Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-11-02' into staging

QAPI patches

# gpg: Signature made Mon 02 Nov 2015 09:07:23 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2015-11-02: (25 commits)
  qapi: Simplify gen_struct_field()
  qapi: Reserve 'u' member name
  qapi: Finish converting to new qapi union layout
  tpm: Convert to new qapi union layout
  memory: Convert to new qapi union layout
  input: Convert to new qapi union layout
  char: Convert to new qapi union layout
  net: Convert to new qapi union layout
  sockets: Convert to new qapi union layout
  block: Convert to new qapi union layout
  tests: Convert to new qapi union layout
  qapi-visit: Convert to new qapi union layout
  qapi: Start converting to new qapi union layout
  qapi-visit: Remove redundant functions for flat union base
  qapi: Unbox base members
  qapi: Prefer typesafe upcasts to qapi base classes
  qapi-types: Refactor base fields output
  qapi-visit: Split off visit_type_FOO_fields forward decl
  vnc: Hoist allocation of VncBasicInfo to callers
  qapi: Reserve 'q_*' and 'has_*' member names
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

74 files changed, 663 insertions, 607 deletions

diff --git a/block/nbd.c b/block/nbd.c
index c2a87e9..cd6a587 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -206,24 +206,24 @@ static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, char **export,
     saddr = g_new0(SocketAddress, 1);
 
     if (qdict_haskey(options, "path")) {
-        saddr->kind = SOCKET_ADDRESS_KIND_UNIX;
-        saddr->q_unix = g_new0(UnixSocketAddress, 1);
-        saddr->q_unix->path = g_strdup(qdict_get_str(options, "path"));
+        saddr->type = SOCKET_ADDRESS_KIND_UNIX;
+        saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
+        saddr->u.q_unix->path = g_strdup(qdict_get_str(options, "path"));
         qdict_del(options, "path");
     } else {
-        saddr->kind = SOCKET_ADDRESS_KIND_INET;
-        saddr->inet = g_new0(InetSocketAddress, 1);
-        saddr->inet->host = g_strdup(qdict_get_str(options, "host"));
+        saddr->type = SOCKET_ADDRESS_KIND_INET;
+        saddr->u.inet = g_new0(InetSocketAddress, 1);
+        saddr->u.inet->host = g_strdup(qdict_get_str(options, "host"));
         if (!qdict_get_try_str(options, "port")) {
-            saddr->inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
+            saddr->u.inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
         } else {
-            saddr->inet->port = g_strdup(qdict_get_str(options, "port"));
+            saddr->u.inet->port = g_strdup(qdict_get_str(options, "port"));
         }
         qdict_del(options, "host");
         qdict_del(options, "port");
     }
 
-    s->client.is_unix = saddr->kind == SOCKET_ADDRESS_KIND_UNIX;
+    s->client.is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
 
     *export = g_strdup(qdict_get_try_str(options, "export"));
     if (*export) {
diff --git a/block/qcow2.c b/block/qcow2.c
index bacc4f2..88f56c8 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2738,18 +2738,16 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs)
     ImageInfoSpecific *spec_info = g_new(ImageInfoSpecific, 1);
 
     *spec_info = (ImageInfoSpecific){
-        .kind  = IMAGE_INFO_SPECIFIC_KIND_QCOW2,
-        {
-            .qcow2 = g_new(ImageInfoSpecificQCow2, 1),
-        },
+        .type  = IMAGE_INFO_SPECIFIC_KIND_QCOW2,
+        .u.qcow2 = g_new(ImageInfoSpecificQCow2, 1),
     };
     if (s->qcow_version == 2) {
-        *spec_info->qcow2 = (ImageInfoSpecificQCow2){
+        *spec_info->u.qcow2 = (ImageInfoSpecificQCow2){
             .compat             = g_strdup("0.10"),
             .refcount_bits      = s->refcount_bits,
         };
     } else if (s->qcow_version == 3) {
-        *spec_info->qcow2 = (ImageInfoSpecificQCow2){
+        *spec_info->u.qcow2 = (ImageInfoSpecificQCow2){
             .compat             = g_strdup("1.1"),
             .lazy_refcounts     = s->compatible_features &
                                   QCOW2_COMPAT_LAZY_REFCOUNTS,
diff --git a/block/vmdk.c b/block/vmdk.c
index 0effb7d..6f819e4 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2161,19 +2161,19 @@ static ImageInfoSpecific *vmdk_get_specific_info(BlockDriverState *bs)
     ImageInfoList **next;
 
     *spec_info = (ImageInfoSpecific){
-        .kind = IMAGE_INFO_SPECIFIC_KIND_VMDK,
+        .type = IMAGE_INFO_SPECIFIC_KIND_VMDK,
         {
             .vmdk = g_new0(ImageInfoSpecificVmdk, 1),
         },
     };
 
-    *spec_info->vmdk = (ImageInfoSpecificVmdk) {
+    *spec_info->u.vmdk = (ImageInfoSpecificVmdk) {
         .create_type = g_strdup(s->create_type),
         .cid = s->cid,
         .parent_cid = s->parent_cid,
     };
 
-    next = &spec_info->vmdk->extents;
+    next = &spec_info->u.vmdk->extents;
     for (i = 0; i < s->num_extents; i++) {
         *next = g_new0(ImageInfoList, 1);
         (*next)->value = vmdk_get_extent_info(&s->extents[i]);
diff --git a/blockdev.c b/blockdev.c
index 18712d2..8b8bfa9 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1137,13 +1137,14 @@ void hmp_commit(Monitor *mon, const QDict *qdict)
     }
 }
 
-static void blockdev_do_action(int kind, void *data, Error **errp)
+static void blockdev_do_action(TransactionActionKind type, void *data,
+                               Error **errp)
 {
     TransactionAction action;
     TransactionActionList list;
 
-    action.kind = kind;
-    action.data = data;
+    action.type = type;
+    action.u.data = data;
     list.value = &action;
     list.next = NULL;
     qmp_transaction(&list, errp);
@@ -1388,9 +1389,9 @@ static void internal_snapshot_prepare(BlkTransactionState *common,
     InternalSnapshotState *state;
     int ret1;
 
-    g_assert(common->action->kind ==
+    g_assert(common->action->type ==
              TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC);
-    internal = common->action->blockdev_snapshot_internal_sync;
+    internal = common->action->u.blockdev_snapshot_internal_sync;
     state = DO_UPCAST(InternalSnapshotState, common, common);
 
     /* 1. parse input */
@@ -1536,22 +1537,22 @@ static void external_snapshot_prepare(BlkTransactionState *common,
     TransactionAction *action = common->action;
 
     /* get parameters */
-    g_assert(action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC);
+    g_assert(action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC);
 
-    has_device = action->blockdev_snapshot_sync->has_device;
-    device = action->blockdev_snapshot_sync->device;
-    has_node_name = action->blockdev_snapshot_sync->has_node_name;
-    node_name = action->blockdev_snapshot_sync->node_name;
+    has_device = action->u.blockdev_snapshot_sync->has_device;
+    device = action->u.blockdev_snapshot_sync->device;
+    has_node_name = action->u.blockdev_snapshot_sync->has_node_name;
+    node_name = action->u.blockdev_snapshot_sync->node_name;
     has_snapshot_node_name =
-        action->blockdev_snapshot_sync->has_snapshot_node_name;
-    snapshot_node_name = action->blockdev_snapshot_sync->snapshot_node_name;
+        action->u.blockdev_snapshot_sync->has_snapshot_node_name;
+    snapshot_node_name = action->u.blockdev_snapshot_sync->snapshot_node_name;
 
-    new_image_file = action->blockdev_snapshot_sync->snapshot_file;
-    if (action->blockdev_snapshot_sync->has_format) {
-        format = action->blockdev_snapshot_sync->format;
+    new_image_file = action->u.blockdev_snapshot_sync->snapshot_file;
+    if (action->u.blockdev_snapshot_sync->has_format) {
+        format = action->u.blockdev_snapshot_sync->format;
     }
-    if (action->blockdev_snapshot_sync->has_mode) {
-        mode = action->blockdev_snapshot_sync->mode;
+    if (action->u.blockdev_snapshot_sync->has_mode) {
+        mode = action->u.blockdev_snapshot_sync->mode;
     }
 
     /* start processing */
@@ -1681,8 +1682,8 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
     DriveBackup *backup;
     Error *local_err = NULL;
 
-    assert(common->action->kind == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
-    backup = common->action->drive_backup;
+    assert(common->action->type == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
+    backup = common->action->u.drive_backup;
 
     blk = blk_by_name(backup->device);
     if (!blk) {
@@ -1754,8 +1755,8 @@ static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
     BlockBackend *blk, *target;
     Error *local_err = NULL;
 
-    assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
-    backup = common->action->blockdev_backup;
+    assert(common->action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
+    backup = common->action->u.blockdev_backup;
 
     blk = blk_by_name(backup->device);
     if (!blk) {
@@ -1887,9 +1888,9 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
         dev_info = dev_entry->value;
         dev_entry = dev_entry->next;
 
-        assert(dev_info->kind < ARRAY_SIZE(actions));
+        assert(dev_info->type < ARRAY_SIZE(actions));
 
-        ops = &actions[dev_info->kind];
+        ops = &actions[dev_info->type];
         assert(ops->instance_size > 0);
 
         state = g_malloc0(ops->instance_size);
diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index 2afab20..4d8c2fc 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -106,12 +106,15 @@ Types, commands, and events share a common namespace.  Therefore,
 generally speaking, type definitions should always use CamelCase for
 user-defined type names, while built-in types are lowercase. Type
 definitions should not end in 'Kind', as this namespace is used for
-creating implicit C enums for visiting union types.  Command names,
+creating implicit C enums for visiting union types, or in 'List', as
+this namespace is used for creating array types.  Command names,
 and field names within a type, should be all lower case with words
 separated by a hyphen.  However, some existing older commands and
 complex types use underscore; when extending such expressions,
 consistency is preferred over blindly avoiding underscore.  Event
-names should be ALL_CAPS with words separated by underscore.
+names should be ALL_CAPS with words separated by underscore.  Field
+names cannot start with 'has-' or 'has_', as this is reserved for
+tracking optional fields.
 
 Any name (command, event, type, field, or enum value) beginning with
 "x-" is marked experimental, and may be withdrawn or changed
@@ -122,9 +125,10 @@ vendor), even if the rest of the name uses dash (example:
 __com.redhat_drive-mirror).  Other than downstream extensions (with
 leading underscore and the use of dots), all names should begin with a
 letter, and contain only ASCII letters, digits, dash, and underscore.
-It is okay to reuse names that match C keywords; the generator will
-rename a field named "default" in the QAPI to "q_default" in the
-generated C code.
+Names beginning with 'q_' are reserved for the generator: QMP names
+that resemble C keywords or other problematic strings will be munged
+in C to use this prefix.  For example, a field named "default" in
+qapi becomes "q_default" in the generated C code.
 
 In the rest of this document, usage lines are given for each
 expression type, with literal strings written in lower case and
diff --git a/hmp.c b/hmp.c
index 5048eee..a15d00c 100644
--- a/hmp.c
+++ b/hmp.c
@@ -569,8 +569,8 @@ void hmp_info_vnc(Monitor *mon, const QDict *qdict)
         for (client = info->clients; client; client = client->next) {
             monitor_printf(mon, "Client:\n");
             monitor_printf(mon, "     address: %s:%s\n",
-                           client->value->base->host,
-                           client->value->base->service);
+                           client->value->host,
+                           client->value->service);
             monitor_printf(mon, "  x509_dname: %s\n",
                            client->value->x509_dname ?
                            client->value->x509_dname : "none");
@@ -638,7 +638,7 @@ void hmp_info_spice(Monitor *mon, const QDict *qdict)
         for (chan = info->channels; chan; chan = chan->next) {
             monitor_printf(mon, "Channel:\n");
             monitor_printf(mon, "     address: %s:%s%s\n",
-                           chan->value->base->host, chan->value->base->port,
+                           chan->value->host, chan->value->port,
                            chan->value->tls ? " [tls]" : "");
             monitor_printf(mon, "     session: %" PRId64 "\n",
                            chan->value->connection_id);
@@ -841,11 +841,11 @@ void hmp_info_tpm(Monitor *mon, const QDict *qdict)
                        c, TpmModel_lookup[ti->model]);
 
         monitor_printf(mon, "  \\ %s: type=%s",
-                       ti->id, TpmTypeOptionsKind_lookup[ti->options->kind]);
+                       ti->id, TpmTypeOptionsKind_lookup[ti->options->type]);
 
-        switch (ti->options->kind) {
+        switch (ti->options->type) {
         case TPM_TYPE_OPTIONS_KIND_PASSTHROUGH:
-            tpo = ti->options->passthrough;
+            tpo = ti->options->u.passthrough;
             monitor_printf(mon, "%s%s%s%s",
                            tpo->has_path ? ",path=" : "",
                            tpo->has_path ? tpo->path : "",
@@ -1735,15 +1735,15 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict)
             if (*endp != '\0') {
                 goto err_out;
             }
-            keylist->value->kind = KEY_VALUE_KIND_NUMBER;
-            keylist->value->number = value;
+            keylist->value->type = KEY_VALUE_KIND_NUMBER;
+            keylist->value->u.number = value;
         } else {
             int idx = index_from_key(keyname_buf);
             if (idx == Q_KEY_CODE_MAX) {
                 goto err_out;
             }
-            keylist->value->kind = KEY_VALUE_KIND_QCODE;
-            keylist->value->qcode = idx;
+            keylist->value->type = KEY_VALUE_KIND_QCODE;
+            keylist->value->u.qcode = idx;
         }
 
         if (!separator) {
@@ -1958,12 +1958,12 @@ void hmp_info_memory_devices(Monitor *mon, const QDict *qdict)
         value = info->value;
 
         if (value) {
-            switch (value->kind) {
+            switch (value->type) {
             case MEMORY_DEVICE_INFO_KIND_DIMM:
-                di = value->dimm;
+                di = value->u.dimm;
 
                 monitor_printf(mon, "Memory device [%s]: \"%s\"\n",
-                               MemoryDeviceInfoKind_lookup[value->kind],
+                               MemoryDeviceInfoKind_lookup[value->type],
                                di->id ? di->id : "");
                 monitor_printf(mon, "  addr: 0x%" PRIx64 "\n", di->addr);
                 monitor_printf(mon, "  slot: %" PRId64 "\n", di->slot);
diff --git a/hw/char/escc.c b/hw/char/escc.c
index 9816154..c9840e1 100644
--- a/hw/char/escc.c
+++ b/hw/char/escc.c
@@ -842,13 +842,13 @@ static void sunkbd_handle_event(DeviceState *dev, QemuConsole *src,
     ChannelState *s = (ChannelState *)dev;
     int qcode, keycode;
 
-    assert(evt->kind == INPUT_EVENT_KIND_KEY);
-    qcode = qemu_input_key_value_to_qcode(evt->key->key);
+    assert(evt->type == INPUT_EVENT_KIND_KEY);
+    qcode = qemu_input_key_value_to_qcode(evt->u.key->key);
     trace_escc_sunkbd_event_in(qcode, QKeyCode_lookup[qcode],
-                               evt->key->down);
+                               evt->u.key->down);
 
     if (qcode == Q_KEY_CODE_CAPS_LOCK) {
-        if (evt->key->down) {
+        if (evt->u.key->down) {
             s->caps_lock_mode ^= 1;
             if (s->caps_lock_mode == 2) {
                 return; /* Drop second press */
@@ -862,7 +862,7 @@ static void sunkbd_handle_event(DeviceState *dev, QemuConsole *src,
     }
 
     if (qcode == Q_KEY_CODE_NUM_LOCK) {
-        if (evt->key->down) {
+        if (evt->u.key->down) {
             s->num_lock_mode ^= 1;
             if (s->num_lock_mode == 2) {
                 return; /* Drop second press */
@@ -876,7 +876,7 @@ static void sunkbd_handle_event(DeviceState *dev, QemuConsole *src,
     }
 
     keycode = qcode_to_keycode[qcode];
-    if (!evt->key->down) {
+    if (!evt->u.key->down) {
         keycode |= 0x80;
     }
     trace_escc_sunkbd_event_out(keycode);
diff --git a/hw/input/hid.c b/hw/input/hid.c
index 21ebd9e..e39269f 100644
--- a/hw/input/hid.c
+++ b/hw/input/hid.c
@@ -119,33 +119,33 @@ static void hid_pointer_event(DeviceState *dev, QemuConsole *src,
     assert(hs->n < QUEUE_LENGTH);
     e = &hs->ptr.queue[(hs->head + hs->n) & QUEUE_MASK];
 
-    switch (evt->kind) {
+    switch (evt->type) {
     case INPUT_EVENT_KIND_REL:
-        if (evt->rel->axis == INPUT_AXIS_X) {
-            e->xdx += evt->rel->value;
-        } else if (evt->rel->axis == INPUT_AXIS_Y) {
-            e->ydy += evt->rel->value;
+        if (evt->u.rel->axis == INPUT_AXIS_X) {
+            e->xdx += evt->u.rel->value;
+        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
+            e->ydy += evt->u.rel->value;
         }
         break;
 
     case INPUT_EVENT_KIND_ABS:
-        if (evt->rel->axis == INPUT_AXIS_X) {
-            e->xdx = evt->rel->value;
-        } else if (evt->rel->axis == INPUT_AXIS_Y) {
-            e->ydy = evt->rel->value;
+        if (evt->u.rel->axis == INPUT_AXIS_X) {
+            e->xdx = evt->u.rel->value;
+        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
+            e->ydy = evt->u.rel->value;
         }
         break;
 
     case INPUT_EVENT_KIND_BTN:
-        if (evt->btn->down) {
-            e->buttons_state |= bmap[evt->btn->button];
-            if (evt->btn->button == INPUT_BUTTON_WHEEL_UP) {
+        if (evt->u.btn->down) {
+            e->buttons_state |= bmap[evt->u.btn->button];
+            if (evt->u.btn->button == INPUT_BUTTON_WHEEL_UP) {
                 e->dz--;
-            } else if (evt->btn->button == INPUT_BUTTON_WHEEL_DOWN) {
+            } else if (evt->u.btn->button == INPUT_BUTTON_WHEEL_DOWN) {
                 e->dz++;
             }
         } else {
-            e->buttons_state &= ~bmap[evt->btn->button];
+            e->buttons_state &= ~bmap[evt->u.btn->button];
         }
         break;
 
