Merge remote-tracking branch 'remotes/elmarco/tags/chardev-pull-request' into staging

Chardev fixes

# gpg: Signature made Wed 13 Feb 2019 16:18:36 GMT
# gpg:                using RSA key DAE8E10975969CE5
# gpg: Good signature from "Marc-André Lureau <marcandre.lureau@redhat.com>" [full]
# gpg:                 aka "Marc-André Lureau <marcandre.lureau@gmail.com>" [full]
# Primary key fingerprint: 87A9 BD93 3F87 C606 D276  F62D DAE8 E109 7596 9CE5

* remotes/elmarco/tags/chardev-pull-request: (25 commits)
  char-pty: remove write_lock usage
  char-pty: remove the check for connection on write
  chardev: add a note about frontend sources and context switch
  terminal3270: do not use backend timer sources
  char: update the mux handlers in class callback
  chardev/wctablet: Fix a typo
  char: allow specifying a GMainContext at opening time
  chardev: ensure termios is fully initialized
  tests: expand coverage of socket chardev test
  chardev: fix race with client connections in tcp_chr_wait_connected
  chardev: disallow TLS/telnet/websocket with tcp_chr_wait_connected
  chardev: honour the reconnect setting in tcp_chr_wait_connected
  chardev: use a state machine for socket connection state
  chardev: split up qmp_chardev_open_socket connection code
  chardev: split tcp_chr_wait_connected into two methods
  chardev: remove unused 'sioc' variable & cleanup paths
  chardev: ensure qemu_chr_parse_compat reports missing driver error
  chardev: remove many local variables in qemu_chr_parse_socket
  chardev: forbid 'wait' option with client sockets
  chardev: forbid 'reconnect' option with server sockets
  ...

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

chardev/char-fe.c

@@ -246,14 +246,15 @@ void qemu_chr_fe_deinit(CharBackend *b, bool del)
     }
 }
 
-void qemu_chr_fe_set_handlers(CharBackend *b,
-                              IOCanReadHandler *fd_can_read,
-                              IOReadHandler *fd_read,
-                              IOEventHandler *fd_event,
-                              BackendChangeHandler *be_change,
-                              void *opaque,
-                              GMainContext *context,
-                              bool set_open)
+void qemu_chr_fe_set_handlers_full(CharBackend *b,
+                                   IOCanReadHandler *fd_can_read,
+                                   IOReadHandler *fd_read,
+                                   IOEventHandler *fd_event,
+                                   BackendChangeHandler *be_change,
+                                   void *opaque,
+                                   GMainContext *context,
+                                   bool set_open,
+                                   bool sync_state)
 {
     Chardev *s;
     int fe_open;
@@ -285,14 +286,24 @@ void qemu_chr_fe_set_handlers(CharBackend *b,
         qemu_chr_fe_take_focus(b);
         /* We're connecting to an already opened device, so let's make sure we
            also get the open event */
-        if (s->be_open) {
+        if (sync_state && s->be_open) {
             qemu_chr_be_event(s, CHR_EVENT_OPENED);
         }
     }
+}
 
-    if (CHARDEV_IS_MUX(s)) {
-        mux_chr_set_handlers(s, context);
-    }
+void qemu_chr_fe_set_handlers(CharBackend *b,
+                              IOCanReadHandler *fd_can_read,
+                              IOReadHandler *fd_read,
+                              IOEventHandler *fd_event,
+                              BackendChangeHandler *be_change,
+                              void *opaque,
+                              GMainContext *context,
+                              bool set_open)
+{
+    qemu_chr_fe_set_handlers_full(b, fd_can_read, fd_read, fd_event, be_change,
+                                  opaque, context, set_open,
+                                  true);
 }
 
 void qemu_chr_fe_take_focus(CharBackend *b)

chardev/char-mux.c

@@ -278,18 +278,18 @@ static void char_mux_finalize(Object *obj)
     qemu_chr_fe_deinit(&d->chr, false);
 }
 
-void mux_chr_set_handlers(Chardev *chr, GMainContext *context)
+static void mux_chr_update_read_handlers(Chardev *chr)
 {
     MuxChardev *d = MUX_CHARDEV(chr);
 
