machine: export register_compat_prop()

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 <peterx@redhat.com>
Message-Id: <1498536619-14548-2-git-send-email-peterx@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
index 39bf4b292e..50ade839b7 100644
--- a/include/hw/qdev-properties.h
+++ b/include/hw/qdev-properties.h
@@ -210,6 +210,29 @@ void error_set_from_qdev_prop_error(Error **errp, int ret, DeviceState *dev,
                                     Property *prop, const char *value);
 
 /**
+ * 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 the property will 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.
  * @prop: The qdev property definition.