chardev: .chr_open(): add boolean return value

Add boolean return value to follow common recommendations for functions
with errrp in include/qapi/error.h

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20260115144606.233252-7-vsementsov@yandex-team.ru>

chardev/baum.c

@@ -642,7 +642,7 @@ static void char_braille_finalize(Object *obj)
     }
 }
 
-static void baum_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool baum_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     BaumChardev *baum = BAUM_CHARDEV(chr);
     brlapi_handle_t *handle;
@@ -656,7 +656,7 @@ static void baum_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
                    brlapi_strerror(brlapi_error_location()));
         g_free(handle);
         baum->brlapi = NULL;
-        return;
+        return false;
     }
     baum->deferred_init = 0;
 
@@ -669,6 +669,7 @@ static void baum_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     qemu_set_fd_handler(baum->brlapi_fd, baum_chr_read, NULL, baum);
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 static void char_braille_class_init(ObjectClass *oc, const void *data)

chardev/char-console.c

@@ -26,11 +26,12 @@
 #include "chardev/char-win.h"
 #include "qemu/module.h"
 
-static void console_chr_open(Chardev *chr, ChardevBackend *backend,
+static bool console_chr_open(Chardev *chr, ChardevBackend *backend,
                              Error **errp)
 {
     win_chr_set_file(chr, GetStdHandle(STD_OUTPUT_HANDLE), true);
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 static void char_console_class_init(ObjectClass *oc, const void *data)

chardev/char-file.c

@@ -34,7 +34,7 @@
 #include "chardev/char-fd.h"
 #endif
 
-static void file_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool file_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevFile *file = backend->u.file.data;
 #ifdef _WIN32
@@ -44,7 +44,7 @@ static void file_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 
     if (file->in) {
         error_setg(errp, "input file not supported");
-        return;
+        return false;
     }
 
     if (file->has_append && file->append) {
@@ -61,7 +61,7 @@ static void file_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
                      FILE_ATTRIBUTE_NORMAL, NULL);
     if (out == INVALID_HANDLE_VALUE) {
         error_setg(errp, "open %s failed", file->out);
-        return;
+        return false;
     }
 
     win_chr_set_file(chr, out, false);
@@ -77,7 +77,7 @@ static void file_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 
     out = qmp_chardev_open_file_source(file->out, flags, errp);
     if (out < 0) {
-        return;
+        return false;
     }
 
     if (file->in) {
@@ -85,7 +85,7 @@ static void file_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         in = qmp_chardev_open_file_source(file->in, flags, errp);
         if (in < 0) {
             qemu_close(out);
-            return;
+            return false;
         }
     }
 
@@ -94,11 +94,12 @@ static void file_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         if (in >= 0) {
             qemu_close(in);
         }
-        return;
+        return false;
     }
 #endif
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 static void file_chr_parse(QemuOpts *opts, ChardevBackend *backend,

chardev/char-hub.c

@@ -203,7 +203,7 @@ static void hub_chr_update_read_handlers(Chardev *chr)
     }
 }
 
-static void hub_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool hub_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevHub *hub = backend->u.hub.data;
     HubChardev *d = HUB_CHARDEV(chr);
@@ -213,7 +213,7 @@ static void hub_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 
     if (list == NULL) {
         error_setg(errp, "hub: 'chardevs' list is not defined");
-        return;
+        return false;
     }
 
     while (list) {
@@ -223,17 +223,17 @@ static void hub_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         if (s == NULL) {
             error_setg(errp, "hub: chardev can't be found by id '%s'",
                        list->value);
-            return;
+            return false;
         }
         if (CHARDEV_IS_HUB(s) || CHARDEV_IS_MUX(s)) {
             error_setg(errp, "hub: multiplexers and hub devices can't be "
                        "stacked, check chardev '%s', chardev should not "
                        "be a hub device or have 'mux=on' enabled",
                        list->value);
-            return;
+            return false;
         }
         if (!hub_chr_attach_chardev(d, s, errp)) {
-            return;
+            return false;
         }
         list = list->next;
     }
@@ -242,6 +242,7 @@ static void hub_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
      * Closed until an explicit event from backend, so we don't
      * send CHR_EVENT_OPENED now.
      */
+    return true;
 }
 
 static void hub_chr_parse(QemuOpts *opts, ChardevBackend *backend, Error **errp)

chardev/char-mux.c

@@ -361,7 +361,7 @@ void mux_set_focus(Chardev *chr, unsigned int focus)
     mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_IN);
 }
 
