qdev: Convert busses to QEMU Object Model

This is far less interesting than it sounds.  We simply add an Object to each
BusState and then register the types appropriately.  Most of the interesting
refactoring will follow in the next patches.

Since we're changing fundamental type names (BusInfo -> BusClass), it all needs
to convert at once.  Fortunately, not a lot of code is affected.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[AF: Made all new bus TypeInfos static const.]
[AF: Made qbus_free() call object_delete(), required {qom,glib}_allocated]
Signed-off-by: Andreas Färber <afaerber@suse.de>

hw/i2c.c

@@ -22,9 +22,13 @@ static Property i2c_props[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
-static struct BusInfo i2c_bus_info = {
-    .name = "I2C",
-    .size = sizeof(i2c_bus),
+#define TYPE_I2C_BUS "i2c-bus"
+#define I2C_BUS(obj) OBJECT_CHECK(i2c_bus, (obj), TYPE_I2C_BUS)
+
+static const TypeInfo i2c_bus_info = {
+    .name = TYPE_I2C_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(i2c_bus),
 };
 
 static void i2c_bus_pre_save(void *opaque)
@@ -62,7 +66,7 @@ i2c_bus *i2c_init_bus(DeviceState *parent, const char *name)
 {
     i2c_bus *bus;
 
-    bus = FROM_QBUS(i2c_bus, qbus_create(&i2c_bus_info, parent, name));
+    bus = FROM_QBUS(i2c_bus, qbus_create(TYPE_I2C_BUS, parent, name));
     vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
     return bus;
 }
@@ -219,7 +223,7 @@ static void i2c_slave_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
     k->init = i2c_slave_qdev_init;
-    k->bus_info = &i2c_bus_info;
+    k->bus_type = TYPE_I2C_BUS;
     k->props = i2c_props;
 }
 
@@ -234,6 +238,7 @@ static TypeInfo i2c_slave_type_info = {
 
 static void i2c_slave_register_types(void)
 {
+    type_register_static(&i2c_bus_info);
     type_register_static(&i2c_slave_type_info);
 }
 

hw/ide/internal.h

@@ -25,6 +25,9 @@ typedef struct IDEState IDEState;
 typedef struct IDEDMA IDEDMA;
 typedef struct IDEDMAOps IDEDMAOps;
 
+#define TYPE_IDE_BUS "IDE"
+#define IDE_BUS(obj) OBJECT_CHECK(IDEBus, (obj), TYPE_IDE_BUS)
+
 /* Bits of HD_STATUS */
 #define ERR_STAT		0x01
 #define INDEX_STAT		0x02

hw/ide/qdev.c

@@ -32,15 +32,23 @@ static Property ide_props[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
-static struct BusInfo ide_bus_info = {
-    .name  = "IDE",
-    .size  = sizeof(IDEBus),
-    .get_fw_dev_path = idebus_get_fw_dev_path,
+static void ide_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->get_fw_dev_path = idebus_get_fw_dev_path;
+}
+
+static const TypeInfo ide_bus_info = {
+    .name = TYPE_IDE_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(IDEBus),
+    .class_init = ide_bus_class_init,
 };
 
 void ide_bus_new(IDEBus *idebus, DeviceState *dev, int bus_id)
 {
-    qbus_create_inplace(&idebus->qbus, &ide_bus_info, dev, NULL);
+    qbus_create_inplace(&idebus->qbus, TYPE_IDE_BUS, dev, NULL);
     idebus->bus_id = bus_id;
 }
 
@@ -249,7 +257,7 @@ static void ide_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
     k->init = ide_qdev_init;
-    k->bus_info = &ide_bus_info;
+    k->bus_type = TYPE_IDE_BUS;
     k->props = ide_props;
 }
 
@@ -264,6 +272,7 @@ static TypeInfo ide_device_type_info = {
 
 static void ide_register_types(void)
 {
+    type_register_static(&ide_bus_info);
     type_register_static(&ide_hd_info);
     type_register_static(&ide_cd_info);
     type_register_static(&ide_drive_info);

hw/intel-hda.c

@@ -34,16 +34,17 @@ static Property hda_props[] = {
     DEFINE_PROP_END_OF_LIST()
 };
 
-static struct BusInfo hda_codec_bus_info = {
-    .name      = "HDA",
-    .size      = sizeof(HDACodecBus),
+static const TypeInfo hda_codec_bus_info = {
+    .name = TYPE_HDA_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(HDACodecBus),
 };
 
 void hda_codec_bus_init(DeviceState *dev, HDACodecBus *bus,
                         hda_codec_response_func response,
                         hda_codec_xfer_func xfer)
 {
-    qbus_create_inplace(&bus->qbus, &hda_codec_bus_info, dev, NULL);
+    qbus_create_inplace(&bus->qbus, TYPE_HDA_BUS, dev, NULL);
     bus->response = response;
     bus->xfer = xfer;
 }
@@ -1276,7 +1277,7 @@ static void hda_codec_device_class_init(ObjectClass *klass, void *data)
     DeviceClass *k = DEVICE_CLASS(klass);
     k->init = hda_codec_dev_init;
     k->exit = hda_codec_dev_exit;
-    k->bus_info = &hda_codec_bus_info;
+    k->bus_type = TYPE_HDA_BUS;
     k->props = hda_props;
 }
 
