Document as used by Linux. Fixes: https://github.com/oasis-tcs/virtio-spec/issues/59 Signed-off-by: Michael S. Tsirkin <> Reviewed-by: Cornelia Huck <> --- changes from v2: fix up units actually there's no way for driver to know that link up changed: it might have changed back. make the device requirement a weaker "SHOULD" and instead ask that driver re-read on each config change notification
content.tex
39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/content.tex b/content.tex index d68cfaf..f7a6971 100644 --- a/content.tex +++ b/content.tex @@ -2823,6 +2823,7 @@ 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} @@ -2882,12 +2883,28 @@ 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 MBit per +second, 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. + +Both field{speed} and field{duplex} can change, thus the driver +is expected to re-read these values after receiving a +configuration change notification. + egin{lstlisting} struct virtio_net_config {
u8 mac[6];
le16 status;
le16 max_virtqueue_pairs;
le16 mtu; +
le32 speed; +
u8 duplex; + }; end{lstlisting}
@@ -2916,6 +2933,19 @@ 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 MBit per second, 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, or 0xff for unknown. + +If VIRTIO_NET_F_SPEED_DUPLEX and VIRTIO_NET_F_STATUS have both +been negotiated, the device SHOULD 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. @@ -2940,6 +2970,15 @@ 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. + +If VIRTIO_NET_F_SPEED_DUPLEX has been negotiated, the driver +SHOULD re-read field{speed} and field{duplex} after a +configuration change notification. + 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
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MST