@@ -223,8 +223,8 @@ static void hid_keyboard_event(DeviceState *dev, QemuConsole *src,
     int scancodes[3], i, count;
     int slot;
 
-    count = qemu_input_key_value_to_scancode(evt->key->key,
-                                             evt->key->down,
+    count = qemu_input_key_value_to_scancode(evt->u.key->key,
+                                             evt->u.key->down,
                                              scancodes);
     if (hs->n + count > QUEUE_LENGTH) {
         fprintf(stderr, "usb-kbd: warning: key event queue full\n");
diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index fdbe565..3d6d496 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -183,8 +183,8 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src,
     int scancodes[3], i, count;
 
     qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
-    count = qemu_input_key_value_to_scancode(evt->key->key,
-                                             evt->key->down,
+    count = qemu_input_key_value_to_scancode(evt->u.key->key,
+                                             evt->u.key->down,
                                              scancodes);
     for (i = 0; i < count; i++) {
         ps2_put_keycode(s, scancodes[i]);
@@ -393,25 +393,25 @@ static void ps2_mouse_event(DeviceState *dev, QemuConsole *src,
     if (!(s->mouse_status & MOUSE_STATUS_ENABLED))
         return;
 
-    switch (evt->kind) {
+    switch (evt->type) {
     case INPUT_EVENT_KIND_REL:
-        if (evt->rel->axis == INPUT_AXIS_X) {
-            s->mouse_dx += evt->rel->value;
-        } else if (evt->rel->axis == INPUT_AXIS_Y) {
-            s->mouse_dy -= evt->rel->value;
+        if (evt->u.rel->axis == INPUT_AXIS_X) {
+            s->mouse_dx += evt->u.rel->value;
+        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
+            s->mouse_dy -= evt->u.rel->value;
         }
         break;
 
     case INPUT_EVENT_KIND_BTN:
-        if (evt->btn->down) {
-            s->mouse_buttons |= bmap[evt->btn->button];
-            if (evt->btn->button == INPUT_BUTTON_WHEEL_UP) {
+        if (evt->u.btn->down) {
+            s->mouse_buttons |= bmap[evt->u.btn->button];
+            if (evt->u.btn->button == INPUT_BUTTON_WHEEL_UP) {
                 s->mouse_dz--;
-            } else if (evt->btn->button == INPUT_BUTTON_WHEEL_DOWN) {
+            } else if (evt->u.btn->button == INPUT_BUTTON_WHEEL_DOWN) {
                 s->mouse_dz++;
             }
         } else {
-            s->mouse_buttons &= ~bmap[evt->btn->button];
+            s->mouse_buttons &= ~bmap[evt->u.btn->button];
         }
         break;
 
diff --git a/hw/input/virtio-input-hid.c b/hw/input/virtio-input-hid.c
index 4d85dad..bdd479c 100644
--- a/hw/input/virtio-input-hid.c
+++ b/hw/input/virtio-input-hid.c
@@ -191,44 +191,45 @@ static void virtio_input_handle_event(DeviceState *dev, QemuConsole *src,
     virtio_input_event event;
     int qcode;
 
-    switch (evt->kind) {
+    switch (evt->type) {
     case INPUT_EVENT_KIND_KEY:
-        qcode = qemu_input_key_value_to_qcode(evt->key->key);
+        qcode = qemu_input_key_value_to_qcode(evt->u.key->key);
         if (qcode && keymap_qcode[qcode]) {
             event.type  = cpu_to_le16(EV_KEY);
             event.code  = cpu_to_le16(keymap_qcode[qcode]);
-            event.value = cpu_to_le32(evt->key->down ? 1 : 0);
+            event.value = cpu_to_le32(evt->u.key->down ? 1 : 0);
             virtio_input_send(vinput, &event);
         } else {
-            if (evt->key->down) {
+            if (evt->u.key->down) {
                 fprintf(stderr, "%s: unmapped key: %d [%s]\n", __func__,
                         qcode, QKeyCode_lookup[qcode]);
             }
         }
         break;
     case INPUT_EVENT_KIND_BTN:
-        if (keymap_button[evt->btn->button]) {
+        if (keymap_button[evt->u.btn->button]) {
             event.type  = cpu_to_le16(EV_KEY);
-            event.code  = cpu_to_le16(keymap_button[evt->btn->button]);
-            event.value = cpu_to_le32(evt->btn->down ? 1 : 0);
+            event.code  = cpu_to_le16(keymap_button[evt->u.btn->button]);
+            event.value = cpu_to_le32(evt->u.btn->down ? 1 : 0);
             virtio_input_send(vinput, &event);
         } else {
-            if (evt->btn->down) {
+            if (evt->u.btn->down) {
                 fprintf(stderr, "%s: unmapped button: %d [%s]\n", __func__,
-                        evt->btn->button, InputButton_lookup[evt->btn->button]);
+                        evt->u.btn->button,
+                        InputButton_lookup[evt->u.btn->button]);
             }
         }
         break;
     case INPUT_EVENT_KIND_REL:
         event.type  = cpu_to_le16(EV_REL);
-        event.code  = cpu_to_le16(axismap_rel[evt->rel->axis]);
-        event.value = cpu_to_le32(evt->rel->value);
+        event.code  = cpu_to_le16(axismap_rel[evt->u.rel->axis]);
+        event.value = cpu_to_le32(evt->u.rel->value);
         virtio_input_send(vinput, &event);
         break;
     case INPUT_EVENT_KIND_ABS:
         event.type  = cpu_to_le16(EV_ABS);
-        event.code  = cpu_to_le16(axismap_abs[evt->abs->axis]);
-        event.value = cpu_to_le32(evt->abs->value);
+        event.code  = cpu_to_le16(axismap_abs[evt->u.abs->axis]);
+        event.value = cpu_to_le32(evt->u.abs->value);
         virtio_input_send(vinput, &event);
         break;
     default:
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 80f424b..d5cdab2 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -179,7 +179,7 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
                                                NULL);
             di->memdev = object_get_canonical_path(OBJECT(dimm->hostmem));
 
-            info->dimm = di;
+            info->u.dimm = di;
             elem->value = info;
             elem->next = NULL;
             **prev = elem;
@@ -203,9 +203,9 @@ ram_addr_t get_current_ram_size(void)
         MemoryDeviceInfo *value = info->value;
 
         if (value) {
-            switch (value->kind) {
+            switch (value->type) {
             case MEMORY_DEVICE_INFO_KIND_DIMM:
-                size += value->dimm->size;
+                size += value->u.dimm->size;
                 break;
             default:
                 break;
diff --git a/net/dump.c b/net/dump.c
index dd0555f..ce16a4b 100644
--- a/net/dump.c
+++ b/net/dump.c
@@ -187,8 +187,8 @@ int net_init_dump(const NetClientOptions *opts, const char *name,
     NetClientState *nc;
     DumpNetClient *dnc;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_DUMP);
-    dump = opts->dump;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_DUMP);
+    dump = opts->u.dump;
 
     assert(peer);
 
diff --git a/net/hub.c b/net/hub.c
index 3047f12..9ae9f01 100644
--- a/net/hub.c
+++ b/net/hub.c
@@ -285,9 +285,9 @@ int net_init_hubport(const NetClientOptions *opts, const char *name,
 {
     const NetdevHubPortOptions *hubport;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_HUBPORT);
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_HUBPORT);
     assert(!peer);
-    hubport = opts->hubport;
+    hubport = opts->u.hubport;
 
     net_hub_add_port(hubport->hubid, name);
     return 0;
diff --git a/net/l2tpv3.c b/net/l2tpv3.c
index 4f9bcee..8e68e54 100644
--- a/net/l2tpv3.c
+++ b/net/l2tpv3.c
@@ -545,8 +545,8 @@ int net_init_l2tpv3(const NetClientOptions *opts,
     s->queue_tail = 0;
     s->header_mismatch = false;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_L2TPV3);
-    l2tpv3 = opts->l2tpv3;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_L2TPV3);
+    l2tpv3 = opts->u.l2tpv3;
 
     if (l2tpv3->has_ipv6 && l2tpv3->ipv6) {
         s->ipv6 = l2tpv3->ipv6;
diff --git a/net/net.c b/net/net.c
index a3e9d1a..ade6051 100644
--- a/net/net.c
+++ b/net/net.c
@@ -882,8 +882,8 @@ static int net_init_nic(const NetClientOptions *opts, const char *name,
     NICInfo *nd;
     const NetLegacyNicOptions *nic;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_NIC);
-    nic = opts->nic;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_NIC);
+    nic = opts->u.nic;
 
     idx = nic_get_free_idx();
     if (idx == -1 || nb_nics >= MAX_NICS) {
@@ -984,9 +984,9 @@ static int net_client_init1(const void *object, int is_netdev, Error **errp)
         opts = netdev->opts;
         name = netdev->id;
 
-        if (opts->kind == NET_CLIENT_OPTIONS_KIND_DUMP ||
-            opts->kind == NET_CLIENT_OPTIONS_KIND_NIC ||
-            !net_client_init_fun[opts->kind]) {
+        if (opts->type == NET_CLIENT_OPTIONS_KIND_DUMP ||
+            opts->type == NET_CLIENT_OPTIONS_KIND_NIC ||
+            !net_client_init_fun[opts->type]) {
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
                        "a netdev backend type");
             return -1;
@@ -997,16 +997,16 @@ static int net_client_init1(const void *object, int is_netdev, Error **errp)
         /* missing optional values have been initialized to "all bits zero" */
         name = net->has_id ? net->id : net->name;
 
-        if (opts->kind == NET_CLIENT_OPTIONS_KIND_NONE) {
+        if (opts->type == NET_CLIENT_OPTIONS_KIND_NONE) {
             return 0; /* nothing to do */
         }
-        if (opts->kind == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
+        if (opts->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
                        "a net type");
             return -1;
         }
 
-        if (!net_client_init_fun[opts->kind]) {
+        if (!net_client_init_fun[opts->type]) {
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
                        "a net backend type (maybe it is not compiled "
                        "into this binary)");
@@ -1014,17 +1014,17 @@ static int net_client_init1(const void *object, int is_netdev, Error **errp)
         }
 
         /* Do not add to a vlan if it's a nic with a netdev= parameter. */
-        if (opts->kind != NET_CLIENT_OPTIONS_KIND_NIC ||
-            !opts->nic->has_netdev) {
+        if (opts->type != NET_CLIENT_OPTIONS_KIND_NIC ||
+            !opts->u.nic->has_netdev) {
             peer = net_hub_add_port(net->has_vlan ? net->vlan : 0, NULL);
         }
     }
 
-    if (net_client_init_fun[opts->kind](opts, name, peer, errp) < 0) {
+    if (net_client_init_fun[opts->type](opts, name, peer, errp) < 0) {
         /* FIXME drop when all init functions store an Error */
         if (errp && !*errp) {
             error_setg(errp, QERR_DEVICE_INIT_FAILED,
-                       NetClientOptionsKind_lookup[opts->kind]);
+                       NetClientOptionsKind_lookup[opts->type]);
         }
         return -1;
     }
diff --git a/net/slirp.c b/net/slirp.c
index 7657b38f..f505570 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -746,8 +746,8 @@ int net_init_slirp(const NetClientOptions *opts, const char *name,
     const NetdevUserOptions *user;
     const char **dnssearch;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_USER);
-    user = opts->user;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_USER);
+    user = opts->u.user;
 
     vnet = user->has_net ? g_strdup(user->net) :
            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
diff --git a/net/socket.c b/net/socket.c
index b1e3b1c..e8605d4 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -706,8 +706,8 @@ int net_init_socket(const NetClientOptions *opts, const char *name,
     Error *err = NULL;
     const NetdevSocketOptions *sock;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_SOCKET);
-    sock = opts->socket;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_SOCKET);
+    sock = opts->u.socket;
 
     if (sock->has_fd + sock->has_listen + sock->has_connect + sock->has_mcast +
         sock->has_udp != 1) {
diff --git a/net/tap-win32.c b/net/tap-win32.c
index 625d53c..4e2fa55 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -767,8 +767,8 @@ int net_init_tap(const NetClientOptions *opts, const char *name,
     /* FIXME error_setg(errp, ...) on failure */
     const NetdevTapOptions *tap;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_TAP);
-    tap = opts->tap;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    tap = opts->u.tap;
 
     if (!tap->has_ifname) {
         error_report("tap: no interface name");
diff --git a/net/tap.c b/net/tap.c
index bd01590..85c4142 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -565,8 +565,8 @@ int net_init_bridge(const NetClientOptions *opts, const char *name,
     TAPState *s;
     int fd, vnet_hdr;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_BRIDGE);
-    bridge = opts->bridge;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_BRIDGE);
+    bridge = opts->u.bridge;
 
     helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER;
     br     = bridge->has_br     ? bridge->br     : DEFAULT_BRIDGE_INTERFACE;
@@ -728,8 +728,8 @@ int net_init_tap(const NetClientOptions *opts, const char *name,
     const char *vhostfdname;
     char ifname[128];
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_TAP);
-    tap = opts->tap;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    tap = opts->u.tap;
     queues = tap->has_queues ? tap->queues : 1;
     vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
 
diff --git a/net/vde.c b/net/vde.c
index dacaa64..4475d92 100644
--- a/net/vde.c
+++ b/net/vde.c
@@ -115,8 +115,8 @@ int net_init_vde(const NetClientOptions *opts, const char *name,
     /* FIXME error_setg(errp, ...) on failure */
     const NetdevVdeOptions *vde;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VDE);
-    vde = opts->vde;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_VDE);
+    vde = opts->u.vde;
 
     /* missing optional values have been initialized to "all bits zero" */
     if (net_vde_init(peer, "vde", name, vde->sock, vde->port, vde->group,
diff --git a/net/vhost-user.c b/net/vhost-user.c
index 17b5c2a..0ebd7df 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -301,8 +301,8 @@ int net_init_vhost_user(const NetClientOptions *opts, const char *name,
     const NetdevVhostUserOptions *vhost_user_opts;
     CharDriverState *chr;
 
-    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
-    vhost_user_opts = opts->vhost_user;
+    assert(opts->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
+    vhost_user_opts = opts->u.vhost_user;
 
     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
     if (!chr) {
diff --git a/numa.c b/numa.c
index e9b18f5..fdfe294 100644
--- a/numa.c
+++ b/numa.c
@@ -226,9 +226,9 @@ static int parse_numa(void *opaque, QemuOpts *opts, Error **errp)
         goto error;
     }
 
-    switch (object->kind) {
+    switch (object->type) {
     case NUMA_OPTIONS_KIND_NODE:
-        numa_node_parse(object->node, opts, &err);
+        numa_node_parse(object->u.node, opts, &err);
         if (err) {
             goto error;
         }
@@ -487,9 +487,9 @@ static void numa_stat_memory_devices(uint64_t node_mem[])
         MemoryDeviceInfo *value = info->value;
 
         if (value) {
-            switch (value->kind) {
+            switch (value->type) {
             case MEMORY_DEVICE_INFO_KIND_DIMM:
-                node_mem[value->dimm->node] += value->dimm->size;
+                node_mem[value->u.dimm->node] += value->u.dimm->size;
                 break;
             default:
                 break;
diff --git a/qapi-schema.json b/qapi-schema.json
index f60be29..702b7b5 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2614,9 +2614,7 @@
 #
 # @host: host part of the address
 #
-# @port: port part of the address, or lowest port if @to is present.
-#        Kernel selects a free port if omitted for listener addresses.
-#        #optional
+# @port: port part of the address, or lowest port if @to is present
 #
 # @to: highest port to try
 #
@@ -2631,7 +2629,7 @@
 { 'struct': 'InetSocketAddress',
   'data': {
     'host': 'str',
-    '*port': 'str',
+    'port': 'str',
     '*to': 'uint16',
     '*ipv4': 'bool',
     '*ipv6': 'bool' } }
diff --git a/qemu-char.c b/qemu-char.c
index c4eb4ee..5448b0f 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -97,18 +97,18 @@ static int SocketAddress_to_str(char *dest, int max_len,
                                 const char *prefix, SocketAddress *addr,
                                 bool is_listen, bool is_telnet)
 {
-    switch (addr->kind) {
+    switch (addr->type) {
     case SOCKET_ADDRESS_KIND_INET:
         return snprintf(dest, max_len, "%s%s:%s:%s%s", prefix,
-                        is_telnet ? "telnet" : "tcp", addr->inet->host,
-                        addr->inet->port, is_listen ? ",server" : "");
+                        is_telnet ? "telnet" : "tcp", addr->u.inet->host,
+                        addr->u.inet->port, is_listen ? ",server" : "");
         break;
     case SOCKET_ADDRESS_KIND_UNIX:
         return snprintf(dest, max_len, "%sunix:%s%s", prefix,
-                        addr->q_unix->path, is_listen ? ",server" : "");
+                        addr->u.q_unix->path, is_listen ? ",server" : "");
         break;
     case SOCKET_ADDRESS_KIND_FD:
-        return snprintf(dest, max_len, "%sfd:%s%s", prefix, addr->fd->str,
+        return snprintf(dest, max_len, "%sfd:%s%s", prefix, addr->u.fd->str,
                         is_listen ? ",server" : "");
         break;
     default:
@@ -661,7 +661,7 @@ static CharDriverState *qemu_chr_open_mux(const char *id,
                                           ChardevBackend *backend,
                                           ChardevReturn *ret, Error **errp)
 {
-    ChardevMux *mux = backend->mux;
+    ChardevMux *mux = backend->u.mux;
     CharDriverState *chr, *drv;
     MuxDriver *d;
 