-static void mux_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool mux_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevMux *mux = backend->u.mux.data;
     Chardev *drv;
@@ -370,12 +370,12 @@ static void mux_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     drv = qemu_chr_find(mux->chardev);
     if (drv == NULL) {
         error_setg(errp, "mux: base chardev %s not found", mux->chardev);
-        return;
+        return false;
     }
 
     d->focus = -1;
     if (!qemu_chr_fe_init(&d->chr, drv, errp)) {
-        return;
+        return false;
     }
 
     /*
@@ -385,6 +385,8 @@ static void mux_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     if (muxes_opened) {
         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
     }
+
+    return true;
 }
 
 static void mux_chr_parse(QemuOpts *opts, ChardevBackend *backend, Error **errp)

chardev/char-null.c

@@ -26,9 +26,9 @@
 #include "chardev/char.h"
 #include "qemu/module.h"
 
-static void null_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool null_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
-    /* do not send CHR_EVENT_OPENED */
+    return true;
 }
 
 static void char_null_class_init(ObjectClass *oc, const void *data)

chardev/char-parallel.c

@@ -157,7 +157,7 @@ static int parallel_chr_ioctl(Chardev *chr, int cmd, void *arg)
     return 0;
 }
 
-static void parallel_chr_open_fd(Chardev *chr, int fd, Error **errp)
+static bool parallel_chr_open_fd(Chardev *chr, int fd, Error **errp)
 {
     ParallelChardev *drv = PARALLEL_CHARDEV(chr);
 
@@ -165,11 +165,12 @@ static void parallel_chr_open_fd(Chardev *chr, int fd, Error **errp)
 
     if (ioctl(fd, PPCLAIM) < 0) {
         error_setg_errno(errp, errno, "not a parallel port");
-        return;
+        return false;
     }
 
     drv->mode = IEEE1284_MODE_COMPAT;
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 #endif /* __linux__ */
 
@@ -225,15 +226,16 @@ static int parallel_chr_ioctl(Chardev *chr, int cmd, void *arg)
     return 0;
 }
 
-static void parallel_chr_open_fd(Chardev *chr, int fd, Error **errp)
+static bool parallel_chr_open_fd(Chardev *chr, int fd, Error **errp)
 {
     ParallelChardev *drv = PARALLEL_CHARDEV(chr);
     drv->fd = fd;
+    return true;
 }
 #endif
 
 #ifdef HAVE_CHARDEV_PARALLEL
-static void parallel_chr_open(Chardev *chr,
+static bool parallel_chr_open(Chardev *chr,
                               ChardevBackend *backend,
                               Error **errp)
 {
@@ -242,9 +244,9 @@ static void parallel_chr_open(Chardev *chr,
 
     fd = qmp_chardev_open_file_source(parallel->device, O_RDWR, errp);
     if (fd < 0) {
-        return;
+        return false;
     }
-    parallel_chr_open_fd(chr, fd, errp);
+    return parallel_chr_open_fd(chr, fd, errp);
 }
 
 static void parallel_chr_parse(QemuOpts *opts, ChardevBackend *backend,

chardev/char-pipe.c

@@ -103,21 +103,22 @@ static int win_chr_pipe_init(Chardev *chr, const char *filename,
     return -1;
 }
 
-static void pipe_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool pipe_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevHostdev *opts = backend->u.pipe.data;
     const char *filename = opts->device;
 
     if (win_chr_pipe_init(chr, filename, errp) < 0) {
-        return;
+        return false;
     }
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 #else
 
-static void pipe_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool pipe_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevHostdev *opts = backend->u.pipe.data;
     int fd_in, fd_out;
@@ -143,7 +144,7 @@ static void pipe_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         );
         if (fd_in < 0) {
             error_setg_file_open(errp, errno, filename);
-            return;
+            return false;
         }
     }
 
@@ -152,10 +153,11 @@ static void pipe_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         if (fd_out != fd_in) {
             close(fd_out);
         }
-        return;
+        return false;
     }
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 #endif /* !_WIN32 */

chardev/char-pty.c

@@ -331,7 +331,7 @@ static int qemu_openpty_raw(int *aslave, char *pty_name)
     return amaster;
 }
 
