Making some global properties optional will let us simplify compat code when a given property works on most (but not all) subclasses of a given type.
Device types will be able to opt out from optional compat properties by simply not registering those properties. Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> --- Changes v2 -> v3: * Don't ignore all errors, ignore property only if it doesn't exist Changes v1 -> v2: * (new patch) Note: the "An error is fatal for non-hotplugged devices [...]" comment that appears in the diff scope is inaccurate, but I will fix that in a separate patch because I don't want this to get into the way of fixing the crash. --- include/hw/qdev-core.h | 3 +++ qom/object.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index bc014c1c9f..29874c8611 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -250,6 +250,8 @@ struct PropertyInfo { /** * GlobalProperty: * @used: Set to true if property was used when initializing a device. + * @optional: If set to true, GlobalProperty will be skipped without errors + * if the property doesn't exist. * * An error is fatal for non-hotplugged devices, when the global is applied. */ @@ -258,6 +260,7 @@ typedef struct GlobalProperty { const char *property; const char *value; bool used; + bool optional; } GlobalProperty; static inline void diff --git a/qom/object.c b/qom/object.c index 4e5226ca12..b8c732063b 100644 --- a/qom/object.c +++ b/qom/object.c @@ -385,6 +385,9 @@ void object_apply_global_props(Object *obj, const GPtrArray *props, Error **errp if (object_dynamic_cast(obj, p->driver) == NULL) { continue; } + if (p->optional && !object_property_find(obj, p->property, NULL)) { + continue; + } p->used = true; object_property_parse(obj, p->value, p->property, &err); if (err != NULL) { -- 2.18.0.rc1.1.g3f1ff2140