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 D8D29C6FD1D for ; Thu, 30 Mar 2023 09:17:09 +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 1079977BE3 for ; Thu, 30 Mar 2023 09:17:09 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 01045986533 for ; Thu, 30 Mar 2023 09:17:08 +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 E4611986528; Thu, 30 Mar 2023 09:17:08 +0000 (UTC) Mailing-List: contact virtio-comment-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 D1E5B986529 for ; Thu, 30 Mar 2023 09:17:08 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: Jx297kYZOA-x4Za3ZJXI-A-1 From: Cornelia Huck To: Parav Pandit , mst@redhat.com, virtio-dev@lists.oasis-open.org, pasic@linux.ibm.com Cc: sgarzare@redhat.com, virtio-comment@lists.oasis-open.org, shahafs@nvidia.com, Parav Pandit In-Reply-To: <20230329212341.465843-9-parav@nvidia.com> Organization: Red Hat GmbH References: <20230329212341.465843-1-parav@nvidia.com> <20230329212341.465843-9-parav@nvidia.com> User-Agent: Notmuch/0.37 (https://notmuchmail.org) Date: Thu, 30 Mar 2023 11:17:04 +0200 Message-ID: <87tty2fvjj.fsf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Subject: [virtio-comment] Re: [PATCH v10 8/8] virtio-net: Describe RSS using rss rq id On Thu, Mar 30 2023, Parav Pandit wrote: > The content of indirection table and unclassified_queue which are > based on math calculation historically. To better describe this, to > avoid intermixing array index with virtqueue index and to use virtqueue > number > > introduce a field rq_handle (receive queue handle) and refer them > to describe unclassified_queue and indirection_table fields. This description is a bit confusing (and you renamed rq_handle as well.) Does "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 virtqueue number, introduce a structure rss_rq_id (RSS receive queue ID) and use it to describe the unclassified_queue and indirection_table fields." capture the intent correctly? > > As part of it, have the example that uses non zero virtqueue "have the example use a non-zero..." ? > number which helps to have better mapping between receiveX > object with virtqueue number and the actual value in the > indirection table. > > Fixes: https://github.com/oasis-tcs/virtio-spec/issues/163 > Signed-off-by: Parav Pandit > > --- > changelog: > 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 435c1fc..c64335d 100644 > --- a/device-types/net/description.tex > +++ b/device-types/net/description.tex > @@ -1423,11 +1423,16 @@ \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 vqn_1_16: 15; /* Bits 1 to 16 of the vq number */ > + le16 reserved: 1; /* Set to zero */ > +}; > + > 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]; > @@ -1442,10 +1447,15 @@ \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{vqn_1_16} > +consists of bits 1 to 16 of a vq number. For example, a > +\field{vqn_1_16} value of 3 corresponds to vq number 6, > +which maps to receiveq4. > + > +Field \field{unclassified_queue} contains the receive virtqueue > +in which to place unclassified packets. > > -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. "an array of receive virtqueues identified via their rss_rq_id" ? > > 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}). > > @@ -1455,7 +1465,8 @@ \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. "only with rss_rq_id references to enabled receive virtqueues" ? > > The number of entries in \field{indirection_table} (\field{indirection_table_mask} + 1) MUST be a power of two. > > @@ -1468,7 +1479,9 @@ \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. Ok, you remove the line here anyway, so please just ignore my suggestion for the previous patch. > \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} This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/ 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 765E0C6FD1D for ; Thu, 30 Mar 2023 09:17:17 +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 D621E7A0C7 for ; Thu, 30 Mar 2023 09:17:16 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id CC65B98653E for ; Thu, 30 Mar 2023 09:17:16 +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 C1A12986528; Thu, 30 Mar 2023 09:17:16 +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 ACD36986530 for ; Thu, 30 Mar 2023 09:17:10 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: Jx297kYZOA-x4Za3ZJXI-A-1 From: Cornelia Huck To: Parav Pandit , mst@redhat.com, virtio-dev@lists.oasis-open.org, pasic@linux.ibm.com Cc: sgarzare@redhat.com, virtio-comment@lists.oasis-open.org, shahafs@nvidia.com, Parav Pandit In-Reply-To: <20230329212341.465843-9-parav@nvidia.com> Organization: Red Hat GmbH References: <20230329212341.465843-1-parav@nvidia.com> <20230329212341.465843-9-parav@nvidia.com> User-Agent: Notmuch/0.37 (https://notmuchmail.org) Date: Thu, 30 Mar 2023 11:17:04 +0200 Message-ID: <87tty2fvjj.fsf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Subject: [virtio-dev] Re: [PATCH v10 8/8] virtio-net: Describe RSS using rss rq id On Thu, Mar 30 2023, Parav Pandit wrote: > The content of indirection table and unclassified_queue which are > based on math calculation historically. To better describe this, to > avoid intermixing array index with virtqueue index and to use virtqueue > number > > introduce a field rq_handle (receive queue handle) and refer them > to describe unclassified_queue and indirection_table fields. This description is a bit confusing (and you renamed rq_handle as well.) Does "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 virtqueue number, introduce a structure rss_rq_id (RSS receive queue ID) and use it to describe the unclassified_queue and indirection_table fields." capture the intent correctly? > > As part of it, have the example that uses non zero virtqueue "have the example use a non-zero..." ? > number which helps to have better mapping between receiveX > object with virtqueue number and the actual value in the > indirection table. > > Fixes: https://github.com/oasis-tcs/virtio-spec/issues/163 > Signed-off-by: Parav Pandit > > --- > changelog: > 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 435c1fc..c64335d 100644 > --- a/device-types/net/description.tex > +++ b/device-types/net/description.tex > @@ -1423,11 +1423,16 @@ \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 vqn_1_16: 15; /* Bits 1 to 16 of the vq number */ > + le16 reserved: 1; /* Set to zero */ > +}; > + > 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]; > @@ -1442,10 +1447,15 @@ \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{vqn_1_16} > +consists of bits 1 to 16 of a vq number. For example, a > +\field{vqn_1_16} value of 3 corresponds to vq number 6, > +which maps to receiveq4. > + > +Field \field{unclassified_queue} contains the receive virtqueue > +in which to place unclassified packets. > > -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. "an array of receive virtqueues identified via their rss_rq_id" ? > > 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}). > > @@ -1455,7 +1465,8 @@ \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. "only with rss_rq_id references to enabled receive virtqueues" ? > > The number of entries in \field{indirection_table} (\field{indirection_table_mask} + 1) MUST be a power of two. > > @@ -1468,7 +1479,9 @@ \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. Ok, you remove the line here anyway, so please just ignore my suggestion for the previous patch. > \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