-static void pty_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool pty_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     PtyChardev *s;
     int master_fd, slave_fd;
@@ -342,13 +342,13 @@ static void pty_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     master_fd = qemu_openpty_raw(&slave_fd, pty_name);
     if (master_fd < 0) {
         error_setg_errno(errp, errno, "Failed to create PTY");
-        return;
+        return false;
     }
 
     close(slave_fd);
     if (!qemu_set_blocking(master_fd, false, errp)) {
         close(master_fd);
-        return;
+        return false;
     }
 
     chr->filename = g_strdup_printf("pty:%s", pty_name);
@@ -368,10 +368,13 @@ static void pty_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 
         if (res != 0) {
             error_setg_errno(errp, errno, "Failed to create PTY symlink");
+            return false;
         } else {
             s->path = g_strdup(path);
         }
     }
+
+    return true;
 }
 
 static void pty_chr_parse(QemuOpts *opts, ChardevBackend *backend, Error **errp)

chardev/char-ringbuf.c

@@ -92,7 +92,7 @@ static void char_ringbuf_finalize(Object *obj)
     g_free(d->cbuf);
 }
 
-static void ringbuf_chr_open(Chardev *chr,
+static bool ringbuf_chr_open(Chardev *chr,
                              ChardevBackend *backend,
                              Error **errp)
 {
@@ -104,7 +104,7 @@ static void ringbuf_chr_open(Chardev *chr,
     /* The size must be power of 2 */
     if (d->size & (d->size - 1)) {
         error_setg(errp, "size of ringbuf chardev must be power of two");
-        return;
+        return false;
     }
 
     d->prod = 0;
@@ -112,6 +112,7 @@ static void ringbuf_chr_open(Chardev *chr,
     d->cbuf = g_malloc0(d->size);
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 void qmp_ringbuf_write(const char *device, const char *data,

chardev/char-serial.c

@@ -41,15 +41,17 @@
 
 #ifdef _WIN32
 
-static void serial_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool serial_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevHostdev *serial = backend->u.serial.data;
     int ret = win_chr_serial_init(chr, serial->device, errp);
     if (ret < 0) {
-        return;
+        return false;
     }
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+
+    return true;
 }
 
 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)      \
@@ -259,7 +261,7 @@ static int serial_chr_ioctl(Chardev *chr, int cmd, void *arg)
     return 0;
 }
 
-static void serial_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool serial_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevHostdev *serial = backend->u.serial.data;
     int fd;
@@ -267,20 +269,21 @@ static void serial_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     fd = qmp_chardev_open_file_source(serial->device, O_RDWR | O_NONBLOCK,
                                       errp);
     if (fd < 0) {
-        return;
+        return false;
     }
     if (!qemu_set_blocking(fd, false, errp)) {
         close(fd);
-        return;
+        return false;
     }
     tty_serial_init(fd, 115200, 'N', 8, 1);
 
     if (!qemu_chr_open_fd(chr, fd, fd, errp)) {
         close(fd);
-        return;
+        return false;
     }
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 #endif /* __linux__ || __sun__ */
 

chardev/char-socket.c

@@ -1365,7 +1365,7 @@ static bool qmp_chardev_validate_socket(ChardevSocket *sock,
 }
 
 
-static void tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     SocketChardev *s = SOCKET_CHARDEV(chr);
     ChardevSocket *sock = backend->u.socket.data;
@@ -1390,7 +1390,7 @@ static void tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         if (!creds) {
             error_setg(errp, "No TLS credentials with id '%s'",
                        sock->tls_creds);
-            return;
+            return false;
         }
         s->tls_creds = (QCryptoTLSCreds *)
             object_dynamic_cast(creds,
@@ -1398,7 +1398,7 @@ static void tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         if (!s->tls_creds) {
             error_setg(errp, "Object with id '%s' is not TLS credentials",
                        sock->tls_creds);
-            return;
+            return false;
         }
         object_ref(OBJECT(s->tls_creds));
         if (!qcrypto_tls_creds_check_endpoint(s->tls_creds,
@@ -1406,7 +1406,7 @@ static void tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
                                           ? QCRYPTO_TLS_CREDS_ENDPOINT_SERVER
                                           : QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
                                           errp)) {
-            return;
+            return false;
         }
     }
     s->tls_authz = g_strdup(sock->tls_authz);
@@ -1414,7 +1414,7 @@ static void tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     s->addr = addr = socket_address_flatten(sock->addr);
 
     if (!qmp_chardev_validate_socket(sock, addr, errp)) {
-        return;
+        return false;
     }
 
     qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE);
@@ -1431,7 +1431,7 @@ static void tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
      */
     if (!chr->handover_yank_instance) {
         if (!yank_register_instance(CHARDEV_YANK_INSTANCE(chr->label), errp)) {
-            return;
+            return false;
         }
     }
     s->registered_yank = true;
@@ -1441,15 +1441,16 @@ static void tcp_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     if (s->is_listen) {
         if (qmp_chardev_open_socket_server(chr, is_telnet || is_tn3270,
                                            is_waitconnect, errp) < 0) {
-            return;
+            return false;
         }
     } else {
         if (qmp_chardev_open_socket_client(chr, reconnect_ms, errp) < 0) {
-            return;
+            return false;
         }
     }
 
