virtio: add a wrapper for virtio-backend initialization

For better code sharing, add a helper function that handles
reference counting of the virtio backend for virtio proxy devices.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/s390x/s390-virtio-bus.c

@@ -159,10 +159,9 @@ static int s390_virtio_net_init(VirtIOS390Device *s390_dev)
 static void s390_virtio_net_instance_init(Object *obj)
 {
     VirtIONetS390 *dev = VIRTIO_NET_S390(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_NET);
 }
 
 static int s390_virtio_blk_init(VirtIOS390Device *s390_dev)
@@ -179,10 +178,9 @@ static int s390_virtio_blk_init(VirtIOS390Device *s390_dev)
 static void s390_virtio_blk_instance_init(Object *obj)
 {
     VirtIOBlkS390 *dev = VIRTIO_BLK_S390(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BLK);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_BLK);
     object_property_add_alias(obj, "iothread", OBJECT(&dev->vdev),"iothread",
                               &error_abort);
 }
@@ -224,10 +222,9 @@ static int s390_virtio_serial_init(VirtIOS390Device *s390_dev)
 static void s390_virtio_serial_instance_init(Object *obj)
 {
     VirtIOSerialS390 *dev = VIRTIO_SERIAL_S390(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
-    object_unref(OBJECT(&dev->vdev));
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SERIAL);
 }
 
 static int s390_virtio_scsi_init(VirtIOS390Device *s390_dev)
@@ -258,10 +255,9 @@ static int s390_virtio_scsi_init(VirtIOS390Device *s390_dev)
 static void s390_virtio_scsi_instance_init(Object *obj)
 {
     VirtIOSCSIS390 *dev = VIRTIO_SCSI_S390(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SCSI);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SCSI);
 }
 
 #ifdef CONFIG_VHOST_SCSI
@@ -281,10 +277,9 @@ static int s390_vhost_scsi_init(VirtIOS390Device *s390_dev)
 static void s390_vhost_scsi_instance_init(Object *obj)
 {
     VHostSCSIS390 *dev = VHOST_SCSI_S390(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VHOST_SCSI);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_SCSI);
 }
 #endif
 
@@ -309,10 +304,9 @@ static int s390_virtio_rng_init(VirtIOS390Device *s390_dev)
 static void s390_virtio_rng_instance_init(Object *obj)
 {
     VirtIORNGS390 *dev = VIRTIO_RNG_S390(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_RNG);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
-    object_unref(OBJECT(&dev->vdev));
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_RNG);
     object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
                              (Object **)&dev->vdev.conf.rng,
                              qdev_prop_allow_set_link_before_realize,

hw/s390x/virtio-ccw.c

@@ -792,10 +792,9 @@ static int virtio_ccw_net_init(VirtioCcwDevice *ccw_dev)
 static void virtio_ccw_net_instance_init(Object *obj)
 {
     VirtIONetCcw *dev = VIRTIO_NET_CCW(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_NET);
 }
 
 static int virtio_ccw_blk_init(VirtioCcwDevice *ccw_dev)
@@ -813,10 +812,9 @@ static int virtio_ccw_blk_init(VirtioCcwDevice *ccw_dev)
 static void virtio_ccw_blk_instance_init(Object *obj)
 {
     VirtIOBlkCcw *dev = VIRTIO_BLK_CCW(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BLK);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_BLK);
     object_property_add_alias(obj, "iothread", OBJECT(&dev->vdev),"iothread",
                               &error_abort);
 }
@@ -850,10 +848,9 @@ static int virtio_ccw_serial_init(VirtioCcwDevice *ccw_dev)
 static void virtio_ccw_serial_instance_init(Object *obj)
 {
     VirtioSerialCcw *dev = VIRTIO_SERIAL_CCW(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
-    object_unref(OBJECT(&dev->vdev));
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SERIAL);
 }
 
 static int virtio_ccw_balloon_init(VirtioCcwDevice *ccw_dev)
@@ -938,10 +935,9 @@ static int virtio_ccw_scsi_init(VirtioCcwDevice *ccw_dev)
 static void virtio_ccw_scsi_instance_init(Object *obj)
 {
     VirtIOSCSICcw *dev = VIRTIO_SCSI_CCW(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SCSI);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SCSI);
 }
 
 #ifdef CONFIG_VHOST_SCSI
@@ -961,10 +957,9 @@ static int vhost_ccw_scsi_init(VirtioCcwDevice *ccw_dev)
 static void vhost_ccw_scsi_instance_init(Object *obj)
 {
     VHostSCSICcw *dev = VHOST_SCSI_CCW(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VHOST_SCSI);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_SCSI);
 }
 #endif
 
