xive: Make some device types not user creatable

Some device types of the XIVE model are exposed to the QEMU command
line:

$ ppc64-softmmu/qemu-system-ppc64 -device help | grep xive
name "xive-end-source", desc "XIVE END Source"
name "xive-source", desc "XIVE Interrupt Source"
name "xive-tctx", desc "XIVE Interrupt Thread Context"

These are internal devices that shouldn't be instantiable by the
user. By the way, they can't be because their respective realize
functions expect link properties that can't be set from the command
line:

qemu-system-ppc64: -device xive-source: required link 'xive' not found:
 Property '.xive' not found
qemu-system-ppc64: -device xive-end-source: required link 'xive' not found:
 Property '.xive' not found
qemu-system-ppc64: -device xive-tctx: required link 'cpu' not found:
 Property '.cpu' not found

Hide them by setting dc->user_creatable to false in their respective
class init functions.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Message-Id: <157017473006.331610.2983143972519884544.stgit@bahia.lan>
Message-Id: <157045578401.865784.6058183726552779559.stgit@bahia.lan>
Reviewed-by: NCédric Le Goater <clg@kaod.org>
[dwg: Folded comment update into base patch]
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/intc/xive.c

@@ -670,6 +670,11 @@ static void xive_tctx_class_init(ObjectClass *klass, void *data)
     dc->realize = xive_tctx_realize;
     dc->unrealize = xive_tctx_unrealize;
     dc->vmsd = &vmstate_xive_tctx;
+    /*
+     * Reason: part of XIVE interrupt controller, needs to be wired up
+     * by xive_tctx_create().
+     */
+    dc->user_creatable = false;
 }
 
 static const TypeInfo xive_tctx_info = {
@@ -1118,6 +1123,11 @@ static void xive_source_class_init(ObjectClass *klass, void *data)
     dc->props   = xive_source_properties;
     dc->realize = xive_source_realize;
     dc->vmsd    = &vmstate_xive_source;
+    /*
+     * Reason: part of XIVE interrupt controller, needs to be wired up,
+     * e.g. by spapr_xive_instance_init().
+     */
+    dc->user_creatable = false;
 }
 
 static const TypeInfo xive_source_info = {
@@ -1853,6 +1863,11 @@ static void xive_end_source_class_init(ObjectClass *klass, void *data)
     dc->desc    = "XIVE END Source";
     dc->props   = xive_end_source_properties;
     dc->realize = xive_end_source_realize;
+    /*
+     * Reason: part of XIVE interrupt controller, needs to be wired up,
+     * e.g. by spapr_xive_instance_init().
+     */
+    dc->user_creatable = false;
 }
 
 static const TypeInfo xive_end_source_info = {