CEST) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id BD7DEBE27 for ; Tue, 20 Oct 2020 12:02:23 +0200 (CEST) IronPort-SDR: UKsfjIwvMiEhcfyY+nvSIryHCXs77uAScKIPOsOBThBjedhYSpmQYo0gcpYUJ2Mgdeq5s4Y60A m9cQOhKJpOiA== X-IronPort-AV: E=McAfee;i="6000,8403,9779"; a="184810000" X-IronPort-AV: E=Sophos;i="5.77,396,1596524400"; d="scan'208";a="184810000" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2020 03:02:13 -0700 IronPort-SDR: j+Zr9xafCvPaFPGuJIFgUmZXbSAoKL8yPgzuIgWPUGUYLUn+g49RdxSoJHJ0Yxg7/mUeDTW3Et eAwiPtxy5HSg== X-IronPort-AV: E=Sophos;i="5.77,396,1596524400"; d="scan'208";a="347806547" Received: from fyigit-mobl1.ger.corp.intel.com (HELO [10.213.247.249]) ([10.213.247.249]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2020 03:02:09 -0700 To: oulijun , Ophir Munk , "wenzhuo.lu@intel.com" , "beilei.xing@intel.com" , NBU-Contact-Adrien Mazarguil Cc: "dev@dpdk.org" , "linuxarm@huawei.com" , Ori Kam References: <1600955105-53176-2-git-send-email-oulijun@huawei.com> <1602765662-43299-1-git-send-email-oulijun@huawei.com> <1b2b0e11-1458-e2d9-5fde-91db35b8bc73@intel.com> <51676746-ec95-aff2-dc00-b76480ab6cba@huawei.com> <8c543941-e881-aa88-b52a-a70bfe8f6fcf@intel.com> <8d592d3e-bace-eb50-a3af-4a0bb87ddae8@intel.com> <7618978b-9675-dbf3-31d0-3abc98fc4304@huawei.com> From: Ferruh Yigit Message-ID: <0fabbf85-156e-f578-ce2d-b1115c8640b8@intel.com> Date: Tue, 20 Oct 2020 11:02:05 +0100 MIME-Version: 1.0 In-Reply-To: <7618978b-9675-dbf3-31d0-3abc98fc4304@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] [PATCH v5] app/testpmd: fix the default RSS key configuration 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" On 10/20/2020 10:00 AM, oulijun wrote: > > > 在 2020/10/16 18:57, Ferruh Yigit 写道: >> On 10/16/2020 11:04 AM, oulijun wrote: >>> >>> >>> 在 2020/10/16 7:53, Ferruh Yigit 写道: >>>> On 10/16/2020 12:21 AM, Ophir Munk wrote: >>>>>> From: Ferruh Yigit >>>>>>>>> On 10/15/2020 1:41 PM, Lijun Ou wrote: >>>>>>>>>> When start the testpmd, the pmd driver initializes the RSS >>>>>>>>>> configuration. Generally, the recommended RSS hash key is used as >>>>>>>>>> the default key in the driver. In addition, the default key is >>>>>>>>>> different from the default RSS flow in testpmd without specifying >>>>>>>>>> RSS hash key. So. if you do not specify the RSS key when creating >>>>>>>>>> an RSS rule, the testpmd uses the default key as the default RSS >>>>>>>>>> key of the RSS rule. As a result, you may mistakenly consider that >>>>>>>>>> the RSS key in use is the valid default key of the NIC, actually, >>>>>>>>>> the key and the valid default key of the NIC are two values. >>>>>>>>>> >>>>>>>>>> Consider the follow usage with testpmd: >>>>>>>>>> 1. first, startup testpmd: >>>>>>>>>> testpmd> show port 0 rss-hash key >>>>>>>>>> RSS functions: >>>>>>>>>>     all ipv4-frag ipv4-other ipv6-frag ipv6-other ip RSS key: >>>>>>>>>> - >>>>>> 6D5A56DA255B0EC24167253D43A38FB0D0CA2BCBAE7B30B477CB2DA3803 >>>>>> 0F >>>>>>>>>> -20C6A42B73BBEAC01FA >>>>>>>>>> 2. create a rss rule >>>>>>>>>> testpmd> flow create 0 ingress pattern eth / ipv4 / udp / end >>>>>>>>>> testpmd> actions rss \ >>>>>>>>>> types ipv4-udp end queues end / end >>>>>>>>>> >>>>>>>>>> 3. show rss-hash key >>>>>>>>>> testpmd> show port 0 rss-hash key >>>>>>>>>> RSS functions: >>>>>>>>>>     all ipv4-udp udp >>>>>>>>>> RSS key: >>>>>>>>>> - >>>>>> 74657374706D6427732064656661756C74205253532068617368206B65792C >>>>>> 206F >>>>>>>>>> -76657272696465 >>>>>>>>>> >>>>>>>>>> In order to solve the above problems, it use the NIC valid default >>>>>>>>>> RSS key instead of the testpmd dummy RSS key in the flow >>>>>>>>>> configuration when the RSS key is not specified in the flow rule. >>>>>>>>>> If the NIC RSS key is invalid, it will use testpmd dummy