Merge remote-tracking branch 'bonzini/virtio' into staging

# By Andreas Färber (18) and Paolo Bonzini (12)
# Via Paolo Bonzini
* bonzini/virtio: (30 commits)
  virtio: Convert exit to unrealize
  virtio: Complete converting VirtioDevice to QOM realize
  virtio-scsi: Convert to QOM realize
  virtio-rng: Convert to QOM realize
  virtio-balloon: Convert to QOM realize
  virtio-net: Convert to QOM realize
  virtio-serial: Convert to QOM realize
  virtio-blk: Convert to QOM realize
  virtio-9p: Convert to QOM realize
  virtio: Start converting VirtioDevice to QOM realize
  virtio-scsi: QOM realize preparations
  virtio-rng: QOM realize preparations
  virtio-balloon: QOM realize preparations
  virtio-net: QOM realize preparations
  virtio-serial: QOM realize preparations
  virtio-blk: QOM realize preparations
  virtio-9p: QOM realize preparations
  virtio-blk-dataplane: Improve error reporting
  virtio-pci: add device_unplugged callback
  virtio-rng: switch exit callback to VirtioDeviceClass
  ...

17 files changed, 387 insertions, 320 deletions

diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index f0ffbe8c0d..15a4983eee 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -41,15 +41,16 @@ static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
     g_free(cfg);
 }
 
-static int virtio_9p_device_init(VirtIODevice *vdev)
+static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 {
-    V9fsState *s = VIRTIO_9P(vdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    V9fsState *s = VIRTIO_9P(dev);
     int i, len;
     struct stat stat;
     FsDriverEntry *fse;
     V9fsPath path;
 
-    virtio_init(VIRTIO_DEVICE(s), "virtio-9p", VIRTIO_ID_9P,
+    virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P,
                 sizeof(struct virtio_9p_config) + MAX_TAG_LEN);
 
     /* initialize pdu allocator */
@@ -67,16 +68,16 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
 
     if (!fse) {
         /* We don't have a fsdev identified by fsdev_id */
-        fprintf(stderr, "Virtio-9p device couldn't find fsdev with the "
-                "id = %s\n",
-                s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
+        error_setg(errp, "Virtio-9p device couldn't find fsdev with the "
+                   "id = %s",
+                   s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
         goto out;
     }
 
     if (!s->fsconf.tag) {
         /* we haven't specified a mount_tag */
-        fprintf(stderr, "fsdev with id %s needs mount_tag arguments\n",
-                s->fsconf.fsdev_id);
+        error_setg(errp, "fsdev with id %s needs mount_tag arguments",
+                   s->fsconf.fsdev_id);
         goto out;
     }
 
@@ -85,8 +86,8 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
     s->ctx.exops.get_st_gen = NULL;
     len = strlen(s->fsconf.tag);
     if (len > MAX_TAG_LEN - 1) {
-        fprintf(stderr, "mount tag '%s' (%d bytes) is longer than "
-                "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
+        error_setg(errp, "mount tag '%s' (%d bytes) is longer than "
+                   "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
         goto out;
     }
 
@@ -99,12 +100,12 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
     qemu_co_rwlock_init(&s->rename_lock);
 
     if (s->ops->init(&s->ctx) < 0) {
-        fprintf(stderr, "Virtio-9p Failed to initialize fs-driver with id:%s"
-                " and export path:%s\n", s->fsconf.fsdev_id, s->ctx.fs_root);
+        error_setg(errp, "Virtio-9p Failed to initialize fs-driver with id:%s"
+                   " and export path:%s", s->fsconf.fsdev_id, s->ctx.fs_root);
         goto out;
     }
     if (v9fs_init_worker_threads() < 0) {
-        fprintf(stderr, "worker thread initialization failed\n");
+        error_setg(errp, "worker thread initialization failed");
         goto out;
     }
 
@@ -114,28 +115,25 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
      * use co-routines here.
      */
     if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
-        fprintf(stderr,
-                "error in converting name to path %s", strerror(errno));
+        error_setg(errp,
+                   "error in converting name to path %s", strerror(errno));
         goto out;
     }
     if (s->ops->lstat(&s->ctx, &path, &stat)) {
-        fprintf(stderr, "share path %s does not exist\n", fse->path);
+        error_setg(errp, "share path %s does not exist", fse->path);
         goto out;
     } else if (!S_ISDIR(stat.st_mode)) {
-        fprintf(stderr, "share path %s is not a directory\n", fse->path);
+        error_setg(errp, "share path %s is not a directory", fse->path);
         goto out;
     }
     v9fs_path_free(&path);
 
-    return 0;
+    return;
 out:
     g_free(s->ctx.fs_root);
     g_free(s->tag);
     virtio_cleanup(vdev);
     v9fs_path_free(&path);
-
-    return -1;
-
 }
 
 /* virtio-9p device */
@@ -149,9 +147,10 @@ static void virtio_9p_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
     dc->props = virtio_9p_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
-    vdc->init = virtio_9p_device_init;
+    vdc->realize = virtio_9p_device_realize;
     vdc->get_features = virtio_9p_get_features;
     vdc->get_config = virtio_9p_get_config;
 }
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index f2d7350a50..1e57f3aabd 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -380,8 +380,9 @@ static void start_data_plane_bh(void *opaque)
                        s, QEMU_THREAD_JOINABLE);
 }
 
-bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
-                                  VirtIOBlockDataPlane **dataplane)
+void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
+                                  VirtIOBlockDataPlane **dataplane,
+                                  Error **errp)
 {
     VirtIOBlockDataPlane *s;
     int fd;
@@ -389,33 +390,35 @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
     *dataplane = NULL;
 
     if (!blk->data_plane) {
-        return true;
+        return;
     }
 
     if (blk->scsi) {
-        error_report("device is incompatible with x-data-plane, use scsi=off");
-        return false;
+        error_setg(errp,
+                   "device is incompatible with x-data-plane, use scsi=off");
+        return;
     }
 
     if (blk->config_wce) {
-        error_report("device is incompatible with x-data-plane, "
-                     "use config-wce=off");
-        return false;
+        error_setg(errp, "device is incompatible with x-data-plane, "
+                         "use config-wce=off");
+        return;
     }
 
     /* If dataplane is (re-)enabled while the guest is running there could be
      * block jobs that can conflict.
      */
     if (bdrv_in_use(blk->conf.bs)) {
-        error_report("cannot start dataplane thread while device is in use");
-        return false;
+        error_setg(errp,
+                   "cannot start dataplane thread while device is in use");
+        return;
     }
 
     fd = raw_get_aio_fd(blk->conf.bs);
     if (fd < 0) {
-        error_report("drive is incompatible with x-data-plane, "
-                     "use format=raw,cache=none,aio=native");
-        return false;
+        error_setg(errp, "drive is incompatible with x-data-plane, "
+                         "use format=raw,cache=none,aio=native");
+        return;
     }
 
     s = g_new0(VirtIOBlockDataPlane, 1);
@@ -427,7 +430,6 @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
     bdrv_set_in_use(blk->conf.bs, 1);
 
     *dataplane = s;
-    return true;
 }
 
 void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
diff --git a/hw/block/dataplane/virtio-blk.h b/hw/block/dataplane/virtio-blk.h
index c90e99f48f..1750c9905b 100644
--- a/hw/block/dataplane/virtio-blk.h
+++ b/hw/block/dataplane/virtio-blk.h
@@ -19,8 +19,9 @@
 
 typedef struct VirtIOBlockDataPlane VirtIOBlockDataPlane;
 
-bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
-                                  VirtIOBlockDataPlane **dataplane);
+void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
+                                  VirtIOBlockDataPlane **dataplane,
+                                  Error **errp);
 void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s);
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 13f6d8276e..19d0961a47 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -657,6 +657,7 @@ static void virtio_blk_migration_state_changed(Notifier *notifier, void *data)
     VirtIOBlock *s = container_of(notifier, VirtIOBlock,
                                   migration_state_notifier);
     MigrationState *mig = data;
+    Error *err = NULL;
 
     if (migration_in_setup(mig)) {
         if (!s->dataplane) {
@@ -671,31 +672,39 @@ static void virtio_blk_migration_state_changed(Notifier *notifier, void *data)
         }
         bdrv_drain_all(); /* complete in-flight non-dataplane requests */
         virtio_blk_data_plane_create(VIRTIO_DEVICE(s), &s->blk,
-                                     &s->dataplane);
+                                     &s->dataplane, &err);
+        if (err != NULL) {
+            error_report("%s", error_get_pretty(err));
+            error_free(err);
+        }
     }
 }
 #endif /* CONFIG_VIRTIO_BLK_DATA_PLANE */
 
