[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: [PATCH v13 10/11] virtio-net: Describe RSS using rss rq id
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 <parav@nvidia.com> --- 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 */ +}; + 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. -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. 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. 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. \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} -- 2.26.2
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]