     /* Fix up the real driver with mux routines */
-    qemu_chr_fe_set_handlers(&d->chr,
-                             mux_chr_can_read,
-                             mux_chr_read,
-                             mux_chr_event,
-                             NULL,
-                             chr,
-                             context, true);
+    qemu_chr_fe_set_handlers_full(&d->chr,
+                                  mux_chr_can_read,
+                                  mux_chr_read,
+                                  mux_chr_event,
+                                  NULL,
+                                  chr,
+                                  chr->gcontext, true, false);
 }
 
 void mux_set_focus(Chardev *chr, int focus)
@@ -367,7 +367,7 @@ static int open_muxes(Chardev *chr)
      * mark mux as OPENED so any new FEs will immediately receive
      * OPENED event
      */
-    qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+    chr->be_open = 1;
 
     return 0;
 }
@@ -383,6 +383,7 @@ static void char_mux_class_init(ObjectClass *oc, void *data)
     cc->chr_add_watch = mux_chr_add_watch;
     cc->chr_be_event = mux_chr_be_event;
     cc->chr_machine_done = open_muxes;
+    cc->chr_update_read_handler = mux_chr_update_read_handlers;
 }
 
 static const TypeInfo char_mux_type_info = {

chardev/char-pty.c

@@ -36,15 +36,12 @@ typedef struct {
     QIOChannel *ioc;
     int read_bytes;
 
-    /* Protected by the Chardev chr_write_lock.  */
     int connected;
     GSource *timer_src;
-    GSource *open_source;
 } PtyChardev;
 
 #define PTY_CHARDEV(obj) OBJECT_CHECK(PtyChardev, (obj), TYPE_CHARDEV_PTY)
 
-static void pty_chr_update_read_handler_locked(Chardev *chr);
 static void pty_chr_state(Chardev *chr, int connected);
 
 static void pty_chr_timer_cancel(PtyChardev *s)
@@ -56,32 +53,19 @@ static void pty_chr_timer_cancel(PtyChardev *s)
     }
 }
 
-static void pty_chr_open_src_cancel(PtyChardev *s)
-{
-    if (s->open_source) {
-        g_source_destroy(s->open_source);
-        g_source_unref(s->open_source);
-        s->open_source = NULL;
-    }
-}
-
 static gboolean pty_chr_timer(gpointer opaque)
 {
     struct Chardev *chr = CHARDEV(opaque);
     PtyChardev *s = PTY_CHARDEV(opaque);
 
-    qemu_mutex_lock(&chr->chr_write_lock);
     pty_chr_timer_cancel(s);
-    pty_chr_open_src_cancel(s);
     if (!s->connected) {
         /* Next poll ... */
-        pty_chr_update_read_handler_locked(chr);
+        qemu_chr_be_update_read_handlers(chr, chr->gcontext);
     }
-    qemu_mutex_unlock(&chr->chr_write_lock);
     return FALSE;
 }
 
-/* Called with chr_write_lock held.  */
 static void pty_chr_rearm_timer(Chardev *chr, int ms)
 {
     PtyChardev *s = PTY_CHARDEV(chr);
@@ -94,8 +78,7 @@ static void pty_chr_rearm_timer(Chardev *chr, int ms)
     g_free(name);
 }
 
-/* Called with chr_write_lock held.  */
-static void pty_chr_update_read_handler_locked(Chardev *chr)
+static void pty_chr_update_read_handler(Chardev *chr)
 {
     PtyChardev *s = PTY_CHARDEV(chr);
     GPollFD pfd;
@@ -117,24 +100,12 @@ static void pty_chr_update_read_handler_locked(Chardev *chr)
     }
 }
 
-static void pty_chr_update_read_handler(Chardev *chr)
-{
-    qemu_mutex_lock(&chr->chr_write_lock);
-    pty_chr_update_read_handler_locked(chr);
-    qemu_mutex_unlock(&chr->chr_write_lock);
-}
-
-/* Called with chr_write_lock held.  */
 static int char_pty_chr_write(Chardev *chr, const uint8_t *buf, int len)
 {
     PtyChardev *s = PTY_CHARDEV(chr);
 
     if (!s->connected) {
-        /* guest sends data, check for (re-)connect */
-        pty_chr_update_read_handler_locked(chr);
-        if (!s->connected) {
-            return len;
-        }
+        return len;
     }
     return io_channel_send(s->ioc, buf, len);
 }
@@ -183,23 +154,11 @@ static gboolean pty_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
     return TRUE;
 }
 