@@ -1540,10 +1535,9 @@ static const TypeInfo vhost_ccw_scsi = {
 static void virtio_ccw_rng_instance_init(Object *obj)
 {
     VirtIORNGCcw *dev = VIRTIO_RNG_CCW(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_RNG);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
-    object_unref(OBJECT(&dev->vdev));
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_RNG);
     object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
                              (Object **)&dev->vdev.conf.rng,
                              qdev_prop_allow_set_link_before_realize,

hw/virtio/virtio-pci.c

@@ -947,10 +947,9 @@ static void virtio_9p_pci_class_init(ObjectClass *klass, void *data)
 static void virtio_9p_pci_instance_init(Object *obj)
 {
     V9fsPCIState *dev = VIRTIO_9P_PCI(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_9P);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
-    object_unref(OBJECT(&dev->vdev));
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_9P);
 }
 
 static const TypeInfo virtio_9p_pci_info = {
@@ -1112,10 +1111,9 @@ static void virtio_blk_pci_class_init(ObjectClass *klass, void *data)
 static void virtio_blk_pci_instance_init(Object *obj)
 {
     VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BLK);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_BLK);
     object_property_add_alias(obj, "iothread", OBJECT(&dev->vdev),"iothread",
                               &error_abort);
 }
@@ -1185,10 +1183,9 @@ static void virtio_scsi_pci_class_init(ObjectClass *klass, void *data)
 static void virtio_scsi_pci_instance_init(Object *obj)
 {
     VirtIOSCSIPCI *dev = VIRTIO_SCSI_PCI(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SCSI);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SCSI);
 }
 
 static const TypeInfo virtio_scsi_pci_info = {
@@ -1242,10 +1239,9 @@ static void vhost_scsi_pci_class_init(ObjectClass *klass, void *data)
 static void vhost_scsi_pci_instance_init(Object *obj)
 {
     VHostSCSIPCI *dev = VHOST_SCSI_PCI(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VHOST_SCSI);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_SCSI);
 }
 
 static const TypeInfo vhost_scsi_pci_info = {
@@ -1408,10 +1404,9 @@ static void virtio_serial_pci_class_init(ObjectClass *klass, void *data)
 static void virtio_serial_pci_instance_init(Object *obj)
 {
     VirtIOSerialPCI *dev = VIRTIO_SERIAL_PCI(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
-    object_unref(OBJECT(&dev->vdev));
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SERIAL);
 }
 
 static const TypeInfo virtio_serial_pci_info = {
@@ -1467,10 +1462,9 @@ static void virtio_net_pci_class_init(ObjectClass *klass, void *data)
 static void virtio_net_pci_instance_init(Object *obj)
 {
     VirtIONetPCI *dev = VIRTIO_NET_PCI(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    object_unref(OBJECT(&dev->vdev));
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_NET);
 }
 
 static const TypeInfo virtio_net_pci_info = {
@@ -1523,10 +1517,9 @@ static void virtio_rng_pci_class_init(ObjectClass *klass, void *data)
 static void virtio_rng_initfn(Object *obj)
 {
     VirtIORngPCI *dev = VIRTIO_RNG_PCI(obj);
-    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_RNG);
-    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
-    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
-    object_unref(OBJECT(&dev->vdev));
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_RNG);
     object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
                              (Object **)&dev->vdev.conf.rng,
                              qdev_prop_allow_set_link_before_realize,

hw/virtio/virtio.c

@@ -1123,6 +1123,17 @@ static void virtio_vmstate_change(void *opaque, int running, RunState state)
     }
 }
 
+void virtio_instance_init_common(Object *proxy_obj, void *data,
+                                 size_t vdev_size, const char *vdev_name)
+{
+    DeviceState *vdev = data;
+
+    object_initialize(vdev, vdev_size, vdev_name);
+    object_property_add_child(proxy_obj, "virtio-backend", OBJECT(vdev), NULL);
+    object_unref(OBJECT(vdev));
+    qdev_alias_all_properties(vdev, proxy_obj);
+}
+
 void virtio_init(VirtIODevice *vdev, const char *name,
                  uint16_t device_id, size_t config_size)
 {

include/hw/virtio/virtio.h

@@ -161,6 +161,9 @@ typedef struct VirtioDeviceClass {
     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
 } VirtioDeviceClass;
 
+void virtio_instance_init_common(Object *proxy_obj, void *data,
+                                 size_t vdev_size, const char *vdev_name);
+
 void virtio_init(VirtIODevice *vdev, const char *name,
                          uint16_t device_id, size_t config_size);
 void virtio_cleanup(VirtIODevice *vdev);