@@ -1291,6 +1292,7 @@ static TypeInfo hda_codec_device_type_info = {
 
 static void intel_hda_register_types(void)
 {
+    type_register_static(&hda_codec_bus_info);
     type_register_static(&intel_hda_info);
     type_register_static(&hda_codec_device_type_info);
 }

hw/intel-hda.h

@@ -14,6 +14,9 @@
 #define HDA_CODEC_DEVICE_GET_CLASS(obj) \
      OBJECT_GET_CLASS(HDACodecDeviceClass, (obj), TYPE_HDA_CODEC_DEVICE)
 
+#define TYPE_HDA_BUS "HDA"
+#define HDA_BUS(obj) OBJECT_CHECK(HDACodecBus, (obj), TYPE_HDA_BUS)
+
 typedef struct HDACodecBus HDACodecBus;
 typedef struct HDACodecDevice HDACodecDevice;
 

hw/isa-bus.c

@@ -28,11 +28,19 @@ target_phys_addr_t isa_mem_base = 0;
 static void isabus_dev_print(Monitor *mon, DeviceState *dev, int indent);
 static char *isabus_get_fw_dev_path(DeviceState *dev);
 
-static struct BusInfo isa_bus_info = {
-    .name      = "ISA",
-    .size      = sizeof(ISABus),
-    .print_dev = isabus_dev_print,
-    .get_fw_dev_path = isabus_get_fw_dev_path,
+static void isa_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->print_dev = isabus_dev_print;
+    k->get_fw_dev_path = isabus_get_fw_dev_path;
+}
+
+static const TypeInfo isa_bus_info = {
+    .name = TYPE_ISA_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(ISABus),
+    .class_init = isa_bus_class_init,
 };
 
 ISABus *isa_bus_new(DeviceState *dev, MemoryRegion *address_space_io)
@@ -46,7 +54,7 @@ ISABus *isa_bus_new(DeviceState *dev, MemoryRegion *address_space_io)
         qdev_init_nofail(dev);
     }
 
-    isabus = FROM_QBUS(ISABus, qbus_create(&isa_bus_info, dev, NULL));
+    isabus = FROM_QBUS(ISABus, qbus_create(TYPE_ISA_BUS, dev, NULL));
     isabus->address_space_io = address_space_io;
     return isabus;
 }
@@ -198,7 +206,7 @@ static void isa_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
     k->init = isa_qdev_init;
-    k->bus_info = &isa_bus_info;
+    k->bus_type = TYPE_ISA_BUS;
 }
 
 static TypeInfo isa_device_type_info = {
@@ -212,6 +220,7 @@ static TypeInfo isa_device_type_info = {
 
 static void isabus_register_types(void)
 {
+    type_register_static(&isa_bus_info);
     type_register_static(&isabus_bridge_info);
     type_register_static(&isa_device_type_info);
 }

hw/isa.h

@@ -19,6 +19,9 @@ typedef struct ISADevice ISADevice;
 #define ISA_DEVICE_GET_CLASS(obj) \
      OBJECT_GET_CLASS(ISADeviceClass, (obj), TYPE_ISA_DEVICE)
 
+#define TYPE_ISA_BUS "ISA"
+#define ISA_BUS(obj) OBJECT_CHECK(ISABus, (obj), TYPE_ISA_BUS)
+
 typedef struct ISADeviceClass {
     DeviceClass parent_class;
     int (*init)(ISADevice *dev);

hw/pci-hotplug.c

@@ -80,11 +80,7 @@ static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
     SCSIBus *scsibus;
     SCSIDevice *scsidev;
 
-    scsibus = DO_UPCAST(SCSIBus, qbus, QLIST_FIRST(&adapter->child_bus));
-    if (!scsibus || strcmp(scsibus->qbus.info->name, "SCSI") != 0) {
-        error_report("Device is not a SCSI adapter");
-        return -1;
-    }
+    scsibus = SCSI_BUS(QLIST_FIRST(&adapter->child_bus));
 
     /*
      * drive_init() tries to find a default for dinfo->unit.  Doesn't

hw/pci.c

@@ -55,13 +55,21 @@ static Property pci_props[] = {
     DEFINE_PROP_END_OF_LIST()
 };
 
-struct BusInfo pci_bus_info = {
-    .name       = "PCI",
-    .size       = sizeof(PCIBus),
-    .print_dev  = pcibus_dev_print,
-    .get_dev_path = pcibus_get_dev_path,
-    .get_fw_dev_path = pcibus_get_fw_dev_path,
-    .reset      = pcibus_reset,
+static void pci_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->print_dev = pcibus_dev_print;
+    k->get_dev_path = pcibus_get_dev_path;
+    k->get_fw_dev_path = pcibus_get_fw_dev_path;
+    k->reset = pcibus_reset;
+}
+
+static const TypeInfo pci_bus_info = {
+    .name = TYPE_PCI_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(PCIBus),
+    .class_init = pci_bus_class_init,
 };
 
 static PCIBus *pci_find_bus_nr(PCIBus *bus, int bus_num);
@@ -266,7 +274,7 @@ void pci_bus_new_inplace(PCIBus *bus, DeviceState *parent,
                          MemoryRegion *address_space_io,
                          uint8_t devfn_min)
 {
-    qbus_create_inplace(&bus->qbus, &pci_bus_info, parent, name);
+    qbus_create_inplace(&bus->qbus, TYPE_PCI_BUS, parent, name);
     assert(PCI_FUNC(devfn_min) == 0);
     bus->devfn_min = devfn_min;
     bus->address_space_mem = address_space_mem;
@@ -287,7 +295,7 @@ PCIBus *pci_bus_new(DeviceState *parent, const char *name,
     PCIBus *bus;
 
     bus = g_malloc0(sizeof(*bus));
-    bus->qbus.qdev_allocated = 1;
+    bus->qbus.glib_allocated = true;
     pci_bus_new_inplace(bus, parent, name, address_space_mem,
                         address_space_io, devfn_min);
     return bus;
@@ -2001,7 +2009,7 @@ static void pci_device_class_init(ObjectClass *klass, void *data)
     k->init = pci_qdev_init;
     k->unplug = pci_unplug_device;
     k->exit = pci_unregister_device;
-    k->bus_info = &pci_bus_info;
+    k->bus_type = TYPE_PCI_BUS;
     k->props = pci_props;
 }
 
