Il 30/05/2014 22:11, mtosa...@redhat.com ha scritto:
Add a link to rtc under /machines providing a stable
location for management apps to query "date" field.
{"execute":"qom-get","arguments":{"path":"/machine/rtc","property":"date"} }
Suggested by Paolo Bonzini.
Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com>
Index: qemu/hw/timer/mc146818rtc.c
===================================================================
--- qemu.orig/hw/timer/mc146818rtc.c
+++ qemu/hw/timer/mc146818rtc.c
@@ -63,6 +63,7 @@
typedef struct RTCState {
ISADevice parent_obj;
+ Object *rtc_object;
MemoryRegion io;
uint8_t cmos_data[128];
uint8_t cmos_index;
@@ -856,6 +857,8 @@ static void rtc_realizefn(DeviceState *d
RTCState *s = MC146818_RTC(dev);
int base = 0x70;
+ s->rtc_object = OBJECT(s);
Adding a new pointer variable is ugly; let's instead add a new function
to create the property, that works the intended way. It can be very
similar to object_property_add_child, like this:
object_property_add_alias(qdev_get_machine(), "rtc", OBJECT(s),
&error_abort);
Of course you don't need to modify child->parent and you also need to
change the new function so that the type becomes "link<%s>" (child<%s>
really means that you have set child->parent); on the other hand you can
reuse the getter (object_get_child_property).
+#ifdef TARGET_I386
The #ifdef is not necessary.
+ object_ref(s->rtc_object);
This means that the RTC cannot be removed anymore unless someone drops
the link property; but no one except the machine knows that the property
is there, so there is a catch-22.
So I think it makes sense to not add a reference. If you do not add a
reference, you do not need object_property_add_alias to add a finalizer
either (like object_release_child_property). However, you need to add
an instance_finalize callback in mc146818rtc_info, which removes the rtc
property from /machine.
Paolo
+ object_property_add_link(qdev_get_machine(), "rtc", TYPE_MC146818_RTC,
+ (Object **)&s->rtc_object, NULL, 0, &error_abort);
+#endif
}
ISADevice *rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq)