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 56F93A034F; Sun, 3 Oct 2021 11:30:19 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id E583240698; Sun, 3 Oct 2021 11:30:18 +0200 (CEST) Received: from shelob.oktetlabs.ru (shelob.oktetlabs.ru [91.220.146.113]) by mails.dpdk.org (Postfix) with ESMTP id 364764068E for ; Sun, 3 Oct 2021 11:30:18 +0200 (CEST) Received: from [100.65.5.102] (unknown [5.144.123.248]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by shelob.oktetlabs.ru (Postfix) with ESMTPSA id 6116F7F53A; Sun, 3 Oct 2021 12:30:17 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 shelob.oktetlabs.ru 6116F7F53A DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=oktetlabs.ru; s=default; t=1633253417; bh=oy3kXYGYGYolCqokpP84NsI7LSioUr88P4CPq64yN1w=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=J291ntD/ylqhD1NnG6LHpWzaxqaakKZd0NC/MpxMWkhCH7HV/2tXlYSwgnPn/d/wO /NjLNFilcqbXmKQZpf7eRD7WrpJi53gN4FMt+8trc/cqonv6fjv3lr6RjERpo8a71u 3MFDhTcjKSlHrTBepOCsXq/m9Wt0/rXLK4QG/ILg= To: Ori Kam , Andrew Rybchenko , "dev@dpdk.org" Cc: Andy Moreton , Ray Kinsella , Jerin Jacob , Wisam Monther , Xiaoyun Li , NBU-Contact-Thomas Monjalon , Ferruh Yigit References: <20210902142359.28138-1-ivan.malov@oktetlabs.ru> <20210923112012.14595-1-ivan.malov@oktetlabs.ru> <20210923112012.14595-2-ivan.malov@oktetlabs.ru> From: Ivan Malov Message-ID: <6e9703ae-9fe0-2656-c08f-da95e44bcdeb@oktetlabs.ru> Date: Sun, 3 Oct 2021 12:30:13 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] [PATCH v3 1/5] ethdev: add API to negotiate delivery of Rx meta data 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 Sender: "dev" Hi Ori, Thanks for reviewing this. On 03/10/2021 10:42, Ori Kam wrote: > Hi Andrew and Ivan, > > >> -----Original Message----- >> From: Andrew Rybchenko >> Sent: Friday, October 1, 2021 9:50 AM >> Subject: Re: [PATCH v3 1/5] ethdev: add API to negotiate delivery of Rx meta >> data >> >> On 9/30/21 10:07 PM, Ivan Malov wrote: >>> Hi Ori, >>> >>> On 30/09/2021 17:59, Ori Kam wrote: >>>> Hi Ivan, >>>> Sorry for jumping in late. >>> >>> No worries. That's OK. >>> >>>> I have a concern that this patch breaks other PMDs. >>> >>> It does no such thing. >>> >>>>> From the rst file " One should negotiate flag delivery beforehand" >>>> since you only added this function for your PMD all other PMD will fail. >>>> I see that you added exception in the  examples, but it doesn't make >>>> sense that applications will also need to add this exception which is >>>> not documented. >>> >>> Say, you have an application, and you use it with some specific PMD. >>> Say, that PMD doesn't run into the problem as ours does. In other >>> words, the user can insert a flow with action MARK at any point and >>> get mark delivery working starting from that moment without any >>> problem. Say, this is exactly the way how it works for you at the moment. >>> >>> Now. This new API kicks in. We update the application to invoke it as >>> early as possible. But your PMD in question still doesn't support this >>> API. The comment in the patch says that if the method returns ENOTSUP, >>> the application should ignore that without batting an eyelid. It >>> should just keep on working as it did before the introduction of this API. >>> > > I understand that it is nice to write in the patch comment that application > should disregard this function in case of > ENOTSUP but in a few month someone will read the official doc, > where it is stated that this function call is a must and then what do you > think the application will do? > I think that the correct way is to add this function to all PMDs. > Another option is to add to the doc that if the function is returning ENOTSUP > the application should assume that all is supported. > > So from this point of view there is API break. So, you mean an API breakage in some formal sense? If the doc is fixed in accordance with the second option you suggest, will it suffice to avoid this formal API breakage? > >>> More specific example: >>> Say, the application doesn't mind using