@@ -2016,6 +2024,7 @@ static TypeInfo pci_device_type_info = {
 
 static void pci_register_types(void)
 {
+    type_register_static(&pci_bus_info);
     type_register_static(&pci_device_type_info);
 }
 

hw/pci_bridge.c

@@ -324,7 +324,7 @@ int pci_bridge_initfn(PCIDevice *dev)
 	    br->bus_name = dev->qdev.id;
     }
 
-    qbus_create_inplace(&sec_bus->qbus, &pci_bus_info, &dev->qdev,
+    qbus_create_inplace(&sec_bus->qbus, TYPE_PCI_BUS, &dev->qdev,
                         br->bus_name);
     sec_bus->parent_dev = dev;
     sec_bus->map_irq = br->map_irq;

hw/pci_internals.h

@@ -12,7 +12,8 @@
  * Use accessor function in pci.h, pci_bridge.h
  */
 
-extern struct BusInfo pci_bus_info;
+#define TYPE_PCI_BUS "PCI"
+#define PCI_BUS(obj) OBJECT_CHECK(PCIBus, (obj), TYPE_PCI_BUS)
 
 struct PCIBus {
     BusState qbus;

hw/qdev-monitor.c

@@ -75,8 +75,8 @@ static void qdev_print_devinfo(ObjectClass *klass, void *opaque)
     }
 
     error_printf("name \"%s\"", object_class_get_name(klass));
-    if (dc->bus_info) {
-        error_printf(", bus %s", dc->bus_info->name);
+    if (dc->bus_type) {
+        error_printf(", bus %s", dc->bus_type);
     }
     if (qdev_class_has_alias(dc)) {
         error_printf(", alias \"%s\"", qdev_class_get_alias(dc));
@@ -262,7 +262,7 @@ static DeviceState *qbus_find_dev(BusState *bus, char *elem)
 }
 
 static BusState *qbus_find_recursive(BusState *bus, const char *name,
-                                     const BusInfo *info)
+                                     const char *bus_typename)
 {
     DeviceState *dev;
     BusState *child, *ret;
@@ -271,7 +271,8 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
     if (name && (strcmp(bus->name, name) != 0)) {
         match = 0;
     }
-    if (info && (bus->info != info)) {
+    if (bus_typename &&
+        (strcmp(object_get_typename(OBJECT(bus)), bus_typename) != 0)) {
         match = 0;
     }
     if (match) {
@@ -280,7 +281,7 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
 
     QTAILQ_FOREACH(dev, &bus->children, sibling) {
         QLIST_FOREACH(child, &dev->child_bus, sibling) {
-            ret = qbus_find_recursive(child, name, info);
+            ret = qbus_find_recursive(child, name, bus_typename);
             if (ret) {
                 return ret;
             }
@@ -415,16 +416,16 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         if (!bus) {
             return NULL;
         }
-        if (bus->info != k->bus_info) {
+        if (strcmp(object_get_typename(OBJECT(bus)), k->bus_type) != 0) {
             qerror_report(QERR_BAD_BUS_FOR_DEVICE,
-                           driver, bus->info->name);
+                          driver, object_get_typename(OBJECT(bus)));
             return NULL;
         }
     } else {
-        bus = qbus_find_recursive(sysbus_get_default(), NULL, k->bus_info);
+        bus = qbus_find_recursive(sysbus_get_default(), NULL, k->bus_type);
         if (!bus) {
             qerror_report(QERR_NO_BUS_FOR_DEVICE,
-                          driver, k->bus_info->name);
+                          driver, k->bus_type);
             return NULL;
         }
     }
@@ -497,6 +498,15 @@ static void qdev_print_props(Monitor *mon, DeviceState *dev, Property *props,
     }
 }
 
+static void bus_print_dev(BusState *bus, Monitor *mon, DeviceState *dev, int indent)
+{
+    BusClass *bc = BUS_GET_CLASS(bus);
+
+    if (bc->print_dev) {
+        bc->print_dev(mon, dev, indent);
+    }
+}
+
 static void qdev_print(Monitor *mon, DeviceState *dev, int indent)
 {
     ObjectClass *class;
@@ -515,8 +525,7 @@ static void qdev_print(Monitor *mon, DeviceState *dev, int indent)
         qdev_print_props(mon, dev, DEVICE_CLASS(class)->props, indent);
         class = object_class_get_parent(class);
     } while (class != object_class_by_name(TYPE_DEVICE));
-    if (dev->parent_bus->info->print_dev)
-        dev->parent_bus->info->print_dev(mon, dev, indent);
+    bus_print_dev(dev->parent_bus, mon, dev, indent + 2);
     QLIST_FOREACH(child, &dev->child_bus, sibling) {
         qbus_print(mon, child, indent);
     }
@@ -528,7 +537,7 @@ static void qbus_print(Monitor *mon, BusState *bus, int indent)
 
