Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* KVM page size fix for PPC
* Support for Linux 4.4's new Hyper-V features
* Eliminate g_slice from areas I maintain
* checkpatch fix
* Peter's cpu_reload_memory_map() cleanups
* More changes to MAINTAINERS
* Require Python 2.6
* chardev creation fixes
* PCI requester id for ARM KVM
* cleanups and doc fixes
* Allow customization of the Hyper-V vendor id

# gpg: Signature made Mon 19 Oct 2015 09:13:10 BST using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"

* remotes/bonzini/tags/for-upstream: (49 commits)
  kvm: Allow the Hyper-V vendor ID to be specified
  kvm: Move x86-specific functions into target-i386/kvm.c
  kvm: Pass PCI device pointer to MSI routing functions
  hw/pci: Introduce pci_requester_id()
  kvm: Make KVM_CAP_SIGNAL_MSI globally available
  doc/rcu: fix g_free_rcu() usage example
  qemu-char: cleanup after completed conversion to cd->create
  qemu-char: convert ringbuf backend to data-driven creation
  qemu-char: convert vc backend to data-driven creation
  qemu-char: convert spice backend to data-driven creation
  qemu-char: convert console backend to data-driven creation
  qemu-char: convert stdio backend to data-driven creation
  qemu-char: convert testdev backend to data-driven creation
  qemu-char: convert braille backend to data-driven creation
  qemu-char: convert msmouse backend to data-driven creation
  qemu-char: convert mux backend to data-driven creation
  qemu-char: convert null backend to data-driven creation
  qemu-char: convert pty backend to data-driven creation
  qemu-char: convert UDP backend to data-driven creation
  qemu-char: convert socket backend to data-driven creation
  ...

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

1 files changed, 208 insertions, 187 deletions

diff --git a/qemu-char.c b/qemu-char.c
index 653ea10d6f..13371c4931 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -383,7 +383,10 @@ static int null_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
     return len;
 }
 
-static CharDriverState *qemu_chr_open_null(void)
+static CharDriverState *qemu_chr_open_null(const char *id,
+                                           ChardevBackend *backend,
+                                           ChardevReturn *ret,
+                                           Error **errp)
 {
     CharDriverState *chr;
 
@@ -679,11 +682,20 @@ static GSource *mux_chr_add_watch(CharDriverState *s, GIOCondition cond)
     return d->drv->chr_add_watch(d->drv, cond);
 }
 
-static CharDriverState *qemu_chr_open_mux(CharDriverState *drv)
+static CharDriverState *qemu_chr_open_mux(const char *id,
+                                          ChardevBackend *backend,
+                                          ChardevReturn *ret, Error **errp)
 {
-    CharDriverState *chr;
+    ChardevMux *mux = backend->mux;
+    CharDriverState *chr, *drv;
     MuxDriver *d;
 
+    drv = qemu_chr_find(mux->chardev);
+    if (drv == NULL) {
+        error_setg(errp, "mux: base chardev %s not found", mux->chardev);
+        return NULL;
+    }
+
     chr = qemu_chr_alloc();
     d = g_new0(MuxDriver, 1);
 
@@ -1078,18 +1090,17 @@ static CharDriverState *qemu_chr_open_fd(int fd_in, int fd_out)
     return chr;
 }
 
-static CharDriverState *qemu_chr_open_pipe(ChardevHostdev *opts)
+static CharDriverState *qemu_chr_open_pipe(const char *id,
+                                           ChardevBackend *backend,
+                                           ChardevReturn *ret,
+                                           Error **errp)
 {
+    ChardevHostdev *opts = backend->pipe;
     int fd_in, fd_out;
     char filename_in[CHR_MAX_FILENAME_SIZE];
     char filename_out[CHR_MAX_FILENAME_SIZE];
     const char *filename = opts->device;
 
-    if (filename == NULL) {
-        fprintf(stderr, "chardev: pipe: no filename given\n");
-        return NULL;
-    }
-
     snprintf(filename_in, CHR_MAX_FILENAME_SIZE, "%s.in", filename);
     snprintf(filename_out, CHR_MAX_FILENAME_SIZE, "%s.out", filename);
     TFR(fd_in = qemu_open(filename_in, O_RDWR | O_BINARY));
@@ -1101,6 +1112,7 @@ static CharDriverState *qemu_chr_open_pipe(ChardevHostdev *opts)
 	    close(fd_out);
         TFR(fd_in = fd_out = qemu_open(filename, O_RDWR | O_BINARY));
         if (fd_in < 0) {
+            error_setg_file_open(errp, errno, filename);
             return NULL;
         }
     }
@@ -1156,19 +1168,23 @@ static void qemu_chr_close_stdio(struct CharDriverState *chr)
     fd_chr_close(chr);
 }
 
