Re: [PATCH v4 2/3] mac_via: fix incorrect creation of mos6522 device in mac_via

[Paolo Bonzini <pbonzini@redhat.com>]

On 16/03/20 07:03, Markus Armbruster wrote:
> Paolo Bonzini <pbonzini@redhat.com> writes:
> 
>> On 15/03/20 15:56, Markus Armbruster wrote:
>>>>
>>>> The question is why they are not, i.e. where does the above reasoning break.
>>> I don't know.  But let's for the sake of the argument assume this
>>> actually worked.  Asking for help in the monitor then *still* has side
>>> effects visible in the time span between .instance_init() and
>>> finalization.
>>>
>>> Why is that harmless?
>>
>> I don't really have an answer, but if that is a problem we could change
>> "info qtree" to skip non-realized devices.
> 
> Can we convince ourselves that "info qtree" is the *only* way to observe
> these side effects?

There is of course qom-get/qom-set, but those _should_ show this side
effect.

If we decide that "info qtree" should only show devices visible to the
guest (as opposed to all objects that have been created), then "show
only realized devices" is not even a hack but the correct implementation
of the concept.

Paolo

> If yes, a hack to ignore unrealized devices "fixes" the problem.
> 
> If no, it sweeps it under the rug.