     qdev_printf("bus: %s\n", bus->name);
     indent += 2;
-    qdev_printf("type %s\n", bus->info->name);
+    qdev_printf("type %s\n", object_get_typename(OBJECT(bus)));
     QTAILQ_FOREACH(dev, &bus->children, sibling) {
         qdev_print(mon, dev, indent);
     }

hw/qdev.c

@@ -81,7 +81,7 @@ DeviceState *qdev_create(BusState *bus, const char *name)
     if (!dev) {
         if (bus) {
             hw_error("Unknown device '%s' for bus '%s'\n", name,
-                     bus->info->name);
+                     object_get_typename(OBJECT(bus)));
         } else {
             hw_error("Unknown device '%s' for default sysbus\n", name);
         }
@@ -186,8 +186,9 @@ static int qdev_reset_one(DeviceState *dev, void *opaque)
 
 static int qbus_reset_one(BusState *bus, void *opaque)
 {
-    if (bus->info->reset) {
-        return bus->info->reset(bus);
+    BusClass *bc = BUS_GET_CLASS(bus);
+    if (bc->reset) {
+        return bc->reset(bus);
     }
     return 0;
 }
@@ -370,13 +371,13 @@ DeviceState *qdev_find_recursive(BusState *bus, const char *id)
     return NULL;
 }
 
-void qbus_create_inplace(BusState *bus, BusInfo *info,
-                         DeviceState *parent, const char *name)
+/* FIXME move this logic into instance_init */
+static void do_qbus_create_inplace(BusState *bus, const char *typename,
+                                   DeviceState *parent, const char *name)
 {
     char *buf;
     int i,len;
 
-    bus->info = info;
     bus->parent = parent;
 
     if (name) {
@@ -390,9 +391,9 @@ void qbus_create_inplace(BusState *bus, BusInfo *info,
         bus->name = buf;
     } else {
         /* no id -> use lowercase bus type for bus name */
-        len = strlen(info->name) + 16;
+        len = strlen(typename) + 16;
         buf = g_malloc(len);
-        len = snprintf(buf, len, "%s.%d", info->name,
+        len = snprintf(buf, len, "%s.%d", typename,
                        parent ? parent->num_child_bus : 0);
         for (i = 0; i < len; i++)
             buf[i] = qemu_tolower(buf[i]);
@@ -410,13 +411,20 @@ void qbus_create_inplace(BusState *bus, BusInfo *info,
     }
 }
 
-BusState *qbus_create(BusInfo *info, DeviceState *parent, const char *name)
+void qbus_create_inplace(BusState *bus, const char *typename,
+                         DeviceState *parent, const char *name)
+{
+    object_initialize(bus, typename);
+    do_qbus_create_inplace(bus, typename, parent, name);
+}
+
+BusState *qbus_create(const char *typename, DeviceState *parent, const char *name)
 {
     BusState *bus;
 
-    bus = g_malloc0(info->size);
-    bus->qdev_allocated = 1;
-    qbus_create_inplace(bus, info, parent, name);
+    bus = BUS(object_new(typename));
+    bus->qom_allocated = true;
+    do_qbus_create_inplace(bus, typename, parent, name);
     return bus;
 }
 
@@ -435,9 +443,25 @@ void qbus_free(BusState *bus)
         qemu_unregister_reset(qbus_reset_all_fn, bus);
     }
     g_free((void*)bus->name);
-    if (bus->qdev_allocated) {
-        g_free(bus);
+    if (bus->qom_allocated) {
+        object_delete(OBJECT(bus));
+    } else {
+        object_finalize(OBJECT(bus));
+        if (bus->glib_allocated) {
+            g_free(bus);
+        }
+    }
+}
+
+static char *bus_get_fw_dev_path(BusState *bus, DeviceState *dev)
+{
+    BusClass *bc = BUS_GET_CLASS(bus);
+
+    if (bc->get_fw_dev_path) {
+        return bc->get_fw_dev_path(dev);
     }
+
+    return NULL;
 }
 
 static int qdev_get_fw_dev_path_helper(DeviceState *dev, char *p, int size)
@@ -447,8 +471,8 @@ static int qdev_get_fw_dev_path_helper(DeviceState *dev, char *p, int size)
     if (dev && dev->parent_bus) {
         char *d;
         l = qdev_get_fw_dev_path_helper(dev->parent_bus->parent, p, size);
-        if (dev->parent_bus->info->get_fw_dev_path) {
-            d = dev->parent_bus->info->get_fw_dev_path(dev);
+        d = bus_get_fw_dev_path(dev->parent_bus, dev);
+        if (d) {
             l += snprintf(p + l, size - l, "%s", d);
             g_free(d);
         } else {
@@ -474,15 +498,15 @@ char* qdev_get_fw_dev_path(DeviceState *dev)
 
 char *qdev_get_dev_path(DeviceState *dev)
 {
-    BusInfo *businfo;
+    BusClass *bc;
 
     if (!dev || !dev->parent_bus) {
         return NULL;
     }
 
-    businfo = dev->parent_bus->info;
-    if (businfo->get_dev_path) {
-        return businfo->get_dev_path(dev);
+    bc = BUS_GET_CLASS(dev->parent_bus);
+    if (bc->get_dev_path) {
+        return bc->get_dev_path(dev);
     }
 
     return NULL;
@@ -700,8 +724,17 @@ static TypeInfo device_type_info = {
     .class_size = sizeof(DeviceClass),
 };
 
