Re: [PATCH v26 00/20] i386 cleanup PART 2

[Claudio Fontana]

On 3/8/21 3:57 PM, Philippe Mathieu-Daudé wrote:
> On 3/8/21 2:52 PM, Claudio Fontana wrote:
>> On 3/8/21 2:27 PM, Philippe Mathieu-Daudé wrote:
>>> Hi Claudio,
>>>
>>> On 3/8/21 1:57 PM, Claudio Fontana wrote:
>>>> Hi,
>>>>
>>>> anything else for me to do here?
>>>>
>>>> The latest rebased state of this series should be always available here:
>>>>
>>>> https://gitlab.com/hw-claudio/qemu/-/tree/i386_cleanup_8
>>>>
>>>> When it comes to the ARM cleanup series,
>>>> I would like to have the tests pass for ARM, before doing even more 
>>>> changes, could you help me there Philippe?
>>>>
>>>> Maybe applying some of your changes on top would fix the failures? I 
>>>> tried, for example with the arm-cpu-features ones, but it didn't work for 
>>>> me..
>>>
>>> TBH I wrote these patches during my personal spare time and this
>>> became a real Pandora box that drained too much energy. I prefer
>>> to step back and focus on finishing smaller tasks before burning
>>> out. That said I appreciate your effort and am interested in
>>> following / reviewing your work.
>>>
>>> Regards,
>>>
>>> Phil.
>>>
>>
>> Thanks Philippe for sharing this, and I agree completely, it is very 
>> draining.
>>
>> The effort of making tests happy that run in artificial environments in 
>> particular often feels to me
>> as too disconnected from actually ensuring that there is no real run time 
>> regression.
>>
>> qtest_enabled() (implicitly, or explicitly via open-ended else statements) 
>> is another painful variable to keep in mind in cpu and machine code, so it 
>> is not helpful in my view.
>>
>> I'll try to push more to get the tests running again, if you have any 
>> comment or idea, feel free to just point me in the right direction,
>> that is very valuable to me, even without working code.
> 
> Basically I gave up after realizing from Daniel reviews that we need
> QMP commands to query QEMU at runtime its built-in features, so we
> have build-agnostic tests easier to maintain. I agree this is the
> best way to resolve this particular case, but also scale for various
> other cases.
> 

Well, yes, but in order to get things to work, even just a kvm-build fix would 
be good until we have the perfect solution, no?

We also fixed the tcg tests when doing this for i386, so I think we can fix 
these issues for arm too.

But this doesn't mean that we don't need the QMP commands to query QEMU at 
runtime for its "built-in"/module-loaded features.
We need that too, and I suspect this will be more and more needed by libvirt, 
as QEMU modularizes.

I just think the two things could proceed in parallel..

Ciao,

Claudio