From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2F3AFCD68E3 for ; Tue, 10 Oct 2023 02:15:08 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 82E6629FD1 for ; Tue, 10 Oct 2023 02:15:07 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 63491986575 for ; Tue, 10 Oct 2023 02:15:07 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id 4E26C986514; Tue, 10 Oct 2023 02:15:07 +0000 (UTC) Mailing-List: contact virtio-dev-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id AE3F9986512; Tue, 10 Oct 2023 02:15:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=hengqi@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0Vtqy34A_1696904096; Message-ID: <52146d75-6110-476a-b157-ec6c20bbb2c1@linux.alibaba.com> Date: Tue, 10 Oct 2023 10:14:50 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Satananda Burla , "virtio-comment@lists.oasis-open.org" , "virtio-dev@lists.oasis-open.org" Cc: "Michael S . Tsirkin" , Parav Pandit , Jason Wang , Xuan Zhuo , Yuri Benditovich References: <20230901093444.115447-1-hengqi@linux.alibaba.com> From: Heng Qi In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [virtio-dev] RE: [EXT] [virtio-dev] Re: [virtio-comment] [PATCH v2] virtio-net: support the RSS context Hi Satananda! 在 2023/10/10 上午7:46, Satananda Burla 写道: > >> -----Original Message----- >> From: virtio-dev@lists.oasis-open.org >> On Behalf Of Heng Qi >> Sent: Tuesday, September 5, 2023 7:04 PM >> To: virtio-comment@lists.oasis-open.org; virtio-dev@lists.oasis-open.org >> Cc: Michael S . Tsirkin ; Parav Pandit >> ; Jason Wang ; Xuan Zhuo >> ; Yuri Benditovich >> >> Subject: [EXT] [virtio-dev] Re: [virtio-comment] [PATCH v2] virtio-net: >> support the RSS context >> >> External Email >> >> ---------------------------------------------------------------------- >> Hi all! >> >> Do you have any comments on this? >> >> Thanks! >> >> 在 2023/9/1 下午5:34, Heng Qi 写道: >>> Commit 84a1d9c48200 ("net: ethtool: extend RXNFC API to support RSS >> spreading of >>> filter matches") adds support for RSS context as a destination for >> receive flow filters >>> (see WIP work: https://urldefense.proofpoint.com/v2/url?u=https- >> 3A__lists.oasis-2Dopen.org_archives_virtio- >> 2Dcomment_202308_msg00194.html&d=DwIDaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=NHDPs >> fcAYlN2z- >> NXHHG4WB09qqS0voo_nf6_kGS625A&m=4OCN2dGMPgHxDFGtU81zZGzzaFYjTALBtQsWL230 >> DoinsHzHA- >> RVOOoF4XqITQuy&s=8MdvZRKdXb3tdMZuldE3Ed6VGmaKPPxc8vGxVyRb_Qc&e= ). >>> An RSS context consists of configurable parameters specified by >> receive-side scaling. >>> Use case: >>> When users want some data flows to be steered to specific multiple >> rxqs, they can set >>> receive flow filter rules for these data flows to an RSS context with >> desired rxqs. >>> How to set/configure an RSS context: >>> Assuming no RSS context has been created before. >>> 1. ethtool -X eth0 context new start 5 equal 8 >>> >>> This command creates an RSS context with an id=1 for eth0, and fills >> in the indirection >>> table with rxq indexes 5-8 circularly. The hash key and hash types >> reuse the default >>> RSS configuration. >>> >>> Then, we can use 'ethtool -x eth0 context 1' to query the above >> configuration. >>> 2. ethtool -X eth0 context new start 6 equal 7 \ >>> hkey 8f:bf:dd:11:23:58:d2:8a:00:31:d0:32:a3:b5:1f:\ >>> >> 1f:e4:d1:fe:47:7f:64:42:fd:d0:61:16:b8:b0:f9:71:e8:2d:36:7f:18:dd:4d:c8: >> f3 >>> This command creates an RSS context with an id=2 for eth0, and fills >> in the indirection >>> table with rxq indexes 6-7 circularly. The hash key is >> 8f:bf:dd:11:23:58:d2:8a:00:31:d0\ >> :32:a3:b5:1f:1f:e4:d1:fe:47:7f:64:42:fd:d0:61:16:b8:b0:f9:71:e8:2d:36:7f >> :18:dd:4d:c8:f3. >>> Hash types reuse the default RSS configuration. >>> >>> 3. ethtool -N eth0 rx-flow-hash tcp4 sdfn context 1 >>> >>> This command specifies the hash types for the RSS context whose id=1 >> on eth0. >>> Now this