Start with explanation, progress to normative requirements. Signed-off-by: Rusty Russell <> --- content.tex
21 ++++++++++++
---------
1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/content.tex b/content.tex index 13e7749..88c6d6a 100644 --- a/content.tex +++ b/content.tex @@ -14,13 +14,10 @@ device consists of the following parts:
section{field{Device Status} Field}label{sec:Basic Facilities of a Virtio Device / Device Status Field}
-The driver MUST update the field{device status} field in the order below to -indicate its progress. This provides a simple low-level diagnostic: -it's most useful to imagine them hooked up to traffic lights on the -console indicating the status of each device. The driver MUST NOT -clear a field{device status} bit. - -field{device status} is 0 upon reset, otherwise at least one bit should be set: +The field{device status} field provides a simple low-level +diagnostic: it's most useful to imagine them hooked up to traffic +lights on the console indicating the status of each device. The +following bits are defined:
egin{description} item[ACKNOWLEDGE (1)] Indicates that the guest OS has found the @@ -40,10 +37,16 @@ clear a field{device status} bit. item[FAILED (128)] Indicates that something went wrong in the guest,
and it has given up on the device. This could be an internal
error, or the driver didn't like the device for some reason, or - even a fatal error during device operation. The driver MUST - reset the device before attempting to re-initialize. + even a fatal error during device operation. end{description}
+The driver MUST update field{device status} in the order above to +indicate the driver's progress. The driver MUST NOT clear a +field{device status} bit. If the driver sets the FAILED bit, +it MUST reset the device before attempting to re-initialize. + +The device MUST initialize field{device status} to 0 upon reset. + section{Feature Bits}label{sec:Basic Facilities of a Virtio Device / Feature Bits}
Each virtio device offers all the features it understands. During -- 1.8.3.2