-static int virtio_blk_device_init(VirtIODevice *vdev)
+static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
 {
-    DeviceState *qdev = DEVICE(vdev);
-    VirtIOBlock *s = VIRTIO_BLK(vdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOBlock *s = VIRTIO_BLK(dev);
     VirtIOBlkConf *blk = &(s->blk);
+#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
+    Error *err = NULL;
+#endif
     static int virtio_blk_id;
 
     if (!blk->conf.bs) {
-        error_report("drive property not set");
-        return -1;
+        error_setg(errp, "drive property not set");
+        return;
     }
     if (!bdrv_is_inserted(blk->conf.bs)) {
-        error_report("Device needs media, but drive is empty");
-        return -1;
+        error_setg(errp, "Device needs media, but drive is empty");
+        return;
     }
 
     blkconf_serial(&blk->conf, &blk->serial);
     s->original_wce = bdrv_enable_write_cache(blk->conf.bs);
     if (blkconf_geometry(&blk->conf, NULL, 65535, 255, 255) < 0) {
-        return -1;
+        error_setg(errp, "Error setting geometry");
+        return;
     }
 
     virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
@@ -708,30 +717,32 @@ static int virtio_blk_device_init(VirtIODevice *vdev)
 
     s->vq = virtio_add_queue(vdev, 128, virtio_blk_handle_output);
 #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
-    if (!virtio_blk_data_plane_create(vdev, blk, &s->dataplane)) {
+    virtio_blk_data_plane_create(vdev, blk, &s->dataplane, &err);
+    if (err != NULL) {
+        error_propagate(errp, err);
         virtio_cleanup(vdev);
-        return -1;
+        return;
     }
     s->migration_state_notifier.notify = virtio_blk_migration_state_changed;
     add_migration_state_change_notifier(&s->migration_state_notifier);
 #endif
 
     s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
-    register_savevm(qdev, "virtio-blk", virtio_blk_id++, 2,
+    register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
                     virtio_blk_save, virtio_blk_load, s);
     bdrv_set_dev_ops(s->bs, &virtio_block_ops, s);
     bdrv_set_buffer_alignment(s->bs, s->conf->logical_block_size);
 
     bdrv_iostatus_enable(s->bs);
 
-    add_boot_device_path(s->conf->bootindex, qdev, "/disk@0,0");
-    return 0;
+    add_boot_device_path(s->conf->bootindex, dev, "/disk@0,0");
 }
 
-static int virtio_blk_device_exit(DeviceState *dev)
+static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOBlock *s = VIRTIO_BLK(dev);
+
 #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
     remove_migration_state_change_notifier(&s->migration_state_notifier);
     virtio_blk_data_plane_destroy(s->dataplane);
@@ -741,7 +752,6 @@ static int virtio_blk_device_exit(DeviceState *dev)
     unregister_savevm(dev, "virtio-blk", s);
     blockdev_mark_auto_del(s->bs);
     virtio_cleanup(vdev);
-    return 0;
 }
 
 static Property virtio_blk_properties[] = {
@@ -753,10 +763,11 @@ static void virtio_blk_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-    dc->exit = virtio_blk_device_exit;
+
     dc->props = virtio_blk_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
-    vdc->init = virtio_blk_device_init;
+    vdc->realize = virtio_blk_device_realize;
+    vdc->unrealize = virtio_blk_device_unrealize;
     vdc->get_config = virtio_blk_update_config;
     vdc->set_config = virtio_blk_set_config;
     vdc->get_features = virtio_blk_get_features;
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index 703f026370..226e9f9a3c 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -889,22 +889,24 @@ static int virtser_port_qdev_exit(DeviceState *qdev)
     return 0;
 }
 
-static int virtio_serial_device_init(VirtIODevice *vdev)
+static void virtio_serial_device_realize(DeviceState *dev, Error **errp)
 {
-    DeviceState *qdev = DEVICE(vdev);
-    VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOSerial *vser = VIRTIO_SERIAL(dev);
+    BusState *bus;
     uint32_t i, max_supported_ports;
 
     if (!vser->serial.max_virtserial_ports) {
-        return -1;
+        error_setg(errp, "Maximum number of serial ports not specified");
+        return;
     }
 
     /* Each port takes 2 queues, and one pair is for the control queue */
     max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
 
     if (vser->serial.max_virtserial_ports > max_supported_ports) {
-        error_report("maximum ports supported: %u", max_supported_ports);
-        return -1;
+        error_setg(errp, "maximum ports supported: %u", max_supported_ports);
+        return;
     }
 
     virtio_init(vdev, "virtio-serial", VIRTIO_ID_CONSOLE,
@@ -912,8 +914,9 @@ static int virtio_serial_device_init(VirtIODevice *vdev)
 
     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
     qbus_create_inplace(&vser->bus, sizeof(vser->bus), TYPE_VIRTIO_SERIAL_BUS,
-                        qdev, vdev->bus_name);
-    vser->bus.qbus.allow_hotplug = 1;
+                        dev, vdev->bus_name);
+    bus = BUS(&vser->bus);
+    bus->allow_hotplug = 1;
     vser->bus.vser = vser;
     QTAILQ_INIT(&vser->ports);
 
@@ -961,10 +964,8 @@ static int virtio_serial_device_init(VirtIODevice *vdev)
      * Register for the savevm section with the virtio-console name
      * to preserve backward compat
      */
-    register_savevm(qdev, "virtio-console", -1, 3, virtio_serial_save,
+    register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
                     virtio_serial_load, vser);
-
-    return 0;
 }
 
 static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
@@ -987,10 +988,10 @@ static const TypeInfo virtio_serial_port_type_info = {
     .class_init = virtio_serial_port_class_init,
 };
 
-static int virtio_serial_device_exit(DeviceState *dev)
+static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIOSerial *vser = VIRTIO_SERIAL(dev);
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOSerial *vser = VIRTIO_SERIAL(dev);
 
     unregister_savevm(dev, "virtio-console", vser);
 
@@ -1004,7 +1005,6 @@ static int virtio_serial_device_exit(DeviceState *dev)
         g_free(vser->post_load);
     }
     virtio_cleanup(vdev);
-    return 0;
 }
 
 static Property virtio_serial_properties[] = {
@@ -1016,10 +1016,11 @@ static void virtio_serial_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-    dc->exit = virtio_serial_device_exit;
+
     dc->props = virtio_serial_properties;
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
-    vdc->init = virtio_serial_device_init;
+    vdc->realize = virtio_serial_device_realize;
+    vdc->unrealize = virtio_serial_device_unrealize;
     vdc->get_features = get_features;
     vdc->get_config = get_config;
     vdc->set_config = set_config;
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index d312b9c83c..36266083b2 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1491,16 +1491,14 @@ void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
     n->netclient_type = g_strdup(type);
 }
 
-static int virtio_net_device_init(VirtIODevice *vdev)
+static void virtio_net_device_realize(DeviceState *dev, Error **errp)
 {
-    int i;
-
-    DeviceState *qdev = DEVICE(vdev);
-    VirtIONet *n = VIRTIO_NET(vdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIONet *n = VIRTIO_NET(dev);
     NetClientState *nc;
+    int i;
 
-    virtio_init(VIRTIO_DEVICE(n), "virtio-net", VIRTIO_ID_NET,
-                                  n->config_size);
+    virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
 
     n->max_queues = MAX(n->nic_conf.queues, 1);
     n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues);
@@ -1540,7 +1538,7 @@ static int virtio_net_device_init(VirtIODevice *vdev)
                               n->netclient_type, n->netclient_name, n);
     } else {
         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
-                              object_get_typename(OBJECT(qdev)), qdev->id, n);
+                              object_get_typename(OBJECT(dev)), dev->id, n);
     }
 
     peer_test_vnet_hdr(n);
@@ -1567,24 +1565,23 @@ static int virtio_net_device_init(VirtIODevice *vdev)
     nc = qemu_get_queue(n->nic);
     nc->rxfilter_notify_enabled = 1;
 
