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| -rw-r--r-- | content.tex | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/content.tex b/content.tex index 67961b3..3831dbe 100644 --- a/content.tex +++ b/content.tex @@ -212,8 +212,8 @@ result. The mechanism for bulk data transport on virtio devices is pretentiously called a virtqueue. Each device can have zero or more -virtqueues: for example, the simplest network device has one for -transmit and one for receive. Each queue has a 16-bit queue size +virtqueues\footnote{For example, the simplest network device has one virtqueue for +transmit and one for receive}. Each queue has a 16-bit queue size parameter, which sets the number of entries and implies the total size of the queue. @@ -250,8 +250,8 @@ The Size column gives the total number of bytes for each part of the virtqueue. Queue Size corresponds to the maximum number of buffers in the -virtqueue. For example, if Queue Size is 4 then at most 4 buffers -can be queued at any given time. Queue Size value is always a +virtqueue.\footnote{For example, if Queue Size is 4 then at most 4 buffers +can be queued at any given time.} Queue Size value is always a power of 2. The maximum Queue Size value is 32768. This value is specified in a bus-specific way. @@ -714,13 +714,16 @@ And Device Operation / Device Initialization / Set DRIVER-OK}. \section{Device Operation}\label{sec:General Initialization And Device Operation / Device Operation} There are two parts to device operation: supplying new buffers to -the device, and processing used buffers from the device. As an +the device, and processing used buffers from the device. + +\begin{note} As an example, the simplest virtio network device has two virtqueues: the transmit virtqueue and the receive virtqueue. The driver adds outgoing (device-readable) packets to the transmit virtqueue, and then frees them after they are used. Similarly, incoming (device-writable) buffers are added to the receive virtqueue, and processed after they are used. +\end{note} \subsection{Supplying Buffers to The Device}\label{sec:General Initialization And Device Operation / Device Operation / Supplying Buffers to The Device} @@ -1630,7 +1633,7 @@ or report device failure. \paragraph{Virtqueue Configuration}\label{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-specific Initialization And Device Operation / Device Initialization / Virtqueue Configuration} As a device can have zero or more virtqueues for bulk data -transport (for example, the simplest network device has two), the driver +transport,\footnote{For example, the simplest network device has two virtqueues} the driver needs to configure them as part of the device-specific configuration. @@ -4870,7 +4873,7 @@ contents of \field{event}. The following events are defined: \end{lstlisting} By sending this event, the device signals that the configuration parameters - (for example the capacity) of a logical unit have changed. + \footnote{for example the capacity} of a logical unit have changed. \field{event} is set to VIRTIO_SCSI_T_PARAM_CHANGE. \field{lun} addresses a logical unit in the SCSI host. |