From d771fca664e40c7d7ec5dfa2c656a282bff705b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Date: Wed, 28 Aug 2019 16:00:19 +0400
Subject: [PATCH] vmstate: add qom interface to get id
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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>
---
 MAINTAINERS                  |  2 ++
 hw/core/Makefile.objs        |  1 +
 hw/core/qdev.c               | 14 +++++++++++++
 hw/core/vmstate-if.c         | 23 +++++++++++++++++++++
 include/hw/vmstate-if.h      | 40 ++++++++++++++++++++++++++++++++++++
 include/migration/register.h |  2 ++
 include/migration/vmstate.h  |  2 ++
 tests/Makefile.include       |  1 +
 8 files changed, 85 insertions(+)
 create mode 100644 hw/core/vmstate-if.c
 create mode 100644 include/hw/vmstate-if.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d6de200453..e2d74d7ec3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2135,6 +2135,8 @@ Migration
 M: Juan Quintela <quintela@redhat.com>
 M: Dr. David Alan Gilbert <dgilbert@redhat.com>
 S: Maintained
+F: hw/core/vmstate-if.c
+F: include/hw/vmstate-if.h
 F: include/migration/
 F: migration/
 F: scripts/vmstate-static-checker.py
diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs
index f8481d959f..54c51583d8 100644
--- a/hw/core/Makefile.objs
+++ b/hw/core/Makefile.objs
@@ -8,6 +8,7 @@ common-obj-y += irq.o
 common-obj-y += hotplug.o
 common-obj-$(CONFIG_SOFTMMU) += nmi.o
 common-obj-$(CONFIG_SOFTMMU) += vm-change-state-handler.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 4b32f2f46d..13931b1117 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -1048,9 +1048,18 @@ 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;
 
@@ -1062,6 +1071,7 @@ 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,
@@ -1119,6 +1129,10 @@ 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);
diff --git a/include/hw/vmstate-if.h b/include/hw/vmstate-if.h
new file mode 100644
index 0000000000..8ff7f0f292
--- /dev/null
+++ b/include/hw/vmstate-if.h
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+#ifndef VMSTATE_IF_H
+#define VMSTATE_IF_H
+
+#include "qom/object.h"
+
+#define TYPE_VMSTATE_IF "vmstate-if"
+
+#define VMSTATE_IF_CLASS(klass)                                     \
+    OBJECT_CLASS_CHECK(VMStateIfClass, (klass), TYPE_VMSTATE_IF)
+#define VMSTATE_IF_GET_CLASS(obj)                           \
+    OBJECT_GET_CLASS(VMStateIfClass, (obj), TYPE_VMSTATE_IF)
+#define VMSTATE_IF(obj)                             \
+    INTERFACE_CHECK(VMStateIf, (obj), TYPE_VMSTATE_IF)
+
+typedef struct VMStateIf VMStateIf;
+
+typedef struct VMStateIfClass {
+    InterfaceClass parent_class;
+
+    char * (*get_id)(VMStateIf *obj);
+} VMStateIfClass;
+
+static inline char *vmstate_if_get_id(VMStateIf *vmif)
+{
+    if (!vmif) {
+        return NULL;
+    }
+
+    return VMSTATE_IF_GET_CLASS(vmif)->get_id(vmif);
+}
+
+#endif /* VMSTATE_IF_H */
diff --git a/include/migration/register.h b/include/migration/register.h
index f3ba10b6ef..158130c8c4 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -14,6 +14,8 @@
 #ifndef MIGRATION_REGISTER_H
 #define MIGRATION_REGISTER_H
 
+#include "hw/vmstate-if.h"
+
 typedef struct SaveVMHandlers {
     /* This runs inside the iothread lock.  */
     SaveStateHandler *save_state;
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 8abd2e3b80..8cc1e19fd9 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -27,6 +27,8 @@
 #ifndef QEMU_VMSTATE_H
 #define QEMU_VMSTATE_H
 
+#include "hw/vmstate-if.h"
+
 typedef struct VMStateInfo VMStateInfo;
 typedef struct VMStateDescription VMStateDescription;
 typedef struct VMStateField VMStateField;
diff --git a/tests/Makefile.include b/tests/Makefile.include
index 3be60ab999..1c7772a230 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -566,6 +566,7 @@ tests/test-qdev-global-props$(EXESUF): tests/test-qdev-global-props.o \
 	hw/core/irq.o \
 	hw/core/fw-path-provider.o \
 	hw/core/reset.o \
+	hw/core/vmstate-if.o \
 	$(test-qapi-obj-y)
 tests/test-vmstate$(EXESUF): tests/test-vmstate.o \
 	migration/vmstate.o migration/vmstate-types.o migration/qemu-file.o \
-- 
2.27.0