-    n->qdev = qdev;
-    register_savevm(qdev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
+    n->qdev = dev;
+    register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
                     virtio_net_save, virtio_net_load, n);
 
-    add_boot_device_path(n->nic_conf.bootindex, qdev, "/ethernet-phy@0");
-    return 0;
+    add_boot_device_path(n->nic_conf.bootindex, dev, "/ethernet-phy@0");
 }
 
-static int virtio_net_device_exit(DeviceState *qdev)
+static void virtio_net_device_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIONet *n = VIRTIO_NET(qdev);
-    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIONet *n = VIRTIO_NET(dev);
     int i;
 
     /* This will stop vhost backend if appropriate. */
     virtio_net_set_status(vdev, 0);
 
-    unregister_savevm(qdev, "virtio-net", n);
+    unregister_savevm(dev, "virtio-net", n);
 
     if (n->netclient_name) {
         g_free(n->netclient_name);
@@ -1615,8 +1612,6 @@ static int virtio_net_device_exit(DeviceState *qdev)
     g_free(n->vqs);
     qemu_del_nic(n->nic);
     virtio_cleanup(vdev);
-
-    return 0;
 }
 
 static void virtio_net_instance_init(Object *obj)
@@ -1643,10 +1638,11 @@ static void virtio_net_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-    dc->exit = virtio_net_device_exit;
+
     dc->props = virtio_net_properties;
     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
-    vdc->init = virtio_net_device_init;
+    vdc->realize = virtio_net_device_realize;
+    vdc->unrealize = virtio_net_device_unrealize;
     vdc->get_config = virtio_net_get_config;
     vdc->set_config = virtio_net_set_config;
     vdc->get_features = virtio_net_get_features;
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index f93a81c7cd..ecc80ecaf7 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -57,9 +57,10 @@ static const TypeInfo virtual_css_bus_info = {
 VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch)
 {
     VirtIODevice *vdev = NULL;
+    VirtioCcwDevice *dev = sch->driver_data;
 
-    if (sch->driver_data) {
-        vdev = ((VirtioCcwDevice *)sch->driver_data)->vdev;
+    if (dev) {
+        vdev = virtio_bus_get_device(&dev->bus);
     }
     return vdev;
 }
@@ -67,7 +68,8 @@ VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch)
 static int virtio_ccw_set_guest2host_notifier(VirtioCcwDevice *dev, int n,
                                               bool assign, bool set_handler)
 {
-    VirtQueue *vq = virtio_get_queue(dev->vdev, n);
+    VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+    VirtQueue *vq = virtio_get_queue(vdev, n);
     EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
     int r = 0;
     SubchDev *sch = dev->sch;
@@ -97,6 +99,7 @@ static int virtio_ccw_set_guest2host_notifier(VirtioCcwDevice *dev, int n,
 
 static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
 {
+    VirtIODevice *vdev;
     int n, r;
 
     if (!(dev->flags & VIRTIO_CCW_FLAG_USE_IOEVENTFD) ||
@@ -104,8 +107,9 @@ static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
         dev->ioeventfd_started) {
         return;
     }
+    vdev = virtio_bus_get_device(&dev->bus);
     for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
-        if (!virtio_queue_get_num(dev->vdev, n)) {
+        if (!virtio_queue_get_num(vdev, n)) {
             continue;
         }
         r = virtio_ccw_set_guest2host_notifier(dev, n, true, true);
@@ -118,7 +122,7 @@ static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
 
   assign_error:
     while (--n >= 0) {
-        if (!virtio_queue_get_num(dev->vdev, n)) {
+        if (!virtio_queue_get_num(vdev, n)) {
             continue;
         }
         r = virtio_ccw_set_guest2host_notifier(dev, n, false, false);
@@ -132,13 +136,15 @@ static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
 
 static void virtio_ccw_stop_ioeventfd(VirtioCcwDevice *dev)
 {
+    VirtIODevice *vdev;
     int n, r;
 
     if (!dev->ioeventfd_started) {
         return;
     }
+    vdev = virtio_bus_get_device(&dev->bus);
     for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
-        if (!virtio_queue_get_num(dev->vdev, n)) {
+        if (!virtio_queue_get_num(vdev, n)) {
             continue;
         }
         r = virtio_ccw_set_guest2host_notifier(dev, n, false, false);
@@ -189,7 +195,7 @@ typedef struct VirtioFeatDesc {
 static int virtio_ccw_set_vqs(SubchDev *sch, uint64_t addr, uint32_t align,
                               uint16_t index, uint16_t num)
 {
-    VirtioCcwDevice *dev = sch->driver_data;
+    VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
 
     if (index > VIRTIO_PCI_QUEUE_MAX) {
         return -EINVAL;
@@ -200,23 +206,23 @@ static int virtio_ccw_set_vqs(SubchDev *sch, uint64_t addr, uint32_t align,
         return -EINVAL;
     }
 
-    if (!dev) {
+    if (!vdev) {
         return -EINVAL;
     }
 
-    virtio_queue_set_addr(dev->vdev, index, addr);
+    virtio_queue_set_addr(vdev, index, addr);
     if (!addr) {
-        virtio_queue_set_vector(dev->vdev, index, 0);
+        virtio_queue_set_vector(vdev, index, 0);
     } else {
         /* Fail if we don't have a big enough queue. */
         /* TODO: Add interface to handle vring.num changing */
-        if (virtio_queue_get_num(dev->vdev, index) > num) {
+        if (virtio_queue_get_num(vdev, index) > num) {
             return -EINVAL;
         }
-        virtio_queue_set_vector(dev->vdev, index, index);
+        virtio_queue_set_vector(vdev, index, index);
     }
     /* tell notify handler in case of config change */
-    dev->vdev->config_vector = VIRTIO_PCI_QUEUE_MAX;
+    vdev->config_vector = VIRTIO_PCI_QUEUE_MAX;
     return 0;
 }
 
@@ -230,6 +236,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
     hwaddr indicators;
     VqConfigBlock vq_config;
     VirtioCcwDevice *dev = sch->driver_data;
+    VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
     bool check_len;
     int len;
     hwaddr hw_len;
@@ -272,7 +279,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
         break;
     case CCW_CMD_VDEV_RESET:
         virtio_ccw_stop_ioeventfd(dev);
-        virtio_reset(dev->vdev);
+        virtio_reset(vdev);
         ret = 0;
         break;
     case CCW_CMD_READ_FEAT:
@@ -319,7 +326,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
             features.features = ldl_le_phys(ccw.cda);
             if (features.index < ARRAY_SIZE(dev->host_features)) {
                 virtio_bus_set_vdev_features(&dev->bus, features.features);
-                dev->vdev->guest_features = features.features;
+                vdev->guest_features = features.features;
             } else {
                 /*
                  * If the guest supports more feature bits, assert that it
@@ -337,30 +344,30 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
         break;
     case CCW_CMD_READ_CONF:
         if (check_len) {
-            if (ccw.count > dev->vdev->config_len) {
+            if (ccw.count > vdev->config_len) {
                 ret = -EINVAL;
                 break;
             }
         }
-        len = MIN(ccw.count, dev->vdev->config_len);
+        len = MIN(ccw.count, vdev->config_len);
         if (!ccw.cda) {
             ret = -EFAULT;
         } else {
-            virtio_bus_get_vdev_config(&dev->bus, dev->vdev->config);
+            virtio_bus_get_vdev_config(&dev->bus, vdev->config);
             /* XXX config space endianness */
-            cpu_physical_memory_write(ccw.cda, dev->vdev->config, len);
+            cpu_physical_memory_write(ccw.cda, vdev->config, len);
             sch->curr_status.scsw.count = ccw.count - len;
             ret = 0;
         }
         break;
     case CCW_CMD_WRITE_CONF:
         if (check_len) {
-            if (ccw.count > dev->vdev->config_len) {
+            if (ccw.count > vdev->config_len) {
                 ret = -EINVAL;
                 break;
             }
         }
-        len = MIN(ccw.count, dev->vdev->config_len);
+        len = MIN(ccw.count, vdev->config_len);
         hw_len = len;
         if (!ccw.cda) {
             ret = -EFAULT;
@@ -371,9 +378,9 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
             } else {
                 len = hw_len;
                 /* XXX config space endianness */
-                memcpy(dev->vdev->config, config, len);
+                memcpy(vdev->config, config, len);
                 cpu_physical_memory_unmap(config, hw_len, 0, hw_len);
-                virtio_bus_set_vdev_config(&dev->bus, dev->vdev->config);
+                virtio_bus_set_vdev_config(&dev->bus, vdev->config);
                 sch->curr_status.scsw.count = ccw.count - len;
                 ret = 0;
             }
@@ -397,9 +404,9 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
             if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
                 virtio_ccw_stop_ioeventfd(dev);
             }
-            virtio_set_status(dev->vdev, status);
-            if (dev->vdev->status == 0) {
-                virtio_reset(dev->vdev);
+            virtio_set_status(vdev, status);
+            if (vdev->status == 0) {
+                virtio_reset(vdev);
             }
             if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
                 virtio_ccw_start_ioeventfd(dev);
@@ -463,7 +470,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
             ret = -EFAULT;
         } else {
             vq_config.index = lduw_phys(ccw.cda);
-            vq_config.num_max = virtio_queue_get_num(dev->vdev,
+            vq_config.num_max = virtio_queue_get_num(vdev,
                                                      vq_config.index);
             stw_phys(ccw.cda + sizeof(vq_config.index), vq_config.num_max);
             sch->curr_status.scsw.count = ccw.count - sizeof(vq_config);
@@ -495,7 +502,6 @@ static int virtio_ccw_device_init(VirtioCcwDevice *dev, VirtIODevice *vdev)
     sch->driver_data = dev;
     dev->sch = sch;
 