@@ -1070,7 +1070,7 @@ static CharDriverState *qemu_chr_open_pipe(const char *id,
                                            ChardevReturn *ret,
                                            Error **errp)
 {
-    ChardevHostdev *opts = backend->pipe;
+    ChardevHostdev *opts = backend->u.pipe;
     int fd_in, fd_out;
     char filename_in[CHR_MAX_FILENAME_SIZE];
     char filename_out[CHR_MAX_FILENAME_SIZE];
@@ -1148,7 +1148,7 @@ static CharDriverState *qemu_chr_open_stdio(const char *id,
                                             ChardevReturn *ret,
                                             Error **errp)
 {
-    ChardevStdio *opts = backend->stdio;
+    ChardevStdio *opts = backend->u.stdio;
     CharDriverState *chr;
     struct sigaction act;
 
@@ -2147,7 +2147,7 @@ static CharDriverState *qemu_chr_open_pipe(const char *id,
                                            ChardevReturn *ret,
                                            Error **errp)
 {
-    ChardevHostdev *opts = backend->pipe;
+    ChardevHostdev *opts = backend->u.pipe;
     const char *filename = opts->device;
     CharDriverState *chr;
     WinCharState *s;
@@ -3202,7 +3202,7 @@ static CharDriverState *qemu_chr_open_ringbuf(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevRingbuf *opts = backend->ringbuf;
+    ChardevRingbuf *opts = backend->u.ringbuf;
     CharDriverState *chr;
     RingBufCharDriver *d;
 
@@ -3477,16 +3477,16 @@ static void qemu_chr_parse_file_out(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: file: no filename given");
         return;
     }
-    backend->file = g_new0(ChardevFile, 1);
-    backend->file->out = g_strdup(path);
+    backend->u.file = g_new0(ChardevFile, 1);
+    backend->u.file->out = g_strdup(path);
 }
 
 static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
                                  Error **errp)
 {
-    backend->stdio = g_new0(ChardevStdio, 1);
-    backend->stdio->has_signal = true;
-    backend->stdio->signal = qemu_opt_get_bool(opts, "signal", true);
+    backend->u.stdio = g_new0(ChardevStdio, 1);
+    backend->u.stdio->has_signal = true;
+    backend->u.stdio->signal = qemu_opt_get_bool(opts, "signal", true);
 }
 
 #ifdef HAVE_CHARDEV_SERIAL
@@ -3499,8 +3499,8 @@ static void qemu_chr_parse_serial(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: serial/tty: no device path given");
         return;
     }
-    backend->serial = g_new0(ChardevHostdev, 1);
-    backend->serial->device = g_strdup(device);
+    backend->u.serial = g_new0(ChardevHostdev, 1);
+    backend->u.serial->device = g_strdup(device);
 }
 #endif
 
@@ -3514,8 +3514,8 @@ static void qemu_chr_parse_parallel(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: parallel: no device path given");
         return;
     }
-    backend->parallel = g_new0(ChardevHostdev, 1);
-    backend->parallel->device = g_strdup(device);
+    backend->u.parallel = g_new0(ChardevHostdev, 1);
+    backend->u.parallel->device = g_strdup(device);
 }
 #endif
 
@@ -3528,8 +3528,8 @@ static void qemu_chr_parse_pipe(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: pipe: no device path given");
         return;
     }
-    backend->pipe = g_new0(ChardevHostdev, 1);
-    backend->pipe->device = g_strdup(device);
+    backend->u.pipe = g_new0(ChardevHostdev, 1);
+    backend->u.pipe->device = g_strdup(device);
 }
 
 static void qemu_chr_parse_ringbuf(QemuOpts *opts, ChardevBackend *backend,
@@ -3537,12 +3537,12 @@ static void qemu_chr_parse_ringbuf(QemuOpts *opts, ChardevBackend *backend,
 {
     int val;
 
-    backend->ringbuf = g_new0(ChardevRingbuf, 1);
+    backend->u.ringbuf = g_new0(ChardevRingbuf, 1);
 
     val = qemu_opt_get_size(opts, "size", 0);
     if (val != 0) {
-        backend->ringbuf->has_size = true;
-        backend->ringbuf->size = val;
+        backend->u.ringbuf->has_size = true;
+        backend->u.ringbuf->size = val;
     }
 }
 
@@ -3555,8 +3555,8 @@ static void qemu_chr_parse_mux(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: mux: no chardev given");
         return;
     }
-    backend->mux = g_new0(ChardevMux, 1);
-    backend->mux->chardev = g_strdup(chardev);
+    backend->u.mux = g_new0(ChardevMux, 1);
+    backend->u.mux->chardev = g_strdup(chardev);
 }
 
 static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
@@ -3583,37 +3583,37 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
         }
     }
 
-    backend->socket = g_new0(ChardevSocket, 1);
+    backend->u.socket = g_new0(ChardevSocket, 1);
 
-    backend->socket->has_nodelay = true;
-    backend->socket->nodelay = do_nodelay;
-    backend->socket->has_server = true;
-    backend->socket->server = is_listen;
-    backend->socket->has_telnet = true;
-    backend->socket->telnet = is_telnet;
-    backend->socket->has_wait = true;
-    backend->socket->wait = is_waitconnect;
-    backend->socket->has_reconnect = true;
-    backend->socket->reconnect = reconnect;
+    backend->u.socket->has_nodelay = true;
+    backend->u.socket->nodelay = do_nodelay;
+    backend->u.socket->has_server = true;
+    backend->u.socket->server = is_listen;
+    backend->u.socket->has_telnet = true;
+    backend->u.socket->telnet = is_telnet;
+    backend->u.socket->has_wait = true;
+    backend->u.socket->wait = is_waitconnect;
+    backend->u.socket->has_reconnect = true;
+    backend->u.socket->reconnect = reconnect;
 
     addr = g_new0(SocketAddress, 1);
     if (path) {
-        addr->kind = SOCKET_ADDRESS_KIND_UNIX;
-        addr->q_unix = g_new0(UnixSocketAddress, 1);
-        addr->q_unix->path = g_strdup(path);
+        addr->type = SOCKET_ADDRESS_KIND_UNIX;
+        addr->u.q_unix = g_new0(UnixSocketAddress, 1);
+        addr->u.q_unix->path = g_strdup(path);
     } else {
-        addr->kind = SOCKET_ADDRESS_KIND_INET;
-        addr->inet = g_new0(InetSocketAddress, 1);
-        addr->inet->host = g_strdup(host);
-        addr->inet->port = g_strdup(port);
-        addr->inet->has_to = qemu_opt_get(opts, "to");
-        addr->inet->to = qemu_opt_get_number(opts, "to", 0);
-        addr->inet->has_ipv4 = qemu_opt_get(opts, "ipv4");
-        addr->inet->ipv4 = qemu_opt_get_bool(opts, "ipv4", 0);
-        addr->inet->has_ipv6 = qemu_opt_get(opts, "ipv6");
-        addr->inet->ipv6 = qemu_opt_get_bool(opts, "ipv6", 0);
+        addr->type = SOCKET_ADDRESS_KIND_INET;
+        addr->u.inet = g_new0(InetSocketAddress, 1);
+        addr->u.inet->host = g_strdup(host);
+        addr->u.inet->port = g_strdup(port);
+        addr->u.inet->has_to = qemu_opt_get(opts, "to");
+        addr->u.inet->to = qemu_opt_get_number(opts, "to", 0);
+        addr->u.inet->has_ipv4 = qemu_opt_get(opts, "ipv4");
+        addr->u.inet->ipv4 = qemu_opt_get_bool(opts, "ipv4", 0);
+        addr->u.inet->has_ipv6 = qemu_opt_get(opts, "ipv6");
+        addr->u.inet->ipv6 = qemu_opt_get_bool(opts, "ipv6", 0);
     }
-    backend->socket->addr = addr;
+    backend->u.socket->addr = addr;
 }
 
 static void qemu_chr_parse_udp(QemuOpts *opts, ChardevBackend *backend,
@@ -3644,27 +3644,27 @@ static void qemu_chr_parse_udp(QemuOpts *opts, ChardevBackend *backend,
         has_local = true;
     }
 
-    backend->udp = g_new0(ChardevUdp, 1);
+    backend->u.udp = g_new0(ChardevUdp, 1);
 
     addr = g_new0(SocketAddress, 1);
-    addr->kind = SOCKET_ADDRESS_KIND_INET;
-    addr->inet = g_new0(InetSocketAddress, 1);
-    addr->inet->host = g_strdup(host);
-    addr->inet->port = g_strdup(port);
-    addr->inet->has_ipv4 = qemu_opt_get(opts, "ipv4");
-    addr->inet->ipv4 = qemu_opt_get_bool(opts, "ipv4", 0);
-    addr->inet->has_ipv6 = qemu_opt_get(opts, "ipv6");
-    addr->inet->ipv6 = qemu_opt_get_bool(opts, "ipv6", 0);
-    backend->udp->remote = addr;
+    addr->type = SOCKET_ADDRESS_KIND_INET;
+    addr->u.inet = g_new0(InetSocketAddress, 1);
+    addr->u.inet->host = g_strdup(host);
+    addr->u.inet->port = g_strdup(port);
+    addr->u.inet->has_ipv4 = qemu_opt_get(opts, "ipv4");
+    addr->u.inet->ipv4 = qemu_opt_get_bool(opts, "ipv4", 0);
+    addr->u.inet->has_ipv6 = qemu_opt_get(opts, "ipv6");
+    addr->u.inet->ipv6 = qemu_opt_get_bool(opts, "ipv6", 0);
+    backend->u.udp->remote = addr;
 
     if (has_local) {
-        backend->udp->has_local = true;
+        backend->u.udp->has_local = true;
         addr = g_new0(SocketAddress, 1);
-        addr->kind = SOCKET_ADDRESS_KIND_INET;
-        addr->inet = g_new0(InetSocketAddress, 1);
-        addr->inet->host = g_strdup(localaddr);
-        addr->inet->port = g_strdup(localport);
-        backend->udp->local = addr;
+        addr->type = SOCKET_ADDRESS_KIND_INET;
+        addr->u.inet = g_new0(InetSocketAddress, 1);
+        addr->u.inet->host = g_strdup(localaddr);
+        addr->u.inet->port = g_strdup(localport);
+        backend->u.udp->local = addr;
     }
 }
 
@@ -3737,7 +3737,7 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
     }
 
     chr = NULL;
-    backend->kind = cd->kind;
+    backend->type = cd->kind;
     if (cd->parse) {
         cd->parse(opts, backend, &local_err);
         if (local_err) {
@@ -3754,9 +3754,9 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
         qapi_free_ChardevBackend(backend);
         qapi_free_ChardevReturn(ret);
         backend = g_new0(ChardevBackend, 1);
-        backend->mux = g_new0(ChardevMux, 1);
-        backend->kind = CHARDEV_BACKEND_KIND_MUX;
-        backend->mux->chardev = g_strdup(bid);
+        backend->u.mux = g_new0(ChardevMux, 1);
+        backend->type = CHARDEV_BACKEND_KIND_MUX;
+        backend->u.mux->chardev = g_strdup(bid);
         ret = qmp_chardev_add(id, backend, errp);
         if (!ret) {
             chr = qemu_chr_find(bid);
@@ -4048,7 +4048,7 @@ static CharDriverState *qmp_chardev_open_file(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevFile *file = backend->file;
+    ChardevFile *file = backend->u.file;
     HANDLE out;
 
     if (file->has_in) {
@@ -4070,7 +4070,7 @@ static CharDriverState *qmp_chardev_open_serial(const char *id,
                                                 ChardevReturn *ret,
                                                 Error **errp)
 {
-    ChardevHostdev *serial = backend->serial;
+    ChardevHostdev *serial = backend->u.serial;
     return qemu_chr_open_win_path(serial->device, errp);
 }
 
@@ -4093,7 +4093,7 @@ static CharDriverState *qmp_chardev_open_file(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevFile *file = backend->file;
+    ChardevFile *file = backend->u.file;
     int flags, in = -1, out;
 
     flags = O_WRONLY | O_TRUNC | O_CREAT | O_BINARY;
@@ -4120,7 +4120,7 @@ static CharDriverState *qmp_chardev_open_serial(const char *id,
                                                 ChardevReturn *ret,
                                                 Error **errp)
 {
-    ChardevHostdev *serial = backend->serial;
+    ChardevHostdev *serial = backend->u.serial;
     int fd;
 
     fd = qmp_chardev_open_file_source(serial->device, O_RDWR, errp);
@@ -4138,7 +4138,7 @@ static CharDriverState *qmp_chardev_open_parallel(const char *id,
                                                   ChardevReturn *ret,
                                                   Error **errp)
 {
-    ChardevHostdev *parallel = backend->parallel;
+    ChardevHostdev *parallel = backend->u.parallel;
     int fd;
 
     fd = qmp_chardev_open_file_source(parallel->device, O_RDWR, errp);
@@ -4183,7 +4183,7 @@ static CharDriverState *qmp_chardev_open_socket(const char *id,
 {
     CharDriverState *chr;
     TCPCharDriver *s;
-    ChardevSocket *sock = backend->socket;
+    ChardevSocket *sock = backend->u.socket;
     SocketAddress *addr = sock->addr;
     bool do_nodelay     = sock->has_nodelay ? sock->nodelay : false;
     bool is_listen      = sock->has_server  ? sock->server  : true;
@@ -4196,7 +4196,7 @@ static CharDriverState *qmp_chardev_open_socket(const char *id,
 
     s->fd = -1;
     s->listen_fd = -1;
-    s->is_unix = addr->kind == SOCKET_ADDRESS_KIND_UNIX;
+    s->is_unix = addr->type == SOCKET_ADDRESS_KIND_UNIX;
     s->is_listen = is_listen;
     s->is_telnet = is_telnet;
     s->do_nodelay = do_nodelay;
@@ -4250,7 +4250,7 @@ static CharDriverState *qmp_chardev_open_udp(const char *id,
                                              ChardevReturn *ret,
                                              Error **errp)
 {
-    ChardevUdp *udp = backend->udp;
+    ChardevUdp *udp = backend->u.udp;
     int fd;
 
     fd = socket_dgram(udp->remote, udp->local, errp);
@@ -4279,7 +4279,7 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
     for (i = backends; i; i = i->next) {
         cd = i->data;
 
-        if (cd->kind == backend->kind) {
+        if (cd->kind == backend->type) {
             chr = cd->create(id, backend, ret, &local_err);
             if (local_err) {
                 error_propagate(errp, local_err);
@@ -4297,9 +4297,9 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
 
     chr->label = g_strdup(id);
     chr->avail_connections =
-        (backend->kind == CHARDEV_BACKEND_KIND_MUX) ? MAX_MUX : 1;
+        (backend->type == CHARDEV_BACKEND_KIND_MUX) ? MAX_MUX : 1;
     if (!chr->filename) {
-        chr->filename = g_strdup(ChardevBackendKind_lookup[backend->kind]);
+        chr->filename = g_strdup(ChardevBackendKind_lookup[backend->type]);
     }
     if (!chr->explicit_be_open) {
         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 422a607..3afec76 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -362,17 +362,17 @@ static SocketAddress *nbd_build_socket_address(const char *sockpath,
 
     saddr = g_new0(SocketAddress, 1);
     if (sockpath) {
-        saddr->kind = SOCKET_ADDRESS_KIND_UNIX;
-        saddr->q_unix = g_new0(UnixSocketAddress, 1);
-        saddr->q_unix->path = g_strdup(sockpath);
+        saddr->type = SOCKET_ADDRESS_KIND_UNIX;
+        saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
+        saddr->u.q_unix->path = g_strdup(sockpath);
     } else {
-        saddr->kind = SOCKET_ADDRESS_KIND_INET;
-        saddr->inet = g_new0(InetSocketAddress, 1);
-        saddr->inet->host = g_strdup(bindto);
+        saddr->type = SOCKET_ADDRESS_KIND_INET;
+        saddr->u.inet = g_new0(InetSocketAddress, 1);
+        saddr->u.inet->host = g_strdup(bindto);
         if (port) {
-            saddr->inet->port = g_strdup(port);
+            saddr->u.inet->port = g_strdup(port);
         } else  {
-            saddr->inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
+            saddr->u.inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
         }
     }
 
diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 43a893b..561e47a 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -175,7 +175,9 @@ def gen_marshal(name, arg_type, ret_type):
     ret += gen_marshal_input_visit(arg_type)
     ret += gen_call(name, arg_type, ret_type)
 
-    if re.search('^ *goto out;', ret, re.MULTILINE):
+    # 'goto out' produced by gen_marshal_input_visit->gen_visit_fields()
+    # for each arg_type member, and by gen_call() for ret_type
+    if (arg_type and arg_type.members) or ret_type:
         ret += mcgen('''
 
 out:
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index 4fe618e..b37900f 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -36,26 +36,37 @@ struct %(c_name)s {
                  c_name=c_name(name), c_type=element_type.c_type())
 
 
-def gen_struct_field(name, typ, optional):
+def gen_struct_field(member):
     ret = ''
 
-    if optional:
+    if member.optional:
         ret += mcgen('''
     bool has_%(c_name)s;
 ''',
-                     c_name=c_name(name))
+                     c_name=c_name(member.name))
     ret += mcgen('''
     %(c_type)s %(c_name)s;
 ''',
-                 c_type=typ.c_type(), c_name=c_name(name))
+                 c_type=member.type.c_type(), c_name=c_name(member.name))
     return ret
 