RSS context only has the hash key to reuse the default RSS >> configuration. >>> 4. ethtool -N eth0 flow-type udp4 src-ip 1.1.1.1 context 1 >>> >>> This command configures a receive flow filter rule for eth0, and the >> data flow matching >>> this rule will continue to select the final rxq according to the RSS >> context configuration >>> with id=1. >>> >>> Signed-off-by: Heng Qi >>> Signed-off-by: Parav Pandit >>> --- >>> v1->v2: >>> 1. u8 to le16 for field rss_ctx_id. >>> 2. Add normativation when device resetting. @Yuri Benditovich >>> 3. Use ctrlq cmd to query rss context capability instead of >> reading config space. @Parav Pandit >>> device-types/net/description.tex | 85 >> +++++++++++++++++++++++++ >>> device-types/net/device-conformance.tex | 1 + >>> device-types/net/driver-conformance.tex | 1 + >>> 3 files changed, 87 insertions(+) >>> >>> diff --git a/device-types/net/description.tex b/device- >> types/net/description.tex >>> index 76585b0..55cd86d 100644 >>> --- a/device-types/net/description.tex >>> +++ b/device-types/net/description.tex >>> @@ -88,6 +88,8 @@ \subsection{Feature bits}\label{sec:Device Types / >> Network Device / Feature bits >>> \item[VIRTIO_NET_F_CTRL_MAC_ADDR(23)] Set MAC address through >> control >>> channel. >>> >>> +\item[VIRTIO_NET_F_RSS_CONTEXT(50)] Device supports multiple RSS >> contexts. >>> + >>> \item[VIRTIO_NET_F_HASH_TUNNEL(51)] Device supports inner header >> hash for encapsulated packets. >>> \item[VIRTIO_NET_F_VQ_NOTF_COAL(52)] Device supports virtqueue >> notification coalescing. >>> @@ -150,6 +152,7 @@ \subsubsection{Feature bit >> requirements}\label{sec:Device Types / Network Device >>> \item[VIRTIO_NET_F_RSS] Requires VIRTIO_NET_F_CTRL_VQ. >>> \item[VIRTIO_NET_F_VQ_NOTF_COAL] Requires VIRTIO_NET_F_CTRL_VQ. >>> \item[VIRTIO_NET_F_HASH_TUNNEL] Requires VIRTIO_NET_F_CTRL_VQ along >> with VIRTIO_NET_F_RSS or VIRTIO_NET_F_HASH_REPORT. >>> +\item[VIRTIO_NET_F_RSS_CONTEXT] Requires VIRTIO_NET_F_CTRL_VQ and >> VIRTIO_NET_F_RSS. >>> \end{description} >>> >>> \subsubsection{Legacy Interface: Feature bits}\label{sec:Device >> Types / Network Device / Feature bits / Legacy Interface: Feature bits} >>> @@ -1606,6 +1609,88 @@ \subsubsection{Control >> Virtqueue}\label{sec:Device Types / Network Device / Devi >>> \item If the destination receive queue is being reset (See >> \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue >> Reset}), the device MUST drop the packet. >>> \end{itemize} >>> >>> +\paragraph{RSS Context}\label{sec:Device Types / Network Device / >> Device Operation / Control Virtqueue / RSS Context} >>> + >>> +An RSS context consists of configurable parameters specified by >> \ref{sec:Device Types / Network Device >>> +/ Device Operation / Control Virtqueue / Receive-side scaling (RSS)}. >>> + >>> +The RSS configuration supported by VIRTIO_NET_F_RSS is considered the >> default RSS configuration. >>> + >>> +The device offers the feature VIRTIO_NET_F_RSS_CONTEXT if it supports >> one or multiple RSS contexts >>> +(excluding the default RSS configuration) and configurable >> parameters. >>> + >>> +\subparagraph{Querying RSS Context Capability}\label{sec:Device Types >> / Network Device / Device Operation / Control Virtqueue / RSS Context / >> Querying RSS Context Capability} >>> + >>> +\begin{lstlisting} >>> +#define VIRTNET_RSS_CTX_CTRL 8 >>> + #define VIRTNET_RSS_CTX_CTRL_CAP_GET 0 >>> + #define VIRTNET_RSS_CTX_CTRL_ADD 1 >>> + #define VIRTNET_RSS_CTX_CTRL_MOD 2 >>> + #define VIRTNET_RSS_CTX_CTRL_DEL 3 >>> + >>> +struct virtnet_rss_ctx_cap { >>> + le16 max_rss_contexts; >>> +} >>> +\end{lstlisting} >>> + >>> +Field \field{max_rss_contexts} specifies the maximum number of RSS >> contexts \ref{sec:Device Types / Network Device / >>> +Device Operation / Control Virtqueue / RSS Context} supported by the >> device. >>> + >>> +The driver queries the RSS context capability of the device