-    dev->vdev = vdev;
     dev->indicators = 0;
 
     /* Initialize subchannel structure. */
@@ -608,7 +614,7 @@ static int virtio_ccw_device_init(VirtioCcwDevice *dev, VirtIODevice *vdev)
     memset(&sch->id, 0, sizeof(SenseId));
     sch->id.reserved = 0xff;
     sch->id.cu_type = VIRTIO_CCW_CU_TYPE;
-    sch->id.cu_model = dev->vdev->device_id;
+    sch->id.cu_model = vdev->device_id;
 
     /* Only the first 32 feature bits are used. */
     dev->host_features[0] = virtio_bus_get_vdev_features(&dev->bus,
@@ -631,7 +637,6 @@ static int virtio_ccw_exit(VirtioCcwDevice *dev)
 {
     SubchDev *sch = dev->sch;
 
-    virtio_ccw_stop_ioeventfd(dev);
     if (sch) {
         css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
         g_free(sch);
@@ -892,9 +897,10 @@ static unsigned virtio_ccw_get_features(DeviceState *d)
 static void virtio_ccw_reset(DeviceState *d)
 {
     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
 
     virtio_ccw_stop_ioeventfd(dev);
-    virtio_reset(dev->vdev);
+    virtio_reset(vdev);
     css_reset_sch(dev->sch);
     dev->indicators = 0;
     dev->indicators2 = 0;
@@ -934,9 +940,10 @@ static int virtio_ccw_set_host_notifier(DeviceState *d, int n, bool assign)
 static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
                                          bool assign, bool with_irqfd)
 {
-    VirtQueue *vq = virtio_get_queue(dev->vdev, n);
+    VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+    VirtQueue *vq = virtio_get_queue(vdev, n);
     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
-    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(dev->vdev);
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
 
     if (assign) {
         int r = event_notifier_init(notifier, 0);
@@ -952,16 +959,16 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
          * land in qemu (and only the irq fd) in this code.
          */
         if (k->guest_notifier_mask) {
-            k->guest_notifier_mask(dev->vdev, n, false);
+            k->guest_notifier_mask(vdev, n, false);
         }
         /* get lost events and re-inject */
         if (k->guest_notifier_pending &&
-            k->guest_notifier_pending(dev->vdev, n)) {
+            k->guest_notifier_pending(vdev, n)) {
             event_notifier_set(notifier);
         }
     } else {
         if (k->guest_notifier_mask) {
-            k->guest_notifier_mask(dev->vdev, n, true);
+            k->guest_notifier_mask(vdev, n, true);
         }
         virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
         event_notifier_cleanup(notifier);
@@ -973,7 +980,7 @@ static int virtio_ccw_set_guest_notifiers(DeviceState *d, int nvqs,
                                           bool assigned)
 {
     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
-    VirtIODevice *vdev = dev->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
     int r, n;
 
     for (n = 0; n < nvqs; n++) {
@@ -1228,6 +1235,8 @@ static int virtio_ccw_busdev_unplug(DeviceState *dev)
     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
     SubchDev *sch = _dev->sch;
 
+    virtio_ccw_stop_ioeventfd(_dev);
+
     /*
      * We should arrive here only for device_del, since we don't support
      * direct hot(un)plug of channels, but only through virtio.
diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
index 96d6f5d5b7..00932c746d 100644
--- a/hw/s390x/virtio-ccw.h
+++ b/hw/s390x/virtio-ccw.h
@@ -77,7 +77,6 @@ typedef struct VirtIOCCWDeviceClass {
 struct VirtioCcwDevice {
     DeviceState parent_obj;
     SubchDev *sch;
-    VirtIODevice *vdev;
     char *bus_id;
     uint32_t host_features[VIRTIO_CCW_FEATURE_SIZE];
     VirtioBusState bus;
diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 9e770fba98..3983a5b464 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -196,29 +196,31 @@ static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
     }
 }
 
-static int vhost_scsi_init(VirtIODevice *vdev)
+static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 {
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
-    VHostSCSI *s = VHOST_SCSI(vdev);
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
+    VHostSCSI *s = VHOST_SCSI(dev);
+    Error *err = NULL;
     int vhostfd = -1;
     int ret;
 
     if (!vs->conf.wwpn) {
-        error_report("vhost-scsi: missing wwpn\n");
-        return -EINVAL;
+        error_setg(errp, "vhost-scsi: missing wwpn");
+        return;
     }
 
     if (vs->conf.vhostfd) {
         vhostfd = monitor_handle_fd_param(cur_mon, vs->conf.vhostfd);
         if (vhostfd == -1) {
-            error_report("vhost-scsi: unable to parse vhostfd\n");
-            return -EINVAL;
+            error_setg(errp, "vhost-scsi: unable to parse vhostfd");
+            return;
         }
     }
 
-    ret = virtio_scsi_common_init(vs);
-    if (ret < 0) {
-        return ret;
+    virtio_scsi_common_realize(dev, &err);
+    if (err != NULL) {
+        error_propagate(errp, err);
+        return;
     }
 
     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
@@ -227,24 +229,21 @@ static int vhost_scsi_init(VirtIODevice *vdev)
 
     ret = vhost_dev_init(&s->dev, vhostfd, "/dev/vhost-scsi", true);
     if (ret < 0) {
-        error_report("vhost-scsi: vhost initialization failed: %s\n",
-                strerror(-ret));
-        return ret;
+        error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
+                   strerror(-ret));
+        return;
     }
     s->dev.backend_features = 0;
 
     error_setg(&s->migration_blocker,
             "vhost-scsi does not support migration");
     migrate_add_blocker(s->migration_blocker);
-
-    return 0;
 }
 