 
-def gen_struct_fields(members):
+def gen_struct_fields(local_members, base=None):
     ret = ''
 
-    for memb in members:
-        ret += gen_struct_field(memb.name, memb.type, memb.optional)
+    if base:
+        ret += mcgen('''
+    /* Members inherited from %(c_name)s: */
+''',
+                     c_name=base.c_name())
+        for memb in base.members:
+            ret += gen_struct_field(memb)
+        ret += mcgen('''
+    /* Own members: */
+''')
+
+    for memb in local_members:
+        ret += gen_struct_field(memb)
     return ret
 
 
@@ -66,16 +77,13 @@ struct %(c_name)s {
 ''',
                 c_name=c_name(name))
 
-    if base:
-        ret += gen_struct_field('base', base, False)
-
-    ret += gen_struct_fields(members)
+    ret += gen_struct_fields(members, base)
 
     # Make sure that all structs have at least one field; this avoids
     # potential issues with attempting to malloc space for zero-length
     # structs in C, and also incompatibility with C++ (where an empty
     # struct is size 1).
-    if not base and not members:
+    if not (base and base.members) and not members:
         ret += mcgen('''
     char qapi_dummy_field_for_empty_struct;
 ''')
@@ -87,6 +95,19 @@ struct %(c_name)s {
     return ret
 
 
+def gen_upcast(name, base):
+    # C makes const-correctness ugly.  We have to cast away const to let
+    # this function work for both const and non-const obj.
+    return mcgen('''
+
+static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
+{
+    return (%(base)s *)obj;
+}
+''',
+                 c_name=c_name(name), base=base.c_name())
+
+
 def gen_alternate_qtypes_decl(name):
     return mcgen('''
 
@@ -126,19 +147,9 @@ struct %(c_name)s {
 ''',
                 c_name=c_name(name))
     if base:
-        ret += mcgen('''
-    /* Members inherited from %(c_name)s: */
-''',
-                     c_name=c_name(base.name))
-        ret += gen_struct_fields(base.members)
-        ret += mcgen('''
-    /* Own members: */
-''')
+        ret += gen_struct_fields([], base)
     else:
-        ret += mcgen('''
-    %(c_type)s kind;
-''',
-                     c_type=c_name(variants.tag_member.type.name))
+        ret += gen_struct_field(variants.tag_member)
 
     # FIXME: What purpose does data serve, besides preventing a union that
     # has a branch named 'data'? We use it in qapi-visit.py to decide
@@ -152,10 +163,7 @@ struct %(c_name)s {
     union { /* union tag is @%(c_name)s */
         void *data;
 ''',
-                 # TODO ugly special case for simple union
-                 # Use same tag name in C as on the wire to get rid of
-                 # it, then: c_name=c_name(variants.tag_member.name)
-                 c_name=c_name(variants.tag_name or 'kind'))
+                 c_name=c_name(variants.tag_member.name))
 
     for var in variants.variants:
         # Ugly special case for simple union TODO get rid of it
@@ -167,7 +175,7 @@ struct %(c_name)s {
                      c_name=c_name(var.name))
 
     ret += mcgen('''
-    };
+    } u;
 };
 ''')
 
@@ -265,6 +273,8 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
             self.decl += gen_union(name, base, variants)
         else:
             self.decl += gen_struct(name, base, members)
+        if base:
+            self.decl += gen_upcast(name, base)
         self._gen_type_cleanup(name)
 
     def visit_alternate_type(self, name, info, variants):
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index d0759d7..f40c3c7 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -15,7 +15,12 @@
 from qapi import *
 import re
 
+# visit_type_FOO_implicit() is emitted as needed; track if it has already
+# been output.
 implicit_structs_seen = set()
+
+# visit_type_FOO_fields() is always emitted; track if a forward declaration
+# or implementation has already been output.
 struct_fields_seen = set()
 
 
@@ -29,19 +34,24 @@ void visit_type_%(c_name)s(Visitor *v, %(c_type)sobj, const char *name, Error **
                  c_name=c_name(name), c_type=c_type)
 
 
-def gen_visit_implicit_struct(typ):
-    if typ in implicit_structs_seen:
-        return ''
-    implicit_structs_seen.add(typ)
-
+def gen_visit_fields_decl(typ):
     ret = ''
     if typ.name not in struct_fields_seen:
-        # Need a forward declaration
         ret += mcgen('''
 
 static void visit_type_%(c_type)s_fields(Visitor *v, %(c_type)s **obj, Error **errp);
 ''',
                      c_type=typ.c_name())
+        struct_fields_seen.add(typ.name)
+    return ret
+
+
+def gen_visit_implicit_struct(typ):
+    if typ in implicit_structs_seen:
+        return ''
+    implicit_structs_seen.add(typ)
+
+    ret = gen_visit_fields_decl(typ)
 
     ret += mcgen('''
 
@@ -62,13 +72,12 @@ static void visit_type_implicit_%(c_type)s(Visitor *v, %(c_type)s **obj, Error *
 
 
 def gen_visit_struct_fields(name, base, members):
-    struct_fields_seen.add(name)
-
     ret = ''
 
     if base:
-        ret += gen_visit_implicit_struct(base)
+        ret += gen_visit_fields_decl(base)
 
+    struct_fields_seen.add(name)
     ret += mcgen('''
 
 static void visit_type_%(c_name)s_fields(Visitor *v, %(c_name)s **obj, Error **errp)
@@ -80,14 +89,15 @@ static void visit_type_%(c_name)s_fields(Visitor *v, %(c_name)s **obj, Error **e
 
     if base:
         ret += mcgen('''
-    visit_type_implicit_%(c_type)s(v, &(*obj)->%(c_name)s, &err);
+    visit_type_%(c_type)s_fields(v, (%(c_type)s **)obj, &err);
 ''',
-                     c_type=base.c_name(), c_name=c_name('base'))
+                     c_type=base.c_name())
         ret += gen_err_check()
 
     ret += gen_visit_fields(members, prefix='(*obj)->')
 
-    if re.search('^ *goto out;', ret, re.MULTILINE):
+    # 'goto out' produced for base, and by gen_visit_fields() for each member
+    if base or members:
         ret += mcgen('''
 
 out:
@@ -179,18 +189,18 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
     if (err) {
         goto out;
     }
-    visit_get_next_type(v, (int*) &(*obj)->kind, %(c_name)s_qtypes, name, &err);
+    visit_get_next_type(v, (int*) &(*obj)->type, %(c_name)s_qtypes, name, &err);
     if (err) {
         goto out_obj;
     }
-    switch ((*obj)->kind) {
+    switch ((*obj)->type) {
 ''',
                 c_name=c_name(name))
 
     for var in variants.variants:
         ret += mcgen('''
     case %(case)s:
-        visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, name, &err);
+        visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, name, &err);
         break;
 ''',
                      case=c_enum_const(variants.tag_member.type.name,
@@ -218,8 +228,7 @@ def gen_visit_union(name, base, variants):
     ret = ''
 
     if base:
-        members = [m for m in base.members if m != variants.tag_member]
-        ret += gen_visit_struct_fields(name, None, members)
+        ret += gen_visit_fields_decl(base)
 
     for var in variants.variants:
         # Ugly special case for simple union TODO get rid of it
@@ -244,31 +253,24 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
 
     if base:
         ret += mcgen('''
-    visit_type_%(c_name)s_fields(v, obj, &err);
+    visit_type_%(c_name)s_fields(v, (%(c_name)s **)obj, &err);
 ''',
-                     c_name=c_name(name))
-        ret += gen_err_check(label='out_obj')
-
-    tag_key = variants.tag_member.name
-    if not variants.tag_name:
-        # we pointlessly use a different key for simple unions
-        tag_key = 'type'
-    ret += mcgen('''
+                     c_name=base.c_name())
+    else:
+        ret += mcgen('''
     visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, "%(name)s", &err);
-    if (err) {
-        goto out_obj;
-    }
-    if (!visit_start_union(v, !!(*obj)->data, &err) || err) {
+''',
+                     c_type=variants.tag_member.type.c_name(),
+                     c_name=c_name(variants.tag_member.name),
+                     name=variants.tag_member.name)
+    ret += gen_err_check(label='out_obj')
+    ret += mcgen('''
+    if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
         goto out_obj;
     }
     switch ((*obj)->%(c_name)s) {
 ''',
-                 c_type=variants.tag_member.type.c_name(),
-                 # TODO ugly special case for simple union
-                 # Use same tag name in C as on the wire to get rid of
-                 # it, then: c_name=c_name(variants.tag_member.name)
-                 c_name=c_name(variants.tag_name or 'kind'),
-                 name=tag_key)
+                 c_name=c_name(variants.tag_member.name))
 
     for var in variants.variants:
         # TODO ugly special case for simple union
@@ -280,13 +282,13 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
                                        var.name))
         if simple_union_type:
             ret += mcgen('''
-        visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, "data", &err);
+        visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, "data", &err);
 ''',
                          c_type=simple_union_type.c_name(),
                          c_name=c_name(var.name))
         else:
             ret += mcgen('''
-        visit_type_implicit_%(c_type)s(v, &(*obj)->%(c_name)s, &err);
+        visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err);
 ''',
                          c_type=var.type.c_name(),
                          c_name=c_name(var.name))
@@ -302,7 +304,7 @@ out_obj:
     error_propagate(errp, err);
     err = NULL;
     if (*obj) {
-        visit_end_union(v, !!(*obj)->data, &err);
+        visit_end_union(v, !!(*obj)->u.data, &err);
     }
     error_propagate(errp, err);
     err = NULL;
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 9d53255..7c50cc4 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -172,7 +172,7 @@ class QAPISchemaParser(object):
 
             if self.tok == '#':
                 self.cursor = self.src.find('\n', self.cursor)
-            elif self.tok in ['{', '}', ':', ',', '[', ']']:
+            elif self.tok in "{}:,[]":
                 return
             elif self.tok == "'":
                 string = ''
@@ -376,7 +376,9 @@ def check_name(expr_info, source, name, allow_optional=False,
     # code always prefixes it with the enum name
     if enum_member:
         membername = '_' + membername
-    if not valid_name.match(membername):
+    # Reserve the entire 'q_' namespace for c_name()
+    if not valid_name.match(membername) or \
+       c_name(membername, False).startswith('q_'):
         raise QAPIExprError(expr_info,
                             "%s uses invalid name '%s'" % (source, name))
 
@@ -390,10 +392,10 @@ def add_name(name, info, meta, implicit=False):
         raise QAPIExprError(info,
                             "%s '%s' is already defined"
                             % (all_names[name], name))
-    if not implicit and name[-4:] == 'Kind':
+    if not implicit and (name.endswith('Kind') or name.endswith('List')):
         raise QAPIExprError(info,
-                            "%s '%s' should not end in 'Kind'"
-                            % (meta, name))
+                            "%s '%s' should not end in '%s'"
+                            % (meta, name, name[-4:]))
     all_names[name] = meta
 
 
@@ -488,6 +490,10 @@ def check_type(expr_info, source, value, allow_array=False,
     for (key, arg) in value.items():
         check_name(expr_info, "Member of %s" % source, key,
                    allow_optional=allow_optional)
+        if c_name(key, False) == 'u' or c_name(key, False).startswith('has_'):
+            raise QAPIExprError(expr_info,
+                                "Member of %s uses reserved name '%s'"
+                                % (source, key))
         # Todo: allow dictionaries to represent default values of
         # an optional argument.
         check_type(expr_info, "Member '%s' of %s" % (key, source), arg,
@@ -542,7 +548,8 @@ def check_union(expr, expr_info):
     base = expr.get('base')
     discriminator = expr.get('discriminator')
     members = expr['data']
-    values = {'MAX': '(automatic)', 'KIND': '(automatic)'}
+    values = {'MAX': '(automatic)', 'KIND': '(automatic)',
+              'TYPE': '(automatic)'}
 
     # Two types of unions, determined by discriminator.
 
@@ -910,7 +917,7 @@ class QAPISchemaEnumType(QAPISchemaType):
 
     def is_implicit(self):
         # See QAPISchema._make_implicit_enum_type()
-        return self.name[-4:] == 'Kind'
+        return self.name.endswith('Kind')
 
     def c_type(self, is_param=False):
         return c_name(self.name)
@@ -1196,9 +1203,7 @@ class QAPISchema(object):
         return name
 
     def _make_array_type(self, element_type, info):
-        # TODO fooList namespace is not reserved; user can create collisions,
-        # or abuse our type system with ['fooList'] for 2D array
-        name = element_type + 'List'
+        name = element_type + 'List'   # Use namespace reserved by add_name()
         if not self.lookup_type(name):
             self._def_entity(QAPISchemaArrayType(name, info, element_type))
         return name
diff --git a/spice-qemu-char.c b/spice-qemu-char.c
index a20fb5c..e70e0f7 100644
--- a/spice-qemu-char.c
+++ b/spice-qemu-char.c
@@ -301,7 +301,7 @@ static CharDriverState *qemu_chr_open_spice_vmc(const char *id,
                                                 ChardevReturn *ret,
                                                 Error **errp)
 {
-    const char *type = backend->spicevmc->type;
+    const char *type = backend->u.spicevmc->type;
     const char **psubtype = spice_server_char_device_recognized_subtypes();
 
     for (; *psubtype != NULL; ++psubtype) {
@@ -324,7 +324,7 @@ static CharDriverState *qemu_chr_open_spice_port(const char *id,
                                                  ChardevReturn *ret,
                                                  Error **errp)
 {
-    const char *name = backend->spiceport->fqdn;
+    const char *name = backend->u.spiceport->fqdn;
     CharDriverState *chr;
     SpiceCharDriver *s;
 
@@ -362,8 +362,8 @@ static void qemu_chr_parse_spice_vmc(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: spice channel: no name given");
         return;
     }
-    backend->spicevmc = g_new0(ChardevSpiceChannel, 1);
-    backend->spicevmc->type = g_strdup(name);
+    backend->u.spicevmc = g_new0(ChardevSpiceChannel, 1);
+    backend->u.spicevmc->type = g_strdup(name);
 }
 
 static void qemu_chr_parse_spice_port(QemuOpts *opts, ChardevBackend *backend,
@@ -375,8 +375,8 @@ static void qemu_chr_parse_spice_port(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: spice port: no name given");
         return;
     }
-    backend->spiceport = g_new0(ChardevSpicePort, 1);
-    backend->spiceport->fqdn = g_strdup(name);
+    backend->u.spiceport = g_new0(ChardevSpicePort, 1);
+    backend->u.spiceport->fqdn = g_strdup(name);
 }
 
 static void register_types(void)
diff --git a/tests/Makefile b/tests/Makefile
index 0739bfe..92969e8 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -265,7 +265,6 @@ qapi-schema += enum-dict-member.json
 qapi-schema += enum-int-member.json
 qapi-schema += enum-max-member.json
 qapi-schema += enum-missing-data.json
-qapi-schema += enum-union-clash.json
 qapi-schema += enum-wrong-data.json
 qapi-schema += escape-outside-string.json
 qapi-schema += escape-too-big.json
@@ -316,12 +315,17 @@ qapi-schema += redefined-builtin.json
 qapi-schema += redefined-command.json
 qapi-schema += redefined-event.json
 qapi-schema += redefined-type.json
+qapi-schema += reserved-command-q.json
+qapi-schema += reserved-member-has.json
+qapi-schema += reserved-member-q.json
+qapi-schema += reserved-member-u.json
+qapi-schema += reserved-type-kind.json
+qapi-schema += reserved-type-list.json
 qapi-schema += returns-alternate.json
 qapi-schema += returns-array-bad.json
 qapi-schema += returns-dict.json
 qapi-schema += returns-unknown.json
 qapi-schema += returns-whitelist.json
-qapi-schema += struct-base-clash-base.json
 qapi-schema += struct-base-clash-deep.json
 qapi-schema += struct-base-clash.json
 qapi-schema += struct-data-invalid.json
diff --git a/tests/qapi-schema/enum-union-clash.err b/tests/qapi-schema/enum-union-clash.err
deleted file mode 100644
index c04e1a8..0000000
--- a/tests/qapi-schema/enum-union-clash.err
+++ /dev/null
@@ -1 +0,0 @@
-tests/qapi-schema/enum-union-clash.json:2: enum 'UnionKind' should not end in 'Kind'
diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json
index 4e2d7c2..48e104b 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -11,6 +11,10 @@
 # An empty enum, although unusual, is currently acceptable
 { 'enum': 'MyEnum', 'data': [ ] }
 
