vmstate: add qom interface to get id

Add an interface to get the instance id, instead of depending on
Device and qdev_get_dev_path().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

3 files changed, 38 insertions, 0 deletions

diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs
index fd0550d1d9..0edd9e635d 100644
--- a/hw/core/Makefile.objs
+++ b/hw/core/Makefile.objs
@@ -9,6 +9,7 @@ common-obj-y += hotplug.o
 common-obj-$(CONFIG_SOFTMMU) += nmi.o
 common-obj-$(CONFIG_SOFTMMU) += vm-change-state-handler.o
 common-obj-y += cpu.o
+common-obj-y += vmstate-if.o
 
 common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o
 common-obj-$(CONFIG_XILINX_AXI) += stream.o
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 82d3ee590a..1a98812be2 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -1087,9 +1087,18 @@ static void device_unparent(Object *obj)
     }
 }
 
+static char *
+device_vmstate_if_get_id(VMStateIf *obj)
+{
+    DeviceState *dev = DEVICE(obj);
+
+    return qdev_get_dev_path(dev);
+}
+
 static void device_class_init(ObjectClass *class, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(class);
+    VMStateIfClass *vc = VMSTATE_IF_CLASS(class);
 
     class->unparent = device_unparent;
 
@@ -1101,6 +1110,7 @@ static void device_class_init(ObjectClass *class, void *data)
      */
     dc->hotpluggable = true;
     dc->user_creatable = true;
+    vc->get_id = device_vmstate_if_get_id;
 }
 
 void device_class_set_parent_reset(DeviceClass *dc,
@@ -1158,6 +1168,10 @@ static const TypeInfo device_type_info = {
     .class_init = device_class_init,
     .abstract = true,
     .class_size = sizeof(DeviceClass),
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_VMSTATE_IF },
+        { }
+    }
 };
 
 static void qdev_register_types(void)
diff --git a/hw/core/vmstate-if.c b/hw/core/vmstate-if.c
new file mode 100644
index 0000000000..bf453620fe
--- /dev/null
+++ b/hw/core/vmstate-if.c
@@ -0,0 +1,23 @@
+/*
+ * VMState interface
+ *
+ * Copyright (c) 2009-2019 Red Hat Inc
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/vmstate-if.h"
+
+static const TypeInfo vmstate_if_info = {
+    .name = TYPE_VMSTATE_IF,
+    .parent = TYPE_INTERFACE,
+    .class_size = sizeof(VMStateIfClass),
+};
+
+static void vmstate_register_types(void)
+{
+    type_register_static(&vmstate_if_info);
+}
+
+type_init(vmstate_register_types);