-static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
+static CharDriverState *qemu_chr_open_stdio(const char *id,
+                                            ChardevBackend *backend,
+                                            ChardevReturn *ret,
+                                            Error **errp)
 {
+    ChardevStdio *opts = backend->stdio;
     CharDriverState *chr;
     struct sigaction act;
 
     if (is_daemonized()) {
-        error_report("cannot use stdio with -daemonize");
+        error_setg(errp, "cannot use stdio with -daemonize");
         return NULL;
     }
 
     if (stdio_in_use) {
-        error_report("cannot use stdio by multiple character devices");
-        exit(1);
+        error_setg(errp, "cannot use stdio by multiple character devices");
+        return NULL;
     }
 
     stdio_in_use = true;
@@ -1196,7 +1212,8 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
     || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
     || defined(__GLIBC__)
 
-#define HAVE_CHARDEV_TTY 1
+#define HAVE_CHARDEV_SERIAL 1
+#define HAVE_CHARDEV_PTY 1
 
 typedef struct {
     GIOChannel *fd;
@@ -1389,7 +1406,9 @@ static void pty_chr_close(struct CharDriverState *chr)
 }
 
 static CharDriverState *qemu_chr_open_pty(const char *id,
-                                          ChardevReturn *ret)
+                                          ChardevBackend *backend,
+                                          ChardevReturn *ret,
+                                          Error **errp)
 {
     CharDriverState *chr;
     PtyCharDriver *s;
@@ -1398,6 +1417,7 @@ static CharDriverState *qemu_chr_open_pty(const char *id,
 
     master_fd = qemu_openpty_raw(&slave_fd, pty_name);
     if (master_fd < 0) {
+        error_setg_errno(errp, errno, "Failed to create PTY");
         return NULL;
     }
 
@@ -1752,12 +1772,13 @@ static void pp_close(CharDriverState *chr)
     qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
 }
 
-static CharDriverState *qemu_chr_open_pp_fd(int fd)
+static CharDriverState *qemu_chr_open_pp_fd(int fd, Error **errp)
 {
     CharDriverState *chr;
     ParallelCharDriver *drv;
 
     if (ioctl(fd, PPCLAIM) < 0) {
+        error_setg_errno(errp, errno, "not a parallel port");
         close(fd);
         return NULL;
     }
@@ -1817,7 +1838,7 @@ static int pp_ioctl(CharDriverState *chr, int cmd, void *arg)
     return 0;
 }
 
-static CharDriverState *qemu_chr_open_pp_fd(int fd)
+static CharDriverState *qemu_chr_open_pp_fd(int fd, Error **errp)
 {
     CharDriverState *chr;
 
@@ -1832,6 +1853,8 @@ static CharDriverState *qemu_chr_open_pp_fd(int fd)
 
 #else /* _WIN32 */
 
+#define HAVE_CHARDEV_SERIAL 1
+
 typedef struct {
     int max_size;
     HANDLE hcom, hrecv, hsend;
@@ -1883,7 +1906,7 @@ static void win_chr_close(CharDriverState *chr)
     qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
 }
 
-static int win_chr_init(CharDriverState *chr, const char *filename)
+static int win_chr_init(CharDriverState *chr, const char *filename, Error **errp)
 {
     WinCharState *s = chr->opaque;
     COMMCONFIG comcfg;
@@ -1894,25 +1917,25 @@ static int win_chr_init(CharDriverState *chr, const char *filename)
 
     s->hsend = CreateEvent(NULL, TRUE, FALSE, NULL);
     if (!s->hsend) {
-        fprintf(stderr, "Failed CreateEvent\n");
+        error_setg(errp, "Failed CreateEvent");
         goto fail;
     }
     s->hrecv = CreateEvent(NULL, TRUE, FALSE, NULL);
     if (!s->hrecv) {
-        fprintf(stderr, "Failed CreateEvent\n");
+        error_setg(errp, "Failed CreateEvent");
         goto fail;
     }
 
     s->hcom = CreateFile(filename, GENERIC_READ|GENERIC_WRITE, 0, NULL,
                       OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
     if (s->hcom == INVALID_HANDLE_VALUE) {
-        fprintf(stderr, "Failed CreateFile (%lu)\n", GetLastError());
+        error_setg(errp, "Failed CreateFile (%lu)", GetLastError());
         s->hcom = NULL;
         goto fail;
     }
 
     if (!SetupComm(s->hcom, NRECVBUF, NSENDBUF)) {
-        fprintf(stderr, "Failed SetupComm\n");
+        error_setg(errp, "Failed SetupComm");
         goto fail;
     }
 
