Re: [virtio] [PATCH] content: document speed, dupex

On Fri, 1 Nov 2019 04:23:45 -0400
"Michael S. Tsirkin" <> wrote:

$SUBJECT: s/dupex/duplex/

> Document as used by Linux.
> 
> Signed-off-by: Michael S. Tsirkin <>
> ---
>  content.tex | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/content.tex b/content.tex
> index bff80d0..e89ae44 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -2951,12 +2951,29 @@ \subsection{Device configuration layout}\label{sec:Device Types / Network Device
>  VIRTIO_NET_F_MTU is set. This field specifies the maximum MTU for the driver to
>  use.
>  
> +The following two fields, \field{speed} and \field{duplex} only

Comma after "duplex"?

> +exist if VIRTIO_NET_F_SPEED_DUPLEX is set.
> +
> +\field{speed} is the device speed, in units of 1MByte, 0 to

s/is/contains/

s/1MByte/1 MByte/ (Have we specified the format for that somewhere,
btw?)

> +0x7FFFF. Driver MUST also treat any

s/Driver MUST also treat/The driver MUST treat/

(Is this a conformance section? Sorry, a bit lost.)

> +other value as representing an unknown duplex state.
> +
> +\field{duplex} has the values of 0x00 for full duplex, 0x01 for
> +half duplex and 0xff for unknown. Driver MUST also treat any

Comma after "half duplex"?

s/Driver MUST also treat/The driver MUST treat/

> +other value as representing an unknown duplex state.
> +
> +Neither \field{speed} not \field{duplex} changes as long as
> +VIRTIO_NET_S_LINK_UP is set.
> +
>  \begin{lstlisting}
>  struct virtio_net_config {
>          u8 mac[6];
>          le16 status;
>          le16 max_virtqueue_pairs;
>          le16 mtu;
> +        le32 speed;
> +        u8 duplex;
> +
>  };
>  \end{lstlisting}
>  
> @@ -2985,6 +3002,10 @@ \subsection{Device configuration layout}\label{sec:Device Types / Network Device
>  If the driver negotiates the VIRTIO_NET_F_STANDBY feature, the device MAY act
>  as a standby device for a primary device with the same MAC address.
>  
> +Device MUST NOT change the \field{speed} and \field{duplex}

s/Device/The device/

> +fields as long as VIRTIO_NET_S_LINK_UP is set in the
> +\field{status}.
> +
>  \drivernormative{\subsubsection}{Device configuration layout}{Device Types / Network Device / Device configuration layout}
>  
>  A driver SHOULD negotiate VIRTIO_NET_F_MAC if the device offers it.
> @@ -3009,6 +3030,10 @@ \subsection{Device configuration layout}\label{sec:Device Types / Network Device
>  
>  A driver SHOULD negotiate the VIRTIO_NET_F_STANDBY feature if the device offers it.
>  
> +A driver MUST treat a value of \field{speed} above

s/a value/any value/ ? (also in the next line)

> +0x000000007fffffff as well as a value of \field{duplex} not
> +matching 0x0 or 0x1 as an unknown value.
> +
>  \subsubsection{Legacy Interface: Device configuration layout}\label{sec:Device Types / Network Device / Device configuration layout / Legacy Interface: Device configuration layout}
>  \label{sec:Device Types / Block Device / Feature bits / Device configuration layout / Legacy Interface: Device configuration layout}
>  When using the legacy interface, transitional devices and drivers