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| -rw-r--r-- | content.tex | 43 |
1 files changed, 21 insertions, 22 deletions
diff --git a/content.tex b/content.tex index 206501d..c9dd28d 100644 --- a/content.tex +++ b/content.tex @@ -2818,16 +2818,16 @@ features. \subsection{Virtqueues}\label{sec:Device Types / Network Device / Virtqueues} \begin{description} -\item[0] receiveq0 -\item[1] transmitq0 +\item[0] receiveq1 +\item[1] transmitq1 \item[\ldots] \item[2N] receiveqN \item[2N+1] transmitqN \item[2N+2] controlq \end{description} - N=0 if VIRTIO_NET_F_MQ is not negotiated, otherwise N is derived - from \field{max_virtqueue_pairs} control field. + N=1 if VIRTIO_NET_F_MQ is not negotiated, otherwise N is set by + \field{max_virtqueue_pairs}. controlq only exists if VIRTIO_NET_F_CTRL_VQ set. @@ -2928,9 +2928,8 @@ VIRTIO_NET_S_LINK_UP and VIRTIO_NET_S_ANNOUNCE. The following driver-read-only field, \field{max_virtqueue_pairs} only exists if VIRTIO_NET_F_MQ is set. This field specifies the maximum number -of each of transmit and receive virtqueues (receiveq0\ldots receiveqN -and transmitq0\ldots transmitqN respectively; - N=\field{max_virtqueue_pairs} - 1) that can be configured once VIRTIO_NET_F_MQ +of each of transmit and receive virtqueues (receiveq1\ldots receiveqN +and transmitq1\ldots transmitqN respectively) that can be configured once VIRTIO_NET_F_MQ is negotiated. \begin{lstlisting} @@ -2972,16 +2971,16 @@ A driver would perform a typical initialization routine like so: \begin{enumerate} \item Identify and initialize the receive and - transmission virtqueues, up to N+1 of each kind. If + transmission virtqueues, up to N of each kind. If VIRTIO_NET_F_MQ feature bit is negotiated, - N=\field{max_virtqueue_pairs}-1, otherwise identify N=0. + N=\field{max_virtqueue_pairs}, otherwise identify N=1. \item If the VIRTIO_NET_F_CTRL_VQ feature bit is negotiated, identify the control virtqueue. \item Fill the receive queues with buffers: see \ref{sec:Device Types / Network Device / Device Operation / Setting Up Receive Buffers}. -\item Even with VIRTIO_NET_F_MQ, only receiveq0, transmitq0 and +\item Even with VIRTIO_NET_F_MQ, only receiveq1, transmitq1 and controlq are used by default. The driver would send the VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command specifying the number of the transmit and receive queues to use. @@ -3021,8 +3020,8 @@ everything else. \subsection{Device Operation}\label{sec:Device Types / Network Device / Device Operation} Packets are transmitted by placing them in the -transmitq0\ldots transmitqN, and buffers for incoming packets are -placed in the receiveq0\ldots receiveqN. In each case, the packet +transmitq1\ldots transmitqN, and buffers for incoming packets are +placed in the receiveq1\ldots receiveqN. In each case, the packet itself is preceeded by a header: \begin{lstlisting} @@ -3176,14 +3175,14 @@ making for 65562 or 1526 bytes. with buffers of at least 1526 bytes. \end{itemize} \item If VIRTIO_NET_F_MRG_RXBUF is negotiated, each buffer MUST be at - least the size of the struct virtio_net_hdr. + greater than the size of the struct virtio_net_hdr. \end{itemize} \begin{note} Obviously each buffer can be split across multiple descriptor elements. \end{note} -If VIRTIO_NET_F_MQ is negotiated, each of receiveq0\ldots receiveqN +If VIRTIO_NET_F_MQ is negotiated, each of receiveq1\ldots receiveqN that will be used SHOULD be populated with receive buffers. \paragraph{Packet Receive Interrupt}\label{sec:Device Types / Network Device / Device Operation / Setting Up Receive Buffers / Packet Receive Interrupt} @@ -3422,8 +3421,8 @@ before marking the buffer as used. If the driver negotiates the VIRTIO_NET_F_MQ feature bit (depends on VIRTIO_NET_F_CTRL_VQ), it MAY transmit outgoing packets on one -of the multiple transmitq0\ldots transmitqN and ask the device to -queue incoming packets into one of the multiple receiveq0\ldots receiveqN +of the multiple transmitq1\ldots transmitqN and ask the device to +queue incoming packets into one of the multiple receiveq1\ldots receiveqN depending on the packet flow. \begin{lstlisting} @@ -3441,16 +3440,16 @@ Multiqueue is disabled by default. The driver enables multiqueue by executing the VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command, specifying the number of the transmit and receive queues to be used up to \field{max_virtqueue_pairs}; subsequently, -transmitq0\ldots transmitqn and receiveq0\ldots receiveqn where -n=virtqueue_pairs-1 MAY be used. +transmitq1\ldots transmitqn and receiveq1\ldots receiveqn where +n=\field{virtqueue_pairs} MAY be used. When multiqueue is enabled, the device MUST use automatic receive steering based on packet flow. Programming of the receive steering classificator is implicit. After the driver transmitted a packet of a -flow on transmitqX, the device MUST cause incoming packets for that flow to +flow on transmitqX, the device SHOULD cause incoming packets for that flow to be steered to receiveqX. For uni-directional protocols, or where no packets have been transmitted yet, the device MAY steer a packet -to a random queue out of the specified receiveq0\ldots receiveqn. +to a random queue out of the specified receiveq1\ldots receiveqn. Multiqueue is disabled by setting \field{virtqueue_pairs} to 1 (this is the default) and waiting for the device to use the command buffer. @@ -3463,7 +3462,7 @@ VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command. The driver MUST NOT request a \field{virtqueue_pairs} of 0 or greater than \field{max_virtqueue_pairs} in the device configuration space. -The driver MUST queue packets only on any transmitq0 before the +The driver MUST queue packets only on any transmitq1 before the VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command. The driver MUST NOT queue packets on transmit queues greater than @@ -3471,7 +3470,7 @@ The driver MUST NOT queue packets on transmit queues greater than \devicenormative{\subparagraph}{Automatic receive steering in multiqueue mode}{Device Types / Network Device / Device Operation / Control Virtqueue / Automatic receive steering in multiqueue mode} -The device MUST queue packets only on any receiveq0 before the +The device MUST queue packets only on any receiveq1 before the VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command. The device MUST NOT queue packets on receive queues greater than |