     /* be isn't opened until we get a connection */
+    return true;
 }
 
 static void tcp_chr_parse(QemuOpts *opts, ChardevBackend *backend, Error **errp)

chardev/char-stdio.c

@@ -85,19 +85,19 @@ static void term_stdio_handler(int sig)
     stdio_chr_set_echo(NULL, stdio_echo_state);
 }
 
-static void stdio_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool stdio_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevStdio *opts = backend->u.stdio.data;
     struct sigaction act;
 
     if (is_daemonized()) {
         error_setg(errp, "cannot use stdio with -daemonize");
-        return;
+        return false;
     }
 
     if (stdio_in_use) {
         error_setg(errp, "cannot use stdio by multiple character devices");
-        return;
+        return false;
     }
 
     stdio_in_use = true;
@@ -105,11 +105,11 @@ static void stdio_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     old_fd1_flags = fcntl(1, F_GETFL);
     tcgetattr(0, &oldtty);
     if (!qemu_set_blocking(0, false, errp)) {
-        return;
+        return false;
     }
 
     if (!qemu_chr_open_fd(chr, 0, 1, errp)) {
-        return;
+        return false;
     }
 
     atexit(term_exit);
@@ -122,6 +122,7 @@ static void stdio_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     stdio_chr_set_echo(chr, false);
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 #endif
 

chardev/char-udp.c

@@ -188,7 +188,7 @@ static void udp_chr_parse(QemuOpts *opts, ChardevBackend *backend, Error **errp)
     }
 }
 
-static void upd_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool upd_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevUdp *udp = backend->u.udp.data;
     SocketAddress *local_addr = socket_address_flatten(udp->local);
@@ -203,7 +203,7 @@ static void upd_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     qapi_free_SocketAddress(remote_addr);
     if (ret < 0) {
         object_unref(OBJECT(sioc));
-        return;
+        return false;
     }
 
     name = g_strdup_printf("chardev-udp-%s", chr->label);
@@ -212,6 +212,7 @@ static void upd_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 
     s->ioc = QIO_CHANNEL(sioc);
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 static void char_udp_class_init(ObjectClass *oc, const void *data)

chardev/char-win-stdio.c

@@ -142,7 +142,7 @@ static void win_stiod_chr_set_echo(Chardev *chr, bool echo)
     }
 }
 
-static void win_stdio_chr_open(Chardev *chr,
+static bool win_stdio_chr_open(Chardev *chr,
                                ChardevBackend *backend,
                                Error **errp)
 {
@@ -155,7 +155,7 @@ static void win_stdio_chr_open(Chardev *chr,
     stdio->hStdIn = GetStdHandle(STD_INPUT_HANDLE);
     if (stdio->hStdIn == INVALID_HANDLE_VALUE) {
         error_setg(errp, "cannot open stdio: invalid handle");
-        return;
+        return false;
     }
 
     is_console = GetConsoleMode(stdio->hStdIn, &dwMode) != 0;
@@ -208,7 +208,7 @@ static void win_stdio_chr_open(Chardev *chr,
     win_stiod_chr_set_echo(chr, false);
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
-    return;
+    return true;
 
 err3:
     qemu_del_wait_object(stdio->hInputReadyEvent, NULL, NULL);
@@ -217,6 +217,7 @@ err2:
     CloseHandle(stdio->hInputDoneEvent);
 err1:
     qemu_del_wait_object(stdio->hStdIn, NULL, NULL);
+    return false;
 }
 
 static void char_win_stdio_finalize(Object *obj)

chardev/msmouse.c

@@ -253,7 +253,7 @@ static void char_msmouse_finalize(Object *obj)
     fifo8_destroy(&mouse->outbuf);
 }
 
-static void msmouse_chr_open(Chardev *chr,
+static bool msmouse_chr_open(Chardev *chr,
                              ChardevBackend *backend,
                              Error **errp)
 {
@@ -265,6 +265,7 @@ static void msmouse_chr_open(Chardev *chr,
     fifo8_create(&mouse->outbuf, MSMOUSE_BUF_SZ);
 
