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 3D0E1C77B78 for ; Mon, 24 Apr 2023 13:22:41 +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 91EBB29FFA for ; Mon, 24 Apr 2023 13:22:39 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 70AC1986394 for ; Mon, 24 Apr 2023 13:22:39 +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 6216298633A; Mon, 24 Apr 2023 13:22:39 +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 4EB4A98634E; Mon, 24 Apr 2023 13:22:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com Date: Mon, 24 Apr 2023 15:22:21 +0200 From: Halil Pasic To: Parav Pandit Cc: , , , , , , Halil Pasic Message-ID: <20230424152221.54c44489.pasic@linux.ibm.com> In-Reply-To: <20230419014639.919458-11-parav@nvidia.com> References: <20230419014639.919458-1-parav@nvidia.com> <20230419014639.919458-11-parav@nvidia.com> Organization: IBM X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) Content-Type: text/plain; charset=US-ASCII X-TM-AS-GCONF: 00 X-Proofpoint-GUID: I15vUxfzdF7YfyFIvlccKCwNU5sea7if X-Proofpoint-ORIG-GUID: Cgd0FOHKb3sBZhDvWKMnCU_wHR-HY0DD Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-24_07,2023-04-21_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 malwarescore=0 phishscore=0 clxscore=1015 impostorscore=0 adultscore=0 priorityscore=1501 mlxscore=0 lowpriorityscore=0 spamscore=0 mlxlogscore=999 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304240118 Subject: [virtio-dev] Re: [PATCH v14 10/11] virtio-net: Describe RSS using rss rq id On Wed, 19 Apr 2023 04:46:38 +0300 Parav Pandit wrote: > The content of the indirection table and unclassified_queue were > originally described based on mathematical operations. In order to > make it easier to understand and to avoid intermixing the array > index with the vq index, introduce a structure > rss_rq_id (RSS receive queue > ID) and use it to describe the unclassified_queue and > indirection_table fields. > > As part of it, have the example that uses non-zero virtqueue > index which helps to have better mapping between receiveX > object with virtqueue index and the actual value in the > indirection table. > > Fixes: https://github.com/oasis-tcs/virtio-spec/issues/163 > Signed-off-by: Parav Pandit > > --- > changelog: > v12->v13: > - rename vqn to vq_index > - renamed vq index to virtqueue index > v11->v12: > - use 'virtqueue index' instead of 'virtqueue number' > v10->v11: > - commit log updated to drop old reference to rq_handle, replaced with > rss_rq_id detail > v8->v9: > - reword rss_rq_id and unclassified_packets description > - use article > - use 'vq number' instead of 'virtqueue number' > v4->v5: > - change subject to reflect rss_rq_id > - fixed accidental removal of "unclassifed packets". > - simplfied text around indirection_table mask to use the term > destination receive virtqueue. This aligns with next line about queue > reset. > - removed rss_rq_id references as indirection table and > unclassified_queue data type is self explanatory > v3->v4: > - renamed rq_handle to rss_rq_id > - moved rss_rq_id definition close to its usage in rss_config struct > v2->v3: > - moved rq_handle definition before using it > - removed duplicate example as rq_handle is now described first > v0->v1: > - new patch suggested by Michael Tsirkin > --- > device-types/net/description.tex | 27 ++++++++++++++++++++------- > 1 file changed, 20 insertions(+), 7 deletions(-) > > diff --git a/device-types/net/description.tex b/device-types/net/description.tex > index f3f9f1d..e4d236e 100644 > --- a/device-types/net/description.tex > +++ b/device-types/net/description.tex > @@ -1434,11 +1434,16 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi > > Driver sends a VIRTIO_NET_CTRL_MQ_RSS_CONFIG command using the following format for \field{command-specific-data}: > \begin{lstlisting} > +struct rss_rq_id { > + le16 vq_index_1_16: 15; /* Bits 1 to 16 of the virtqueue index */ > + le16 reserved: 1; /* Set to zero */ > +}; > + I'm not a fan of this being done with bitmaps, as I have stated before, but I can live with it. > struct virtio_net_rss_config { > le32 hash_types; > le16 indirection_table_mask; > - le16 unclassified_queue; > - le16 indirection_table[indirection_table_length]; > + struct rss_rq_id unclassified_queue; > + struct rss_rq_id indirection_table[indirection_table_length]; > le16 max_tx_vq; > u8 hash_key_length; > u8 hash_key_data[hash_key_length]; > @@ -1453,10 +1458,15 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi > \field{indirection_table} array. > Number of entries in \field{indirection_table} is (\field{indirection_table_mask} + 1). > > -Field \field{unclassified_queue} contains the 0-based index of > -the receive virtqueue to place unclassified packets in. Index 0 corresponds to receiveq1. > +\field{rss_rq_id} is a receive virtqueue id. \field{vq_index_1_16} > +consists of bits 1 to 16 of a virtqueue index. For example, a > +\field{vq_index_1_16} value of 3 corresponds to virtqueue index 6, > +which maps to receiveq4. > + > +Field \field{unclassified_queue} contains the receive virtqueue > +in which to place unclassified packets. It does not contain a receive virtqueue but its \field{rss_rq_id}, i.e. it's "receive virtqueue id". > > -Field \field{indirection_table} contains an array of 0-based indices of receive virtqueues. Index 0 corresponds to receiveq1. > +Field \field{indirection_table} is an array of receive virtqueues. Same here. > > A driver sets \field{max_tx_vq} to inform a device how many transmit virtqueues it may use (transmitq1\ldots transmitq \field{max_tx_vq}). > > @@ -1466,7 +1476,8 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi > > A driver MUST NOT send the VIRTIO_NET_CTRL_MQ_RSS_CONFIG command if the feature VIRTIO_NET_F_RSS has not been negotiated. > > -A driver MUST fill the \field{indirection_table} array only with indices of enabled queues. Index 0 corresponds to receiveq1. > +A driver MUST fill the \field{indirection_table} array only with > +enabled receive virtqueues. Same here. > > The number of entries in \field{indirection_table} (\field{indirection_table_mask} + 1) MUST be a power of two. > > @@ -1479,7 +1490,9 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi > \begin{itemize} > \item Calculate the hash of the packet as defined in \ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets}. > \item If the device did not calculate the hash for the specific packet, the device directs the packet to the receiveq specified by \field{unclassified_queue} of virtio_net_rss_config structure. > -\item Apply \field{indirection_table_mask} to the calculated hash and use the result as the index in the indirection table to get 0-based number of destination receiveq. > +\item Apply \field{indirection_table_mask} to the calculated hash > +and use the result as the index in the indirection table to get > +the destination receive virtqueue. Same here. > \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} > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org