Eric Blake <eblake@xxxxxxxxxx> writes:
> On Thu, Oct 28, 2021 at 12:25:20PM +0200, Markus Armbruster wrote:
>> New option parameters unstable-input and unstable-output set policy
>> for unstable interfaces just like deprecated-input and
>> deprecated-output set policy for deprecated interfaces (see commit
>> 6dd75472d5 "qemu-options: New -compat to set policy for deprecated
>> interfaces"). This is intended for testing users of the management
>> interfaces. It is experimental.
>>
>> For now, this covers only syntactic aspects of QMP, i.e. stuff tagged
>> with feature 'unstable'. We may want to extend it to cover semantic
>> aspects, or the command line.
>>
>> Note that there is no good way for management application to detect
>> presence of these new option parameters: they are not visible output
>> of query-qmp-schema or query-command-line-options. Tolerable, because
>> it's meant for testing. If running with -compat fails, skip the test.
>
> Not to mention, once we finish QAPIfying the command line, we could
> make sure it is visible through introspection at that time (it may
> require tagging the command line option with a feature, if nothing
> else makes it pop through).
>
>>
>> Signed-off-by: Markus Armbruster <armbru@xxxxxxxxxx>
>> Acked-by: John Snow <jsnow@xxxxxxxxxx>
>> ---
>> qapi/compat.json | 6 +++++-
>> include/qapi/util.h | 1 +
>> qapi/qmp-dispatch.c | 6 ++++++
>> qapi/qobject-output-visitor.c | 8 ++++++--
>> qemu-options.hx | 20 +++++++++++++++++++-
>> scripts/qapi/events.py | 10 ++++++----
>> scripts/qapi/schema.py | 10 ++++++----
>> 7 files changed, 49 insertions(+), 12 deletions(-)
>>
>> diff --git a/qapi/compat.json b/qapi/compat.json
>> index 74a8493d3d..9bc9804abb 100644
>> --- a/qapi/compat.json
>> +++ b/qapi/compat.json
>> @@ -47,9 +47,13 @@
>> #
>> # @deprecated-input: how to handle deprecated input (default 'accept')
>> # @deprecated-output: how to handle deprecated output (default 'accept')
>> +# @unstable-input: how to handle unstable input (default 'accept')
>> +# @unstable-output: how to handle unstable output (default 'accept')
>
> Missing '(since 6.2)' doc tags on the two new policies.
Fixing...
>> #
>> # Since: 6.0
>> ##
>> { 'struct': 'CompatPolicy',
>> 'data': { '*deprecated-input': 'CompatPolicyInput',
>> - '*deprecated-output': 'CompatPolicyOutput' } }
>> + '*deprecated-output': 'CompatPolicyOutput',
>> + '*unstable-input': 'CompatPolicyInput',
>> + '*unstable-output': 'CompatPolicyOutput' } }
>> diff --git a/include/qapi/util.h b/include/qapi/util.h
>> index 0cc98db9f9..81a2b13a33 100644
>> --- a/include/qapi/util.h
>> +++ b/include/qapi/util.h
>> @@ -13,6 +13,7 @@
>>
>> typedef enum {
>> QAPI_DEPRECATED,
>> + QAPI_UNSTABLE,
>> } QapiSpecialFeature;
>
>> +++ b/qemu-options.hx
>> @@ -3641,7 +3641,9 @@ DEFHEADING(Debug/Expert options:)
>>
>> DEF("compat", HAS_ARG, QEMU_OPTION_compat,
>> "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n"
>> - " Policy for handling deprecated management interfaces\n",
>> + " Policy for handling deprecated management interfaces\n"
>> + "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n"
>> + " Policy for handling unstable management interfaces\n",
>
> It may not be machine-introspectible, but at least we can grep --help
> output to see when the policy is usable for testing.
>
>> QEMU_ARCH_ALL)
>> SRST
>> ``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]``
>> @@ -3659,6 +3661,22 @@ SRST
>> Suppress deprecated command results and events
>>
>> Limitation: covers only syntactic aspects of QMP.
>> +
>> +``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]``
>> + Set policy for handling unstable management interfaces (experimental):
>
> Once we QAPIfy the command line, this says we would add the 'unstable'
> feature flag to '-compat unstable-input'. How meta ;)
Yes :)
> And goes along
> with your comments earlier in the series about how we may use the
> 'unstable' feature even without the 'x-' naming prefix, once it is
> machine-detectible.
>
> With the doc tweak,
> Reviewed-by: Eric Blake <eblake@xxxxxxxxxx>
Thanks!
