On Fri, Jun 23, 2017 at 12:46:37PM +0800, Peter Xu wrote:
> We have HW_COMPAT_*, however that's only bound to machines, not other
> things (like accelerators). Behind it, it was register_compat_prop()
> that played the trick. Let's export the function for further use
> outside HW_COMPAT_* magic.
>
> Meanwhile, move it to qdev-properties.c where seems more proper (since
> it'll be used not only in machine codes).
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
> ---
> hw/core/machine.c | 13 -------------
> hw/core/qdev-properties.c | 13 +++++++++++++
> include/hw/qdev-properties.h | 3 +++
> 3 files changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 2e7e977..ecb5552 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -770,19 +770,6 @@ static void machine_class_finalize(ObjectClass *klass,
> void *data)
> g_free(mc->name);
> }
>
> -static void register_compat_prop(const char *driver,
> - const char *property,
> - const char *value)
> -{
> - GlobalProperty *p = g_new0(GlobalProperty, 1);
> - /* Machine compat_props must never cause errors: */
> - p->errp = &error_abort;
> - p->driver = driver;
> - p->property = property;
> - p->value = value;
> - qdev_prop_register_global(p);
> -}
> -
> static void machine_register_compat_for_subclass(ObjectClass *oc, void
> *opaque)
> {
> GlobalProperty *p = opaque;
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index 9f1a497..6ff1ac3 100644
> --- a/hw/core/qdev-properties.c
> +++ b/hw/core/qdev-properties.c
> @@ -1047,6 +1047,19 @@ void qdev_prop_register_global(GlobalProperty *prop)
> global_props = g_list_append(global_props, prop);
> }
>
> +void register_compat_prop(const char *driver,
> + const char *property,
> + const char *value)
> +{
> + GlobalProperty *p = g_new0(GlobalProperty, 1);
> + /* Machine compat_props must never cause errors: */
Now this won't be used only for machine compat_props, so this comment
needs to be deleted or updated (see suggestion below).
> + p->errp = &error_abort;
> + p->driver = driver;
> + p->property = property;
> + p->value = value;
> + qdev_prop_register_global(p);
> +}
> +
> void qdev_prop_register_global_list(GlobalProperty *props)
> {
> int i;
> diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
> index d206fc9..1722ca4 100644
> --- a/include/hw/qdev-properties.h
> +++ b/include/hw/qdev-properties.h
> @@ -201,6 +201,9 @@ void qdev_prop_set_globals(DeviceState *dev);
> void error_set_from_qdev_prop_error(Error **errp, int ret, DeviceState *dev,
> Property *prop, const char *value);
>
As this function is very easy to be misused, I suggest including the
following documentation:
/**
* register_compat_prop:
*
* Register internal (not user-provided) global property, changing the
* default value of a given property in a device type. This can be used
* for enabling machine-type compatibility or for enabling
* accelerator-specific defaults in devices.
*
* The property values set using this function must be always valid and
* never report setter errors, as they property have
* GlobalProperty::errp set to &error_abort.
*
* User-provided global properties should override internal global
* properties, so callers of this function should ensure that it is
* called before user-provided global properties are registered.
*
* @driver: Device type to be affected
* @property: Property whose default value is going to be changed
* @value: New default value for the property
*/
> +void register_compat_prop(const char *driver, const char *property,
> + const char *value);
> +
> /**
> * qdev_property_add_static:
> * @dev: Device to add the property to.
> --
> 2.7.4
>
>
--
Eduardo