+static const TypeInfo bus_info = {
+    .name = TYPE_BUS,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(BusState),
+    .abstract = true,
+    .class_size = sizeof(BusClass),
+};
+
 static void qdev_register_types(void)
 {
+    type_register_static(&bus_info);
     type_register_static(&device_type_info);
 }
 

hw/qdev.h

@@ -17,7 +17,7 @@ typedef struct CompatProperty CompatProperty;
 
 typedef struct BusState BusState;
 
-typedef struct BusInfo BusInfo;
+typedef struct BusClass BusClass;
 
 enum DevState {
     DEV_STATE_CREATED = 1,
@@ -55,7 +55,7 @@ typedef struct DeviceClass {
     qdev_initfn init;
     qdev_event unplug;
     qdev_event exit;
-    BusInfo *bus_info;
+    const char *bus_type;
 } DeviceClass;
 
 /* This structure should not be accessed directly.  We declare it here
@@ -79,31 +79,40 @@ struct DeviceState {
     int alias_required_for_version;
 };
 
-typedef void (*bus_dev_printfn)(Monitor *mon, DeviceState *dev, int indent);
-typedef char *(*bus_get_dev_path)(DeviceState *dev);
 /*
  * This callback is used to create Open Firmware device path in accordance with
  * OF spec http://forthworks.com/standards/of1275.pdf. Indicidual bus bindings
  * can be found here http://playground.sun.com/1275/bindings/.
  */
-typedef char *(*bus_get_fw_dev_path)(DeviceState *dev);
-typedef int (qbus_resetfn)(BusState *bus);
 
-struct BusInfo {
-    const char *name;
-    size_t size;
-    bus_dev_printfn print_dev;
-    bus_get_dev_path get_dev_path;
-    bus_get_fw_dev_path get_fw_dev_path;
-    qbus_resetfn *reset;
+#define TYPE_BUS "bus"
+#define BUS(obj) OBJECT_CHECK(BusState, (obj), TYPE_BUS)
+#define BUS_CLASS(klass) OBJECT_CLASS_CHECK(BusClass, (klass), TYPE_BUS)
+#define BUS_GET_CLASS(obj) OBJECT_GET_CLASS(BusClass, (obj), TYPE_BUS)
+
+struct BusClass {
+    ObjectClass parent_class;
+
+    /* FIXME first arg should be BusState */
+    void (*print_dev)(Monitor *mon, DeviceState *dev, int indent);
+    char *(*get_dev_path)(DeviceState *dev);
+    char *(*get_fw_dev_path)(DeviceState *dev);
+    int (*reset)(BusState *bus);
 };
 
+/**
+ * BusState:
+ * @qom_allocated: Indicates whether the object was allocated by QOM.
+ * @glib_allocated: Indicates whether the object was initialized in-place
+ * yet is expected to be freed with g_free().
+ */
 struct BusState {
+    Object obj;
     DeviceState *parent;
-    BusInfo *info;
     const char *name;
     int allow_hotplug;
-    int qdev_allocated;
+    bool qom_allocated;
+    bool glib_allocated;
     QTAILQ_HEAD(ChildrenHead, DeviceState) children;
     QLIST_ENTRY(BusState) sibling;
 };
@@ -174,9 +183,9 @@ DeviceState *qdev_find_recursive(BusState *bus, const char *id);
 typedef int (qbus_walkerfn)(BusState *bus, void *opaque);
 typedef int (qdev_walkerfn)(DeviceState *dev, void *opaque);
 
-void qbus_create_inplace(BusState *bus, BusInfo *info,
+void qbus_create_inplace(BusState *bus, const char *typename,
                          DeviceState *parent, const char *name);
-BusState *qbus_create(BusInfo *info, DeviceState *parent, const char *name);
+BusState *qbus_create(const char *typename, DeviceState *parent, const char *name);
 /* Returns > 0 if either devfn or busfn skip walk somewhere in cursion,
  *         < 0 if either devfn or busfn terminate walk somewhere in cursion,
  *           0 otherwise. */
@@ -317,9 +326,6 @@ void error_set_from_qdev_prop_error(Error **errp, int ret, DeviceState *dev,
 
 char *qdev_get_fw_dev_path(DeviceState *dev);
 
-/* This is a nasty hack to allow passing a NULL bus to qdev_create.  */
-extern struct BusInfo system_bus_info;
-
 /**
  * @qdev_property_add_static - add a @Property to a device referencing a
  * field in a struct.

hw/s390-virtio-bus.c

@@ -45,9 +45,10 @@
 
 #define VIRTIO_EXT_CODE   0x2603
 
-struct BusInfo s390_virtio_bus_info = {
-    .name       = "s390-virtio",
-    .size       = sizeof(VirtIOS390Bus),
+static const TypeInfo s390_virtio_bus_info = {
+    .name = TYPE_S390_VIRTIO_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(VirtIOS390Bus),
 };
 
 static const VirtIOBindings virtio_s390_bindings;
@@ -92,7 +93,7 @@ VirtIOS390Bus *s390_virtio_bus_init(ram_addr_t *ram_size)
 
