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 0BCD4433EB; Tue, 28 Nov 2023 02:35:00 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 7A10D402BF; Tue, 28 Nov 2023 02:34:59 +0100 (CET) Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by mails.dpdk.org (Postfix) with ESMTP id C27924029E for ; Tue, 28 Nov 2023 02:34:57 +0100 (CET) Received: from kwepemm000004.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4SfQ0701YdzsRZB; Tue, 28 Nov 2023 09:31:18 +0800 (CST) Received: from [10.67.121.59] (10.67.121.59) by kwepemm000004.china.huawei.com (7.193.23.18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Tue, 28 Nov 2023 09:34:55 +0800 Message-ID: <52c309ea-7c83-8b64-e581-5f313227f622@huawei.com> Date: Tue, 28 Nov 2023 09:34:50 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v3 1/6] doc: add RSS hash algorithm feature To: Ferruh Yigit , CC: , , Chengwen Feng , Dongdong Liu , Jie Hai References: <20231123135916.33315-1-lihuisong@huawei.com> <20231125014745.61348-1-lihuisong@huawei.com> <20231125014745.61348-2-lihuisong@huawei.com> <89b73632-8a7a-e54c-2957-04c347027c2e@huawei.com> <8968ac41-bf19-40ac-a057-aad7b46b7ca8@amd.com> From: "lihuisong (C)" In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.121.59] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm000004.china.huawei.com (7.193.23.18) X-CFilter-Loop: Reflected 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 在 2023/11/28 0:35, Ferruh Yigit 写道: > On 11/27/2023 3:43 PM, Ferruh Yigit wrote: >> On 11/27/2023 1:12 PM, lihuisong (C) wrote: >>> 在 2023/11/27 20:19, Ferruh Yigit 写道: >>>> On 11/25/2023 1:47 AM, Huisong Li wrote: >>>>> Add hash algorithm feature introduced by 23.11 and fix some RSS features >>>>> description. >>>>> >>>>> Fixes: 34ff088cc241 ("ethdev: set and query RSS hash algorithm") >>>>> >>>>> Signed-off-by: Huisong Li >>>>> Acked-by: Chengwen Feng >>>>> --- >>>>>   doc/guides/nics/features.rst | 26 ++++++++++++++++++++++---- >>>>>   1 file changed, 22 insertions(+), 4 deletions(-) >>>>> >>>>> diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst >>>>> index 1a1dc16c1e..0d38c5c525 100644 >>>>> --- a/doc/guides/nics/features.rst >>>>> +++ b/doc/guides/nics/features.rst >>>>> @@ -277,10 +277,12 @@ RSS hash >>>>>   Supports RSS hashing on RX. >>>>>     * **[uses]     user config**: ``dev_conf.rxmode.mq_mode`` = >>>>> ``RTE_ETH_MQ_RX_RSS_FLAG``. >>>>> -* **[uses]     user config**: ``dev_conf.rx_adv_conf.rss_conf``. >>>>> +* **[uses]     user config**: ``rss_conf.rss_hf``. >>>>> >>>> Feature title is "RSS hash", it can be two things, >>>> 1. "Receive Side Scaling" support >>>> 2. Provide RSS hash to application >>>> >>>> When this document first prepared RSS hash value was always provided to >>>> the application when RSS enabled. >>>> So intention with this feature was "Receive Side Scaling" support, hence >>>> 'RTE_ETH_MQ_RX_RSS_FLAG' added. >>>> >>>> Later providing RSS has to the application separated as optimization, >>>> 'RTE_ETH_RX_OFFLOAD_RSS_HASH' & 'RTE_MBUF_F_RX_RSS_HASH' added for this >>>> support. >>> What should I do for above two comments？ >>> To tell application how to use it? >>> >> Just tried to give some context. >> >> >>>> As the intention of this feature is "Receive Side Scaling" support, we >>>> shouldn't reduce configuration struct to 'rss_conf.rss_hf'. >>>> >>>> Instead perhaps can expand to: >>>> 'rte_eth_conf.rx_adv_conf.rss_conf', 'rte_eth_rss_conf' >>>  I just pick their common part.😁 >>> >>> ok, will fix it. >>> >>>> >>>>>   * **[uses]     rte_eth_rxconf,rte_eth_rxmode**: >>>>> ``offloads:RTE_ETH_RX_OFFLOAD_RSS_HASH``. >>>>>   * **[provides] rte_eth_dev_info**: ``flow_type_rss_offloads``. >>>>>   * **[provides] mbuf**: ``mbuf.ol_flags:RTE_MBUF_F_RX_RSS_HASH``, >>>>> ``mbuf.rss``. >>>>> +* **[related]  API**: ``rte_eth_dev_configure``, >>>>> ``rte_eth_dev_rss_hash_update`` >>>>> +  ``rte_eth_dev_rss_hash_conf_get()``. >>>>> >>>> ack >>>> >>>>>     .. _nic_features_inner_rss: >>>>> @@ -288,7 +290,7 @@ Supports RSS hashing on RX. >>>>>   Inner RSS >>>>>   --------- >>>>>   -Supports RX RSS hashing on Inner headers. >>>>> +Supports