Re: [Qemu-devel] [PATCH v4 7/8] qmp: Support abstract classes on device-list-properties

[Igor Mammedov]

On Fri, 28 Oct 2016 23:48:06 -0200
Eduardo Habkost <address@hidden> wrote:

> When an abstract class is used on device-list-properties, we can
> simply return the class properties registered for the class.
> 
> This will be useful if management software needs to query for
> supported options that apply to all devices of a given type (e.g.
> options supported by all CPU models, options supported by all PCI
> devices).
Patch looks fine to me but I'm not qmp interface guru
so I'd leave review up to maintainers.

One question though,
How would management software discover typename of abstract class?

Perhaps this patch should be part of some other series.

> Signed-off-by: Eduardo Habkost <address@hidden>
> ---
> Changes series v1 -> v2:
> * (none)
> 
> Changes series v2 -> v3:
> * Reworded commit message
> 
> Changes series v3 -> v4:
> * (none)
> ---
>  qmp.c | 21 +++++++++------------
>  1 file changed, 9 insertions(+), 12 deletions(-)
> 
> diff --git a/qmp.c b/qmp.c
> index a06cb7b..1e7e60d 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -518,7 +518,7 @@ DevicePropertyInfoList *qmp_device_list_properties(const 
> char *typename,
>                                                     Error **errp)
>  {
>      ObjectClass *klass;
> -    Object *obj;
> +    Object *obj = NULL;
>      ObjectProperty *prop;
>      ObjectPropertyIterator iter;
>      DevicePropertyInfoList *prop_list = NULL;
> @@ -537,19 +537,16 @@ DevicePropertyInfoList 
> *qmp_device_list_properties(const char *typename,
>      }
>  
>      if (object_class_is_abstract(klass)) {
> -        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "name",
> -                   "non-abstract device type");
> -        return NULL;
> -    }
> -
> -    if (DEVICE_CLASS(klass)->cannot_destroy_with_object_finalize_yet) {
> -        error_setg(errp, "Can't list properties of device '%s'", typename);
> -        return NULL;
> +        object_class_property_iter_init(&iter, klass);
> +    } else {
> +        if (DEVICE_CLASS(klass)->cannot_destroy_with_object_finalize_yet) {
> +            error_setg(errp, "Can't list properties of device '%s'", 
> typename);
> +            return NULL;
> +        }
> +        obj = object_new(typename);
> +        object_property_iter_init(&iter, obj);
>      }
>  
> -    obj = object_new(typename);
> -
> -    object_property_iter_init(&iter, obj);
>      while ((prop = object_property_iter_next(&iter))) {
>          DevicePropertyInfo *info;
>          DevicePropertyInfoList *entry;