either "RSS + MARK" or tunnel >>> offload. What it does right now is attempt to insert tunnel flows >>> first and, if this fails, fall back to "RSS + MARK". With this API, >>> the application will try to invoke this API with "USER_MARK | >>> TUNNEL_ID" in adapter initialised state. If the PMD says that it can >>> only enable the tunnel offload, then the application will get the >>> knowledge that it doesn't make sense to even try inserting "RSS + >>> MARK" flows. It just can skip useless actions. But if the PMD doesn't >>> support the method, the application will see ENOTSUP and handle this >>> gracefully: it will make no assumptions about what's guaranteed to be >>> supported and what's not and will just keep on its old behavior: try >>> to insert a flow, fail, fall back to another type of flow. >>> > > I fully agree with your example, and think that this is the way > to go, application should supply as much info as possible during startup. Right. > My question/comment is the negotiated result means that all of the actions > are supported on the same rule? > for example if application wants to add mark and tag on the same rule. > (I know it doesn't make much sense) and the PMD can support both of them > but not on the same rule, what should it return? > Or for example if using the mark can only be supported if no decap action is set > on this rule what should be the result? > From my undstanding this function is only to let the PMD know that on some > rules the application will use those actions, the checking if the action combination > is valid only happens on validate function right? This API does not bind itself to flow API. It's *not* about enabling support for metadata *actions* (they are conducted entirely *inside* the NIC). It's about enabling *delivery* of metadata from the NIC to host. Say, you insert a flow rule to mark some packets. The NIC, internally (in the e-switch) adds the mark to matching packets. Yes, in the boundaries of the NIC HW, the packets bear the mark on them. It has been set, yes. But when time comes to *deliver* the packets to the host, the NIC (at least, in net/sfc case) has two options: either provide only a small chunk of the metadata for each packet *to the host*, which doesn't include mark ID, flag and RSS hash, OR, alternatively, provide the full set of metadata. In the former option, the mark is simply not delivered. Once again: it *has been set*, but simply will not be *delivered to the host*. So, this API is about negotiating *delivery* of metadata. In pure technical sense. And the set of flags that this API returns indicates which kinds of metadata the NIC will be able to deliver simultaneously. For example, as I understand, in the case of tunnel offload, MLX5 claims Rx mark entirely for tunnel ID metadata, so, if an application requests "MARK | TUNNEL_ID" with this API, this PMD should probably want to respond with just "TUNNEL_ID". The application will see the response and realise that, even if it adds its *own* (user) action MARK to a flow and if the flow is not rejected by the PMD, it won't be able to see the mark in the received mbufs (or the mark will be incorrect). But some other PMDs (net/sfc, for instance) claim only a small fraction of bits in Rx mark to deliver tunnel ID information. Remaining bits are still available for delivery of *user* mark ID. Please see an example at https://patches.dpdk.org/project/dpdk/patch/20210929205730.775-2-ivan.malov@oktetlabs.ru/ . In this case, the PMD may want to return both flags in the response: "MARK | TUNNEL_ID". This way, the application knows that both features are enabled and available for use. Now. I anticipate more questions asking why wouldn't we prefer flow API terminology or why wouldn't we add an API for negotiating support for metadata *actions* and not just metadata *delivery*. There's an answer. Always has been. The thing is, the use of *actions* is very complicated. For example, the PMD may support action MARK for "transfer" flows but not for non-"transfer" ones. Also, simultaneous use of