-static gboolean qemu_chr_be_generic_open_func(gpointer opaque)
-{
-    Chardev *chr = CHARDEV(opaque);
-    PtyChardev *s = PTY_CHARDEV(opaque);
-
-    s->open_source = NULL;
-    qemu_chr_be_event(chr, CHR_EVENT_OPENED);
-    return FALSE;
-}
-
-/* Called with chr_write_lock held.  */
 static void pty_chr_state(Chardev *chr, int connected)
 {
     PtyChardev *s = PTY_CHARDEV(chr);
 
     if (!connected) {
-        pty_chr_open_src_cancel(s);
         remove_fd_in_watch(chr);
         s->connected = 0;
         /* (re-)connect poll interval for idle guests: once per second.
@@ -209,13 +168,8 @@ static void pty_chr_state(Chardev *chr, int connected)
     } else {
         pty_chr_timer_cancel(s);
         if (!s->connected) {
-            g_assert(s->open_source == NULL);
-            s->open_source = g_idle_source_new();
             s->connected = 1;
-            g_source_set_callback(s->open_source,
-                                  qemu_chr_be_generic_open_func,
-                                  chr, NULL);
-            g_source_attach(s->open_source, chr->gcontext);
+            qemu_chr_be_event(chr, CHR_EVENT_OPENED);
         }
         if (!chr->gsource) {
             chr->gsource = io_add_watch_poll(chr, s->ioc,
@@ -231,11 +185,9 @@ static void char_pty_finalize(Object *obj)
     Chardev *chr = CHARDEV(obj);
     PtyChardev *s = PTY_CHARDEV(obj);
 
-    qemu_mutex_lock(&chr->chr_write_lock);
     pty_chr_state(chr, 0);
     object_unref(OBJECT(s->ioc));
     pty_chr_timer_cancel(s);
-    qemu_mutex_unlock(&chr->chr_write_lock);
     qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
 }
 

chardev/char-serial.c

@@ -57,7 +57,7 @@ static void qmp_chardev_open_serial(Chardev *chr,
 static void tty_serial_init(int fd, int speed,
                             int parity, int data_bits, int stop_bits)
 {
-    struct termios tty;
+    struct termios tty = {0};
     speed_t spd;
 
 #if 0

chardev/char.c

@@ -490,6 +490,8 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
         return opts;
     }
 
+    error_report("'%s' is not a valid char driver", filename);
+
 fail:
     qemu_opts_del(opts);
     return NULL;
@@ -634,7 +636,8 @@ ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
     return backend;
 }
 
-Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
+Chardev *qemu_chr_new_from_opts(QemuOpts *opts, GMainContext *context,
+                                Error **errp)
 {
     const ChardevClass *cc;
     Chardev *chr = NULL;
@@ -674,7 +677,7 @@ Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
 
     chr = qemu_chardev_new(bid ? bid : id,
                            object_class_get_name(OBJECT_CLASS(cc)),
-                           backend, errp);
+                           backend, context, errp);
 
     if (chr == NULL) {
         goto out;
@@ -687,7 +690,7 @@ Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
         backend->type = CHARDEV_BACKEND_KIND_MUX;
         backend->u.mux.data = g_new0(ChardevMux, 1);
         backend->u.mux.data->chardev = g_strdup(bid);
-        mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, errp);
+        mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, context, errp);
         if (mux == NULL) {
             object_unparent(OBJECT(chr));
             chr = NULL;
@@ -703,7 +706,7 @@ out:
 }
 
 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
-                               bool permit_mux_mon)
+                               bool permit_mux_mon, GMainContext *context)
 {
     const char *p;
     Chardev *chr;
@@ -718,7 +721,7 @@ Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
     if (!opts)
         return NULL;
 
-    chr = qemu_chr_new_from_opts(opts, &err);
+    chr = qemu_chr_new_from_opts(opts, context, &err);
     if (!chr) {
         error_report_err(err);
         goto out;
@@ -736,10 +739,11 @@ out:
 
 static Chardev *qemu_chr_new_permit_mux_mon(const char *label,
                                           const char *filename,
-                                          bool permit_mux_mon)
+                                          bool permit_mux_mon,
+                                          GMainContext *context)
 {
     Chardev *chr;
-    chr = qemu_chr_new_noreplay(label, filename, permit_mux_mon);
+    chr = qemu_chr_new_noreplay(label, filename, permit_mux_mon, context);
     if (chr) {
         if (replay_mode != REPLAY_MODE_NONE) {
             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
@@ -753,14 +757,16 @@ static Chardev *qemu_chr_new_permit_mux_mon(const char *label,
     return chr;
 }
 