-static int vhost_scsi_exit(DeviceState *qdev)
+static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
-    VHostSCSI *s = VHOST_SCSI(qdev);
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(qdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostSCSI *s = VHOST_SCSI(dev);
 
     migrate_del_blocker(s->migration_blocker);
     error_free(s->migration_blocker);
@@ -253,7 +252,8 @@ static int vhost_scsi_exit(DeviceState *qdev)
     vhost_scsi_set_status(vdev, 0);
 
     g_free(s->dev.vqs);
-    return virtio_scsi_common_exit(vs);
+
+    virtio_scsi_common_unrealize(dev, errp);
 }
 
 static Property vhost_scsi_properties[] = {
@@ -265,10 +265,11 @@ static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-    dc->exit = vhost_scsi_exit;
+
     dc->props = vhost_scsi_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
-    vdc->init = vhost_scsi_init;
+    vdc->realize = vhost_scsi_realize;
+    vdc->unrealize = vhost_scsi_unrealize;
     vdc->get_features = vhost_scsi_get_features;
     vdc->set_config = vhost_scsi_set_config;
     vdc->set_status = vhost_scsi_set_status;
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 26d95a14ec..6dcdd1b91c 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -589,12 +589,13 @@ static struct SCSIBusInfo virtio_scsi_scsi_info = {
     .load_request = virtio_scsi_load_request,
 };
 
-int virtio_scsi_common_init(VirtIOSCSICommon *s)
+void virtio_scsi_common_realize(DeviceState *dev, Error **errp)
 {
-    VirtIODevice *vdev = VIRTIO_DEVICE(s);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
     int i;
 
-    virtio_init(VIRTIO_DEVICE(s), "virtio-scsi", VIRTIO_ID_SCSI,
+    virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
                 sizeof(VirtIOSCSIConfig));
 
     s->cmd_vqs = g_malloc0(s->conf.num_queues * sizeof(VirtQueue *));
@@ -609,57 +610,52 @@ int virtio_scsi_common_init(VirtIOSCSICommon *s)
         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
                                          virtio_scsi_handle_cmd);
     }
-
-    return 0;
 }
 
-static int virtio_scsi_device_init(VirtIODevice *vdev)
+static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 {
-    DeviceState *qdev = DEVICE(vdev);
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
-    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOSCSI *s = VIRTIO_SCSI(dev);
     static int virtio_scsi_id;
     Error *err = NULL;
-    int ret;
 
-    ret = virtio_scsi_common_init(vs);
-    if (ret < 0) {
-        return ret;
+    virtio_scsi_common_realize(dev, &err);
+    if (err != NULL) {
+        error_propagate(errp, err);
+        return;
     }
 
-    scsi_bus_new(&s->bus, sizeof(s->bus), qdev,
+    scsi_bus_new(&s->bus, sizeof(s->bus), dev,
                  &virtio_scsi_scsi_info, vdev->bus_name);
 
-    if (!qdev->hotplugged) {
+    if (!dev->hotplugged) {
         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
         if (err != NULL) {
-            error_free(err);
-            return -1;
+            error_propagate(errp, err);
+            return;
         }
     }
 
-    register_savevm(qdev, "virtio-scsi", virtio_scsi_id++, 1,
+    register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
                     virtio_scsi_save, virtio_scsi_load, s);
-
-    return 0;
 }
 
-int virtio_scsi_common_exit(VirtIOSCSICommon *vs)
+void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIODevice *vdev = VIRTIO_DEVICE(vs);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 
     g_free(vs->cmd_vqs);
     virtio_cleanup(vdev);
-    return 0;
 }
 
-static int virtio_scsi_device_exit(DeviceState *qdev)
+static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIOSCSI *s = VIRTIO_SCSI(qdev);
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(qdev);
+    VirtIOSCSI *s = VIRTIO_SCSI(dev);
+
+    unregister_savevm(dev, "virtio-scsi", s);
 
-    unregister_savevm(qdev, "virtio-scsi", s);
-    return virtio_scsi_common_exit(vs);
+    virtio_scsi_common_unrealize(dev, errp);
 }
 
 static Property virtio_scsi_properties[] = {
@@ -680,10 +676,11 @@ static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-    dc->exit = virtio_scsi_device_exit;
+
     dc->props = virtio_scsi_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
-    vdc->init = virtio_scsi_device_init;
+    vdc->realize = virtio_scsi_device_realize;
+    vdc->unrealize = virtio_scsi_device_unrealize;
     vdc->set_config = virtio_scsi_set_config;
     vdc->get_features = virtio_scsi_get_features;
     vdc->reset = virtio_scsi_reset;
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 9504877120..d9754dbd33 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -337,10 +337,10 @@ static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id)
     return 0;
 }
 
-static int virtio_balloon_device_init(VirtIODevice *vdev)
+static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
 {
-    DeviceState *qdev = DEVICE(vdev);
-    VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOBalloon *s = VIRTIO_BALLOON(dev);
     int ret;
 
     virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON, 8);
@@ -349,37 +349,36 @@ static int virtio_balloon_device_init(VirtIODevice *vdev)
                                    virtio_balloon_stat, s);
 
     if (ret < 0) {
-        virtio_cleanup(VIRTIO_DEVICE(s));
-        return -1;
+        error_setg(errp, "Adding balloon handler failed");
+        virtio_cleanup(vdev);
+        return;
     }
 
     s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
     s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
     s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
 
-    register_savevm(qdev, "virtio-balloon", -1, 1,
+    register_savevm(dev, "virtio-balloon", -1, 1,
                     virtio_balloon_save, virtio_balloon_load, s);
 
-    object_property_add(OBJECT(qdev), "guest-stats", "guest statistics",
+    object_property_add(OBJECT(dev), "guest-stats", "guest statistics",
                         balloon_stats_get_all, NULL, NULL, s, NULL);
 
-    object_property_add(OBJECT(qdev), "guest-stats-polling-interval", "int",
+    object_property_add(OBJECT(dev), "guest-stats-polling-interval", "int",
                         balloon_stats_get_poll_interval,
                         balloon_stats_set_poll_interval,
                         NULL, s, NULL);
-    return 0;
 }
 
-static int virtio_balloon_device_exit(DeviceState *qdev)
+static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIOBalloon *s = VIRTIO_BALLOON(qdev);
-    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOBalloon *s = VIRTIO_BALLOON(dev);
 
     balloon_stats_destroy_timer(s);
     qemu_remove_balloon_handler(s);
-    unregister_savevm(qdev, "virtio-balloon", s);
+    unregister_savevm(dev, "virtio-balloon", s);
     virtio_cleanup(vdev);
-    return 0;
 }
 
 static Property virtio_balloon_properties[] = {
@@ -390,10 +389,11 @@ static void virtio_balloon_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-    dc->exit = virtio_balloon_device_exit;
+
     dc->props = virtio_balloon_properties;
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
-    vdc->init = virtio_balloon_device_init;
+    vdc->realize = virtio_balloon_device_realize;
+    vdc->unrealize = virtio_balloon_device_unrealize;
     vdc->get_config = virtio_balloon_get_config;
     vdc->set_config = virtio_balloon_set_config;
     vdc->get_features = virtio_balloon_get_features;
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index e6b103c991..eb77019267 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -37,8 +37,8 @@ do { printf("virtio_bus: " fmt , ## __VA_ARGS__); } while (0)
 #define DPRINTF(fmt, ...) do { } while (0)
 #endif
 
-/* Plug the VirtIODevice */
-int virtio_bus_plug_device(VirtIODevice *vdev)
+/* A VirtIODevice is being plugged */
+int virtio_bus_device_plugged(VirtIODevice *vdev)
 {
     DeviceState *qdev = DEVICE(vdev);
     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
@@ -46,8 +46,6 @@ int virtio_bus_plug_device(VirtIODevice *vdev)
     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
     DPRINTF("%s: plug device.\n", qbus->name);
 
-    bus->vdev = vdev;
-
     if (klass->device_plugged != NULL) {
         klass->device_plugged(qbus->parent);
     }
@@ -58,73 +56,83 @@ int virtio_bus_plug_device(VirtIODevice *vdev)
 /* Reset the virtio_bus */
 void virtio_bus_reset(VirtioBusState *bus)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
+
     DPRINTF("%s: reset device.\n", qbus->name);
-    if (bus->vdev != NULL) {
-        virtio_reset(bus->vdev);
+    if (vdev != NULL) {
+        virtio_reset(vdev);
     }
 }
 
-/* Destroy the VirtIODevice */
-void virtio_bus_destroy_device(VirtioBusState *bus)
+/* A VirtIODevice is being unplugged */
+void virtio_bus_device_unplugged(VirtIODevice *vdev)
 {
-    BusState *qbus = BUS(bus);
-    VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
+    DeviceState *qdev = DEVICE(vdev);
+    BusState *qbus = BUS(qdev_get_parent_bus(qdev));
+    VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
+
     DPRINTF("%s: remove device.\n", qbus->name);
 