RX RSS hashing on Inner headers by rte_flow API. >>>>> >>>> This should be clarified with details below, not sure if it required to >>>> limit description to rte_flow. >>> But this block like rte_flow_action_rss is from rte_flow. >>> And ethdev ops doesn't support inner RSS. >>> So I think it is ok. >>> >> Yes it is supported by rte_flow, and '[uses]' information should already >> clarify it. >> >> >>>> >>>> And I guess similar confusion exist with the providing hash to user. >>>> Need to check if rte_flow implementation puts hash to mbuf along with >>>> doing the RSS, or if it checks 'RTE_ETH_RX_OFFLOAD_RSS_HASH' offload, >>>> and update below items accordingly. >>> Do we need to tell user how to use it here? >>> I feel this document is a little simple and main to list interface for >>> user. >>> In addition, it is better that the more detail about RSS should be >>> presented  in rte_flow features. >>> >> No, I am not suggesting to add more detail. >> >> My concern is 'RTE_ETH_RX_OFFLOAD_RSS_HASH' information may not be >> correct, ethdev APIs checks offload flags, but does rte_flow >> implementation check it? >> >> My suggestion is double check that piece of information and fix it if >> required. >> > Thinking twice, ethdev API or rte_flow or different ways to configure > RSS, but datapath that puts hash value to mbuf is same. > So same 'RTE_ETH_RX_OFFLOAD_RSS_HASH' check is used for both method, and > it is OK to have it documented. There was a check for  RTE_ETH_RX_OFFLOAD_RSS_HASH in rte_eth_dev_configure(). This offload flag depends on the RTE_ETH_MQ_RX_RSS_FLAG mode. As far as I know, ethdev ops allows to enable RSS hash only when RTE_ETH_MQ_RX_RSS_FLAG mode is set. But rte flow API enable RSS hash doesn't depend on this MQ mode. So I guess that the mbuf.ol_flags:RTE_MBUF_F_RX_RSS_HASH and mbuf.rss also be set to report application when create RSS hash flow, even if application don't set RTE_ETH_MQ_RX_RSS_FLAG mode by ethdev ops. > > > >>>> >>>>>   * **[uses]    rte_flow_action_rss**: ``level``. >>>>>   * **[uses]    rte_eth_rxconf,rte_eth_rxmode**: >>>>> ``offloads:RTE_ETH_RX_OFFLOAD_RSS_HASH``. >>>>> @@ -303,9 +305,25 @@ RSS key update >>>>>   Supports configuration of Receive Side Scaling (RSS) hash >>>>> computation. Updating >>>>>   Receive Side Scaling (RSS) hash key. >>>>>   -* **[implements] eth_dev_ops**: ``rss_hash_update``, >>>>> ``rss_hash_conf_get``. >>>>> +* **[implements] eth_dev_ops**: ``dev_configure``, >>>>> ``rss_hash_update``, ``rss_hash_conf_get``. >>>>> +* **[uses]     user config**: ``rss_conf.rss_key``, >>>>> ``rss_conf.rss_key_len`` >>>>>   * **[provides]   rte_eth_dev_info**: ``hash_key_size``. >>>>> -* **[related]    API**: ``rte_eth_dev_rss_hash_update()``, >>>>> +* **[related]    API**: ``rte_eth_dev_configure``, >>>>> ``rte_eth_dev_rss_hash_update()``, >>>>> +  ``rte_eth_dev_rss_hash_conf_get()``. >>>>> + >>>> ack >>>> >>>> There is an inconsistency in the documentation but I think it is good to >>>> use '()' when documenting API, like: 'rte_eth_dev_configure()' >>> +1 will fix it. >>>> >>>>> + >>>>> +.. _nic_features_rss_hash_algo_update: >>>>> + >>>>> +RSS hash algorithm update >>>>> +------------------------- >>>>> + >>>>> +Supports configuration of Receive Side Scaling (RSS) hash algorithm. >>>>> Updating >>>>> +RSS hash algorithm. >>>>> + >>>>> +* **[implements] eth_dev_ops**: ``dev_configure``, >>>>> ``rss_hash_update``, ``rss_hash_conf_get``. >>>>> +* **[uses]     user config**: ``rss_conf.algorithm`` >>>>> +* **[provides]   rte_eth_dev_info**: ``rss_algo_capa``. >>>>> +* **[related]    API**: ``rte_eth_dev_configure``, >>>>> ``rte_eth_dev_rss_hash_update()``, >>>>>     ``rte_eth_dev_rss_hash_conf_get()``. >>>>> >>>> This document describes features listed in the 'default.ini', so we >>>> shouldn't have above. >>>> >>>> And I don't think RSS hash algorithm update is a big enough feature to >>>> list in the feature list, perhaps it can be embedded in the RSS support >>>> block, what do you think? >>> Yes it is not a bit feature. >>> so put it to RSS hash, right? >>> >> Yes please. >> > .