multiple different metadata actions may not be possible. And, last but not least, if we force the application to check support for *actions* on action-after-action basis, the order of checks will be very confusing to applications. Previously, in this thread, Thomas suggested to go for exactly this type of API, to check support for actions one-by-one, without any context ("transfer" / non-"transfer"). I'm afraid, this won't be OK. > > In any case I think this is good idea and I will see how we can add a more generic approach of > this API to the new API that I'm going to present. > > >>> So no breakages with this API. >>> >>>> >>>> Please see more comments inline. >>>> >>>> Thanks, >>>> Ori >>>> >>>>> -----Original Message----- >>>>> From: Ivan Malov >>>>> Sent: Thursday, September 23, 2021 2:20 PM >>>>> Subject: [PATCH v3 1/5] ethdev: add API to negotiate delivery of Rx >>>>> meta data >>>>> >>>>> Delivery of mark, flag and the likes might affect small packet >>>>> performance. >>>>> If these features are disabled by default, enabling them in started >>>>> state without causing traffic disruption may not always be possible. >>>>> >>>>> Let applications negotiate delivery of Rx meta data beforehand. >>>>> >>>>> Signed-off-by: Ivan Malov >>>>> Reviewed-by: Andrew Rybchenko >>>>> Reviewed-by: Andy Moreton >>>>> Acked-by: Ray Kinsella >>>>> Acked-by: Jerin Jacob >>>>> --- >>>>>   app/test-flow-perf/main.c              | 21 ++++++++++++ >>>>>   app/test-pmd/testpmd.c                 | 26 +++++++++++++++ >>>>>   doc/guides/rel_notes/release_21_11.rst |  9 ++++++ >>>>>   lib/ethdev/ethdev_driver.h             | 19 +++++++++++ >>>>>   lib/ethdev/rte_ethdev.c                | 25 ++++++++++++++ >>>>>   lib/ethdev/rte_ethdev.h                | 45 >>>>> ++++++++++++++++++++++++++ >>>>>   lib/ethdev/rte_flow.h                  | 12 +++++++ >>>>>   lib/ethdev/version.map                 |  3 ++ >>>>>   8 files changed, 160 insertions(+) >>>>> >>>>> diff --git a/app/test-flow-perf/main.c b/app/test-flow-perf/main.c >>>>> index 9be8edc31d..48eafffb1d 100644 >>>>> --- a/app/test-flow-perf/main.c >>>>> +++ b/app/test-flow-perf/main.c >>>>> @@ -1760,6 +1760,27 @@ init_port(void) >>>>>           rte_exit(EXIT_FAILURE, "Error: can't init mbuf pool\n"); >>>>> >>>>>       for (port_id = 0; port_id < nr_ports; port_id++) { >>>>> +        uint64_t rx_meta_features = 0; >>>>> + >>>>> +        rx_meta_features |= RTE_ETH_RX_META_USER_FLAG; >>>>> +        rx_meta_features |= RTE_ETH_RX_META_USER_MARK; >>>>> + >>>>> +        ret = rte_eth_rx_meta_negotiate(port_id, >>>>> &rx_meta_features); >>>>> +        if (ret == 0) { >>>>> +            if (!(rx_meta_features & >>>>> RTE_ETH_RX_META_USER_FLAG)) { >>>>> +                printf(":: flow action FLAG will not affect Rx >>>>> mbufs on port=%u\n", >>>>> +                       port_id); >>>>> +            } >>>>> + >>>>> +            if (!(rx_meta_features & >>>>> RTE_ETH_RX_META_USER_MARK)) { >>>>> +                printf(":: flow action MARK will not affect Rx >>>>> mbufs on port=%u\n", >>>>> +                       port_id); >>>>> +            } >>>>> +        } else if (ret != -ENOTSUP) { >>>>> +            rte_exit(EXIT_FAILURE, "Error when negotiating Rx >>>>> meta features on port=%u: %s\n", >>>>> +                 port_id, rte_strerror(-ret)); >>>>> +        } >>>>> + >>>>>           ret = rte_eth_dev_info_get(port_id, &dev_info); >>>>>           if (ret != 0) >>>>>               rte_exit(EXIT_FAILURE, diff --git >>>>> a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index >>>>> 97ae52e17e..7a8da3d7ab 100644 >>>>> --- a/app/test-pmd/testpmd.c >>>>> +++ b/app/test-pmd/testpmd.c >>>>> @@ -1485,10 +1485,36 @@ static void >>>>>   init_config_port_offloads(portid_t pid, uint32_t socket_id)  { >>>>>       struct rte_port *port = &ports[pid]; >>>>> +    uint64_t rx_meta_features = 0; >>>>>       uint16_t data_size; >>>>>       int ret; >>>>>       int i; >>>>> >>>>> +    rx_meta_features |= RTE_ETH_RX_META_USER_FLAG; >>>>> +    rx_meta_features |= RTE_ETH_RX_META_USER_MARK; >>>>> +    rx_meta_features |= RTE_ETH_RX_META_TUNNEL_ID; >>>>> + >>>>> +    ret = rte_eth_rx_meta_negotiate(pid, &rx_meta_features); >>>>> +    if (ret == 0) { >>>>> +        if (!