-Chardev *qemu_chr_new(const char *label, const char *filename)
+Chardev *qemu_chr_new(const char *label, const char *filename,
+                      GMainContext *context)
 {
-    return qemu_chr_new_permit_mux_mon(label, filename, false);
+    return qemu_chr_new_permit_mux_mon(label, filename, false, context);
 }
 
-Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename)
+Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename,
+                              GMainContext *context)
 {
-    return qemu_chr_new_permit_mux_mon(label, filename, true);
+    return qemu_chr_new_permit_mux_mon(label, filename, true, context);
 }
 
 static int qmp_query_chardev_foreach(Object *obj, void *data)
@@ -935,6 +941,7 @@ void qemu_chr_set_feature(Chardev *chr,
 
 Chardev *qemu_chardev_new(const char *id, const char *typename,
                           ChardevBackend *backend,
+                          GMainContext *gcontext,
                           Error **errp)
 {
     Object *obj;
@@ -947,6 +954,7 @@ Chardev *qemu_chardev_new(const char *id, const char *typename,
     obj = object_new(typename);
     chr = CHARDEV(obj);
     chr->label = g_strdup(id);
+    chr->gcontext = gcontext;
 
     qemu_char_open(chr, backend, &be_opened, &local_err);
     if (local_err) {
@@ -991,7 +999,7 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
     }
 
     chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
-                           backend, errp);
+                           backend, NULL, errp);
     if (!chr) {
         return NULL;
     }
@@ -1049,7 +1057,7 @@ ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
     }
 
     chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
-                               backend, errp);
+                               backend, chr->gcontext, errp);
     if (!chr_new) {
         return NULL;
     }

chardev/wctablet.c

@@ -177,7 +177,7 @@ static void wctablet_input_sync(DeviceState *dev)
 }
 
 static QemuInputHandler wctablet_handler = {
-    .name  = "QEMU Wacome Pen Tablet",
+    .name  = "QEMU Wacom Pen Tablet",
     .mask  = INPUT_EVENT_MASK_BTN | INPUT_EVENT_MASK_ABS,
     .event = wctablet_input_event,
     .sync  = wctablet_input_sync,

gdbstub.c

@@ -2531,7 +2531,7 @@ int gdbserver_start(const char *device)
          * FIXME: it's a bit weird to allow using a mux chardev here
          * and implicitly setup a monitor. We may want to break this.
          */
-        chr = qemu_chr_new_noreplay("gdb", device, true);
+        chr = qemu_chr_new_noreplay("gdb", device, true, NULL);
         if (!chr)
             return -1;
     }
@@ -2545,7 +2545,7 @@ int gdbserver_start(const char *device)
 
         /* Initialize a monitor terminal for gdb */
         mon_chr = qemu_chardev_new(NULL, TYPE_CHARDEV_GDB,
-                                   NULL, &error_abort);
+                                   NULL, NULL, &error_abort);
         monitor_init(mon_chr, 0);
     } else {
         qemu_chr_fe_deinit(&s->chr, true);

hmp.c

@@ -2395,7 +2395,7 @@ void hmp_chardev_add(Monitor *mon, const QDict *qdict)
     if (opts == NULL) {
         error_setg(&err, "Parsing chardev args failed");
     } else {
-        qemu_chr_new_from_opts(opts, &err);
+        qemu_chr_new_from_opts(opts, NULL, &err);
         qemu_opts_del(opts);
     }
     hmp_handle_error(mon, &err);

hw/arm/omap2.c

@@ -799,7 +799,7 @@ static struct omap_sti_s *omap_sti_init(struct omap_target_agent_s *ta,
     s->irq = irq;
     omap_sti_reset(s);
 