     /* Create bus on bridge device */
 
-    _bus = qbus_create(&s390_virtio_bus_info, dev, "s390-virtio");
+    _bus = qbus_create(TYPE_S390_VIRTIO_BUS, dev, "s390-virtio");
     bus = DO_UPCAST(VirtIOS390Bus, bus, _bus);
 
     bus->dev_page = *ram_size;
@@ -460,7 +461,7 @@ static void virtio_s390_device_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->init = s390_virtio_busdev_init;
-    dc->bus_info = &s390_virtio_bus_info;
+    dc->bus_type = TYPE_S390_VIRTIO_BUS;
     dc->unplug = qdev_simple_unplug_cb;
 }
 
@@ -521,6 +522,7 @@ static TypeInfo s390_virtio_bridge_info = {
 
 static void s390_virtio_register_types(void)
 {
+    type_register_static(&s390_virtio_bus_info);
     type_register_static(&virtio_s390_device_info);
     type_register_static(&s390_virtio_serial);
     type_register_static(&s390_virtio_blk);

hw/s390-virtio-bus.h

@@ -52,6 +52,10 @@
 #define VIRTIO_S390_DEVICE_GET_CLASS(obj) \
      OBJECT_GET_CLASS(VirtIOS390DeviceClass, (obj), TYPE_VIRTIO_S390_DEVICE)
 
+#define TYPE_S390_VIRTIO_BUS "s390-virtio-bus"
+#define S390_VIRTIO_BUS(obj) \
+     OBJECT_CHECK(VirtIOS390Bus, (obj), TYPE_S390_VIRTIO_BUS)
+
 typedef struct VirtIOS390Device VirtIOS390Device;
 
 typedef struct VirtIOS390DeviceClass {

hw/scsi-bus.c

@@ -19,11 +19,19 @@ static Property scsi_props[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
-static struct BusInfo scsi_bus_info = {
-    .name  = "SCSI",
-    .size  = sizeof(SCSIBus),
-    .get_dev_path = scsibus_get_dev_path,
-    .get_fw_dev_path = scsibus_get_fw_dev_path,
+static void scsi_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->get_dev_path = scsibus_get_dev_path;
+    k->get_fw_dev_path = scsibus_get_fw_dev_path;
+}
+
+static const TypeInfo scsi_bus_info = {
+    .name = TYPE_SCSI_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(SCSIBus),
+    .class_init = scsi_bus_class_init,
 };
 static int next_scsi_bus;
 
@@ -66,7 +74,7 @@ static void scsi_device_unit_attention_reported(SCSIDevice *s)
 /* Create a scsi bus, and attach devices to it.  */
 void scsi_bus_new(SCSIBus *bus, DeviceState *host, const SCSIBusInfo *info)
 {
-    qbus_create_inplace(&bus->qbus, &scsi_bus_info, host, NULL);
+    qbus_create_inplace(&bus->qbus, TYPE_SCSI_BUS, host, NULL);
     bus->busnr = next_scsi_bus++;
     bus->info = info;
     bus->qbus.allow_hotplug = 1;
@@ -1594,7 +1602,7 @@ const VMStateDescription vmstate_scsi_device = {
 static void scsi_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
-    k->bus_info = &scsi_bus_info;
+    k->bus_type = TYPE_SCSI_BUS;
     k->init     = scsi_qdev_init;
     k->unplug   = qdev_simple_unplug_cb;
     k->exit     = scsi_qdev_exit;
@@ -1612,6 +1620,7 @@ static TypeInfo scsi_device_type_info = {
 
 static void scsi_register_types(void)
 {
+    type_register_static(&scsi_bus_info);
     type_register_static(&scsi_device_type_info);
 }
 

hw/scsi.h

@@ -136,6 +136,9 @@ struct SCSIBusInfo {
     void *(*load_request)(QEMUFile *f, SCSIRequest *req);
 };
 
+#define TYPE_SCSI_BUS "SCSI"
+#define SCSI_BUS(obj) OBJECT_CHECK(SCSIBus, (obj), TYPE_SCSI_BUS)
+
 struct SCSIBus {
     BusState qbus;
     int busnr;

hw/spapr_vio.c

@@ -54,9 +54,10 @@ static Property spapr_vio_props[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
-static struct BusInfo spapr_vio_bus_info = {
-    .name       = "spapr-vio",
-    .size       = sizeof(VIOsPAPRBus),
+static const TypeInfo spapr_vio_bus_info = {
+    .name = TYPE_SPAPR_VIO_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(VIOsPAPRBus),
 };
 
 VIOsPAPRDevice *spapr_vio_find_by_reg(VIOsPAPRBus *bus, uint32_t reg)
@@ -743,7 +744,7 @@ VIOsPAPRBus *spapr_vio_bus_init(void)
 
     /* Create bus on bridge device */
 
-    qbus = qbus_create(&spapr_vio_bus_info, dev, "spapr-vio");
+    qbus = qbus_create(TYPE_SPAPR_VIO_BUS, dev, "spapr-vio");
     bus = DO_UPCAST(VIOsPAPRBus, bus, qbus);
     bus->next_reg = 0x1000;
 
@@ -795,7 +796,7 @@ static void vio_spapr_device_class_init(ObjectClass *klass, void *data)
     DeviceClass *k = DEVICE_CLASS(klass);
     k->init = spapr_vio_busdev_init;
     k->reset = spapr_vio_busdev_reset;
-    k->bus_info = &spapr_vio_bus_info;
+    k->bus_type = TYPE_SPAPR_VIO_BUS;
     k->props = spapr_vio_props;
 }
 