RSS key as the >>>>>> default key. >>>>>>>>>> >>>>>>>>>> Fixes: ac8d22de2394 ("ethdev: flatten RSS configuration in flow >>>>>>>>>> API") >>>>>>>>>> Cc: stable@dpdk.org >>>>>>>>>> >>>>>>>>>> Signed-off-by: Lijun Ou >>>>>>>>>> Reviewed-by: Phil Yang >>>>>>>>>> --- >>>>>>>>>> V4->V5: >>>>>>>>>> -rewrite the commit log >>>>>>>>>> -add reviewed-by >>>>>>>>> >>>>>>>>> Hi Lijun, >>>>>>>>> >>>>>>>>> There were multiple other comments, it seems they are not addressed >>>>>>>>> but only updated the commit log, can you please check comments to >>>>>> prev versions. >>>>>>>>> >>>>>>>>> Before going into the details, my question was what happens if >>>>>>>>> default key not provided at all? >>>>>>>>> It seems this has been already tried by Ophir [1], later reverted >>>>>>>>> back [2] bringing the initial issue back. >>>>>>>>> >>>>>>>>> According commit, the reason of revert is to support following >>>>>> command: >>>>>>>>> "flow create 0 actions rss queues 0 1 end key_len 40 / end" >>>>>>>>> >>>>>>>>> @Ophir, @Lijun, >>>>>>>>> Can we ignore the 'key_len' if the 'key' is not supported and solve >>>>>>>>> current issue as initially intended ([1])? >>>>>>>>> >>>>>>>> Hi, Ferruh >>>>>>>>     I have discussed with Phil Yang about the problem in [1]. I think >>>>>>>> there may be other problems with the idea and there is no better >>>>>>>> solution. and we need to remove key_len definition from rte_rss_conf >>>>>>>> structure. They don't have a plan. And [1] was eventually reverted. >>>>>>>> >>>>>>> >>>>>>> Why ignoring 'key_len' (set it to zero) when there is no 'key' >>>>>>> provided doesn't work? >>>>>>> >>>>>> >>>>>> What do you think [1] + following update, will it work? >>>>>> >>>>>>    diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c >>>>>>    index ee4f3464fe..e7789c87b3 100644 >>>>>>    --- a/lib/librte_ethdev/rte_flow.c >>>>>>    +++ b/lib/librte_ethdev/rte_flow.c >>>>>>    @@ -535,7 +535,7 @@ rte_flow_conv_action_conf(void *buf, const size_t >>>>>> size, >>>>>>                               }), >>>>>>                               size > sizeof(*dst.rss) ? sizeof(*dst.rss) : >>>>>> size); >>>>>>                    off = sizeof(*dst.rss); >>>>>>    -               if (src.rss->key_len) { >>>>>>    +               if (src.rss->key_len && src.rss->key) { >>>>>>                            off = RTE_ALIGN_CEIL(off, sizeof(*dst.rss->key)); >>>>>>                            tmp = sizeof(*src.rss->key) * src.rss->key_len; >>>>>>                            if (size >= off + tmp) >>>>>> >>>>> >>>>> Ferruh, your suggestion ([1] + update) looks correct. I also verified it on >>>>> mlx5 PMD. >>>>> Advantage: it's a generic fix for all dpdk applications using rte_flows >>>>> (not just testpmd). >>>>> It reduces code. >>>>> With this fix the responsibility of handling key==NULL and/or len==0 is >>>>> moved to the PMDs (which is good). >>>>> With regard to Lijun patch - I liked the approach of overriding the default >>>>> testpmd key with the default PMD key. >>>>> But it only addresses testpmd. More code was added. >>>>> It seems OK to call rte_eth_dev_rss_hash_conf_get() as part of parsing RSS, >>>>> but it would feel more confident if we could confirm it for all the PMDs >>>>> (by testing) or at least review the PMDs rss_hash_conf_get() implementations. >>>>> >>>> >>>> Lijun's idea can work. There was a problem in implementation related to the >>>> key size assumption, which can be fixed. >>>> >>>> Even it is fixed, when user gives a rss rule without a key, we are getting >>>> key from device and feeding same key back to device, this is unnecessary I >>>> think. >>>> When user didn't provide a key, rss rule shouldn't touch the key at all. >>>> >>> Do you mean that the driver should not configure the key to