Re: [PATCH 16/24] virt: Register "its" as class property

[Peter Maydell]

On Mon, 21 Sep 2020 at 23:11, Eduardo Habkost <ehabkost@redhat.com> wrote:
>
> Class properties make QOM introspection simpler and easier, as
> they don't require an object to be instantiated.
>
> Note: "its" is currently registered conditionally, but this makes
> the feature be registered unconditionally.  The only side effect
> is that it will be now possible to set its=on on virt-2.7 and
> older.
>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: qemu-arm@nongnu.org
> Cc: qemu-devel@nongnu.org
> ---
>  hw/arm/virt.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index d1ab660fa60..986b75a6b89 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -2484,6 +2484,13 @@ static void virt_machine_class_init(ObjectClass *oc, 
> void *data)
>                                            "Set on/off to enable/disable 
> emulating a "
>                                            "guest CPU which implements the 
> ARM "
>                                            "Memory Tagging Extension");
> +
> +    object_class_property_add_bool(oc, "its", virt_get_its,
> +                                   virt_set_its);
> +    object_class_property_set_description(oc, "its",
> +                                          "Set on/off to enable/disable "
> +                                          "ITS instantiation");
> +
>  }
>
>  static void virt_instance_init(Object *obj)
> @@ -2511,11 +2518,6 @@ static void virt_instance_init(Object *obj)
>      } else {
>          /* Default allows ITS instantiation */
>          vms->its = true;
> -        object_property_add_bool(obj, "its", virt_get_its,
> -                                 virt_set_its);
> -        object_property_set_description(obj, "its",
> -                                        "Set on/off to enable/disable "
> -                                        "ITS instantiation");
>      }

This leaves the code reading
  if (vmc->no_its) {
      vms->its = false;
  } else {
      vms->its = true;
  }

which is more simply written "vms->its = !vmc->no_its;"

thanks
-- PMM