+# Likewise for an empty struct, including an empty base
+{ 'struct': 'Empty1', 'data': { } }
+{ 'struct': 'Empty2', 'base': 'Empty1', 'data': { } }
+
 # for testing override of default naming heuristic
 { 'enum': 'QEnumTwo',
   'prefix': 'QENUM_TWO',
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index a6c80e0..a7e9aab 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -81,6 +81,9 @@ event EVENT_A None
 event EVENT_B None
 event EVENT_C :obj-EVENT_C-arg
 event EVENT_D :obj-EVENT_D-arg
+object Empty1
+object Empty2
+    base Empty1
 enum EnumOne ['value1', 'value2', 'value3']
 object EventStructOne
     member struct1: UserDefOne optional=False
diff --git a/tests/qapi-schema/reserved-command-q.err b/tests/qapi-schema/reserved-command-q.err
new file mode 100644
index 0000000..f939e04
--- /dev/null
+++ b/tests/qapi-schema/reserved-command-q.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-command-q.json:5: 'command' uses invalid name 'q-unix'
diff --git a/tests/qapi-schema/enum-union-clash.exit b/tests/qapi-schema/reserved-command-q.exit
index d00491f..d00491f 100644
--- a/tests/qapi-schema/enum-union-clash.exit
+++ b/tests/qapi-schema/reserved-command-q.exit
diff --git a/tests/qapi-schema/reserved-command-q.json b/tests/qapi-schema/reserved-command-q.json
new file mode 100644
index 0000000..99f8aae
--- /dev/null
+++ b/tests/qapi-schema/reserved-command-q.json
@@ -0,0 +1,5 @@
+# C entity name collision
+# We reject names like 'q-unix', because they can collide with the mangled
+# name for 'unix' in generated C.
+{ 'command': 'unix' }
+{ 'command': 'q-unix' }
diff --git a/tests/qapi-schema/enum-union-clash.out b/tests/qapi-schema/reserved-command-q.out
index e69de29..e69de29 100644
--- a/tests/qapi-schema/enum-union-clash.out
+++ b/tests/qapi-schema/reserved-command-q.out
diff --git a/tests/qapi-schema/reserved-member-has.err b/tests/qapi-schema/reserved-member-has.err
new file mode 100644
index 0000000..e755771
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-has.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-member-has.json:5: Member of 'data' for command 'oops' uses reserved name 'has-a'
diff --git a/tests/qapi-schema/reserved-member-has.exit b/tests/qapi-schema/reserved-member-has.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-has.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/reserved-member-has.json b/tests/qapi-schema/reserved-member-has.json
new file mode 100644
index 0000000..45b9109
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-has.json
@@ -0,0 +1,5 @@
+# C member name collision
+# We reject names like 'has-a', because they can collide with the flag
+# for an optional 'a' in generated C.
+# TODO we could munge the optional flag name to avoid the collision.
+{ 'command': 'oops', 'data': { '*a': 'str', 'has-a': 'str' } }
diff --git a/tests/qapi-schema/struct-base-clash-base.err b/tests/qapi-schema/reserved-member-has.out
index e69de29..e69de29 100644
--- a/tests/qapi-schema/struct-base-clash-base.err
+++ b/tests/qapi-schema/reserved-member-has.out
diff --git a/tests/qapi-schema/reserved-member-q.err b/tests/qapi-schema/reserved-member-q.err
new file mode 100644
index 0000000..f3d5dd7
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-q.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-member-q.json:4: Member of 'data' for struct 'Foo' uses invalid name 'q-unix'
diff --git a/tests/qapi-schema/reserved-member-q.exit b/tests/qapi-schema/reserved-member-q.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-q.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/reserved-member-q.json b/tests/qapi-schema/reserved-member-q.json
new file mode 100644
index 0000000..62fed8f
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-q.json
@@ -0,0 +1,4 @@
+# C member name collision
+# We reject names like 'q-unix', because they can collide with the mangled
+# name for 'unix' in generated C.
+{ 'struct': 'Foo', 'data': { 'unix':'int', 'q-unix':'bool' } }
diff --git a/tests/qapi-schema/reserved-member-q.out b/tests/qapi-schema/reserved-member-q.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-q.out
diff --git a/tests/qapi-schema/reserved-member-u.err b/tests/qapi-schema/reserved-member-u.err
new file mode 100644
index 0000000..87d4229
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-u.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-member-u.json:7: Member of 'data' for struct 'Oops' uses reserved name 'u'
diff --git a/tests/qapi-schema/reserved-member-u.exit b/tests/qapi-schema/reserved-member-u.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-u.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/reserved-member-u.json b/tests/qapi-schema/reserved-member-u.json
new file mode 100644
index 0000000..1eaf0f3
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-u.json
@@ -0,0 +1,7 @@
+# Potential C member name collision
+# We reject use of 'u' as a member name, to allow it for internal use in
+# putting union branch members in a separate namespace from QMP members.
+# This is true even for non-unions, because it is possible to convert a
+# struct to flat union while remaining backwards compatible in QMP.
+# TODO - we could munge the member name to 'q_u' to avoid the collision
+{ 'struct': 'Oops', 'data': { 'u': 'str' } }
diff --git a/tests/qapi-schema/reserved-member-u.out b/tests/qapi-schema/reserved-member-u.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-u.out
diff --git a/tests/qapi-schema/reserved-type-kind.err b/tests/qapi-schema/reserved-type-kind.err
new file mode 100644
index 0000000..0a38efa
--- /dev/null
+++ b/tests/qapi-schema/reserved-type-kind.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-type-kind.json:2: enum 'UnionKind' should not end in 'Kind'
diff --git a/tests/qapi-schema/reserved-type-kind.exit b/tests/qapi-schema/reserved-type-kind.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/tests/qapi-schema/reserved-type-kind.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/enum-union-clash.json b/tests/qapi-schema/reserved-type-kind.json
index 593282b..9ecaba1 100644
--- a/tests/qapi-schema/enum-union-clash.json
+++ b/tests/qapi-schema/reserved-type-kind.json
@@ -1,4 +1,2 @@
 # we reject types that would conflict with implicit union enum
 { 'enum': 'UnionKind', 'data': [ 'oops' ] }
-{ 'union': 'Union',
-  'data': { 'a': 'int' } }
diff --git a/tests/qapi-schema/reserved-type-kind.out b/tests/qapi-schema/reserved-type-kind.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/qapi-schema/reserved-type-kind.out
diff --git a/tests/qapi-schema/reserved-type-list.err b/tests/qapi-schema/reserved-type-list.err
new file mode 100644
index 0000000..4510fa6
--- /dev/null
+++ b/tests/qapi-schema/reserved-type-list.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-type-list.json:5: struct 'FooList' should not end in 'List'
diff --git a/tests/qapi-schema/reserved-type-list.exit b/tests/qapi-schema/reserved-type-list.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/tests/qapi-schema/reserved-type-list.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/reserved-type-list.json b/tests/qapi-schema/reserved-type-list.json
new file mode 100644
index 0000000..98d53bf
--- /dev/null
+++ b/tests/qapi-schema/reserved-type-list.json
@@ -0,0 +1,5 @@
+# Potential C name collision
+# We reserve names ending in 'List' for use by array types.
+# TODO - we could choose array names to avoid collision with user types,
+# in order to let this compile
+{ 'struct': 'FooList', 'data': { 's': 'str' } }
diff --git a/tests/qapi-schema/reserved-type-list.out b/tests/qapi-schema/reserved-type-list.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/qapi-schema/reserved-type-list.out
diff --git a/tests/qapi-schema/struct-base-clash-base.exit b/tests/qapi-schema/struct-base-clash-base.exit
deleted file mode 100644
index 573541a..0000000
--- a/tests/qapi-schema/struct-base-clash-base.exit
+++ /dev/null
@@ -1 +0,0 @@
-0
diff --git a/tests/qapi-schema/struct-base-clash-base.json b/tests/qapi-schema/struct-base-clash-base.json
deleted file mode 100644
index 0c84025..0000000
--- a/tests/qapi-schema/struct-base-clash-base.json
+++ /dev/null
@@ -1,9 +0,0 @@
-# Struct member 'base'
-# FIXME: this parses, but then fails to compile due to a duplicate 'base'
-# (one explicit in QMP, the other used to box the base class members).
-# We should either reject the collision at parse time, or change the
-# generated struct to allow this to compile.
-{ 'struct': 'Base', 'data': {} }
-{ 'struct': 'Sub',
-  'base': 'Base',
-  'data': { 'base': 'str' } }
diff --git a/tests/qapi-schema/struct-base-clash-base.out b/tests/qapi-schema/struct-base-clash-base.out
deleted file mode 100644
index e69a416..0000000
--- a/tests/qapi-schema/struct-base-clash-base.out
+++ /dev/null
@@ -1,5 +0,0 @@
-object :empty
-object Base
-object Sub
-    base Base
-    member base: str optional=False
diff --git a/tests/test-qmp-commands.c b/tests/test-qmp-commands.c
index bc59835..f23d8ea 100644
--- a/tests/test-qmp-commands.c
+++ b/tests/test-qmp-commands.c
@@ -25,11 +25,9 @@ UserDefTwo *qmp_user_def_cmd2(UserDefOne *ud1a,
     UserDefOne *ud1d = g_malloc0(sizeof(UserDefOne));
 
     ud1c->string = strdup(ud1a->string);
-    ud1c->base = g_new0(UserDefZero, 1);
-    ud1c->base->integer = ud1a->base->integer;
+    ud1c->integer = ud1a->integer;
     ud1d->string = strdup(has_udb1 ? ud1b->string : "blah0");
-    ud1d->base = g_new0(UserDefZero, 1);
-    ud1d->base->integer = has_udb1 ? ud1b->base->integer : 0;
+    ud1d->integer = has_udb1 ? ud1b->integer : 0;
 
     ret = g_new0(UserDefTwo, 1);
     ret->string0 = strdup("blah1");
@@ -64,8 +62,8 @@ __org_qemu_x_Union1 *qmp___org_qemu_x_command(__org_qemu_x_EnumList *a,
 {
     __org_qemu_x_Union1 *ret = g_new0(__org_qemu_x_Union1, 1);
 
-    ret->kind = ORG_QEMU_X_UNION1_KIND___ORG_QEMU_X_BRANCH;
-    ret->__org_qemu_x_branch = strdup("blah1");
+    ret->type = ORG_QEMU_X_UNION1_KIND___ORG_QEMU_X_BRANCH;
+    ret->u.__org_qemu_x_branch = strdup("blah1");
 
     return ret;
 }
@@ -176,20 +174,17 @@ static void test_dealloc_types(void)
     UserDefOneList *ud1list;
 
     ud1test = g_malloc0(sizeof(UserDefOne));
-    ud1test->base = g_new0(UserDefZero, 1);
-    ud1test->base->integer = 42;
+    ud1test->integer = 42;
     ud1test->string = g_strdup("hi there 42");
 
     qapi_free_UserDefOne(ud1test);
 
     ud1a = g_malloc0(sizeof(UserDefOne));
-    ud1a->base = g_new0(UserDefZero, 1);
-    ud1a->base->integer = 43;
+    ud1a->integer = 43;
     ud1a->string = g_strdup("hi there 43");
 
     ud1b = g_malloc0(sizeof(UserDefOne));
-    ud1b->base = g_new0(UserDefZero, 1);
-    ud1b->base->integer = 44;
+    ud1b->integer = 44;
     ud1b->string = g_strdup("hi there 44");
 
     ud1list = g_malloc0(sizeof(UserDefOneList));
diff --git a/tests/test-qmp-event.c b/tests/test-qmp-event.c
index 28f146d..035c65c 100644
--- a/tests/test-qmp-event.c
+++ b/tests/test-qmp-event.c
@@ -179,9 +179,7 @@ static void test_event_c(TestEventData *data,
     QDict *d, *d_data, *d_b;
 
     UserDefOne b;
-    UserDefZero z;
-    z.integer = 2;
-    b.base = &z;
+    b.integer = 2;
     b.string = g_strdup("test1");
     b.has_enum1 = false;
 
@@ -209,11 +207,9 @@ static void test_event_d(TestEventData *data,
 {
     UserDefOne struct1;
     EventStructOne a;
-    UserDefZero z;
     QDict *d, *d_data, *d_a, *d_struct1;
 
-    z.integer = 2;
-    struct1.base = &z;
+    struct1.integer = 2;
     struct1.string = g_strdup("test1");
     struct1.has_enum1 = true;
     struct1.enum1 = ENUM_ONE_VALUE1;
diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c
index 8941963..de65982 100644
--- a/tests/test-qmp-input-visitor.c
+++ b/tests/test-qmp-input-visitor.c
@@ -262,7 +262,7 @@ static void test_visitor_in_struct_nested(TestInputVisitorData *data,
 
     check_and_free_str(udp->string0, "string0");
     check_and_free_str(udp->dict1->string1, "string1");
-    g_assert_cmpint(udp->dict1->dict2->userdef->base->integer, ==, 42);
+    g_assert_cmpint(udp->dict1->dict2->userdef->integer, ==, 42);
     check_and_free_str(udp->dict1->dict2->userdef->string, "string");
     check_and_free_str(udp->dict1->dict2->string, "string2");
     g_assert(udp->dict1->has_dict3 == false);
@@ -292,7 +292,7 @@ static void test_visitor_in_list(TestInputVisitorData *data,
 
         snprintf(string, sizeof(string), "string%d", i);
         g_assert_cmpstr(item->value->string, ==, string);
-        g_assert_cmpint(item->value->base->integer, ==, 42 + i);
+        g_assert_cmpint(item->value->integer, ==, 42 + i);
     }
 
     qapi_free_UserDefOneList(head);
@@ -347,6 +347,7 @@ static void test_visitor_in_union_flat(TestInputVisitorData *data,
     Visitor *v;
     Error *err = NULL;
     UserDefFlatUnion *tmp;
+    UserDefUnionBase *base;
 
     v = visitor_input_test_init(data,
                                 "{ 'enum1': 'value1', "
@@ -359,7 +360,11 @@ static void test_visitor_in_union_flat(TestInputVisitorData *data,
     g_assert_cmpint(tmp->enum1, ==, ENUM_ONE_VALUE1);
     g_assert_cmpstr(tmp->string, ==, "str");
     g_assert_cmpint(tmp->integer, ==, 41);
-    g_assert_cmpint(tmp->value1->boolean, ==, true);
+    g_assert_cmpint(tmp->u.value1->boolean, ==, true);
+
+    base = qapi_UserDefFlatUnion_base(tmp);
+    g_assert(&base->enum1 == &tmp->enum1);
+
     qapi_free_UserDefFlatUnion(tmp);
 }
 
@@ -372,15 +377,15 @@ static void test_visitor_in_alternate(TestInputVisitorData *data,
 
     v = visitor_input_test_init(data, "42");
     visit_type_UserDefAlternate(v, &tmp, NULL, &error_abort);
-    g_assert_cmpint(tmp->kind, ==, USER_DEF_ALTERNATE_KIND_I);
-    g_assert_cmpint(tmp->i, ==, 42);
+    g_assert_cmpint(tmp->type, ==, USER_DEF_ALTERNATE_KIND_I);
+    g_assert_cmpint(tmp->u.i, ==, 42);
     qapi_free_UserDefAlternate(tmp);
     visitor_input_teardown(data, NULL);
 
     v = visitor_input_test_init(data, "'string'");
     visit_type_UserDefAlternate(v, &tmp, NULL, &error_abort);
-    g_assert_cmpint(tmp->kind, ==, USER_DEF_ALTERNATE_KIND_S);
-    g_assert_cmpstr(tmp->s, ==, "string");
+    g_assert_cmpint(tmp->type, ==, USER_DEF_ALTERNATE_KIND_S);
+    g_assert_cmpstr(tmp->u.s, ==, "string");
     qapi_free_UserDefAlternate(tmp);
     visitor_input_teardown(data, NULL);
 
@@ -419,8 +424,8 @@ static void test_visitor_in_alternate_number(TestInputVisitorData *data,
      * parse the same as ans */
     v = visitor_input_test_init(data, "42");
     visit_type_AltStrNum(v, &asn, NULL, &err);
-    /* FIXME g_assert_cmpint(asn->kind, == ALT_STR_NUM_KIND_N); */
-    /* FIXME g_assert_cmpfloat(asn->n, ==, 42); */
+    /* FIXME g_assert_cmpint(asn->type, == ALT_STR_NUM_KIND_N); */
+    /* FIXME g_assert_cmpfloat(asn->u.n, ==, 42); */
     g_assert(err);
     error_free(err);
     err = NULL;
@@ -429,29 +434,29 @@ static void test_visitor_in_alternate_number(TestInputVisitorData *data,
 
     v = visitor_input_test_init(data, "42");
     visit_type_AltNumStr(v, &ans, NULL, &error_abort);
-    g_assert_cmpint(ans->kind, ==, ALT_NUM_STR_KIND_N);
-    g_assert_cmpfloat(ans->n, ==, 42);
+    g_assert_cmpint(ans->type, ==, ALT_NUM_STR_KIND_N);
+    g_assert_cmpfloat(ans->u.n, ==, 42);
     qapi_free_AltNumStr(ans);
     visitor_input_teardown(data, NULL);
 
     v = visitor_input_test_init(data, "42");
     visit_type_AltStrInt(v, &asi, NULL, &error_abort);
-    g_assert_cmpint(asi->kind, ==, ALT_STR_INT_KIND_I);
-    g_assert_cmpint(asi->i, ==, 42);
+    g_assert_cmpint(asi->type, ==, ALT_STR_INT_KIND_I);
+    g_assert_cmpint(asi->u.i, ==, 42);
     qapi_free_AltStrInt(asi);
     visitor_input_teardown(data, NULL);
 
     v = visitor_input_test_init(data, "42");
     visit_type_AltIntNum(v, &ain, NULL, &error_abort);
-    g_assert_cmpint(ain->kind, ==, ALT_INT_NUM_KIND_I);
-    g_assert_cmpint(ain->i, ==, 42);
+    g_assert_cmpint(ain->type, ==, ALT_INT_NUM_KIND_I);
+    g_assert_cmpint(ain->u.i, ==, 42);
     qapi_free_AltIntNum(ain);
     visitor_input_teardown(data, NULL);
 
     v = visitor_input_test_init(data, "42");
     visit_type_AltNumInt(v, &ani, NULL, &error_abort);
-    g_assert_cmpint(ani->kind, ==, ALT_NUM_INT_KIND_I);
-    g_assert_cmpint(ani->i, ==, 42);
+    g_assert_cmpint(ani->type, ==, ALT_NUM_INT_KIND_I);
+    g_assert_cmpint(ani->u.i, ==, 42);
     qapi_free_AltNumInt(ani);
     visitor_input_teardown(data, NULL);
 