-    if (bus->vdev != NULL) {
-        if (klass->device_unplug != NULL) {
-            klass->device_unplug(qbus->parent);
+    if (vdev != NULL) {
+        if (klass->device_unplugged != NULL) {
+            klass->device_unplugged(qbus->parent);
         }
-        object_unparent(OBJECT(bus->vdev));
-        bus->vdev = NULL;
     }
 }
 
 /* Get the device id of the plugged device. */
 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
 {
-    assert(bus->vdev != NULL);
-    return bus->vdev->device_id;
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
+    assert(vdev != NULL);
+    return vdev->device_id;
 }
 
 /* Get the config_len field of the plugged device. */
 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
 {
-    assert(bus->vdev != NULL);
-    return bus->vdev->config_len;
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
+    assert(vdev != NULL);
+    return vdev->config_len;
 }
 
 /* Get the features of the plugged device. */
 uint32_t virtio_bus_get_vdev_features(VirtioBusState *bus,
                                     uint32_t requested_features)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
     VirtioDeviceClass *k;
-    assert(bus->vdev != NULL);
-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
+
+    assert(vdev != NULL);
+    k = VIRTIO_DEVICE_GET_CLASS(vdev);
     assert(k->get_features != NULL);
-    return k->get_features(bus->vdev, requested_features);
+    return k->get_features(vdev, requested_features);
 }
 
 /* Set the features of the plugged device. */
 void virtio_bus_set_vdev_features(VirtioBusState *bus,
                                       uint32_t requested_features)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
     VirtioDeviceClass *k;
-    assert(bus->vdev != NULL);
-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
+
+    assert(vdev != NULL);
+    k = VIRTIO_DEVICE_GET_CLASS(vdev);
     if (k->set_features != NULL) {
-        k->set_features(bus->vdev, requested_features);
+        k->set_features(vdev, requested_features);
     }
 }
 
 /* Get bad features of the plugged device. */
 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
     VirtioDeviceClass *k;
-    assert(bus->vdev != NULL);
-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
+
+    assert(vdev != NULL);
+    k = VIRTIO_DEVICE_GET_CLASS(vdev);
     if (k->bad_features != NULL) {
-        return k->bad_features(bus->vdev);
+        return k->bad_features(vdev);
     } else {
         return 0;
     }
@@ -133,22 +141,26 @@ uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
 /* Get config of the plugged device. */
 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
     VirtioDeviceClass *k;
-    assert(bus->vdev != NULL);
-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
+
+    assert(vdev != NULL);
+    k = VIRTIO_DEVICE_GET_CLASS(vdev);
     if (k->get_config != NULL) {
-        k->get_config(bus->vdev, config);
+        k->get_config(vdev, config);
     }
 }
 
 /* Set config of the plugged device. */
 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
     VirtioDeviceClass *k;
-    assert(bus->vdev != NULL);
-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
+
+    assert(vdev != NULL);
+    k = VIRTIO_DEVICE_GET_CLASS(vdev);
     if (k->set_config != NULL) {
-        k->set_config(bus->vdev, config);
+        k->set_config(vdev, config);
     }
 }
 
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 29cf284d12..8829eb0e26 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -95,7 +95,7 @@ static void virtio_mmio_bus_new(VirtioBusState *bus, size_t bus_size,
 static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
 {
     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
-    VirtIODevice *vdev = proxy->bus.vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
     DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
 
@@ -185,7 +185,7 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
                               unsigned size)
 {
     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
-    VirtIODevice *vdev = proxy->bus.vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
     DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
             (int)offset, value);
@@ -298,12 +298,13 @@ static const MemoryRegionOps virtio_mem_ops = {
 static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     int level;
 
-    if (!proxy->bus.vdev) {
+    if (!vdev) {
         return;
     }
-    level = (proxy->bus.vdev->isr != 0);
+    level = (vdev->isr != 0);
     DPRINTF("virtio_mmio setting IRQ %d\n", level);
     qemu_set_irq(proxy->irq, level);
 }
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 7647be8a3c..30c9f2b698 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -113,31 +113,40 @@ static inline VirtIOPCIProxy *to_virtio_pci_proxy_fast(DeviceState *d)
 static void virtio_pci_notify(DeviceState *d, uint16_t vector)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy_fast(d);
+
     if (msix_enabled(&proxy->pci_dev))
         msix_notify(&proxy->pci_dev, vector);
-    else
-        pci_set_irq(&proxy->pci_dev, proxy->vdev->isr & 1);
+    else {
+        VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+        pci_set_irq(&proxy->pci_dev, vdev->isr & 1);
+    }
 }
 
 static void virtio_pci_save_config(DeviceState *d, QEMUFile *f)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
     pci_device_save(&proxy->pci_dev, f);
     msix_save(&proxy->pci_dev, f);
     if (msix_present(&proxy->pci_dev))
-        qemu_put_be16(f, proxy->vdev->config_vector);
+        qemu_put_be16(f, vdev->config_vector);
 }
 
 static void virtio_pci_save_queue(DeviceState *d, int n, QEMUFile *f)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
     if (msix_present(&proxy->pci_dev))
-        qemu_put_be16(f, virtio_queue_vector(proxy->vdev, n));
+        qemu_put_be16(f, virtio_queue_vector(vdev, n));
 }
 
 static int virtio_pci_load_config(DeviceState *d, QEMUFile *f)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
     int ret;
     ret = pci_device_load(&proxy->pci_dev, f);
     if (ret) {
@@ -146,12 +155,12 @@ static int virtio_pci_load_config(DeviceState *d, QEMUFile *f)
     msix_unuse_all_vectors(&proxy->pci_dev);
     msix_load(&proxy->pci_dev, f);
     if (msix_present(&proxy->pci_dev)) {
-        qemu_get_be16s(f, &proxy->vdev->config_vector);
+        qemu_get_be16s(f, &vdev->config_vector);
     } else {
-        proxy->vdev->config_vector = VIRTIO_NO_VECTOR;
+        vdev->config_vector = VIRTIO_NO_VECTOR;
     }
-    if (proxy->vdev->config_vector != VIRTIO_NO_VECTOR) {
-        return msix_vector_use(&proxy->pci_dev, proxy->vdev->config_vector);
+    if (vdev->config_vector != VIRTIO_NO_VECTOR) {
+        return msix_vector_use(&proxy->pci_dev, vdev->config_vector);
     }
     return 0;
 }
@@ -159,13 +168,15 @@ static int virtio_pci_load_config(DeviceState *d, QEMUFile *f)
 static int virtio_pci_load_queue(DeviceState *d, int n, QEMUFile *f)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
     uint16_t vector;
     if (msix_present(&proxy->pci_dev)) {
         qemu_get_be16s(f, &vector);
     } else {
         vector = VIRTIO_NO_VECTOR;
     }
-    virtio_queue_set_vector(proxy->vdev, n, vector);
+    virtio_queue_set_vector(vdev, n, vector);
     if (vector != VIRTIO_NO_VECTOR) {
         return msix_vector_use(&proxy->pci_dev, vector);
     }
@@ -175,7 +186,8 @@ static int virtio_pci_load_queue(DeviceState *d, int n, QEMUFile *f)
 static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy,
                                                  int n, bool assign, bool set_handler)
 {
-    VirtQueue *vq = virtio_get_queue(proxy->vdev, n);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+    VirtQueue *vq = virtio_get_queue(vdev, n);
     EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
     int r = 0;
 
@@ -200,6 +212,7 @@ static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy,
 
 static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     int n, r;
 
     if (!(proxy->flags & VIRTIO_PCI_FLAG_USE_IOEVENTFD) ||
@@ -209,7 +222,7 @@ static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
     }
 
     for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
-        if (!virtio_queue_get_num(proxy->vdev, n)) {
+        if (!virtio_queue_get_num(vdev, n)) {
             continue;
         }
 
@@ -223,7 +236,7 @@ static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
 
 assign_error:
     while (--n >= 0) {
-        if (!virtio_queue_get_num(proxy->vdev, n)) {
+        if (!virtio_queue_get_num(vdev, n)) {
             continue;
         }
 