     /* Never send CHR_EVENT_OPENED */
+    return true;
 }
 
 static void char_msmouse_class_init(ObjectClass *oc, const void *data)

chardev/spice.c

@@ -251,7 +251,7 @@ static void chr_open(Chardev *chr, const char *subtype)
     s->sin.subtype = g_strdup(subtype);
 }
 
-static void spice_vmc_chr_open(Chardev *chr, ChardevBackend *backend,
+static bool spice_vmc_chr_open(Chardev *chr, ChardevBackend *backend,
                                Error **errp)
 {
     ChardevSpiceChannel *spicevmc = backend->u.spicevmc.data;
@@ -272,13 +272,14 @@ static void spice_vmc_chr_open(Chardev *chr, ChardevBackend *backend,
                           subtypes);
 
         g_free(subtypes);
-        return;
+        return false;
     }
 
     chr_open(chr, type);
+    return true;
 }
 
-static void spice_port_chr_open(Chardev *chr, ChardevBackend *backend,
+static bool spice_port_chr_open(Chardev *chr, ChardevBackend *backend,
                                 Error **errp)
 {
     ChardevSpicePort *spiceport = backend->u.spiceport.data;
@@ -287,12 +288,12 @@ static void spice_port_chr_open(Chardev *chr, ChardevBackend *backend,
 
     if (name == NULL) {
         error_setg(errp, "missing name parameter");
-        return;
+        return false;
     }
 
     if (!using_spice) {
         error_setg(errp, "spice not enabled");
-        return;
+        return false;
     }
 
     chr_open(chr, "port");
@@ -301,6 +302,7 @@ static void spice_port_chr_open(Chardev *chr, ChardevBackend *backend,
     s->sin.portname = g_strdup(name);
 
     vmc_register_interface(s);
+    return true;
 }
 
 static void spice_vmc_chr_parse(QemuOpts *opts, ChardevBackend *backend,

chardev/wctablet.c

@@ -324,7 +324,7 @@ static void wctablet_chr_finalize(Object *obj)
     }
 }
 
-static void wctablet_chr_open(Chardev *chr,
+static bool wctablet_chr_open(Chardev *chr,
                               ChardevBackend *backend,
                               Error **errp)
 {
@@ -339,6 +339,7 @@ static void wctablet_chr_open(Chardev *chr,
                                              &wctablet_handler);
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 static void wctablet_chr_class_init(ObjectClass *oc, const void *data)

gdbstub/system.c

@@ -233,9 +233,10 @@ static int gdb_chr_write(Chardev *chr, const uint8_t *buf, int len)
     return len;
 }
 
-static void gdb_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool gdb_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     /* Never send CHR_EVENT_OPENED */
+    return true;
 }
 
 static void char_gdb_class_init(ObjectClass *oc, const void *data)

include/chardev/char.h

@@ -260,7 +260,7 @@ struct ChardevClass {
     void (*chr_parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 
     /* called after construction, open/starts the backend */
-    void (*chr_open)(Chardev *chr, ChardevBackend *backend, Error **errp);
+    bool (*chr_open)(Chardev *chr, ChardevBackend *backend, Error **errp);
 
     /* write buf to the backend */
     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);

ui/console-vc.c

@@ -1093,7 +1093,7 @@ void qemu_text_console_update_size(QemuTextConsole *c)
     dpy_text_resize(QEMU_CONSOLE(c), c->width, c->height);
 }
 
-static void vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ChardevVC *vc = backend->u.vc.data;
     VCChardev *drv = VC_CHARDEV(chr);
@@ -1142,6 +1142,7 @@ static void vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     }
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 static void vc_chr_parse(QemuOpts *opts, ChardevBackend *backend, Error **errp)

ui/dbus-chardev.c

@@ -176,7 +176,7 @@ dbus_chr_send_break(
     return DBUS_METHOD_INVOCATION_HANDLED;
 }
 
-static void dbus_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool dbus_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     ERRP_GUARD();
 