@@ -467,15 +472,15 @@ static void test_visitor_in_alternate_number(TestInputVisitorData *data,
 
     v = visitor_input_test_init(data, "42.5");
     visit_type_AltStrNum(v, &asn, NULL, &error_abort);
-    g_assert_cmpint(asn->kind, ==, ALT_STR_NUM_KIND_N);
-    g_assert_cmpfloat(asn->n, ==, 42.5);
+    g_assert_cmpint(asn->type, ==, ALT_STR_NUM_KIND_N);
+    g_assert_cmpfloat(asn->u.n, ==, 42.5);
     qapi_free_AltStrNum(asn);
     visitor_input_teardown(data, NULL);
 
     v = visitor_input_test_init(data, "42.5");
     visit_type_AltNumStr(v, &ans, NULL, &error_abort);
-    g_assert_cmpint(ans->kind, ==, ALT_NUM_STR_KIND_N);
-    g_assert_cmpfloat(ans->n, ==, 42.5);
+    g_assert_cmpint(ans->type, ==, ALT_NUM_STR_KIND_N);
+    g_assert_cmpfloat(ans->u.n, ==, 42.5);
     qapi_free_AltNumStr(ans);
     visitor_input_teardown(data, NULL);
 
@@ -489,15 +494,15 @@ static void test_visitor_in_alternate_number(TestInputVisitorData *data,
 
     v = visitor_input_test_init(data, "42.5");
     visit_type_AltIntNum(v, &ain, NULL, &error_abort);
-    g_assert_cmpint(ain->kind, ==, ALT_INT_NUM_KIND_N);
-    g_assert_cmpfloat(ain->n, ==, 42.5);
+    g_assert_cmpint(ain->type, ==, ALT_INT_NUM_KIND_N);
+    g_assert_cmpfloat(ain->u.n, ==, 42.5);
     qapi_free_AltIntNum(ain);
     visitor_input_teardown(data, NULL);
 
     v = visitor_input_test_init(data, "42.5");
     visit_type_AltNumInt(v, &ani, NULL, &error_abort);
-    g_assert_cmpint(ani->kind, ==, ALT_NUM_INT_KIND_N);
-    g_assert_cmpfloat(ani->n, ==, 42.5);
+    g_assert_cmpint(ani->type, ==, ALT_NUM_INT_KIND_N);
+    g_assert_cmpfloat(ani->u.n, ==, 42.5);
     qapi_free_AltNumInt(ani);
     visitor_input_teardown(data, NULL);
 }
@@ -527,68 +532,68 @@ static void test_native_list_integer_helper(TestInputVisitorData *data,
     visit_type_UserDefNativeListUnion(v, &cvalue, NULL, &err);
     g_assert(err == NULL);
     g_assert(cvalue != NULL);
-    g_assert_cmpint(cvalue->kind, ==, kind);
+    g_assert_cmpint(cvalue->type, ==, kind);
 
     switch (kind) {
     case USER_DEF_NATIVE_LIST_UNION_KIND_INTEGER: {
         intList *elem = NULL;
-        for (i = 0, elem = cvalue->integer; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.integer; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S8: {
         int8List *elem = NULL;
-        for (i = 0, elem = cvalue->s8; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.s8; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S16: {
         int16List *elem = NULL;
-        for (i = 0, elem = cvalue->s16; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.s16; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S32: {
         int32List *elem = NULL;
-        for (i = 0, elem = cvalue->s32; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.s32; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S64: {
         int64List *elem = NULL;
-        for (i = 0, elem = cvalue->s64; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.s64; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U8: {
         uint8List *elem = NULL;
-        for (i = 0, elem = cvalue->u8; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.u8; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U16: {
         uint16List *elem = NULL;
-        for (i = 0, elem = cvalue->u16; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.u16; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U32: {
         uint32List *elem = NULL;
-        for (i = 0, elem = cvalue->u32; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.u32; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U64: {
         uint64List *elem = NULL;
-        for (i = 0, elem = cvalue->u64; elem; elem = elem->next, i++) {
+        for (i = 0, elem = cvalue->u.u64; elem; elem = elem->next, i++) {
             g_assert_cmpint(elem->value, ==, i);
         }
         break;
@@ -690,9 +695,9 @@ static void test_visitor_in_native_list_bool(TestInputVisitorData *data,
     visit_type_UserDefNativeListUnion(v, &cvalue, NULL, &err);
     g_assert(err == NULL);
     g_assert(cvalue != NULL);
-    g_assert_cmpint(cvalue->kind, ==, USER_DEF_NATIVE_LIST_UNION_KIND_BOOLEAN);
+    g_assert_cmpint(cvalue->type, ==, USER_DEF_NATIVE_LIST_UNION_KIND_BOOLEAN);
 
-    for (i = 0, elem = cvalue->boolean; elem; elem = elem->next, i++) {
+    for (i = 0, elem = cvalue->u.boolean; elem; elem = elem->next, i++) {
         g_assert_cmpint(elem->value, ==, (i % 3 == 0) ? 1 : 0);
     }
 
@@ -725,9 +730,9 @@ static void test_visitor_in_native_list_string(TestInputVisitorData *data,
     visit_type_UserDefNativeListUnion(v, &cvalue, NULL, &err);
     g_assert(err == NULL);
     g_assert(cvalue != NULL);
-    g_assert_cmpint(cvalue->kind, ==, USER_DEF_NATIVE_LIST_UNION_KIND_STRING);
+    g_assert_cmpint(cvalue->type, ==, USER_DEF_NATIVE_LIST_UNION_KIND_STRING);
 
-    for (i = 0, elem = cvalue->string; elem; elem = elem->next, i++) {
+    for (i = 0, elem = cvalue->u.string; elem; elem = elem->next, i++) {
         gchar str[8];
         sprintf(str, "%d", i);
         g_assert_cmpstr(elem->value, ==, str);
@@ -764,9 +769,9 @@ static void test_visitor_in_native_list_number(TestInputVisitorData *data,
     visit_type_UserDefNativeListUnion(v, &cvalue, NULL, &err);
     g_assert(err == NULL);
     g_assert(cvalue != NULL);
-    g_assert_cmpint(cvalue->kind, ==, USER_DEF_NATIVE_LIST_UNION_KIND_NUMBER);
+    g_assert_cmpint(cvalue->type, ==, USER_DEF_NATIVE_LIST_UNION_KIND_NUMBER);
 
-    for (i = 0, elem = cvalue->number; elem; elem = elem->next, i++) {
+    for (i = 0, elem = cvalue->u.number; elem; elem = elem->next, i++) {
         GString *double_expected = g_string_new("");
         GString *double_actual = g_string_new("");
 
diff --git a/tests/test-qmp-output-visitor.c b/tests/test-qmp-output-visitor.c
index c84002e..09d0dd8 100644
--- a/tests/test-qmp-output-visitor.c
+++ b/tests/test-qmp-output-visitor.c
@@ -250,16 +250,14 @@ static void test_visitor_out_struct_nested(TestOutputVisitorData *data,
     ud2->dict1->dict2 = g_malloc0(sizeof(*ud2->dict1->dict2));
     ud2->dict1->dict2->userdef = g_new0(UserDefOne, 1);
     ud2->dict1->dict2->userdef->string = g_strdup(string);
-    ud2->dict1->dict2->userdef->base = g_new0(UserDefZero, 1);
-    ud2->dict1->dict2->userdef->base->integer = value;
+    ud2->dict1->dict2->userdef->integer = value;
     ud2->dict1->dict2->string = g_strdup(strings[2]);
 
     ud2->dict1->dict3 = g_malloc0(sizeof(*ud2->dict1->dict3));
     ud2->dict1->has_dict3 = true;
     ud2->dict1->dict3->userdef = g_new0(UserDefOne, 1);
     ud2->dict1->dict3->userdef->string = g_strdup(string);
-    ud2->dict1->dict3->userdef->base = g_new0(UserDefZero, 1);
-    ud2->dict1->dict3->userdef->base->integer = value;
+    ud2->dict1->dict3->userdef->integer = value;
     ud2->dict1->dict3->string = g_strdup(strings[3]);
 
     visit_type_UserDefTwo(data->ov, &ud2, "unused", &err);
@@ -301,8 +299,8 @@ static void test_visitor_out_struct_errors(TestOutputVisitorData *data,
                                            const void *unused)
 {
     EnumOne bad_values[] = { ENUM_ONE_MAX, -1 };
-    UserDefZero b;
-    UserDefOne u = { .base = &b }, *pu = &u;
+    UserDefOne u = {0};
+    UserDefOne *pu = &u;
     Error *err;
     int i;
 
@@ -416,8 +414,7 @@ static void test_visitor_out_list_qapi_free(TestOutputVisitorData *data,
         p->value->dict1->dict2 = g_new0(UserDefTwoDictDict, 1);
         p->value->dict1->dict2->userdef = g_new0(UserDefOne, 1);
         p->value->dict1->dict2->userdef->string = g_strdup(string);
-        p->value->dict1->dict2->userdef->base = g_new0(UserDefZero, 1);
-        p->value->dict1->dict2->userdef->base->integer = 42;
+        p->value->dict1->dict2->userdef->integer = 42;
         p->value->dict1->dict2->string = g_strdup(string);
         p->value->dict1->has_dict3 = false;
 
@@ -490,9 +487,9 @@ static void test_visitor_out_union_flat(TestOutputVisitorData *data,
     UserDefFlatUnion *tmp = g_malloc0(sizeof(UserDefFlatUnion));
     tmp->enum1 = ENUM_ONE_VALUE1;
     tmp->string = g_strdup("str");
-    tmp->value1 = g_malloc0(sizeof(UserDefA));
-    /* TODO when generator bug is fixed: tmp->integer = 41; */
-    tmp->value1->boolean = true;
+    tmp->u.value1 = g_malloc0(sizeof(UserDefA));
+    tmp->integer = 41;
+    tmp->u.value1->boolean = true;
 
     visit_type_UserDefFlatUnion(data->ov, &tmp, NULL, &err);
     g_assert(err == NULL);
@@ -503,7 +500,7 @@ static void test_visitor_out_union_flat(TestOutputVisitorData *data,
 
     g_assert_cmpstr(qdict_get_str(qdict, "enum1"), ==, "value1");
     g_assert_cmpstr(qdict_get_str(qdict, "string"), ==, "str");
-    /* TODO g_assert_cmpint(qdict_get_int(qdict, "integer"), ==, 41); */
+    g_assert_cmpint(qdict_get_int(qdict, "integer"), ==, 41);
     g_assert_cmpint(qdict_get_bool(qdict, "boolean"), ==, true);
 
     qapi_free_UserDefFlatUnion(tmp);
@@ -517,8 +514,8 @@ static void test_visitor_out_alternate(TestOutputVisitorData *data,
     Error *err = NULL;
 
     UserDefAlternate *tmp = g_malloc0(sizeof(UserDefAlternate));
-    tmp->kind = USER_DEF_ALTERNATE_KIND_I;
-    tmp->i = 42;
+    tmp->type = USER_DEF_ALTERNATE_KIND_I;
+    tmp->u.i = 42;
 
     visit_type_UserDefAlternate(data->ov, &tmp, NULL, &err);
     g_assert(err == NULL);
@@ -543,9 +540,9 @@ static void test_visitor_out_empty(TestOutputVisitorData *data,
 static void init_native_list(UserDefNativeListUnion *cvalue)
 {
     int i;
-    switch (cvalue->kind) {
+    switch (cvalue->type) {
     case USER_DEF_NATIVE_LIST_UNION_KIND_INTEGER: {
-        intList **list = &cvalue->integer;
+        intList **list = &cvalue->u.integer;
         for (i = 0; i < 32; i++) {
             *list = g_new0(intList, 1);
             (*list)->value = i;
@@ -555,7 +552,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S8: {
-        int8List **list = &cvalue->s8;
+        int8List **list = &cvalue->u.s8;
         for (i = 0; i < 32; i++) {
             *list = g_new0(int8List, 1);
             (*list)->value = i;
@@ -565,7 +562,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S16: {
-        int16List **list = &cvalue->s16;
+        int16List **list = &cvalue->u.s16;
         for (i = 0; i < 32; i++) {
             *list = g_new0(int16List, 1);
             (*list)->value = i;
@@ -575,7 +572,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S32: {
-        int32List **list = &cvalue->s32;
+        int32List **list = &cvalue->u.s32;
         for (i = 0; i < 32; i++) {
             *list = g_new0(int32List, 1);
             (*list)->value = i;
@@ -585,7 +582,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_S64: {
-        int64List **list = &cvalue->s64;
+        int64List **list = &cvalue->u.s64;
         for (i = 0; i < 32; i++) {
             *list = g_new0(int64List, 1);
             (*list)->value = i;
@@ -595,7 +592,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U8: {
-        uint8List **list = &cvalue->u8;
+        uint8List **list = &cvalue->u.u8;
         for (i = 0; i < 32; i++) {
             *list = g_new0(uint8List, 1);
             (*list)->value = i;
@@ -605,7 +602,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U16: {
-        uint16List **list = &cvalue->u16;
+        uint16List **list = &cvalue->u.u16;
         for (i = 0; i < 32; i++) {
             *list = g_new0(uint16List, 1);
             (*list)->value = i;
@@ -615,7 +612,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U32: {
-        uint32List **list = &cvalue->u32;
+        uint32List **list = &cvalue->u.u32;
         for (i = 0; i < 32; i++) {
             *list = g_new0(uint32List, 1);
             (*list)->value = i;
@@ -625,7 +622,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_U64: {
-        uint64List **list = &cvalue->u64;
+        uint64List **list = &cvalue->u.u64;
         for (i = 0; i < 32; i++) {
             *list = g_new0(uint64List, 1);
             (*list)->value = i;
@@ -635,7 +632,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_BOOLEAN: {
-        boolList **list = &cvalue->boolean;
+        boolList **list = &cvalue->u.boolean;
         for (i = 0; i < 32; i++) {
             *list = g_new0(boolList, 1);
             (*list)->value = (i % 3 == 0);
@@ -645,7 +642,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_STRING: {
-        strList **list = &cvalue->string;
+        strList **list = &cvalue->u.string;
         for (i = 0; i < 32; i++) {
             *list = g_new0(strList, 1);
             (*list)->value = g_strdup_printf("%d", i);
@@ -655,7 +652,7 @@ static void init_native_list(UserDefNativeListUnion *cvalue)
         break;
     }
     case USER_DEF_NATIVE_LIST_UNION_KIND_NUMBER: {
-        numberList **list = &cvalue->number;
+        numberList **list = &cvalue->u.number;
         for (i = 0; i < 32; i++) {
             *list = g_new0(numberList, 1);
             (*list)->value = (double)i / 3;
@@ -764,14 +761,14 @@ static void test_native_list(TestOutputVisitorData *data,
     Error *err = NULL;
     QObject *obj;
 
-    cvalue->kind = kind;
+    cvalue->type = kind;
     init_native_list(cvalue);
 
     visit_type_UserDefNativeListUnion(data->ov, &cvalue, NULL, &err);
     g_assert(err == NULL);
 
     obj = qmp_output_get_qobject(data->qov);
-    check_native_list(obj, cvalue->kind);
+    check_native_list(obj, cvalue->type);
     qapi_free_UserDefNativeListUnion(cvalue);
     qobject_decref(obj);
 }
diff --git a/tests/test-visitor-serialization.c b/tests/test-visitor-serialization.c
index fa86cae..634563b 100644
--- a/tests/test-visitor-serialization.c
+++ b/tests/test-visitor-serialization.c
@@ -258,15 +258,13 @@ static UserDefTwo *nested_struct_create(void)
     udnp->dict1->string1 = strdup("test_string1");
     udnp->dict1->dict2 = g_malloc0(sizeof(*udnp->dict1->dict2));
     udnp->dict1->dict2->userdef = g_new0(UserDefOne, 1);
-    udnp->dict1->dict2->userdef->base = g_new0(UserDefZero, 1);
-    udnp->dict1->dict2->userdef->base->integer = 42;
+    udnp->dict1->dict2->userdef->integer = 42;
     udnp->dict1->dict2->userdef->string = strdup("test_string");
     udnp->dict1->dict2->string = strdup("test_string2");
     udnp->dict1->dict3 = g_malloc0(sizeof(*udnp->dict1->dict3));
     udnp->dict1->has_dict3 = true;
     udnp->dict1->dict3->userdef = g_new0(UserDefOne, 1);
-    udnp->dict1->dict3->userdef->base = g_new0(UserDefZero, 1);
-    udnp->dict1->dict3->userdef->base->integer = 43;
+    udnp->dict1->dict3->userdef->integer = 43;
     udnp->dict1->dict3->userdef->string = strdup("test_string");
     udnp->dict1->dict3->string = strdup("test_string3");
     return udnp;
@@ -278,15 +276,15 @@ static void nested_struct_compare(UserDefTwo *udnp1, UserDefTwo *udnp2)
     g_assert(udnp2);
     g_assert_cmpstr(udnp1->string0, ==, udnp2->string0);
     g_assert_cmpstr(udnp1->dict1->string1, ==, udnp2->dict1->string1);
-    g_assert_cmpint(udnp1->dict1->dict2->userdef->base->integer, ==,
-                    udnp2->dict1->dict2->userdef->base->integer);
+    g_assert_cmpint(udnp1->dict1->dict2->userdef->integer, ==,
+                    udnp2->dict1->dict2->userdef->integer);
     g_assert_cmpstr(udnp1->dict1->dict2->userdef->string, ==,
                     udnp2->dict1->dict2->userdef->string);
     g_assert_cmpstr(udnp1->dict1->dict2->string, ==,
                     udnp2->dict1->dict2->string);
     g_assert(udnp1->dict1->has_dict3 == udnp2->dict1->has_dict3);
-    g_assert_cmpint(udnp1->dict1->dict3->userdef->base->integer, ==,
-                    udnp2->dict1->dict3->userdef->base->integer);
+    g_assert_cmpint(udnp1->dict1->dict3->userdef->integer, ==,
+                    udnp2->dict1->dict3->userdef->integer);
     g_assert_cmpstr(udnp1->dict1->dict3->userdef->string, ==,
                     udnp2->dict1->dict3->userdef->string);
     g_assert_cmpstr(udnp1->dict1->dict3->string, ==,
diff --git a/tpm.c b/tpm.c
index 4e9b109..f2c59d1 100644
--- a/tpm.c
+++ b/tpm.c
@@ -260,9 +260,9 @@ static TPMInfo *qmp_query_tpm_inst(TPMBackend *drv)
 
     switch (drv->ops->type) {
     case TPM_TYPE_PASSTHROUGH:
-        res->options->kind = TPM_TYPE_OPTIONS_KIND_PASSTHROUGH;
+        res->options->type = TPM_TYPE_OPTIONS_KIND_PASSTHROUGH;
         tpo = g_new0(TPMPassthroughOptions, 1);
-        res->options->passthrough = tpo;
+        res->options->u.passthrough = tpo;
         if (drv->path) {
             tpo->path = g_strdup(drv->path);
             tpo->has_path = true;
diff --git a/ui/console.c b/ui/console.c
index cf649b2..f26544e 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -2016,7 +2016,7 @@ static VcHandler *vc_handler = text_console_init;
 static CharDriverState *vc_init(const char *id, ChardevBackend *backend,
                                 ChardevReturn *ret, Error **errp)
 {
-    return vc_handler(backend->vc, errp);
+    return vc_handler(backend->u.vc, errp);
 }
 
 void register_vc_handler(VcHandler *handler)
@@ -2057,30 +2057,30 @@ static void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend,
 {
     int val;
 