@@ -236,6 +249,7 @@ assign_error:
 
 static void virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy)
 {
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     int r;
     int n;
 
@@ -244,7 +258,7 @@ static void virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy)
     }
 
     for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
-        if (!virtio_queue_get_num(proxy->vdev, n)) {
+        if (!virtio_queue_get_num(vdev, n)) {
             continue;
         }
 
@@ -257,7 +271,7 @@ static void virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy)
 static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 {
     VirtIOPCIProxy *proxy = opaque;
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     hwaddr pa;
 
     switch (addr) {
@@ -272,7 +286,7 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
         pa = (hwaddr)val << VIRTIO_PCI_QUEUE_ADDR_SHIFT;
         if (pa == 0) {
             virtio_pci_stop_ioeventfd(proxy);
-            virtio_reset(proxy->vdev);
+            virtio_reset(vdev);
             msix_unuse_all_vectors(&proxy->pci_dev);
         }
         else
@@ -299,7 +313,7 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
         }
 
         if (vdev->status == 0) {
-            virtio_reset(proxy->vdev);
+            virtio_reset(vdev);
             msix_unuse_all_vectors(&proxy->pci_dev);
         }
 
@@ -335,7 +349,7 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 
 static uint32_t virtio_ioport_read(VirtIOPCIProxy *proxy, uint32_t addr)
 {
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     uint32_t ret = 0xFFFFFFFF;
 
     switch (addr) {
@@ -381,6 +395,7 @@ static uint64_t virtio_pci_config_read(void *opaque, hwaddr addr,
                                        unsigned size)
 {
     VirtIOPCIProxy *proxy = opaque;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
     uint64_t val = 0;
     if (addr < config) {
@@ -390,16 +405,16 @@ static uint64_t virtio_pci_config_read(void *opaque, hwaddr addr,
 
     switch (size) {
     case 1:
-        val = virtio_config_readb(proxy->vdev, addr);
+        val = virtio_config_readb(vdev, addr);
         break;
     case 2:
-        val = virtio_config_readw(proxy->vdev, addr);
+        val = virtio_config_readw(vdev, addr);
         if (virtio_is_big_endian()) {
             val = bswap16(val);
         }
         break;
     case 4:
-        val = virtio_config_readl(proxy->vdev, addr);
+        val = virtio_config_readl(vdev, addr);
         if (virtio_is_big_endian()) {
             val = bswap32(val);
         }
@@ -413,6 +428,7 @@ static void virtio_pci_config_write(void *opaque, hwaddr addr,
 {
     VirtIOPCIProxy *proxy = opaque;
     uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     if (addr < config) {
         virtio_ioport_write(proxy, addr, val);
         return;
@@ -424,19 +440,19 @@ static void virtio_pci_config_write(void *opaque, hwaddr addr,
      */
     switch (size) {
     case 1:
-        virtio_config_writeb(proxy->vdev, addr, val);
+        virtio_config_writeb(vdev, addr, val);
         break;
     case 2:
         if (virtio_is_big_endian()) {
             val = bswap16(val);
         }
-        virtio_config_writew(proxy->vdev, addr, val);
+        virtio_config_writew(vdev, addr, val);
         break;
     case 4:
         if (virtio_is_big_endian()) {
             val = bswap32(val);
         }
-        virtio_config_writel(proxy->vdev, addr, val);
+        virtio_config_writel(vdev, addr, val);
         break;
     }
 }
@@ -455,6 +471,7 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,
                                 uint32_t val, int len)
 {
     VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
     pci_default_write_config(pci_dev, address, val, len);
 
@@ -462,8 +479,7 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,
         !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) &&
         !(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) {
         virtio_pci_stop_ioeventfd(proxy);
-        virtio_set_status(proxy->vdev,
-                          proxy->vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK);
+        virtio_set_status(vdev, vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK);
     }
 }
 
@@ -506,7 +522,8 @@ static int kvm_virtio_pci_irqfd_use(VirtIOPCIProxy *proxy,
                                  unsigned int vector)
 {
     VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
-    VirtQueue *vq = virtio_get_queue(proxy->vdev, queue_no);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+    VirtQueue *vq = virtio_get_queue(vdev, queue_no);
     EventNotifier *n = virtio_queue_get_guest_notifier(vq);
     int ret;
     ret = kvm_irqchip_add_irqfd_notifier(kvm_state, n, NULL, irqfd->virq);
@@ -517,7 +534,8 @@ static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
                                       unsigned int queue_no,
                                       unsigned int vector)
 {
-    VirtQueue *vq = virtio_get_queue(proxy->vdev, queue_no);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+    VirtQueue *vq = virtio_get_queue(vdev, queue_no);
     EventNotifier *n = virtio_queue_get_guest_notifier(vq);
     VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
     int ret;
@@ -529,7 +547,7 @@ static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
 static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
 {
     PCIDevice *dev = &proxy->pci_dev;
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
     unsigned int vector;
     int ret, queue_no;
@@ -578,7 +596,7 @@ undo:
 static void kvm_virtio_pci_vector_release(VirtIOPCIProxy *proxy, int nvqs)
 {
     PCIDevice *dev = &proxy->pci_dev;
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     unsigned int vector;
     int queue_no;
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
@@ -606,8 +624,9 @@ static int virtio_pci_vq_vector_unmask(VirtIOPCIProxy *proxy,
                                        unsigned int vector,
                                        MSIMessage msg)
 {
-    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(proxy->vdev);
-    VirtQueue *vq = virtio_get_queue(proxy->vdev, queue_no);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    VirtQueue *vq = virtio_get_queue(vdev, queue_no);
     EventNotifier *n = virtio_queue_get_guest_notifier(vq);
     VirtIOIRQFD *irqfd;
     int ret = 0;
@@ -626,10 +645,10 @@ static int virtio_pci_vq_vector_unmask(VirtIOPCIProxy *proxy,
      * Otherwise, set it up now.
      */
     if (k->guest_notifier_mask) {
-        k->guest_notifier_mask(proxy->vdev, queue_no, false);
+        k->guest_notifier_mask(vdev, queue_no, false);
         /* Test after unmasking to avoid losing events. */
         if (k->guest_notifier_pending &&
-            k->guest_notifier_pending(proxy->vdev, queue_no)) {
+            k->guest_notifier_pending(vdev, queue_no)) {
             event_notifier_set(n);
         }
     } else {
@@ -642,13 +661,14 @@ static void virtio_pci_vq_vector_mask(VirtIOPCIProxy *proxy,
                                              unsigned int queue_no,
                                              unsigned int vector)
 {
-    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(proxy->vdev);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
 
     /* If guest supports masking, keep irqfd but mask it.
      * Otherwise, clean it up now.
      */ 
     if (k->guest_notifier_mask) {
-        k->guest_notifier_mask(proxy->vdev, queue_no, true);
+        k->guest_notifier_mask(vdev, queue_no, true);
     } else {
         kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
     }
@@ -658,7 +678,7 @@ static int virtio_pci_vector_unmask(PCIDevice *dev, unsigned vector,
                                     MSIMessage msg)
 {
     VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     int ret, queue_no;
 
     for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) {
@@ -688,7 +708,7 @@ undo:
 static void virtio_pci_vector_mask(PCIDevice *dev, unsigned vector)
 {
     VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     int queue_no;
 
     for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) {
@@ -707,7 +727,7 @@ static void virtio_pci_vector_poll(PCIDevice *dev,
                                    unsigned int vector_end)
 {
     VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
     int queue_no;
     unsigned int vector;
@@ -739,8 +759,9 @@ static int virtio_pci_set_guest_notifier(DeviceState *d, int n, bool assign,
                                          bool with_irqfd)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
-    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(proxy->vdev);
-    VirtQueue *vq = virtio_get_queue(proxy->vdev, n);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+    VirtQueue *vq = virtio_get_queue(vdev, n);
     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
 
     if (assign) {
@@ -755,7 +776,7 @@ static int virtio_pci_set_guest_notifier(DeviceState *d, int n, bool assign,
     }
 
     if (!msix_enabled(&proxy->pci_dev) && vdc->guest_notifier_mask) {
-        vdc->guest_notifier_mask(proxy->vdev, n, !assign);
+        vdc->guest_notifier_mask(vdev, n, !assign);
     }
 
     return 0;
@@ -770,7 +791,7 @@ static bool virtio_pci_query_guest_notifiers(DeviceState *d)
 static int virtio_pci_set_guest_notifiers(DeviceState *d, int nvqs, bool assign)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
-    VirtIODevice *vdev = proxy->vdev;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
     int r, n;
     bool with_irqfd = msix_enabled(&proxy->pci_dev) &&
@@ -864,11 +885,12 @@ static int virtio_pci_set_host_notifier(DeviceState *d, int n, bool assign)
 static void virtio_pci_vmstate_change(DeviceState *d, bool running)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
     if (running) {
         /* Try to find out if the guest has bus master disabled, but is
            in ready state. Then we have a buggy guest OS. */
-        if ((proxy->vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+        if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
             !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
             proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
         }
@@ -943,8 +965,6 @@ static void virtio_pci_device_plugged(DeviceState *d)
     uint8_t *config;
     uint32_t size;
 