-    qemu_chr_fe_init(&s->chr, chr ?: qemu_chr_new("null", "null"),
+    qemu_chr_fe_init(&s->chr, chr ?: qemu_chr_new("null", "null", NULL),
                      &error_abort);
 
     memory_region_init_io(&s->iomem, NULL, &omap_sti_ops, s, "omap.sti",

hw/bt/hci-csr.c

@@ -501,7 +501,7 @@ static const TypeInfo char_hci_type_info = {
 Chardev *uart_hci_init(void)
 {
     return qemu_chardev_new(NULL, TYPE_CHARDEV_HCI,
-                            NULL, &error_abort);
+                            NULL, NULL, &error_abort);
 }
 
 static void register_types(void)

hw/char/omap_uart.c

@@ -63,7 +63,7 @@ struct omap_uart_s *omap_uart_init(hwaddr base,
     s->irq = irq;
     s->serial = serial_mm_init(get_system_memory(), base, 2, irq,
                                omap_clk_getrate(fclk)/16,
-                               chr ?: qemu_chr_new(label, "null"),
+                               chr ?: qemu_chr_new(label, "null", NULL),
                                DEVICE_NATIVE_ENDIAN);
     return s;
 }
@@ -183,6 +183,6 @@ void omap_uart_attach(struct omap_uart_s *s, Chardev *chr)
     /* TODO: Should reuse or destroy current s->serial */
     s->serial = serial_mm_init(get_system_memory(), s->base, 2, s->irq,
                                omap_clk_getrate(s->fclk) / 16,
-                               chr ?: qemu_chr_new("null", "null"),
+                               chr ?: qemu_chr_new("null", "null", NULL),
                                DEVICE_NATIVE_ENDIAN);
 }

hw/char/terminal3270.c

@@ -31,7 +31,7 @@ typedef struct Terminal3270 {
     uint8_t outv[OUTPUT_BUFFER_SIZE];
     int in_len;
     bool handshake_done;
-    GSource *timer_src;
+    guint timer_tag;
 } Terminal3270;
 
 #define TYPE_TERMINAL_3270 "x-terminal3270"
@@ -47,10 +47,9 @@ static int terminal_can_read(void *opaque)
 
 static void terminal_timer_cancel(Terminal3270 *t)
 {
-    if (t->timer_src) {
-        g_source_destroy(t->timer_src);
-        g_source_unref(t->timer_src);
-        t->timer_src = NULL;
+    if (t->timer_tag) {
+        g_source_remove(t->timer_tag);
+        t->timer_tag = 0;
     }
 }
 
@@ -100,8 +99,7 @@ static void terminal_read(void *opaque, const uint8_t *buf, int size)
     assert(size <= (INPUT_BUFFER_SIZE - t->in_len));
 
     terminal_timer_cancel(t);
-    t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
-                                           send_timing_mark_cb, t);
+    t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
     memcpy(&t->inv[t->in_len], buf, size);
     t->in_len += size;
     if (t->in_len < 2) {
@@ -160,8 +158,7 @@ static void chr_event(void *opaque, int event)
          * char-socket.c. Once qemu receives the terminal-type of the
          * client, mark handshake done and trigger everything rolling again.
          */
-        t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
-                                               send_timing_mark_cb, t);
+        t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
         break;
     case CHR_EVENT_CLOSED:
         sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;

hw/char/xen_console.c

@@ -211,7 +211,8 @@ static int con_init(struct XenLegacyDevice *xendev)
                           * FIXME: sure we want to support implicit
                           * muxed monitors here?
                           */
-                         qemu_chr_new_mux_mon(label, output), &error_abort);
+                         qemu_chr_new_mux_mon(label, output, NULL),
+                         &error_abort);
     }
 
     xenstore_store_pv_console_info(con->xendev.dev,

hw/isa/isa-superio.c

@@ -44,7 +44,7 @@ static void isa_superio_realize(DeviceState *dev, Error **errp)
             chr = parallel_hds[i];
             if (chr == NULL) {
                 name = g_strdup_printf("discarding-parallel%d", i);
-                chr = qemu_chr_new(name, "null");
+                chr = qemu_chr_new(name, "null", NULL);
             } else {
                 name = g_strdup_printf("parallel%d", i);
             }
@@ -84,7 +84,7 @@ static void isa_superio_realize(DeviceState *dev, Error **errp)
             chr = serial_hd(i);
             if (chr == NULL) {
                 name = g_strdup_printf("discarding-serial%d", i);
-                chr = qemu_chr_new(name, "null");
+                chr = qemu_chr_new(name, "null", NULL);
             } else {
                 name = g_strdup_printf("serial%d", i);
             }

hw/mips/boston.c

@@ -512,7 +512,7 @@ static void boston_mach_init(MachineState *machine)
     memory_region_init_io(lcd, NULL, &boston_lcd_ops, s, "boston-lcd", 0x8);
     memory_region_add_subregion_overlap(sys_mem, 0x17fff000, lcd, 0);
 
