Signed-off-by: Michael S. Tsirkin <> --- content.tex
31 +++++++++++++++++++++
----------
1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/content.tex b/content.tex index f2f3132..9f01ab0 100644 --- a/content.tex +++ b/content.tex @@ -91,8 +91,9 @@ space. Earlier drafts of this specification (up to 0.9.X) defined a similar, but different interface between the hypervisor and the guest. Since these are widely deployed, this specification -accommodates optional features to simplify transition -from these earlier draft interfaces. Specifically: +accommodates OPTIONAL features to simplify transition +from these earlier draft interfaces. Specifically +devices and drivers MAY support:
egin{description} item[Legacy Interface] @@ -110,33 +111,43 @@ Legacy devices and legacy drivers are not compliant with this specification.
To simplify transition from these earlier draft interfaces, -it is possible to implement: +a device MAY implement:
egin{description} item[Transitional Device]
a device supporting both drivers conforming to this
specification, and allowing legacy drivers. +end{description}
+Similarly, a driver MAY implement: +egin{description} item[Transitional Driver]
a driver supporting both devices conforming to this
specification, and legacy devices. end{description}
-Transitional devices and transitional drivers can be compliant with -this specification (ie. when not operating in legacy mode). - Devices or drivers with no legacy compatibility are referred to as non-transitional devices and drivers, respectively.
-Transitional Drivers can detect Legacy Devices by detecting that +Transitional Drivers MUST detect Legacy Devices by detecting that the feature bit VIRTIO_F_VERSION_1 is not offered. -Transitional devices can detect Legacy drivers by detecting that +Transitional devices MUST detect Legacy drivers by detecting that VIRTIO_F_VERSION_1 has not been acknowledged by the driver. In this case device is used through the legacy interface.
+Legacy interface support is OPTIONAL. +Thus, both transitional and non-transitional devices and +drivers are compliant with this specification. + To make them easier to locate, specification sections documenting -these transitional features are explicitly marked with 'Legacy -Interface' in the section title. +features limited to transitional devices and transitional drivers +are explicitly marked with 'Legacy Interface' in the section title. + +When device is used through the legacy interface, transitional +devices and transitional drivers MUST operate according to the +requirements documented within these legacy interface sections. +Specification text within these sections generally does not apply +to non-transitional devices.
section{Device Configuration Space}label{sec:Basic Facilities of a Virtio Device / Device Configuration Space}
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MST
