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

[Igor Mammedov <imammedo@redhat.com>]

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>

-- 
Regards,
  Igor