Re: [Qemu-devel] [PATCH v2] qdev: Don't assume existence of parent bus on unparenting

["Andreas Färber" <afaerber@suse.de>]

Am 07.01.2013 14:47, schrieb Igor Mammedov:
> On Fri,  4 Jan 2013 18:34:40 +0100
> Andreas Färber <afaerber@suse.de> wrote:
> 
>> Commit 667d22d1ae59da46b4c1fbd094ca61145f19b8c3 (qdev: move bus removal
>> to object_unparent) made the assumption that at unparenting time
>> parent_bus is not NULL. This assumption is unjustified since
>> object_unparent() may well be called directly after object_initialize(),
>> without any qdev_set_parent_bus().
>>
>> This did not cause any issues yet because qdev_[try_]create() does call
>> qdev_set_parent_bus(), falling back to SysBus if unsupplied.
>>
>> While at it, ensure that this new function uses the device_ prefix and
>> make the name more neutral in light of this semantic change.
>>
>> Reported-by: Eduardo Habkost <ehabkost@redhat.com>
>> Signed-off-by: Andreas Färber <afaerber@suse.de>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>>  Planning to insert this before the final CPU-as-a-device patch on qom-cpu,
>>  to avoid a regression for, e.g., -cpu Haswell,enforce if unsupported by host.
>>
>>  This supersedes my cosmetic patch in the "QOM realize, device-only" series:
>>
>>  v1 -> v2:
>>  * Make bus removal conditional on parent bus
>>  * Rename function further
>>
>>  hw/qdev.c |    8 +++++---
>>  1 Datei geändert, 5 Zeilen hinzugefügt(+), 3 Zeilen entfernt(-)
>>
>> diff --git a/hw/qdev.c b/hw/qdev.c
>> index f2c2484..e2a5c57 100644
>> --- a/hw/qdev.c
>> +++ b/hw/qdev.c
>> @@ -698,16 +698,18 @@ static void device_class_base_init(ObjectClass *class, void *data)
>>      klass->props = NULL;
>>  }
>>  
>> -static void qdev_remove_from_bus(Object *obj)
>> +static void device_unparent(Object *obj)
>>  {
>>      DeviceState *dev = DEVICE(obj);
>>  
>> -    bus_remove_child(dev->parent_bus, dev);
>> +    if (dev->parent_bus != NULL) {
>> +        bus_remove_child(dev->parent_bus, dev);
>> +    }
>>  }
>>  
>>  static void device_class_init(ObjectClass *class, void *data)
>>  {
>> -    class->unparent = qdev_remove_from_bus;
>> +    class->unparent = device_unparent;
>>  }
>>  
>>  void device_reset(DeviceState *dev)
>> -- 
>> 1.7.10.4
>>
>>
> Works for me,
> 
> Tested-By: Igor Mammedov <imammedo@redhat.com>

Thanks, inserted into qom-cpu queue:
https://github.com/afaerber/qemu-cpu/commits/qom-cpu

Andreas

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