[PATCH for-5.0 1/8] xive: Link "cpu" property to XiveTCTX::cs pointer

[Greg Kurz]

The TCTX object has both a pointer and a "cpu" property pointing to the
vCPU object. Confusing bugs could arise if these ever go out of sync.

Change the property definition so that it explicitely sets the pointer.

Signed-off-by: Greg Kurz <address@hidden>
---
 hw/intc/xive.c |   25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index 75dce82fb205..5363fcaa416c 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -580,19 +580,11 @@ static void xive_tctx_realize(DeviceState *dev, Error 
**errp)
     XiveTCTX *tctx = XIVE_TCTX(dev);
     PowerPCCPU *cpu;
     CPUPPCState *env;
-    Object *obj;
     Error *local_err = NULL;
 
-    obj = object_property_get_link(OBJECT(dev), "cpu", &local_err);
-    if (!obj) {
-        error_propagate(errp, local_err);
-        error_prepend(errp, "required link 'cpu' not found: ");
-        return;
-    }
-
-    cpu = POWERPC_CPU(obj);
-    tctx->cs = CPU(obj);
+    assert(tctx->cs);
 
+    cpu = POWERPC_CPU(tctx->cs);
     env = &cpu->env;
     switch (PPC_INPUT(env)) {
     case PPC_FLAGS_INPUT_POWER9:
@@ -676,10 +668,19 @@ static void xive_tctx_class_init(ObjectClass *klass, void 
*data)
     dc->user_creatable = false;
 }
 
+static void xive_tctx_instance_init(Object *obj)
+{
+    object_property_add_link(obj, "cpu", TYPE_CPU,
+                             (Object **) &XIVE_TCTX(obj)->cs,
+                             qdev_prop_allow_set_link_before_realize,
+                             OBJ_PROP_LINK_STRONG, &error_abort);
+}
+
 static const TypeInfo xive_tctx_info = {
     .name          = TYPE_XIVE_TCTX,
     .parent        = TYPE_DEVICE,
     .instance_size = sizeof(XiveTCTX),
+    .instance_init = xive_tctx_instance_init,
     .class_init    = xive_tctx_class_init,
 };
 
@@ -691,8 +692,7 @@ Object *xive_tctx_create(Object *cpu, XiveRouter *xrtr, 
Error **errp)
     obj = object_new(TYPE_XIVE_TCTX);
     object_property_add_child(cpu, TYPE_XIVE_TCTX, obj, &error_abort);
     object_unref(obj);
-    object_ref(cpu);
-    object_property_add_const_link(obj, "cpu", cpu, &error_abort);
+    object_property_set_link(obj, cpu, "cpu", &error_abort);
     object_property_set_bool(obj, true, "realized", &local_err);
     if (local_err) {
         goto error;
@@ -710,7 +710,6 @@ void xive_tctx_destroy(XiveTCTX *tctx)
 {
     Object *obj = OBJECT(tctx);
 
-    object_unref(object_property_get_link(obj, "cpu", &error_abort));
     object_unparent(obj);
 }