Re: [PATCH-for-5.1] hw/isa/isa-superio: Fix IDE controller realization

[Philippe Mathieu-Daudé]

On 7/21/20 10:15 AM, Markus Armbruster wrote:
> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:
> 
>> When realizing a Super I/O with IDE controller [*], we get:
>>
>>   qom/object.c:1684: object_property_try_add_child: Assertion 
>> `!child->parent' failed.
>>   Aborted (core dumped)
>>
>> This is because the device is already realized when we try to
>> add the QOM property to the parent. Fix by realizing *after*
>> adding the QOM relationship.
>>
>> [*] Set ISASuperIOClass::ide.count = N with N not zero
> 
> Is this a latent bug, or can it bite in master?  If the latter, can you
> show how to reproduce?

Latent bug for master:

$ git grep ide.count
hw/isa/isa-superio.c:149:    if (k->ide.count && (!k->ide.is_enabled ||
k->ide.is_enabled(sio, 0))) {
hw/isa/isa-superio.c:197:    sc->ide.count = 0;
hw/isa/smc37c669-superio.c:100:    sc->ide.count = 0;
hw/isa/vt82c686.c:529:    sc->ide.count = 0;

I hit it rebasing undergoing series for 5.2 and testing them.

> 
>> Fixes: e508430619 ("hw/isa/superio: Make the components QOM children")
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>  hw/isa/isa-superio.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/isa/isa-superio.c b/hw/isa/isa-superio.c
>> index e2e47d8fd9..179c185695 100644
>> --- a/hw/isa/isa-superio.c
>> +++ b/hw/isa/isa-superio.c
>> @@ -158,8 +158,8 @@ static void isa_superio_realize(DeviceState *dev, Error 
>> **errp)
>>          if (k->ide.get_irq) {
>>              qdev_prop_set_uint32(d, "irq", k->ide.get_irq(sio, 0));
>>          }
>> -        isa_realize_and_unref(isa, bus, &error_fatal);
>>          object_property_add_child(OBJECT(sio), "isa-ide", OBJECT(isa));
>> +        isa_realize_and_unref(isa, bus, &error_fatal);
>>          sio->ide = isa;
>>          trace_superio_create_ide(0,
>>                                   k->ide.get_iobase ?
> 
>