@@ -810,6 +811,7 @@ static TypeInfo spapr_vio_type_info = {
 
 static void spapr_vio_register_types(void)
 {
+    type_register_static(&spapr_vio_bus_info);
     type_register_static(&spapr_vio_bridge_info);
     type_register_static(&spapr_vio_type_info);
 }

hw/spapr_vio.h

@@ -40,6 +40,9 @@ enum VIOsPAPR_TCEAccess {
 #define VIO_SPAPR_DEVICE_GET_CLASS(obj) \
      OBJECT_GET_CLASS(VIOsPAPRDeviceClass, (obj), TYPE_VIO_SPAPR_DEVICE)
 
+#define TYPE_SPAPR_VIO_BUS "spapr-vio-bus"
+#define SPAPR_VIO_BUS(obj) OBJECT_CHECK(VIOsPAPRBus, (obj), TYPE_SPAPR_VIO_BUS)
+
 struct VIOsPAPRDevice;
 
 typedef struct VIOsPAPR_RTCE {

hw/ssi.c

@@ -16,9 +16,13 @@ struct SSIBus {
     BusState qbus;
 };
 
-static struct BusInfo ssi_bus_info = {
-    .name = "SSI",
-    .size = sizeof(SSIBus),
+#define TYPE_SSI_BUS "SSI"
+#define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
+
+static const TypeInfo ssi_bus_info = {
+    .name = TYPE_SSI_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(SSIBus),
 };
 
 static int ssi_slave_init(DeviceState *dev)
@@ -40,7 +44,7 @@ static void ssi_slave_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     dc->init = ssi_slave_init;
-    dc->bus_info = &ssi_bus_info;
+    dc->bus_type = TYPE_SSI_BUS;
 }
 
 static TypeInfo ssi_slave_info = {
@@ -62,7 +66,7 @@ DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 {
     BusState *bus;
-    bus = qbus_create(&ssi_bus_info, parent, name);
+    bus = qbus_create(TYPE_SSI_BUS, parent, name);
     return FROM_QBUS(SSIBus, bus);
 }
 
@@ -82,6 +86,7 @@ uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 
 static void ssi_slave_register_types(void)
 {
+    type_register_static(&ssi_bus_info);
     type_register_static(&ssi_slave_info);
 }
 

hw/sysbus.c

@@ -24,11 +24,19 @@
 static void sysbus_dev_print(Monitor *mon, DeviceState *dev, int indent);
 static char *sysbus_get_fw_dev_path(DeviceState *dev);
 
-struct BusInfo system_bus_info = {
-    .name       = "System",
-    .size       = sizeof(BusState),
-    .print_dev  = sysbus_dev_print,
-    .get_fw_dev_path = sysbus_get_fw_dev_path,
+static void system_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->print_dev = sysbus_dev_print;
+    k->get_fw_dev_path = sysbus_get_fw_dev_path;
+}
+
+static const TypeInfo system_bus_info = {
+    .name = TYPE_SYSTEM_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(BusState),
+    .class_init = system_bus_class_init,
 };
 
 void sysbus_connect_irq(SysBusDevice *dev, int n, qemu_irq irq)
@@ -244,7 +252,7 @@ static void sysbus_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
     k->init = sysbus_device_init;
-    k->bus_info = &system_bus_info;
+    k->bus_type = TYPE_SYSTEM_BUS;
 }
 
 static TypeInfo sysbus_device_type_info = {
@@ -263,10 +271,10 @@ static void main_system_bus_create(void)
 {
     /* assign main_system_bus before qbus_create_inplace()
      * in order to make "if (bus != sysbus_get_default())" work */
-    main_system_bus = g_malloc0(system_bus_info.size);
-    main_system_bus->qdev_allocated = 1;
-    qbus_create_inplace(main_system_bus, &system_bus_info, NULL,
+    main_system_bus = g_malloc0(system_bus_info.instance_size);
+    qbus_create_inplace(main_system_bus, TYPE_SYSTEM_BUS, NULL,
                         "main-system-bus");
+    main_system_bus->glib_allocated = true;
 }
 
 BusState *sysbus_get_default(void)
@@ -279,6 +287,7 @@ BusState *sysbus_get_default(void)
 
 static void sysbus_register_types(void)
 {
+    type_register_static(&system_bus_info);
     type_register_static(&sysbus_device_type_info);
 }
 

hw/sysbus.h

@@ -10,6 +10,9 @@
 #define QDEV_MAX_PIO 32
 #define QDEV_MAX_IRQ 512
 
+#define TYPE_SYSTEM_BUS "System"
+#define SYSTEM_BUS(obj) OBJECT_CHECK(IDEBus, (obj), TYPE_IDE_BUS)
+
 typedef struct SysBusDevice SysBusDevice;
 
 #define TYPE_SYS_BUS_DEVICE "sys-bus-device"

hw/usb.h

@@ -421,6 +421,9 @@ void musb_set_size(MUSBState *s, int epnum, int size, int is_tx);
 
 /* usb-bus.c */
 
+#define TYPE_USB_BUS "usb-bus"
+#define USB_BUS(obj) OBJECT_CHECK(USBBus, (obj), TYPE_USB_BUS)
+
 struct USBBus {
     BusState qbus;
     USBBusOps *ops;

hw/usb/bus.c

@@ -18,12 +18,20 @@ static Property usb_props[] = {
     DEFINE_PROP_END_OF_LIST()
 };
 