-    chr = qemu_chr_new("lcd", "vc:320x240");
+    chr = qemu_chr_new("lcd", "vc:320x240", NULL);
     qemu_chr_fe_init(&s->lcd_display, chr, NULL);
     qemu_chr_fe_set_handlers(&s->lcd_display, NULL, NULL,
                              boston_lcd_event, NULL, s, NULL, true);

hw/mips/mips_malta.c

@@ -568,7 +568,7 @@ static MaltaFPGAState *malta_fpga_init(MemoryRegion *address_space,
     memory_region_add_subregion(address_space, base, &s->iomem_lo);
     memory_region_add_subregion(address_space, base + 0xa00, &s->iomem_hi);
 
-    chr = qemu_chr_new("fpga", "vc:320x200");
+    chr = qemu_chr_new("fpga", "vc:320x200", NULL);
     qemu_chr_fe_init(&s->display, chr, NULL);
     qemu_chr_fe_set_handlers(&s->display, NULL, NULL,
                              malta_fgpa_display_event, NULL, s, NULL, true);

hw/usb/dev-serial.c

@@ -514,7 +514,7 @@ static USBDevice *usb_braille_init(USBBus *bus, const char *unused)
     USBDevice *dev;
     Chardev *cdrv;
 
-    cdrv = qemu_chr_new("braille", "braille");
+    cdrv = qemu_chr_new("braille", "braille", NULL);
     if (!cdrv)
         return NULL;
 

include/chardev/char-fe.h

@@ -67,7 +67,7 @@ bool qemu_chr_fe_backend_connected(CharBackend *be);
 bool qemu_chr_fe_backend_open(CharBackend *be);
 
 /**
- * qemu_chr_fe_set_handlers:
+ * qemu_chr_fe_set_handlers_full:
  * @b: a CharBackend
  * @fd_can_read: callback to get the amount of data the frontend may
  *               receive
@@ -79,12 +79,28 @@ bool qemu_chr_fe_backend_open(CharBackend *be);
  * @context: a main loop context or NULL for the default
  * @set_open: whether to call qemu_chr_fe_set_open() implicitely when
  * any of the handler is non-NULL
+ * @sync_state: whether to issue event callback with updated state
  *
  * Set the front end char handlers. The front end takes the focus if
  * any of the handler is non-NULL.
  *
  * Without associated Chardev, nothing is changed.
  */
+void qemu_chr_fe_set_handlers_full(CharBackend *b,
+                                   IOCanReadHandler *fd_can_read,
+                                   IOReadHandler *fd_read,
+                                   IOEventHandler *fd_event,
+                                   BackendChangeHandler *be_change,
+                                   void *opaque,
+                                   GMainContext *context,
+                                   bool set_open,
+                                   bool sync_state);
+
+/**
+ * qemu_chr_fe_set_handlers:
+ *
+ * Version of qemu_chr_fe_set_handlers_full() with sync_state = true.
+ */
 void qemu_chr_fe_set_handlers(CharBackend *b,
                               IOCanReadHandler *fd_can_read,
                               IOReadHandler *fd_read,
@@ -168,6 +184,9 @@ void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
  * is active; return the #GSource's tag.  If it is disconnected,
  * or without associated Chardev, return 0.
  *
+ * Note that you are responsible to update the front-end sources if
+ * you are switching the main context with qemu_chr_fe_set_handlers().
+ *
  * Returns: the source tag
  */
 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,

include/chardev/char-mux.h

@@ -55,7 +55,6 @@ typedef struct MuxChardev {
 #define CHARDEV_IS_MUX(chr)                             \
     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_MUX)
 
-void mux_chr_set_handlers(Chardev *chr, GMainContext *context);
 void mux_set_focus(Chardev *chr, int focus);
 void mux_chr_send_all_event(Chardev *chr, int event);