the hardware when >>> the RSS key is not specified? >> >> We are talking about 'key' in RSS rte flow rule, not generally configuring the >> device for RSS. >> > Yes, I know. However, I am talking about some implementations. The configuration > interface may be the same as that for configuring RSS > parameters of the device in general mode. >> If a specific rss rte flow rule, lets say to filter some defined packets to >> some specific queues, don't have 'key' as a part of rule, I am suggesting not >> touch 'key' configuration of the device. >> > Yes, I agree. I think your point of view is very reasonable and a more > appropriate implementation. However, for the sake of simplicity and > other considerations in the architecture design of some devices, the > hardware may support reasonable hybrid configuration for paramter configuration > in the RSS config, rather than independent configuration > for hw, that is, maybe touch A of rss configuration of the device and > must touch B of rss configuration. As a result, If the preceding scenario > occurs, it is reasonable to configure an RSS config that does not change and > specified.What do you think? >>> If so, we cannot identify when the user does not specify the RSS key to >>> determine whether to configure the key. >> >> I think we can. If the rule has 'key' attribute, driver can use that key to >> program the device, if 'key' attribute is missing, don't do anything related >> to the rss key. >> > Yes, if 'key' attribute is missing, don't do anything related to the rss key. > It's more reasonable. > But, If he can't do that, I think it is reasonable to configure the default key > that already exists on the device. The only disadvantage is wasteful. >>> In hardware design, most vendors do not configure keys for hardware >>> independently, which may be associated with other RSS config parameters. >>> I think it would be reasonable for us to reconfigure the RSS key with the >>> default value configured and valid in the hardware as the default value if >>> the user does not specify the RSS key. >> >> There are already APIs to update the RSS configuration, like RSS key, hash >> functions etc.. They are independent from the rte flow RSS rule. >> Application should configure RSS according needs using those APIs. >> > Yes, should do this. Are there any unreasonable users who simply do not know > these APIs or do not want to use them and want to configure some parameters > through the rte flow RSS rule without changing other parameters? >> The question here is about each RSS rte flow rule that can update the key. Am >> I missing something? > I don't think you've misunderstood the general situation. > Even if the RSS key is not specified in a rule, the driver uses the default key > value to re-touch the device. >> >>>> Complication was when user provides key_len without a key, I think both >>>> ignoring or returning error in this case is OK. >>> I agree. However, I think it is meaningless to expose the RSS key length to >>> users. Do you consider deleting the RSS key length directly? >> >> Isn't both 'key' and 'key_len' needed to program the RSS key? Can the driver >> know the size of the 'key' without 'key_len'? >> And driver should verify these provided values. >> > I know and agree.It is only during the analysis of the [1] scheme, from the time > it was proposed to the time it was withdrawn, that I found some guys in the > community questioned the significance of key_len. > > Back to the subject, what is your plan for the solution in the patch? I think, Ophir's old reverted patch [1] + 'rte_flow_conv_action_conf()' update I proposed above can work. Is this working for you? If so can you please send a patch? [1] https://git.dpdk.org/dpdk/commit/?id=a4391f8bae8