-static struct BusInfo usb_bus_info = {
-    .name      = "USB",
-    .size      = sizeof(USBBus),
-    .print_dev = usb_bus_dev_print,
-    .get_dev_path = usb_get_dev_path,
-    .get_fw_dev_path = usb_get_fw_dev_path,
+static void usb_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->print_dev = usb_bus_dev_print;
+    k->get_dev_path = usb_get_dev_path;
+    k->get_fw_dev_path = usb_get_fw_dev_path;
+}
+
+static const TypeInfo usb_bus_info = {
+    .name = TYPE_USB_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(USBBus),
+    .class_init = usb_bus_class_init,
 };
 
 static int next_usb_bus = 0;
@@ -47,7 +55,7 @@ const VMStateDescription vmstate_usb_device = {
 
 void usb_bus_new(USBBus *bus, USBBusOps *ops, DeviceState *host)
 {
-    qbus_create_inplace(&bus->qbus, &usb_bus_info, host, NULL);
+    qbus_create_inplace(&bus->qbus, TYPE_USB_BUS, host, NULL);
     bus->ops = ops;
     bus->busnr = next_usb_bus++;
     bus->qbus.allow_hotplug = 1; /* Yes, we can */
@@ -577,7 +585,7 @@ USBDevice *usbdevice_create(const char *cmdline)
 static void usb_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
-    k->bus_info = &usb_bus_info;
+    k->bus_type = TYPE_USB_BUS;
     k->init     = usb_qdev_init;
     k->unplug   = qdev_simple_unplug_cb;
     k->exit     = usb_qdev_exit;
@@ -595,6 +603,7 @@ static TypeInfo usb_device_type_info = {
 
 static void usb_register_types(void)
 {
+    type_register_static(&usb_bus_info);
     type_register_static(&usb_device_type_info);
 }
 

hw/usb/dev-smartcard-reader.c

@@ -1060,9 +1060,13 @@ static Property ccid_props[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
-static struct BusInfo ccid_bus_info = {
-    .name = "ccid-bus",
-    .size = sizeof(CCIDBus),
+#define TYPE_CCID_BUS "ccid-bus"
+#define CCID_BUS(obj) OBJECT_CHECK(CCIDBus, (obj), TYPE_CCID_BUS)
+
+static const TypeInfo ccid_bus_info = {
+    .name = TYPE_CCID_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(CCIDBus),
 };
 
 void ccid_card_send_apdu_to_guest(CCIDCardState *card,
@@ -1192,7 +1196,7 @@ static int ccid_initfn(USBDevice *dev)
 
     usb_desc_create_serial(dev);
     usb_desc_init(dev);
-    qbus_create_inplace(&s->bus.qbus, &ccid_bus_info, &dev->qdev, NULL);
+    qbus_create_inplace(&s->bus.qbus, TYPE_CCID_BUS, &dev->qdev, NULL);
     s->intr = usb_ep_get(dev, USB_TOKEN_IN, CCID_INT_IN_EP);
     s->bus.qbus.allow_hotplug = 1;
     s->card = NULL;
@@ -1343,7 +1347,7 @@ static TypeInfo ccid_info = {
 static void ccid_card_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
-    k->bus_info = &ccid_bus_info;
+    k->bus_type = TYPE_CCID_BUS;
     k->init = ccid_card_init;
     k->exit = ccid_card_exit;
     k->props = ccid_props;
@@ -1360,6 +1364,7 @@ static TypeInfo ccid_card_type_info = {
 
 static void ccid_register_types(void)
 {
+    type_register_static(&ccid_bus_info);
     type_register_static(&ccid_card_type_info);
     type_register_static(&ccid_info);
     usb_legacy_register(CCID_DEV_NAME, "ccid", NULL);

hw/virtio-serial-bus.c

@@ -734,10 +734,21 @@ static Property virtser_props[] = {
     DEFINE_PROP_END_OF_LIST()
 };
 
-static struct BusInfo virtser_bus_info = {
-    .name      = "virtio-serial-bus",
-    .size      = sizeof(VirtIOSerialBus),
-    .print_dev = virtser_bus_dev_print,
+#define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
+#define VIRTIO_SERIAL_BUS(obj) \
+      OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
+
+static void virtser_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+    k->print_dev = virtser_bus_dev_print;
+}
+
+static const TypeInfo virtser_bus_info = {
+    .name = TYPE_VIRTIO_SERIAL_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(VirtIOSerialBus),
+    .class_init = virtser_bus_class_init,
 };
 
 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
@@ -905,7 +916,7 @@ VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *conf)
     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 
     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
-    qbus_create_inplace(&vser->bus.qbus, &virtser_bus_info, dev, NULL);
+    qbus_create_inplace(&vser->bus.qbus, TYPE_VIRTIO_SERIAL_BUS, dev, NULL);
     vser->bus.qbus.allow_hotplug = 1;
     vser->bus.vser = vser;
     QTAILQ_INIT(&vser->ports);
@@ -981,7 +992,7 @@ static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
     k->init = virtser_port_qdev_init;
-    k->bus_info = &virtser_bus_info;
+    k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
     k->exit = virtser_port_qdev_exit;
     k->unplug = qdev_simple_unplug_cb;
     k->props = virtser_props;
@@ -998,6 +1009,7 @@ static TypeInfo virtio_serial_port_type_info = {
 
 static void virtio_serial_register_types(void)
 {
+    type_register_static(&virtser_bus_info);
     type_register_static(&virtio_serial_port_type_info);
 }