virtio — archive

[Michael S. Tsirkin]

Document as used by Linux. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- 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 +exist if VIRTIO_NET_F_SPEED_DUPLEX is set. + +field{speed} is the device speed, in units of 1MByte, 0 to +0x7FFFF. Driver MUST also treat any +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 +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. + egin{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} +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 +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 -- MST