by >> sending the command VIRTNET_RSS_CTX_CTRL_CAP_GET >>> +with the structure virtnet_rss_ctx_cap. >>> + >>> +For the command VIRTNET_RSS_CTX_CTRL_CAP_GET, the structure >> virtnet_rss_ctx_cap is write-only for the device. >>> + >>> +\subparagraph{Setting RSS Context Parameters}\label{sec:Device Types >> / Network Device / Device Operation / Control Virtqueue / RSS Context / >> Setting RSS Context Parameters} >>> + >>> +\begin{lstlisting} >>> +struct virtnet_rss_ctx_add_modify { >>> + le16 rss_ctx_id; >>> + le16 padding; >>> + struct virtio_net_rss_config rss; >>> +}; >>> + >>> +struct virtnet_rss_ctx_del { >>> + le16 rss_ctx_id; >>> +}; >>> +\end{lstlisting} >>> + >>> +RSS context parameters: >>> +\begin{itemize} >>> +\item \field{rss_ctx_id}: ID of the specific RSS context. >>> +\item \field{rss}: RSS context parameters of the specific RSS >> context whose id is \field{rss_ctx_id}. >>> +\end{itemize} >>> + >>> +\field{padding} is reserved and it is ignored by the device. >>> + >>> +If the feature VIRTIO_NET_F_RSS_CONTEXT has been negotiated, the >> driver can send the following >>> +VIRTNET_RSS_CTX_CTRL class commands: >>> +\begin{enumerate} >>> +\item VIRTNET_RSS_CTX_CTRL_ADD: use the structure >> virtnet_rss_ctx_add_modify to >>> + add an RSS context configured as \field{rss} and id as >> \field{rss_ctx_id} for the device. >>> +\item VIRTNET_RSS_CTX_CTRL_MOD: use the structure >> virtnet_rss_ctx_add_modify to >>> + configure parameters of the RSS context whose id is >> \field{rss_ctx_id} as \field{rss} for the device. >>> +\item VIRTNET_RSS_CTX_CTRL_DEL: use the structure virtnet_rss_ctx_del >> to delete >>> + the RSS context whose id is \field{rss_ctx_id} for the device. >>> +\end{enumerate} >>> + >>> +For commands VIRTNET_RSS_CTX_CTRL_ADD and VIRTNET_RSS_CTX_CTRL_MOD, >> the structure virtnet_rss_ctx_add_modify is read-only for the device. >>> +For the command VIRTNET_RSS_CTX_CTRL_DEL, the structure >> virtnet_rss_ctx_del is read-only for the device. >>> + >>> +\devicenormative{\subparagraph}{RSS Context}{Device Types / Network >> Device / Device Operation / Control Virtqueue / RSS Context} >>> + >>> +The device MUST set \field{max_rss_contexts} to at least 1 if it >> offers VIRTIO_NET_F_RSS_CONTEXT. >>> + >>> +Upon reset, the device MUST clear all previously configured RSS >> contexts. >>> + >>> +\drivernormative{\subparagraph}{RSS Context}{Device Types / Network >> Device / Device Operation / Control Virtqueue / RSS Context} >>> + >>> +The driver MUST have negotiated the VIRTIO_NET_F_RSS_CONTEXT feature >> when issuing the VIRTNET_RSS_CTX_CTRL class commands. >>> + >>> +The driver MUST set \field{rss_ctx_id} to between 1 and >> \field{max_rss_contexts} inclusive. >>> + >>> +The driver MUST NOT send the command VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET >> when the device has successfully configured at least one RSS context. >>> + > What happens if a rss context with flow classification rules associated > with it is deleted? Are the rules are also then deleted? > Or is such a delete operation not allowed? Can we add a statement describing The RSS context cannot be deleted when it is referenced by a rule in RFF. The RSS context can then be deleted when all rules that referenced it have been removed. Why is this not added to the requirement: RSS context is not yet referenced by RFF (i.e. the destination of RFF is a single rxq). This is because we keep the RSS context and RFF orthogonal for the time being. So that the RSS context does not block the advancement of RFF. Also, RFF is not merged into mainline now. When the RSS context is complete, we can update the statement in the RFF requirements; or when the RFF is complete, we can update the statement in both the RFF and RSS context. Thanks! > the behavior? > Otherwise looks good to me. > > Regards > Satananda > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org