qdev: Move bus properties to abstract superclasses

In qdev, each bus in practice identified an abstract superclass, but
this was mostly hidden.  In QOM, instead, these abstract classes are
explicit so we can move bus properties there.

All bus property walks are removed, and all device property walks
are changed to look along the class hierarchy instead.

We would have duplicates if class A defines some properties and its
subclass B does not define any, because class_b->props will be
left equal to class_a->props.

The solution here is to reintroduce the class_base_init TypeInfo
callback, that was present in one of the early QOM versions but
removed (on my request...) before committing.

This breaks global bus properties, an obscure feature when used
with the command-line which is actually useful and used when used by
backwards-compatible machine types.  So this patch also adjusts the
global bus properties in hw/pc_piix.c to refer to the abstract class.

Globals and other properties must be modified in the same patch to
avoid complications related to initialization ordering.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

2 files changed, 2 insertions, 2 deletions

diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index 3faf4cb..64887d5 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -24,7 +24,6 @@ static struct BusInfo usb_bus_info = {
     .print_dev = usb_bus_dev_print,
     .get_dev_path = usb_get_dev_path,
     .get_fw_dev_path = usb_get_fw_dev_path,
-    .props     = usb_props,
 };
 
 static int next_usb_bus = 0;
@@ -583,6 +582,7 @@ static void usb_device_class_init(ObjectClass *klass, void *data)
     k->init     = usb_qdev_init;
     k->unplug   = qdev_simple_unplug_cb;
     k->exit     = usb_qdev_exit;
+    k->props    = usb_props;
 }
 
 static TypeInfo usb_device_type_info = {
diff --git a/hw/usb/dev-smartcard-reader.c b/hw/usb/dev-smartcard-reader.c
index 357b7e8..a4ab6e5 100644
--- a/hw/usb/dev-smartcard-reader.c
+++ b/hw/usb/dev-smartcard-reader.c
@@ -1063,7 +1063,6 @@ static Property ccid_props[] = {
 static struct BusInfo ccid_bus_info = {
     .name = "ccid-bus",
     .size = sizeof(CCIDBus),
-    .props = ccid_props,
 };
 
 void ccid_card_send_apdu_to_guest(CCIDCardState *card,
@@ -1347,6 +1346,7 @@ static void ccid_card_class_init(ObjectClass *klass, void *data)
     k->bus_info = &ccid_bus_info;
     k->init = ccid_card_init;
     k->exit = ccid_card_exit;
+    k->props = ccid_props;
 }
 
 static TypeInfo ccid_card_type_info = {