@@ -206,9 +206,9 @@ static void dbus_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     CHARDEV_CLASS(object_class_by_name(TYPE_CHARDEV_SOCKET))->chr_parse(
         opts, be, errp);
     if (*errp) {
-        return;
+        return false;
     }
-    CHARDEV_CLASS(object_class_by_name(TYPE_CHARDEV_SOCKET))->chr_open(
+    return CHARDEV_CLASS(object_class_by_name(TYPE_CHARDEV_SOCKET))->chr_open(
         chr, be, errp);
 }
 

ui/gtk.c

@@ -1963,11 +1963,11 @@ static void gd_vc_chr_set_echo(Chardev *chr, bool echo)
 
 static int nb_vcs;
 static Chardev *vcs[MAX_VCS];
-static void gd_vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool gd_vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     if (nb_vcs == MAX_VCS) {
         error_setg(errp, "Maximum number of consoles reached");
-        return;
+        return false;
     }
 
     vcs[nb_vcs++] = chr;
@@ -1976,6 +1976,7 @@ static void gd_vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
      * console/chardev init sometimes completes elsewhere in a 2nd
      * stage, so defer OPENED events until they are fully initialized
      */
+    return true;
 }
 
 static void char_gd_vc_class_init(ObjectClass *oc, const void *data)

ui/spice-app.c

@@ -49,7 +49,7 @@ struct VCChardev {
 
 struct VCChardevClass {
     ChardevClass parent;
-    void (*parent_open)(Chardev *chr, ChardevBackend *backend, Error **errp);
+    bool (*parent_init)(Chardev *chr, ChardevBackend *backend, Error **errp);
 };
 
 #define TYPE_CHARDEV_VC "chardev-vc"
@@ -66,11 +66,12 @@ chr_spice_backend_new(void)
     return be;
 }
 
-static void vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
+static bool vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
 {
     VCChardevClass *vc = CHARDEV_VC_GET_CLASS(chr);
     ChardevBackend *be;
     const char *fqdn = NULL;
+    bool ok;
 
     if (strstart(chr->label, "serial", NULL)) {
         fqdn = "org.qemu.console.serial.0";
@@ -83,8 +84,9 @@ static void vc_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     be = chr_spice_backend_new();
     be->u.spiceport.data->fqdn = fqdn ?
         g_strdup(fqdn) : g_strdup_printf("org.qemu.console.%s", chr->label);
-    vc->parent_open(chr, be, errp);
+    ok = vc->parent_init(chr, be, errp);
     qapi_free_ChardevBackend(be);
+    return ok;
 }
 
 static void vc_chr_set_echo(Chardev *chr, bool echo)
@@ -102,7 +104,7 @@ static void char_vc_class_init(ObjectClass *oc, const void *data)
     VCChardevClass *vc = CHARDEV_VC_CLASS(oc);
     ChardevClass *cc = CHARDEV_CLASS(oc);
 
-    vc->parent_open = cc->chr_open;
+    vc->parent_init = cc->chr_open;
 
     cc->chr_parse = vc_chr_parse;
     cc->chr_open = vc_chr_open;

ui/vdagent.c

@@ -660,8 +660,7 @@ static void vdagent_chr_recv_clipboard(VDAgentChardev *vd, VDAgentMessage *msg)
 /* ------------------------------------------------------------------ */
 /* chardev backend                                                    */
 
-static void vdagent_chr_open(Chardev *chr,
-                             ChardevBackend *backend,
+static bool vdagent_chr_open(Chardev *chr, ChardevBackend *backend,
                              Error **errp)
 {
     VDAgentChardev *vd = QEMU_VDAGENT_CHARDEV(chr);
@@ -673,7 +672,7 @@ static void vdagent_chr_open(Chardev *chr,
      * so we have to byteswap everything on BE hosts.
      */
     error_setg(errp, "vdagent is not supported on bigendian hosts");
-    return;
+    return false;
 #endif
 
     vd->mouse = VDAGENT_MOUSE_DEFAULT;
@@ -692,6 +691,7 @@ static void vdagent_chr_open(Chardev *chr,
     }
 
     qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    return true;
 }
 
 static void vdagent_clipboard_peer_register(VDAgentChardev *vd)
@@ -1074,7 +1074,7 @@ static const VMStateDescription vmstate_vdagent = {
     }
 };
 
-static void vdagent_chr_init(Object *obj)
+static void vdagent_chr_instance_init(Object *obj)
 {
     VDAgentChardev *vd = QEMU_VDAGENT_CHARDEV(obj);
 
@@ -1097,7 +1097,7 @@ static const TypeInfo vdagent_chr_type_info = {
     .name = TYPE_CHARDEV_QEMU_VDAGENT,
     .parent = TYPE_CHARDEV,
     .instance_size = sizeof(VDAgentChardev),
-    .instance_init = vdagent_chr_init,
+    .instance_init = vdagent_chr_instance_init,
     .instance_finalize = vdagent_chr_fini,
     .class_init = vdagent_chr_class_init,
 };