-    backend->vc = g_new0(ChardevVC, 1);
+    backend->u.vc = g_new0(ChardevVC, 1);
 
     val = qemu_opt_get_number(opts, "width", 0);
     if (val != 0) {
-        backend->vc->has_width = true;
-        backend->vc->width = val;
+        backend->u.vc->has_width = true;
+        backend->u.vc->width = val;
     }
 
     val = qemu_opt_get_number(opts, "height", 0);
     if (val != 0) {
-        backend->vc->has_height = true;
-        backend->vc->height = val;
+        backend->u.vc->has_height = true;
+        backend->u.vc->height = val;
     }
 
     val = qemu_opt_get_number(opts, "cols", 0);
     if (val != 0) {
-        backend->vc->has_cols = true;
-        backend->vc->cols = val;
+        backend->u.vc->has_cols = true;
+        backend->u.vc->cols = val;
     }
 
     val = qemu_opt_get_number(opts, "rows", 0);
     if (val != 0) {
-        backend->vc->has_rows = true;
-        backend->vc->rows = val;
+        backend->u.vc->has_rows = true;
+        backend->u.vc->rows = val;
     }
 }
 
diff --git a/ui/input-keymap.c b/ui/input-keymap.c
index 7635cb0..d36be4b 100644
--- a/ui/input-keymap.c
+++ b/ui/input-keymap.c
@@ -139,11 +139,11 @@ static int number_to_qcode[0x100];
 
 int qemu_input_key_value_to_number(const KeyValue *value)
 {
-    if (value->kind == KEY_VALUE_KIND_QCODE) {
-        return qcode_to_number[value->qcode];
+    if (value->type == KEY_VALUE_KIND_QCODE) {
+        return qcode_to_number[value->u.qcode];
     } else {
-        assert(value->kind == KEY_VALUE_KIND_NUMBER);
-        return value->number;
+        assert(value->type == KEY_VALUE_KIND_NUMBER);
+        return value->u.number;
     }
 }
 
@@ -166,11 +166,11 @@ int qemu_input_key_number_to_qcode(uint8_t nr)
 
 int qemu_input_key_value_to_qcode(const KeyValue *value)
 {
-    if (value->kind == KEY_VALUE_KIND_QCODE) {
-        return value->qcode;
+    if (value->type == KEY_VALUE_KIND_QCODE) {
+        return value->u.qcode;
     } else {
-        assert(value->kind == KEY_VALUE_KIND_NUMBER);
-        return qemu_input_key_number_to_qcode(value->number);
+        assert(value->type == KEY_VALUE_KIND_NUMBER);
+        return qemu_input_key_number_to_qcode(value->u.number);
     }
 }
 
@@ -180,8 +180,8 @@ int qemu_input_key_value_to_scancode(const KeyValue *value, bool down,
     int keycode = qemu_input_key_value_to_number(value);
     int count = 0;
 
-    if (value->kind == KEY_VALUE_KIND_QCODE &&
-        value->qcode == Q_KEY_CODE_PAUSE) {
+    if (value->type == KEY_VALUE_KIND_QCODE &&
+        value->u.qcode == Q_KEY_CODE_PAUSE) {
         /* specific case */
         int v = down ? 0 : 0x80;
         codes[count++] = 0xe1;
diff --git a/ui/input-legacy.c b/ui/input-legacy.c
index e50f296..a67ed32 100644
--- a/ui/input-legacy.c
+++ b/ui/input-legacy.c
@@ -113,8 +113,8 @@ static void legacy_kbd_event(DeviceState *dev, QemuConsole *src,
     if (!entry || !entry->put_kbd) {
         return;
     }
-    count = qemu_input_key_value_to_scancode(evt->key->key,
-                                             evt->key->down,
+    count = qemu_input_key_value_to_scancode(evt->u.key->key,
+                                             evt->u.key->down,
                                              scancodes);
     for (i = 0; i < count; i++) {
         entry->put_kbd(entry->opaque, scancodes[i]);
@@ -150,21 +150,22 @@ static void legacy_mouse_event(DeviceState *dev, QemuConsole *src,
     };
     QEMUPutMouseEntry *s = (QEMUPutMouseEntry *)dev;
 
-    switch (evt->kind) {
+    switch (evt->type) {
     case INPUT_EVENT_KIND_BTN:
-        if (evt->btn->down) {
-            s->buttons |= bmap[evt->btn->button];
+        if (evt->u.btn->down) {
+            s->buttons |= bmap[evt->u.btn->button];
         } else {
-            s->buttons &= ~bmap[evt->btn->button];
+            s->buttons &= ~bmap[evt->u.btn->button];
         }
-        if (evt->btn->down && evt->btn->button == INPUT_BUTTON_WHEEL_UP) {
+        if (evt->u.btn->down && evt->u.btn->button == INPUT_BUTTON_WHEEL_UP) {
             s->qemu_put_mouse_event(s->qemu_put_mouse_event_opaque,
                                     s->axis[INPUT_AXIS_X],
                                     s->axis[INPUT_AXIS_Y],
                                     -1,
                                     s->buttons);
         }
-        if (evt->btn->down && evt->btn->button == INPUT_BUTTON_WHEEL_DOWN) {
+        if (evt->u.btn->down &&
+            evt->u.btn->button == INPUT_BUTTON_WHEEL_DOWN) {
             s->qemu_put_mouse_event(s->qemu_put_mouse_event_opaque,
                                     s->axis[INPUT_AXIS_X],
                                     s->axis[INPUT_AXIS_Y],
@@ -173,10 +174,10 @@ static void legacy_mouse_event(DeviceState *dev, QemuConsole *src,
         }
         break;
     case INPUT_EVENT_KIND_ABS:
-        s->axis[evt->abs->axis] = evt->abs->value;
+        s->axis[evt->u.abs->axis] = evt->u.abs->value;
         break;
     case INPUT_EVENT_KIND_REL:
-        s->axis[evt->rel->axis] += evt->rel->value;
+        s->axis[evt->u.rel->axis] += evt->u.rel->value;
         break;
     default:
         break;
diff --git a/ui/input.c b/ui/input.c
index 1a552d1..643f885 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -147,10 +147,10 @@ void qmp_x_input_send_event(bool has_console, int64_t console,
     for (e = events; e != NULL; e = e->next) {
         InputEvent *event = e->value;
 
-        if (!qemu_input_find_handler(1 << event->kind, con)) {
+        if (!qemu_input_find_handler(1 << event->type, con)) {
             error_setg(errp, "Input handler not found for "
                              "event type %s",
-                            InputEventKind_lookup[event->kind]);
+                            InputEventKind_lookup[event->type]);
             return;
         }
     }
@@ -168,22 +168,22 @@ static void qemu_input_transform_abs_rotate(InputEvent *evt)
 {
     switch (graphic_rotate) {
     case 90:
-        if (evt->abs->axis == INPUT_AXIS_X) {
-            evt->abs->axis = INPUT_AXIS_Y;
-        } else if (evt->abs->axis == INPUT_AXIS_Y) {
-            evt->abs->axis = INPUT_AXIS_X;
-            evt->abs->value = INPUT_EVENT_ABS_SIZE - 1 - evt->abs->value;
+        if (evt->u.abs->axis == INPUT_AXIS_X) {
+            evt->u.abs->axis = INPUT_AXIS_Y;
+        } else if (evt->u.abs->axis == INPUT_AXIS_Y) {
+            evt->u.abs->axis = INPUT_AXIS_X;
+            evt->u.abs->value = INPUT_EVENT_ABS_SIZE - 1 - evt->u.abs->value;
         }
         break;
     case 180:
-        evt->abs->value = INPUT_EVENT_ABS_SIZE - 1 - evt->abs->value;
+        evt->u.abs->value = INPUT_EVENT_ABS_SIZE - 1 - evt->u.abs->value;
         break;
     case 270:
-        if (evt->abs->axis == INPUT_AXIS_X) {
-            evt->abs->axis = INPUT_AXIS_Y;
-            evt->abs->value = INPUT_EVENT_ABS_SIZE - 1 - evt->abs->value;
-        } else if (evt->abs->axis == INPUT_AXIS_Y) {
-            evt->abs->axis = INPUT_AXIS_X;
+        if (evt->u.abs->axis == INPUT_AXIS_X) {
+            evt->u.abs->axis = INPUT_AXIS_Y;
+            evt->u.abs->value = INPUT_EVENT_ABS_SIZE - 1 - evt->u.abs->value;
+        } else if (evt->u.abs->axis == INPUT_AXIS_Y) {
+            evt->u.abs->axis = INPUT_AXIS_X;
         }
         break;
     }
@@ -197,18 +197,18 @@ static void qemu_input_event_trace(QemuConsole *src, InputEvent *evt)
     if (src) {
         idx = qemu_console_get_index(src);
     }
-    switch (evt->kind) {
+    switch (evt->type) {
     case INPUT_EVENT_KIND_KEY:
-        switch (evt->key->key->kind) {
+        switch (evt->u.key->key->type) {
         case KEY_VALUE_KIND_NUMBER:
-            qcode = qemu_input_key_number_to_qcode(evt->key->key->number);
+            qcode = qemu_input_key_number_to_qcode(evt->u.key->key->u.number);
             name = QKeyCode_lookup[qcode];
-            trace_input_event_key_number(idx, evt->key->key->number,
-                                         name, evt->key->down);
+            trace_input_event_key_number(idx, evt->u.key->key->u.number,
+                                         name, evt->u.key->down);
             break;
         case KEY_VALUE_KIND_QCODE:
-            name = QKeyCode_lookup[evt->key->key->qcode];
-            trace_input_event_key_qcode(idx, name, evt->key->down);
+            name = QKeyCode_lookup[evt->u.key->key->u.qcode];
+            trace_input_event_key_qcode(idx, name, evt->u.key->down);
             break;
         case KEY_VALUE_KIND_MAX:
             /* keep gcc happy */
@@ -216,16 +216,16 @@ static void qemu_input_event_trace(QemuConsole *src, InputEvent *evt)
         }
         break;
     case INPUT_EVENT_KIND_BTN:
-        name = InputButton_lookup[evt->btn->button];
-        trace_input_event_btn(idx, name, evt->btn->down);
+        name = InputButton_lookup[evt->u.btn->button];
+        trace_input_event_btn(idx, name, evt->u.btn->down);
         break;
     case INPUT_EVENT_KIND_REL:
-        name = InputAxis_lookup[evt->rel->axis];
-        trace_input_event_rel(idx, name, evt->rel->value);
+        name = InputAxis_lookup[evt->u.rel->axis];
+        trace_input_event_rel(idx, name, evt->u.rel->value);
         break;
     case INPUT_EVENT_KIND_ABS:
-        name = InputAxis_lookup[evt->abs->axis];
-        trace_input_event_abs(idx, name, evt->abs->value);
+        name = InputAxis_lookup[evt->u.abs->axis];
+        trace_input_event_abs(idx, name, evt->u.abs->value);
         break;
     case INPUT_EVENT_KIND_MAX:
         /* keep gcc happy */
@@ -311,12 +311,12 @@ void qemu_input_event_send(QemuConsole *src, InputEvent *evt)
     qemu_input_event_trace(src, evt);
 
     /* pre processing */
-    if (graphic_rotate && (evt->kind == INPUT_EVENT_KIND_ABS)) {
+    if (graphic_rotate && (evt->type == INPUT_EVENT_KIND_ABS)) {
             qemu_input_transform_abs_rotate(evt);
     }
 
     /* send event */
-    s = qemu_input_find_handler(1 << evt->kind, src);
+    s = qemu_input_find_handler(1 << evt->type, src);
     if (!s) {
         return;
     }
@@ -348,10 +348,10 @@ void qemu_input_event_sync(void)
 InputEvent *qemu_input_event_new_key(KeyValue *key, bool down)
 {
     InputEvent *evt = g_new0(InputEvent, 1);
-    evt->key = g_new0(InputKeyEvent, 1);
-    evt->kind = INPUT_EVENT_KIND_KEY;
-    evt->key->key = key;
-    evt->key->down = down;
+    evt->u.key = g_new0(InputKeyEvent, 1);
+    evt->type = INPUT_EVENT_KIND_KEY;
+    evt->u.key->key = key;
+    evt->u.key->down = down;
     return evt;
 }
 
@@ -372,16 +372,16 @@ void qemu_input_event_send_key(QemuConsole *src, KeyValue *key, bool down)
 void qemu_input_event_send_key_number(QemuConsole *src, int num, bool down)
 {
     KeyValue *key = g_new0(KeyValue, 1);
-    key->kind = KEY_VALUE_KIND_NUMBER;
-    key->number = num;
+    key->type = KEY_VALUE_KIND_NUMBER;
+    key->u.number = num;
     qemu_input_event_send_key(src, key, down);
 }
 
 void qemu_input_event_send_key_qcode(QemuConsole *src, QKeyCode q, bool down)
 {
     KeyValue *key = g_new0(KeyValue, 1);
-    key->kind = KEY_VALUE_KIND_QCODE;
-    key->qcode = q;
+    key->type = KEY_VALUE_KIND_QCODE;
+    key->u.qcode = q;
     qemu_input_event_send_key(src, key, down);
 }
 
@@ -398,10 +398,10 @@ void qemu_input_event_send_key_delay(uint32_t delay_ms)
 InputEvent *qemu_input_event_new_btn(InputButton btn, bool down)
 {
     InputEvent *evt = g_new0(InputEvent, 1);
-    evt->btn = g_new0(InputBtnEvent, 1);
-    evt->kind = INPUT_EVENT_KIND_BTN;
-    evt->btn->button = btn;
-    evt->btn->down = down;
+    evt->u.btn = g_new0(InputBtnEvent, 1);
+    evt->type = INPUT_EVENT_KIND_BTN;
+    evt->u.btn->button = btn;
+    evt->u.btn->down = down;
     return evt;
 }
 
@@ -451,8 +451,8 @@ InputEvent *qemu_input_event_new_move(InputEventKind kind,
     InputEvent *evt = g_new0(InputEvent, 1);
     InputMoveEvent *move = g_new0(InputMoveEvent, 1);
 
-    evt->kind = kind;
-    evt->data = move;
+    evt->type = kind;
+    evt->u.data = move;
     move->axis = axis;
     move->value = value;
     return evt;
diff --git a/ui/spice-core.c b/ui/spice-core.c
index bf4fd07..6a62d71 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -200,8 +200,6 @@ static void channel_event(int event, SpiceChannelEventInfo *info)
 {
     SpiceServerInfo *server = g_malloc0(sizeof(*server));
     SpiceChannel *client = g_malloc0(sizeof(*client));
-    server->base = g_malloc0(sizeof(*server->base));
-    client->base = g_malloc0(sizeof(*client->base));
 
     /*
      * Spice server might have called us from spice worker thread
@@ -218,9 +216,11 @@ static void channel_event(int event, SpiceChannelEventInfo *info)
     }
 
     if (info->flags & SPICE_CHANNEL_EVENT_FLAG_ADDR_EXT) {
-        add_addr_info(client->base, (struct sockaddr *)&info->paddr_ext,
+        add_addr_info(qapi_SpiceChannel_base(client),
+                      (struct sockaddr *)&info->paddr_ext,
                       info->plen_ext);
-        add_addr_info(server->base, (struct sockaddr *)&info->laddr_ext,
+        add_addr_info(qapi_SpiceServerInfo_base(server),
+                      (struct sockaddr *)&info->laddr_ext,
                       info->llen_ext);
     } else {
         error_report("spice: %s, extended address is expected",
@@ -229,7 +229,9 @@ static void channel_event(int event, SpiceChannelEventInfo *info)
 
     switch (event) {
     case SPICE_CHANNEL_EVENT_CONNECTED:
-        qapi_event_send_spice_connected(server->base, client->base, &error_abort);
+        qapi_event_send_spice_connected(qapi_SpiceServerInfo_base(server),
+                                        qapi_SpiceChannel_base(client),
+                                        &error_abort);
         break;
     case SPICE_CHANNEL_EVENT_INITIALIZED:
         if (auth) {
@@ -242,7 +244,9 @@ static void channel_event(int event, SpiceChannelEventInfo *info)
         break;
     case SPICE_CHANNEL_EVENT_DISCONNECTED:
         channel_list_del(info);
-        qapi_event_send_spice_disconnected(server->base, client->base, &error_abort);
+        qapi_event_send_spice_disconnected(qapi_SpiceServerInfo_base(server),
+                                           qapi_SpiceChannel_base(client),
+                                           &error_abort);
         break;
     default:
         break;
@@ -378,16 +382,15 @@ static SpiceChannelList *qmp_query_spice_channels(void)
 
         chan = g_malloc0(sizeof(*chan));
         chan->value = g_malloc0(sizeof(*chan->value));
-        chan->value->base = g_malloc0(sizeof(*chan->value->base));
 
         paddr = (struct sockaddr *)&item->info->paddr_ext;
         plen = item->info->plen_ext;
         getnameinfo(paddr, plen,
                     host, sizeof(host), port, sizeof(port),
                     NI_NUMERICHOST | NI_NUMERICSERV);
-        chan->value->base->host = g_strdup(host);
-        chan->value->base->port = g_strdup(port);
-        chan->value->base->family = inet_netfamily(paddr->sa_family);
+        chan->value->host = g_strdup(host);
+        chan->value->port = g_strdup(port);
+        chan->value->family = inet_netfamily(paddr->sa_family);
 
         chan->value->connection_id = item->info->connection_id;
         chan->value->channel_type = item->info->type;
diff --git a/ui/vnc.c b/ui/vnc.c
index faff054..7b37e3b 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -156,10 +156,11 @@ char *vnc_socket_remote_addr(const char *format, int fd) {
     return addr_to_string(format, &sa, salen);
 }
 
