Re: [virtio] [PATCH v4] conformance: clarify transitional/non-transitional

[Halil Pasic <pasic@linux.ibm.com>]

On Tue, 12 Mar 2019 21:48:13 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> We already have a specification for conformance targets for
> non-transitional devices.
> Just add another clause that transitional devices satisfy.
> 
> VIRTIO-167
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> 
> Same patch was previouly sent as v2.
> 
>  conformance.tex | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/conformance.tex b/conformance.tex
> index 6df113b..8b69e39 100644
> --- a/conformance.tex
> +++ b/conformance.tex
> @@ -341,13 +341,9 @@ A conformant implementation MUST be either transitional or
>  non-transitional, see \ref{intro:Legacy
>  Interface: Terminology}.
>  
> -A non-transitional implementation conforms to this specification
> -if it satisfies all of the MUST or REQUIRED level requirements
> -defined above.
> -
> -An implementation MAY choose to implement OPTIONAL support for the
> +A transitional implementation MUST implement support for the
>  legacy interface, including support for legacy drivers
> -or devices, by additionally conforming to all of the MUST or
> +or devices, by conforming to all of the MUST or
>  REQUIRED level requirements for the legacy interface
>  for the transitional devices and drivers.
>  

Hm, I actually liked that v3 spelled out, that legacy is not
standardized (no normative exists). v4 makes things look like
'transitional' is a separate conformance profile, and that the
description of  the legacy interface is normative.

I took the liberty and tweaked your v3. As stated before, I don't think
transitional vs non-transitional is a big issue. I'm basically fine with
anything.

Regards,
Halil

--------------------------------8<--------------------------------------
diff --git a/conformance.tex b/conformance.tex
index ad7e82e..53be96e 100644
--- a/conformance.tex
+++ b/conformance.tex
@@ -338,22 +338,18 @@ A socket device MUST conform to the following normative statements:
 Transitional Driver Conformance}\label{sec:Conformance / Legacy
 Interface: Transitional Device and 
 Transitional Driver Conformance}
-A conformant implementation MUST be either transitional or
-non-transitional, see \ref{intro:Legacy
-Interface: Terminology}.
-
-A non-transitional implementation conforms to this specification
-if it satisfies all of the MUST or REQUIRED level requirements
-defined above.
-
-An implementation MAY choose to implement OPTIONAL support for the
-legacy interface, including support for legacy drivers
-or devices, by additionally conforming to all of the MUST or
-REQUIRED level requirements for the legacy interface
-for the transitional devices and drivers.
-
-The requirements for the legacy interface for transitional implementations
-are located in sections named ``Legacy Interface'' listed below:
+
+A transitional driver or device is a conforming driver or device (as
+defined by section \ref{sec:Conformance / Conformance Targets}) that aims
+for interoperability with the existing body of legacy devices or drivers
+(see \ref{intro:Legacy Interface: Terminology}).
+
+No normative specification for the legacy interface exists, but to
+facilitate inter-operability with non-conforming legacy implementations,
+known differences between the legacy interface and the standard interface
+are documented in non-normative sections named ``Legacy Interface''
+listed below:
 \begin{itemize}
 \item Section \ref{sec:Basic Facilities of a Virtio Device /
 Feature Bits / Legacy Interface: A Note on Feature Bits}