Re: [Qemu-ppc] [Qemu-devel] [Qemu-arm] [RFC PATCH] tests/device-introspect: Test devices with all machines, not only with "none"

[Markus Armbruster]

Peter Maydell <address@hidden> writes:

> On 17 April 2018 at 13:12, Markus Armbruster <address@hidden> wrote:
>> Thomas Huth <address@hidden> writes:
>>>  In case someone wants to help with creating some bug fix patches
>>>  during the QEMU hard freeze phase: This test can now be used to
>>>  trigger lots of introspection bugs that we were not aware of yet.
>>>  I think most of the bugs are due to wrong handling of instance_init
>>>  vs. realize functions.
>>
>> Yes, that's a common class of bugs.  There's little guidance on what
>> kind of work belongs where, and plenty of bad examples.  Some of the bad
>> examples crash (as you found).  Some work fine, typically because the
>> device doesn't support unplug.
>
> I've been vaguely wondering if we should start to recommend that
> all devices have a correctly implemented code path for destroying
> them post-realize, even if they don't actually implement hotplug...

Possibly crazy idea: make devices implement *cold* unplug.  Not really
useful in practice, but it would make the destroy path testable.