-static VncBasicInfo *vnc_basic_info_get(struct sockaddr_storage *sa,
-                                        socklen_t salen)
+static void vnc_init_basic_info(struct sockaddr_storage *sa,
+                                socklen_t salen,
+                                VncBasicInfo *info,
+                                Error **errp)
 {
-    VncBasicInfo *info;
     char host[NI_MAXHOST];
     char serv[NI_MAXSERV];
     int err;
@@ -168,42 +169,44 @@ static VncBasicInfo *vnc_basic_info_get(struct sockaddr_storage *sa,
                            host, sizeof(host),
                            serv, sizeof(serv),
                            NI_NUMERICHOST | NI_NUMERICSERV)) != 0) {
-        VNC_DEBUG("Cannot resolve address %d: %s\n",
-                  err, gai_strerror(err));
-        return NULL;
+        error_setg(errp, "Cannot resolve address: %s",
+                   gai_strerror(err));
+        return;
     }
 
-    info = g_malloc0(sizeof(VncBasicInfo));
     info->host = g_strdup(host);
     info->service = g_strdup(serv);
     info->family = inet_netfamily(sa->ss_family);
-    return info;
 }
 
-static VncBasicInfo *vnc_basic_info_get_from_server_addr(int fd)
+static void vnc_init_basic_info_from_server_addr(int fd, VncBasicInfo *info,
+                                                 Error **errp)
 {
     struct sockaddr_storage sa;
     socklen_t salen;
 
     salen = sizeof(sa);
     if (getsockname(fd, (struct sockaddr*)&sa, &salen) < 0) {
-        return NULL;
+        error_setg_errno(errp, errno, "getsockname failed");
+        return;
     }
 
-    return vnc_basic_info_get(&sa, salen);
+    vnc_init_basic_info(&sa, salen, info, errp);
 }
 
-static VncBasicInfo *vnc_basic_info_get_from_remote_addr(int fd)
+static void vnc_init_basic_info_from_remote_addr(int fd, VncBasicInfo *info,
+                                                 Error **errp)
 {
     struct sockaddr_storage sa;
     socklen_t salen;
 
     salen = sizeof(sa);
     if (getpeername(fd, (struct sockaddr*)&sa, &salen) < 0) {
-        return NULL;
+        error_setg_errno(errp, errno, "getpeername failed");
+        return;
     }
 
-    return vnc_basic_info_get(&sa, salen);
+    vnc_init_basic_info(&sa, salen, info, errp);
 }
 
 static const char *vnc_auth_name(VncDisplay *vd) {
@@ -256,15 +259,18 @@ static const char *vnc_auth_name(VncDisplay *vd) {
 static VncServerInfo *vnc_server_info_get(VncDisplay *vd)
 {
     VncServerInfo *info;
-    VncBasicInfo *bi = vnc_basic_info_get_from_server_addr(vd->lsock);
-    if (!bi) {
-        return NULL;
-    }
+    Error *err = NULL;
 
     info = g_malloc(sizeof(*info));
-    info->base = bi;
+    vnc_init_basic_info_from_server_addr(vd->lsock,
+                                         qapi_VncServerInfo_base(info), &err);
     info->has_auth = true;
     info->auth = g_strdup(vnc_auth_name(vd));
+    if (err) {
+        qapi_free_VncServerInfo(info);
+        info = NULL;
+        error_free(err);
+    }
     return info;
 }
 
@@ -291,11 +297,16 @@ static void vnc_client_cache_auth(VncState *client)
 
 static void vnc_client_cache_addr(VncState *client)
 {
-    VncBasicInfo *bi = vnc_basic_info_get_from_remote_addr(client->csock);
+    Error *err = NULL;
 
-    if (bi) {
-        client->info = g_malloc0(sizeof(*client->info));
-        client->info->base = bi;
+    client->info = g_malloc0(sizeof(*client->info));
+    vnc_init_basic_info_from_remote_addr(client->csock,
+                                         qapi_VncClientInfo_base(client->info),
+                                         &err);
+    if (err) {
+        qapi_free_VncClientInfo(client->info);
+        client->info = NULL;
+        error_free(err);
     }
 }
 
@@ -306,7 +317,6 @@ static void vnc_qmp_event(VncState *vs, QAPIEvent event)
     if (!vs->info) {
         return;
     }
-    g_assert(vs->info->base);
 
     si = vnc_server_info_get(vs->vd);
     if (!si) {
@@ -315,7 +325,8 @@ static void vnc_qmp_event(VncState *vs, QAPIEvent event)
 
     switch (event) {
     case QAPI_EVENT_VNC_CONNECTED:
-        qapi_event_send_vnc_connected(si, vs->info->base, &error_abort);
+        qapi_event_send_vnc_connected(si, qapi_VncClientInfo_base(vs->info),
+                                      &error_abort);
         break;
     case QAPI_EVENT_VNC_INITIALIZED:
         qapi_event_send_vnc_initialized(si, vs->info, &error_abort);
@@ -350,11 +361,10 @@ static VncClientInfo *qmp_query_vnc_client(const VncState *client)
     }
 
     info = g_malloc0(sizeof(*info));
-    info->base = g_malloc0(sizeof(*info->base));
-    info->base->host = g_strdup(host);
-    info->base->service = g_strdup(serv);
-    info->base->family = inet_netfamily(sa.ss_family);
-    info->base->websocket = client->websocket;
+    info->host = g_strdup(host);
+    info->service = g_strdup(serv);
+    info->family = inet_netfamily(sa.ss_family);
+    info->websocket = client->websocket;
 
     if (client->tls) {
         info->x509_dname = qcrypto_tls_session_get_peer_name(client->tls);
@@ -3514,9 +3524,9 @@ void vnc_display_open(const char *id, Error **errp)
         }
 
         if (strncmp(vnc, "unix:", 5) == 0) {
-            saddr->kind = SOCKET_ADDRESS_KIND_UNIX;
-            saddr->q_unix = g_new0(UnixSocketAddress, 1);
-            saddr->q_unix->path = g_strdup(vnc + 5);
+            saddr->type = SOCKET_ADDRESS_KIND_UNIX;
+            saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
+            saddr->u.q_unix->path = g_strdup(vnc + 5);
 
             if (vs->ws_enabled) {
                 error_setg(errp, "UNIX sockets not supported with websock");
@@ -3524,12 +3534,12 @@ void vnc_display_open(const char *id, Error **errp)
             }
         } else {
             unsigned long long baseport;
-            saddr->kind = SOCKET_ADDRESS_KIND_INET;
-            saddr->inet = g_new0(InetSocketAddress, 1);
+            saddr->type = SOCKET_ADDRESS_KIND_INET;
+            saddr->u.inet = g_new0(InetSocketAddress, 1);
             if (vnc[0] == '[' && vnc[hlen - 1] == ']') {
-                saddr->inet->host = g_strndup(vnc + 1, hlen - 2);
+                saddr->u.inet->host = g_strndup(vnc + 1, hlen - 2);
             } else {
-                saddr->inet->host = g_strndup(vnc, hlen);
+                saddr->u.inet->host = g_strndup(vnc, hlen);
             }
             if (parse_uint_full(h + 1, &baseport, 10) < 0) {
                 error_setg(errp, "can't convert to a number: %s", h + 1);
@@ -3540,28 +3550,28 @@ void vnc_display_open(const char *id, Error **errp)
                 error_setg(errp, "port %s out of range", h + 1);
                 goto fail;
             }
-            saddr->inet->port = g_strdup_printf(
+            saddr->u.inet->port = g_strdup_printf(
                 "%d", (int)baseport + 5900);
 
             if (to) {
-                saddr->inet->has_to = true;
-                saddr->inet->to = to;
+                saddr->u.inet->has_to = true;
+                saddr->u.inet->to = to;
             }
-            saddr->inet->ipv4 = saddr->inet->has_ipv4 = has_ipv4;
-            saddr->inet->ipv6 = saddr->inet->has_ipv6 = has_ipv6;
+            saddr->u.inet->ipv4 = saddr->u.inet->has_ipv4 = has_ipv4;
+            saddr->u.inet->ipv6 = saddr->u.inet->has_ipv6 = has_ipv6;
 
             if (vs->ws_enabled) {
-                wsaddr->kind = SOCKET_ADDRESS_KIND_INET;
-                wsaddr->inet = g_new0(InetSocketAddress, 1);
-                wsaddr->inet->host = g_strdup(saddr->inet->host);
-                wsaddr->inet->port = g_strdup(websocket);
+                wsaddr->type = SOCKET_ADDRESS_KIND_INET;
+                wsaddr->u.inet = g_new0(InetSocketAddress, 1);
+                wsaddr->u.inet->host = g_strdup(saddr->u.inet->host);
+                wsaddr->u.inet->port = g_strdup(websocket);
 
                 if (to) {
-                    wsaddr->inet->has_to = true;
-                    wsaddr->inet->to = to;
+                    wsaddr->u.inet->has_to = true;
+                    wsaddr->u.inet->to = to;
                 }
-                wsaddr->inet->ipv4 = wsaddr->inet->has_ipv4 = has_ipv4;
-                wsaddr->inet->ipv6 = wsaddr->inet->has_ipv6 = has_ipv6;
+                wsaddr->u.inet->ipv4 = wsaddr->u.inet->has_ipv4 = has_ipv4;
+                wsaddr->u.inet->ipv6 = wsaddr->u.inet->has_ipv6 = has_ipv6;
             }
         }
     } else {
@@ -3760,7 +3770,7 @@ void vnc_display_open(const char *id, Error **errp)
         if (csock < 0) {
             goto fail;
         }
-        vs->is_unix = saddr->kind == SOCKET_ADDRESS_KIND_UNIX;
+        vs->is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
         vnc_connect(vs, csock, false, false);
     } else {
         /* listen for connects */
@@ -3768,7 +3778,7 @@ void vnc_display_open(const char *id, Error **errp)
         if (vs->lsock < 0) {
             goto fail;
         }
-        vs->is_unix = saddr->kind == SOCKET_ADDRESS_KIND_UNIX;
+        vs->is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
         if (vs->ws_enabled) {
             vs->lwebsock = socket_listen(wsaddr, errp);
             if (vs->lwebsock < 0) {
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index 9142917..dfe4587 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -918,23 +918,23 @@ SocketAddress *socket_parse(const char *str, Error **errp)
             error_setg(errp, "invalid Unix socket address");
             goto fail;
         } else {
-            addr->kind = SOCKET_ADDRESS_KIND_UNIX;
-            addr->q_unix = g_new(UnixSocketAddress, 1);
-            addr->q_unix->path = g_strdup(str + 5);
+            addr->type = SOCKET_ADDRESS_KIND_UNIX;
+            addr->u.q_unix = g_new(UnixSocketAddress, 1);
+            addr->u.q_unix->path = g_strdup(str + 5);
         }
     } else if (strstart(str, "fd:", NULL)) {
         if (str[3] == '\0') {
             error_setg(errp, "invalid file descriptor address");
             goto fail;
         } else {
-            addr->kind = SOCKET_ADDRESS_KIND_FD;
-            addr->fd = g_new(String, 1);
-            addr->fd->str = g_strdup(str + 3);
+            addr->type = SOCKET_ADDRESS_KIND_FD;
+            addr->u.fd = g_new(String, 1);
+            addr->u.fd->str = g_strdup(str + 3);
         }
     } else {
-        addr->kind = SOCKET_ADDRESS_KIND_INET;
-        addr->inet = inet_parse(str, errp);
-        if (addr->inet == NULL) {
+        addr->type = SOCKET_ADDRESS_KIND_INET;
+        addr->u.inet = inet_parse(str, errp);
+        if (addr->u.inet == NULL) {
             goto fail;
         }
     }
@@ -952,19 +952,19 @@ int socket_connect(SocketAddress *addr, Error **errp,
     int fd;
 
     opts = qemu_opts_create(&socket_optslist, NULL, 0, &error_abort);
-    switch (addr->kind) {
+    switch (addr->type) {
     case SOCKET_ADDRESS_KIND_INET:
-        inet_addr_to_opts(opts, addr->inet);
+        inet_addr_to_opts(opts, addr->u.inet);
         fd = inet_connect_opts(opts, errp, callback, opaque);
         break;
 
     case SOCKET_ADDRESS_KIND_UNIX:
-        qemu_opt_set(opts, "path", addr->q_unix->path, &error_abort);
+        qemu_opt_set(opts, "path", addr->u.q_unix->path, &error_abort);
         fd = unix_connect_opts(opts, errp, callback, opaque);
         break;
 
     case SOCKET_ADDRESS_KIND_FD:
-        fd = monitor_get_fd(cur_mon, addr->fd->str, errp);
+        fd = monitor_get_fd(cur_mon, addr->u.fd->str, errp);
         if (fd >= 0 && callback) {
             qemu_set_nonblock(fd);
             callback(fd, NULL, opaque);
@@ -984,19 +984,19 @@ int socket_listen(SocketAddress *addr, Error **errp)
     int fd;
 
     opts = qemu_opts_create(&socket_optslist, NULL, 0, &error_abort);
-    switch (addr->kind) {
+    switch (addr->type) {
     case SOCKET_ADDRESS_KIND_INET:
-        inet_addr_to_opts(opts, addr->inet);
+        inet_addr_to_opts(opts, addr->u.inet);
         fd = inet_listen_opts(opts, 0, errp);
         break;
 
     case SOCKET_ADDRESS_KIND_UNIX:
-        qemu_opt_set(opts, "path", addr->q_unix->path, &error_abort);
+        qemu_opt_set(opts, "path", addr->u.q_unix->path, &error_abort);
         fd = unix_listen_opts(opts, errp);
         break;
 
     case SOCKET_ADDRESS_KIND_FD:
-        fd = monitor_get_fd(cur_mon, addr->fd->str, errp);
+        fd = monitor_get_fd(cur_mon, addr->u.fd->str, errp);
         break;
 
     default:
@@ -1012,12 +1012,12 @@ int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp)
     int fd;
 
     opts = qemu_opts_create(&socket_optslist, NULL, 0, &error_abort);
-    switch (remote->kind) {
+    switch (remote->type) {
     case SOCKET_ADDRESS_KIND_INET:
-        inet_addr_to_opts(opts, remote->inet);
+        inet_addr_to_opts(opts, remote->u.inet);
         if (local) {
-            qemu_opt_set(opts, "localaddr", local->inet->host, &error_abort);
-            qemu_opt_set(opts, "localport", local->inet->port, &error_abort);
+            qemu_opt_set(opts, "localaddr", local->u.inet->host, &error_abort);
+            qemu_opt_set(opts, "localport", local->u.inet->port, &error_abort);
         }
         fd = inet_dgram_opts(opts, errp);
         break;
@@ -1052,14 +1052,14 @@ socket_sockaddr_to_address_inet(struct sockaddr_storage *sa,
     }
 
     addr = g_new0(SocketAddress, 1);
-    addr->kind = SOCKET_ADDRESS_KIND_INET;
-    addr->inet = g_new0(InetSocketAddress, 1);
-    addr->inet->host = g_strdup(host);
-    addr->inet->port = g_strdup(serv);
+    addr->type = SOCKET_ADDRESS_KIND_INET;
+    addr->u.inet = g_new0(InetSocketAddress, 1);
+    addr->u.inet->host = g_strdup(host);
+    addr->u.inet->port = g_strdup(serv);
     if (sa->ss_family == AF_INET) {
-        addr->inet->has_ipv4 = addr->inet->ipv4 = true;
+        addr->u.inet->has_ipv4 = addr->u.inet->ipv4 = true;
     } else {
-        addr->inet->has_ipv6 = addr->inet->ipv6 = true;
+        addr->u.inet->has_ipv6 = addr->u.inet->ipv6 = true;
     }
 
     return addr;
@@ -1076,11 +1076,11 @@ socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
     struct sockaddr_un *su = (struct sockaddr_un *)sa;
 
     addr = g_new0(SocketAddress, 1);
-    addr->kind = SOCKET_ADDRESS_KIND_UNIX;
-    addr->q_unix = g_new0(UnixSocketAddress, 1);
+    addr->type = SOCKET_ADDRESS_KIND_UNIX;
+    addr->u.q_unix = g_new0(UnixSocketAddress, 1);
     if (su->sun_path[0]) {
-        addr->q_unix->path = g_strndup(su->sun_path,
-                                       sizeof(su->sun_path));
+        addr->u.q_unix->path = g_strndup(su->sun_path,
+                                         sizeof(su->sun_path));
     }
 
     return addr;