(rx_meta_features & RTE_ETH_RX_META_USER_FLAG)) { >>>>> +            TESTPMD_LOG(INFO, "Flow action FLAG will not >>>>> affect Rx mbufs on port %u\n", >>>>> +                    pid); >>>>> +        } >>>>> + >>>>> +        if (!(rx_meta_features & RTE_ETH_RX_META_USER_MARK)) >>>>> { >>>>> +            TESTPMD_LOG(INFO, "Flow action MARK will not >>>>> affect Rx mbufs on port %u\n", >>>>> +                    pid); >>>>> +        } >>>>> + >>>>> +        if (!(rx_meta_features & RTE_ETH_RX_META_TUNNEL_ID)) { >>>>> +            TESTPMD_LOG(INFO, "Flow tunnel offload support >>>>> might be limited or unavailable on port %u\n", >>>>> +                    pid); >>>>> +        } >>>>> +    } else if (ret != -ENOTSUP) { >>>>> +        rte_exit(EXIT_FAILURE, "Error when negotiating Rx meta >>>>> features on port %u: %s\n", >>>>> +             pid, rte_strerror(-ret)); >>>>> +    } >>>>> + >>>>>       port->dev_conf.txmode = tx_mode; >>>>>       port->dev_conf.rxmode = rx_mode; >>>>> >>>>> diff --git a/doc/guides/rel_notes/release_21_11.rst >>>>> b/doc/guides/rel_notes/release_21_11.rst >>>>> index 19356ac53c..6674d4474c 100644 >>>>> --- a/doc/guides/rel_notes/release_21_11.rst >>>>> +++ b/doc/guides/rel_notes/release_21_11.rst >>>>> @@ -106,6 +106,15 @@ New Features >>>>>     Added command-line options to specify total number of processes >>>>> and >>>>>     current process ID. Each process owns subset of Rx and Tx queues. >>>>> >>>>> +* **Added an API to negotiate delivery of specific parts of Rx meta >>>>> +data** >>>>> + >>>>> +  A new API, ``rte_eth_rx_meta_negotiate()``, was added. >>>>> +  The following parts of Rx meta data were defined: >>>>> + >>>>> +  * ``RTE_ETH_RX_META_USER_FLAG`` >>>>> +  * ``RTE_ETH_RX_META_USER_MARK`` >>>>> +  * ``RTE_ETH_RX_META_TUNNEL_ID`` >>>>> + >>>>> >>>>>   Removed Items >>>>>   ------------- >>>>> diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h >>>>> index 40e474aa7e..96e0c60cae 100644 >>>>> --- a/lib/ethdev/ethdev_driver.h >>>>> +++ b/lib/ethdev/ethdev_driver.h >>>>> @@ -789,6 +789,22 @@ typedef int (*eth_get_monitor_addr_t)(void >>>>> *rxq, typedef int (*eth_representor_info_get_t)(struct rte_eth_dev >>>>> *dev, >>>>>       struct rte_eth_representor_info *info); >>>>> >>>>> +/** >>>>> + * @internal >>>>> + * Negotiate delivery of specific parts of Rx meta data. >>>>> + * >>>>> + * @param dev >>>>> + *   Port (ethdev) handle >>>>> + * >>>>> + * @param[inout] features >>>>> + *   Feature selection buffer >>>>> + * >>>>> + * @return >>>>> + *   Negative errno value on error, zero otherwise */ typedef int >>>>> +(*eth_rx_meta_negotiate_t)(struct rte_eth_dev *dev, >>>>> +                       uint64_t *features); >>>>> + >>>>>   /** >>>>>    * @internal A structure containing the functions exported by an >>>>> Ethernet driver. >>>>>    */ >>>>> @@ -949,6 +965,9 @@ struct eth_dev_ops { >>>>> >>>>>       eth_representor_info_get_t representor_info_get; >>>>>       /**< Get representor info. */ >>>>> + >>>>> +    eth_rx_meta_negotiate_t rx_meta_negotiate; >>>>> +    /**< Negotiate delivery of specific parts of Rx meta data. */ >>>>>   }; >>>>> >>>>>   /** >>>>> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c index >>>>> daf5ca9242..49cb84d64c 100644 >>>>> --- a/lib/ethdev/rte_ethdev.c >>>>> +++ b/lib/ethdev/rte_ethdev.c >>>>> @@ -6310,6 +6310,31 @@ rte_eth_representor_info_get(uint16_t >>>>> port_id, >>>>>       return eth_err(port_id, (*dev->dev_ops- >>>>>> representor_info_get)(dev, info));  } >>>>> >>>>> +int >>>>> +rte_eth_rx_meta_negotiate(uint16_t port_id, uint64_t *features) { >>>>> +    struct rte_eth_dev *dev; >>>>> + >>>>> +    RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV); >>>>> +    dev = &rte_eth_devices[port_id]; >>>>> + >>>>> +    if (dev->data->dev_configured != 0) { >>>>> +        RTE_ETHDEV_LOG(ERR, >>>>> +            "The port (id=%"PRIu16") is