Re: [PATCH] qom: reverse order of instance_post_init calls

[Paolo Bonzini <pbonzini@redhat.com>]

On 2/4/25 16:08, Philippe Mathieu-Daudé wrote:
> Hi Paolo,
> 
> On 3/2/25 12:41, Paolo Bonzini wrote:
>> Currently, the instance_post_init calls are performed from the leaf
>> class and all the way up to Object.  This is incorrect because the
>> leaf class cannot observe property values applied by the superclasses;
>> for example, a compat property will be set on a device *after*
>> the class's post_init callback has run.
>>
>> In particular this makes it impossible for implementations of
>> accel_cpu_instance_init() to operate based on the actual values of
>> the properties, though it seems that cxl_dsp_instance_post_init and
>> rp_instance_post_init might have similar issues.
> 
> I'm not opposed to this change as I had a similar issue there few weeks
> ago, but I feel we are changing one problem by another. IIRC some class
> post_init() handlers check the instance correctly did something.

There are five - one does not have any subclass and the other four are 
all mentioned in the commit message:

- x86 and risc-v use accel_cpu_instance_init(), which is where I found 
the bug

- the other two seem broken too

>    * @instance_post_init: This function is called to finish
>    *                      initialization of an object, after
>    *                      all @instance_init functions were
>    *                      called.

Yeah I didn't adjust it because it now is simply the same order as 
instance_init (and the opposite as instance_finalize).  I can change it 
to "after all @instance_init functions were called, as well as the 
@instance_post_init functions for the parent classes".

Paolo