Re: [PATCH v6 01/10] qemu-options: New -compat to set policy for deprecated interfaces

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> On 3/12/21 9:32 AM, Markus Armbruster wrote:
>> New option -compat lets you configure what to do when deprecated
>> interfaces get used.  This is intended for testing users of the
>> management interfaces.  It is experimental.
>> 
>> -compat deprecated-input=<input-policy> configures what to do when
>> deprecated input is received.  Input policy can be "accept" (accept
>> silently), or "reject" (reject the request with an error).
>> 
>> -compat deprecated-output=<out-policy> configures what to do when
>> deprecated output is sent.  Output policy can be "accept" (pass on
>> unchanged), or "hide" (filter out the deprecated parts).
>> 
>> Default is "accept".  Policies other than "accept" are implemented
>> later in this series.
>> 
>> For now, -compat covers only syntactic aspects of QMP, i.e. stuff
>> tagged with feature 'deprecated'.  We may want to extend it to cover
>> semantic aspects, CLI, and experimental features.
>> 
>> Note that there is no good way for management application to detect
>> presence of -compat: it's 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.
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> ---
>
>> +++ b/qapi/compat.json
>> @@ -0,0 +1,51 @@
>> +# -*- Mode: Python -*-
>> +
>> +##
>> +# = Compatibility policy
>> +##
>> +
>> +##
>> +# @CompatPolicyInput:
>> +#
>> +# Policy for handling "funny" input.
>> +#
>> +# @accept: Accept silently
>> +# @reject: Reject with an error
>> +#
>> +# Since: 5.2
>
> 6.0
>
>> +##
>> +{ 'enum': 'CompatPolicyInput',
>> +  'data': [ 'accept', 'reject' ] }
>> +
>> +##
>> +# @CompatPolicyOutput:
>> +#
>> +# Policy for handling "funny" output.
>> +#
>> +# @accept: Pass on unchanged
>> +# @hide: Filter out
>> +#
>> +# Since: 5.2
>
> and here
>
>> +##
>> +{ 'enum': 'CompatPolicyOutput',
>> +  'data': [ 'accept', 'hide' ] }
>> +
>> +##
>> +# @CompatPolicy:
>> +#
>> +# Policy for handling deprecated management interfaces.
>> +#
>> +# This is intended for testing users of the management interfaces.
>> +#
>> +# Limitation: covers only syntactic aspects of QMP, i.e. stuff tagged
>> +# with feature 'deprecated'.  We may want to extend it to cover
>> +# semantic aspects, CLI, and experimental features.
>> +#
>> +# @deprecated-input: how to handle deprecated input (default 'accept')
>> +# @deprecated-output: how to handle deprecated output (default 'accept')
>> +#
>> +# Since: 5.2
>
> and here
>
>> +##
>> +{ 'struct': 'CompatPolicy',
>> +  'data': { '*deprecated-input': 'CompatPolicyInput',
>> +            '*deprecated-output': 'CompatPolicyOutput' } }
>> diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json
>> index 3441c9a9ae..4912b9744e 100644
>
> R-b still stands once you make the necessary tweaks.

I thought I had updated these...  Thanks for catching my mistake!