already configured\n", >>>>> +            port_id); >>>>> +        return -EBUSY; >>>>> +    } >>>>> + >>>>> +    if (features == NULL) { >>>>> +        RTE_ETHDEV_LOG(ERR, "Invalid features (NULL)\n"); >>>>> +        return -EINVAL; >>>>> +    } >>>>> + >>>>> +    RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rx_meta_negotiate, >>>>> -ENOTSUP); >>>>> +    return eth_err(port_id, >>>>> +               (*dev->dev_ops->rx_meta_negotiate)(dev, features)); >>>>> +} >>>>> + >>>>>   RTE_LOG_REGISTER_DEFAULT(rte_eth_dev_logtype, INFO); >>>>> >>>>>   RTE_INIT(ethdev_init_telemetry) >>>>> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h index >>>>> 1da37896d8..8467a7a362 100644 >>>>> --- a/lib/ethdev/rte_ethdev.h >>>>> +++ b/lib/ethdev/rte_ethdev.h >>>>> @@ -4888,6 +4888,51 @@ __rte_experimental  int >>>>> rte_eth_representor_info_get(uint16_t port_id, >>>>>                    struct rte_eth_representor_info *info); >>>>> >>>>> +/** The ethdev sees flagged packets if there are flows with action >>>>> +FLAG. */ #define RTE_ETH_RX_META_USER_FLAG (UINT64_C(1) << 0) >>>>> + >>>>> +/** The ethdev sees mark IDs in packets if there are flows with >>>>> +action MARK. */ #define RTE_ETH_RX_META_USER_MARK >> (UINT64_C(1) << >>>>> +1) >>>>> + >>>>> +/** The ethdev detects missed packets if there are "tunnel_set" >>>>> +flows in use. */ #define RTE_ETH_RX_META_TUNNEL_ID (UINT64_C(1) >> << >>>>> +2) >>>>> + >>>>> +/** >>>>> + * @warning >>>>> + * @b EXPERIMENTAL: this API may change without prior notice >>>>> + * >>>>> + * Negotiate delivery of specific parts of Rx meta data. >>>>> + * >>>>> + * Invoke this API before the first rte_eth_dev_configure() >>>>> +invocation >>>>> + * to let the PMD make preparations that are inconvenient to do later. >>>>> + * >>>>> + * The negotiation process is as follows: >>>>> + * >>>>> + * - the application requests features intending to use at least >>>>> +some of them; >>>>> + * - the PMD responds with the guaranteed subset of the requested >>>>> +feature set; >>>>> + * - the application can retry negotiation with another set of >>>>> +features; >>>>> + * - the application can pass zero to clear the negotiation result; >>>>> + * - the last negotiated result takes effect upon the ethdev start. >>>>> + * >>>>> + * If this API is unsupported, the application should gracefully >>>>> ignore that. >>>>> + * >>>>> + * @param port_id >>>>> + *   Port (ethdev) identifier >>>>> + * >>>>> + * @param[inout] features >>>>> + *   Feature selection buffer >>>>> + * >>>>> + * @return >>>>> + *   - (-EBUSY) if the port can't handle this in its current state; >>>>> + *   - (-ENOTSUP) if the method itself is not supported by the PMD; >>>>> + *   - (-ENODEV) if *port_id* is invalid; >>>>> + *   - (-EINVAL) if *features* is NULL; >>>>> + *   - (-EIO) if the device is removed; >>>>> + *   - (0) on success >>>>> + */ >>>>> +__rte_experimental >>>>> +int rte_eth_rx_meta_negotiate(uint16_t port_id, uint64_t >>>>> +*features); >>>> >>>> I don't think meta is the best name since we also have meta item and >>>> the word meta can be used in other cases. >>> >>> I'm no expert in naming. What could be a better term for this? >>> Personally, I'd rather not perceive "meta" the way you describe. It's >>> not just "meta". It's "rx_meta", and the flags supplied with this API >>> provide enough context to explain what it's all about. >> >> Thinking overnight about it I'd suggest full "metadata". >> Yes, it will name a bit longer, but less confusing versus term META already >> used in flow API. >> > Following my above comments, I think it should be part of the new API > but in any case what about rx_flow_action_negotiate? See my thoughts above. It makes no sense to negotiate *support for actions*. Existing "rte_flow_validate()" already does that job. The new "negotiate Rx metadata* API is all about *delivery* of metadata which is supposed to be *already* set for the packets *inside* the NIC. So, we negotiate *delivery from the NIC to the host*. Nothing more. > >> Andrew. > Best, > Ori > -- Ivan M