Re: [Qemu-devel] [PATCH 13/30] qdev: hotplug: set handler only if HOTPLUG_HANDLER interface is supported

[Tang Chen]

On 09/24/2014 07:48 PM, Igor Mammedov wrote:
> Check if 'handler' implements HOTPLUG_HANDLER interface
> before setting it, if it's not then do nothing and leave
> bus not hotpluggable.
>
> That would allow to reuse the same code for creating bus
> for example 'scsi_bus_new()' for both hotpluggable and not
> hotpluggable controllers.
>
> Signed-off-by: Igor Mammedov <address@hidden>
> ---
> PS:
> Keep allow_hotplug = 1 before check to preserve legacy
> behaviour for incremental conversion without breaking
> bisect-ability. I will be removed later in series.
> ---
>   include/hw/qdev-core.h | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index ba812c5..653ff4a 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -366,9 +366,14 @@ char *qdev_get_dev_path(DeviceState *dev);
>   static inline void qbus_set_hotplug_handler(BusState *bus, DeviceState 
> *handler,
>                                               Error **errp)
>   {
> +    bus->allow_hotplug = 1;

BTW, why not make allow_hotplug a bool ?

Thanks.

> +
> +    if (!object_dynamic_cast(OBJECT(handler), TYPE_HOTPLUG_HANDLER)) {
> +        return;
> +    }
> +
>       object_property_set_link(OBJECT(bus), OBJECT(handler),
>                                QDEV_HOTPLUG_HANDLER_PROPERTY, errp);
> -    bus->allow_hotplug = 1;
>   }
>   
>   static inline bool qbus_is_hotpluggable(BusState *bus)