Document as used by Linux. Fixes: https://github.com/oasis-tcs/virtio-spec/issues/59 Signed-off-by: Michael S. Tsirkin <m...@redhat.com> ---
changes from v2 - address comments by Cornelia - fix more typos - consistent upper/lower case for hex values - explicitly ask that devices use 0xffffffff for unknown speed (this is what Linux uses) content.tex | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/content.tex b/content.tex index bff80d0..678afbe 100644 --- a/content.tex +++ b/content.tex @@ -2892,6 +2892,7 @@ \subsection{Feature bits}\label{sec:Device Types / Network Device / Feature bits \item[VIRTIO_NET_F_STANDBY(62)] Device may act as a standby for a primary device with the same MAC address. +\item[VIRTIO_NET_F_SPEED_DUPLEX(63)] Device reports speed and duplex. \end{description} \subsubsection{Feature bit requirements}\label{sec:Device Types / Network Device / Feature bits / Feature bit requirements} @@ -2951,12 +2952,27 @@ \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} contains the device speed, in units of 1 MByte, 0 +to 0x7ffffffff, or 0xfffffffff for unknown speed. + +\field{duplex} has the values of 0x00 for full duplex, 0x01 for +half duplex and 0xff for 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 +3001,18 @@ \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. +If VIRTIO_NET_F_SPEED_DUPLEX has been negotiated, \field{speed} +MUST contain the device speed, in units of 1 MByte, 0 to +0x7ffffffff, or 0xfffffffff for unknown. + +If VIRTIO_NET_F_SPEED_DUPLEX has been negotiated, \field{duplex} +MUST have the values of 0x00 for full duplex, 0x01 for half +duplex and 0xff for unknown. + +If VIRTIO_NET_F_SPEED_DUPLEX has been negotiated, the 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 +3037,11 @@ \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. +If VIRTIO_NET_F_SPEED_DUPLEX has been negotiated, +the driver MUST treat any value of \field{speed} above +0x7fffffff as well as any value of \field{duplex} not +matching 0x00 or 0x01 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 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org