-    proxy->vdev = bus->vdev;
-
     config = proxy->pci_dev.config;
     if (proxy->class_code) {
         pci_config_set_class(config, proxy->class_code);
@@ -982,6 +1002,15 @@ static void virtio_pci_device_plugged(DeviceState *d)
                                                       proxy->host_features);
 }
 
+static void virtio_pci_device_unplugged(DeviceState *d)
+{
+    PCIDevice *pci_dev = PCI_DEVICE(d);
+    VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
+
+    virtio_pci_stop_ioeventfd(proxy);
+    msix_uninit_exclusive_bar(pci_dev);
+}
+
 static int virtio_pci_init(PCIDevice *pci_dev)
 {
     VirtIOPCIProxy *dev = VIRTIO_PCI(pci_dev);
@@ -996,9 +1025,7 @@ static int virtio_pci_init(PCIDevice *pci_dev)
 static void virtio_pci_exit(PCIDevice *pci_dev)
 {
     VirtIOPCIProxy *proxy = VIRTIO_PCI(pci_dev);
-    virtio_pci_stop_ioeventfd(proxy);
     memory_region_destroy(&proxy->bar);
-    msix_uninit_exclusive_bar(pci_dev);
 }
 
 static void virtio_pci_reset(DeviceState *qdev)
@@ -1533,6 +1560,7 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
     k->set_guest_notifiers = virtio_pci_set_guest_notifiers;
     k->vmstate_change = virtio_pci_vmstate_change;
     k->device_plugged = virtio_pci_device_plugged;
+    k->device_unplugged = virtio_pci_device_unplugged;
 }
 
 static const TypeInfo virtio_pci_bus_info = {
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 917bcc5348..dc332ae774 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -82,7 +82,6 @@ typedef struct VirtioPCIClass {
 
 struct VirtIOPCIProxy {
     PCIDevice pci_dev;
-    VirtIODevice *vdev;
     MemoryRegion bar;
     uint32_t flags;
     uint32_t class_code;
diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
index b22ccf1008..755fdee628 100644
--- a/hw/virtio/virtio-rng.c
+++ b/hw/virtio/virtio-rng.c
@@ -133,27 +133,27 @@ static void check_rate_limit(void *opaque)
                    qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + vrng->conf.period_ms);
 }
 
-static int virtio_rng_device_init(VirtIODevice *vdev)
+static void virtio_rng_device_realize(DeviceState *dev, Error **errp)
 {
-    DeviceState *qdev = DEVICE(vdev);
-    VirtIORNG *vrng = VIRTIO_RNG(vdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIORNG *vrng = VIRTIO_RNG(dev);
     Error *local_err = NULL;
 
     if (!vrng->conf.period_ms > 0) {
-        qerror_report(QERR_INVALID_PARAMETER_VALUE, "period",
-                      "a positive number");
-        return -1;
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "period",
+                  "a positive number");
+        return;
     }
 
     if (vrng->conf.rng == NULL) {
         vrng->conf.default_backend = RNG_RANDOM(object_new(TYPE_RNG_RANDOM));
 
-        object_property_add_child(OBJECT(qdev),
+        object_property_add_child(OBJECT(dev),
                                   "default-backend",
                                   OBJECT(vrng->conf.default_backend),
                                   NULL);
 
-        object_property_set_link(OBJECT(qdev),
+        object_property_set_link(OBJECT(dev),
                                  OBJECT(vrng->conf.default_backend),
                                  "rng", NULL);
     }
@@ -162,15 +162,14 @@ static int virtio_rng_device_init(VirtIODevice *vdev)
 
     vrng->rng = vrng->conf.rng;
     if (vrng->rng == NULL) {
-        qerror_report(QERR_INVALID_PARAMETER_VALUE, "rng", "a valid object");
-        return -1;
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "rng", "a valid object");
+        return;
     }
 
     rng_backend_open(vrng->rng, &local_err);
     if (local_err) {
-        qerror_report_err(local_err);
-        error_free(local_err);
-        return -1;
+        error_propagate(errp, local_err);
+        return;
     }
 
     vrng->vq = virtio_add_queue(vdev, 8, handle_input);
@@ -184,22 +183,19 @@ static int virtio_rng_device_init(VirtIODevice *vdev)
     timer_mod(vrng->rate_limit_timer,
                    qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + vrng->conf.period_ms);
 
-    register_savevm(qdev, "virtio-rng", -1, 1, virtio_rng_save,
+    register_savevm(dev, "virtio-rng", -1, 1, virtio_rng_save,
                     virtio_rng_load, vrng);
-
-    return 0;
 }
 
-static int virtio_rng_device_exit(DeviceState *qdev)
+static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIORNG *vrng = VIRTIO_RNG(qdev);
-    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIORNG *vrng = VIRTIO_RNG(dev);
 
     timer_del(vrng->rate_limit_timer);
     timer_free(vrng->rate_limit_timer);
-    unregister_savevm(qdev, "virtio-rng", vrng);
+    unregister_savevm(dev, "virtio-rng", vrng);
     virtio_cleanup(vdev);
-    return 0;
 }
 
 static Property virtio_rng_properties[] = {
@@ -211,10 +207,11 @@ static void virtio_rng_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-    dc->exit = virtio_rng_device_exit;
+
     dc->props = virtio_rng_properties;
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
-    vdc->init = virtio_rng_device_init;
+    vdc->realize = virtio_rng_device_realize;
+    vdc->unrealize = virtio_rng_device_unrealize;
     vdc->get_features = get_features;
 }
 
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 2f1e73bc75..144b9ca2ef 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1150,35 +1150,49 @@ void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name)
     }
 }
 
-static int virtio_device_init(DeviceState *qdev)
+static void virtio_device_realize(DeviceState *dev, Error **errp)
 {
-    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
-    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(qdev);
-    assert(k->init != NULL);
-    if (k->init(vdev) < 0) {
-        return -1;
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
+    Error *err = NULL;
+
+    if (vdc->realize != NULL) {
+        vdc->realize(dev, &err);
+        if (err != NULL) {
+            error_propagate(errp, err);
+            return;
+        }
     }
-    virtio_bus_plug_device(vdev);
-    return 0;
+    virtio_bus_device_plugged(vdev);
 }
 
-static int virtio_device_exit(DeviceState *qdev)
+static void virtio_device_unrealize(DeviceState *dev, Error **errp)
 {
-    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
+    Error *err = NULL;
+
+    if (vdc->unrealize != NULL) {
+        vdc->unrealize(dev, &err);
+        if (err != NULL) {
+            error_propagate(errp, err);
+            return;
+        }
+    }
 
     if (vdev->bus_name) {
         g_free(vdev->bus_name);
         vdev->bus_name = NULL;
     }
-    return 0;
 }
 
 static void virtio_device_class_init(ObjectClass *klass, void *data)
 {
     /* Set the default value here. */
     DeviceClass *dc = DEVICE_CLASS(klass);
-    dc->init = virtio_device_init;
-    dc->exit = virtio_device_exit;
+
+    dc->realize = virtio_device_realize;
+    dc->unrealize = virtio_device_unrealize;
     dc->bus_type = TYPE_VIRTIO_BUS;
 }