[PATCH for-5.0 3/4] xics: Link ICP_PROP_CPU property to ICPState::cs pointer

[Greg Kurz]

The ICP object has both a pointer and an ICP_PROP_CPU property pointing
to the cpu. 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 <address@hidden>
---
 hw/intc/xics.c |   21 ++++-----------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/hw/intc/xics.c b/hw/intc/xics.c
index 35dddb88670e..0b259a09c545 100644
--- a/hw/intc/xics.c
+++ b/hw/intc/xics.c
@@ -305,25 +305,13 @@ void icp_reset(ICPState *icp)
 static void icp_realize(DeviceState *dev, Error **errp)
 {
     ICPState *icp = ICP(dev);
-    PowerPCCPU *cpu;
     CPUPPCState *env;
-    Object *obj;
     Error *err = NULL;
 
     assert(icp->xics);
+    assert(icp->cs);
 
-    obj = object_property_get_link(OBJECT(dev), ICP_PROP_CPU, &err);
-    if (!obj) {
-        error_propagate_prepend(errp, err,
-                                "required link '" ICP_PROP_CPU
-                                "' not found: ");
-        return;
-    }
-
-    cpu = POWERPC_CPU(obj);
-    icp->cs = CPU(obj);
-
-    env = &cpu->env;
+    env = &POWERPC_CPU(icp->cs)->env;
     switch (PPC_INPUT(env)) {
     case PPC_FLAGS_INPUT_POWER7:
         icp->output = env->irq_inputs[POWER7_INPUT_INT];
@@ -363,6 +351,7 @@ static void icp_unrealize(DeviceState *dev, Error **errp)
 static Property icp_properties[] = {
     DEFINE_PROP_LINK(ICP_PROP_XICS, ICPState, xics, TYPE_XICS_FABRIC,
                      XICSFabric *),
+    DEFINE_PROP_LINK(ICP_PROP_CPU, ICPState, cs, TYPE_CPU, CPUState *),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -397,8 +386,7 @@ Object *icp_create(Object *cpu, const char *type, 
XICSFabric *xi, Error **errp)
     object_property_add_child(cpu, type, obj, &error_abort);
     object_unref(obj);
     object_property_set_link(obj, OBJECT(xi), ICP_PROP_XICS, &error_abort);
-    object_ref(cpu);
-    object_property_add_const_link(obj, ICP_PROP_CPU, cpu, &error_abort);
+    object_property_set_link(obj, cpu, ICP_PROP_CPU, &error_abort);
     object_property_set_bool(obj, true, "realized", &local_err);
     if (local_err) {
         object_unparent(obj);
@@ -413,7 +401,6 @@ void icp_destroy(ICPState *icp)
 {
     Object *obj = OBJECT(icp);
 
-    object_unref(object_property_get_link(obj, ICP_PROP_CPU, &error_abort));
     object_unparent(obj);
 }