Re: [PATCH v3] target/s390x: filter deprecated properties based on model expansion type

[David Hildenbrand <david@redhat.com>]

On 26.07.24 21:11, Collin Walling wrote:
> On 7/26/24 3:15 AM, Markus Armbruster wrote:
>> Collin Walling <walling@linux.ibm.com> writes:
>>
>>> On 7/25/24 3:39 AM, David Hildenbrand wrote:
>>>> On 25.07.24 09:35, Markus Armbruster wrote:
>>>>> Markus Armbruster <armbru@redhat.com> writes:
>>
>> [...]
>>
>>>>>> Arguments that are silently ignored is bad interface design.
>>>>>>
>>>>>> Observe: when CpuModelInfo is an argument, @deprecated-props is always
>>>>>> ignored.  When it's a return value, absent means {}, and it can be
>>>>>> present only for certain targets (currently S390).
>>>>>>
>>>>>> The reason we end up with an argument we ignore is laziness: we use the
>>>>>> same type for both roles.  We can fix that easily:
>>>>>>
>>>>>>       { 'struct': 'CpuModel',
>>>>>>         'data': { 'name': 'str',
>>>>>>                   '*props': 'any' } }
>>>>>>
>>>>>>       { 'struct': 'CpuModelInfo',
>>>>>>         'base': 'CpuModel',
>>>>>>         'data': { '*deprecated-props': ['str'] } }
>>>>>>
>>>>>> Use CpuModel for arguments, CpuModelInfo for return values.
>>>>>>
>>>>>> Since @deprecated-props is used only by some targets, I'd make it
>>>>>> conditional, i.e. 'if': 'TARGET_S390X'.
>>>>>
>>>>> If we want just query-cpu-model-expansion return deprecated properties,
>>>>> we can instead move @deprecated-props from CpuModelInfo to
>>>>> CpuModelExpansionInfo.
>>>>
>>>> That might a bit more sense, because deprecated-props does not make any
>>>> sense as input parameter, for example.
>>>
>>> Will do.  Thanks for the feedback.  v4 in the works.
>>
>> We better get this into 9.1.  Plan B: mark @deprecated-props unstable to
>> avoid backward compatibility pain.
>>
>>
> 
> Agreed, it would go a long way to squeeze this in before things get too
> messy.
> 
> v4 is posted.  I think Thomas is unavailable, so if @David would not
> mind handling this?

Will do!

-- 
Cheers,

David / dhildenb