xics: Link ICS_PROP_XICS property to ICSState::xics pointer

The ICS object has both a pointer and an ICS_PROP_XICS property pointing
to the XICS fabric. Confusing bugs could arise if these ever go out of
sync.

Change the property definition so that it explicitely sets the pointer.
The property isn't optional : not being able to set the link is a bug
and QEMU should rather abort than exit in this case.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <157403283596.409804.17347207690271971987.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/intc/xics.c

@@ -609,17 +609,8 @@ static void ics_reset_handler(void *dev)
 static void ics_realize(DeviceState *dev, Error **errp)
 {
     ICSState *ics = ICS(dev);
-    Error *local_err = NULL;
-    Object *obj;
 
-    obj = object_property_get_link(OBJECT(dev), ICS_PROP_XICS, &local_err);
-    if (!obj) {
-        error_propagate_prepend(errp, local_err,
-                                "required link '" ICS_PROP_XICS
-                                "' not found: ");
-        return;
-    }
-    ics->xics = XICS_FABRIC(obj);
+    assert(ics->xics);
 
     if (!ics->nr_irqs) {
         error_setg(errp, "Number of interrupts needs to be greater 0");
@@ -699,6 +690,8 @@ static const VMStateDescription vmstate_ics = {
 
 static Property ics_properties[] = {
     DEFINE_PROP_UINT32("nr-irqs", ICSState, nr_irqs, 0),
+    DEFINE_PROP_LINK(ICS_PROP_XICS, ICSState, xics, TYPE_XICS_FABRIC,
+                     XICSFabric *),
     DEFINE_PROP_END_OF_LIST(),
 };
 

hw/ppc/pnv_psi.c

@@ -497,8 +497,7 @@ static void pnv_psi_power8_realize(DeviceState *dev, Error **errp)
     }
 
     /* Create PSI interrupt control source */
-    object_property_add_const_link(OBJECT(ics), ICS_PROP_XICS, obj,
-                                   &error_abort);
+    object_property_set_link(OBJECT(ics), obj, ICS_PROP_XICS, &error_abort);
     object_property_set_int(OBJECT(ics), PSI_NUM_INTERRUPTS, "nr-irqs", &err);
     if (err) {
         error_propagate(errp, err);

hw/ppc/spapr_irq.c

@@ -319,13 +319,8 @@ void spapr_irq_init(SpaprMachineState *spapr, Error **errp)
             return;
         }
 
-        object_property_add_const_link(obj, ICS_PROP_XICS, OBJECT(spapr),
-                                       &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
-            return;
-        }
-
+        object_property_set_link(obj, OBJECT(spapr), ICS_PROP_XICS,
+                                 &error_abort);
         object_property_set_int(obj, smc->nr_xirqs, "nr-irqs", &local_err);
         if (local_err) {
             error_propagate(errp, local_err);