@@ -1923,23 +1946,23 @@ static int win_chr_init(CharDriverState *chr, const char *filename)
     CommConfigDialog(filename, NULL, &comcfg);
 
     if (!SetCommState(s->hcom, &comcfg.dcb)) {
-        fprintf(stderr, "Failed SetCommState\n");
+        error_setg(errp, "Failed SetCommState");
         goto fail;
     }
 
     if (!SetCommMask(s->hcom, EV_ERR)) {
-        fprintf(stderr, "Failed SetCommMask\n");
+        error_setg(errp, "Failed SetCommMask");
         goto fail;
     }
 
     cto.ReadIntervalTimeout = MAXDWORD;
     if (!SetCommTimeouts(s->hcom, &cto)) {
-        fprintf(stderr, "Failed SetCommTimeouts\n");
+        error_setg(errp, "Failed SetCommTimeouts");
         goto fail;
     }
 
     if (!ClearCommError(s->hcom, &err, &comstat)) {
-        fprintf(stderr, "Failed ClearCommError\n");
+        error_setg(errp, "Failed ClearCommError");
         goto fail;
     }
     qemu_add_polling_cb(win_chr_poll, chr);
@@ -2044,7 +2067,8 @@ static int win_chr_poll(void *opaque)
     return 0;
 }
 
-static CharDriverState *qemu_chr_open_win_path(const char *filename)
+static CharDriverState *qemu_chr_open_win_path(const char *filename,
+                                               Error **errp)
 {
     CharDriverState *chr;
     WinCharState *s;
@@ -2055,7 +2079,7 @@ static CharDriverState *qemu_chr_open_win_path(const char *filename)
     chr->chr_write = win_chr_write;
     chr->chr_close = win_chr_close;
 
-    if (win_chr_init(chr, filename) < 0) {
+    if (win_chr_init(chr, filename, errp) < 0) {
         g_free(s);
         g_free(chr);
         return NULL;
@@ -2079,7 +2103,8 @@ static int win_chr_pipe_poll(void *opaque)
     return 0;
 }
 
-static int win_chr_pipe_init(CharDriverState *chr, const char *filename)
+static int win_chr_pipe_init(CharDriverState *chr, const char *filename,
+                             Error **errp)
 {
     WinCharState *s = chr->opaque;
     OVERLAPPED ov;
@@ -2091,12 +2116,12 @@ static int win_chr_pipe_init(CharDriverState *chr, const char *filename)
 
     s->hsend = CreateEvent(NULL, TRUE, FALSE, NULL);
     if (!s->hsend) {
-        fprintf(stderr, "Failed CreateEvent\n");
+        error_setg(errp, "Failed CreateEvent");
         goto fail;
     }
     s->hrecv = CreateEvent(NULL, TRUE, FALSE, NULL);
     if (!s->hrecv) {
-        fprintf(stderr, "Failed CreateEvent\n");
+        error_setg(errp, "Failed CreateEvent");
         goto fail;
     }
 
@@ -2106,7 +2131,7 @@ static int win_chr_pipe_init(CharDriverState *chr, const char *filename)
                               PIPE_WAIT,
                               MAXCONNECT, NSENDBUF, NRECVBUF, NTIMEOUT, NULL);
     if (s->hcom == INVALID_HANDLE_VALUE) {
-        fprintf(stderr, "Failed CreateNamedPipe (%lu)\n", GetLastError());
+        error_setg(errp, "Failed CreateNamedPipe (%lu)", GetLastError());
         s->hcom = NULL;
         goto fail;
     }
@@ -2115,13 +2140,13 @@ static int win_chr_pipe_init(CharDriverState *chr, const char *filename)
     ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
     ret = ConnectNamedPipe(s->hcom, &ov);
     if (ret) {
-        fprintf(stderr, "Failed ConnectNamedPipe\n");
+        error_setg(errp, "Failed ConnectNamedPipe");
         goto fail;
     }
 
     ret = GetOverlappedResult(s->hcom, &ov, &size, TRUE);
     if (!ret) {
-        fprintf(stderr, "Failed GetOverlappedResult\n");
+        error_setg(errp, "Failed GetOverlappedResult");
         if (ov.hEvent) {
             CloseHandle(ov.hEvent);
             ov.hEvent = NULL;
@@ -2142,8 +2167,12 @@ static int win_chr_pipe_init(CharDriverState *chr, const char *filename)
 }
 
 
-static CharDriverState *qemu_chr_open_pipe(ChardevHostdev *opts)
+static CharDriverState *qemu_chr_open_pipe(const char *id,
+                                           ChardevBackend *backend,
+                                           ChardevReturn *ret,
+                                           Error **errp)
 {
+    ChardevHostdev *opts = backend->pipe;
     const char *filename = opts->device;
     CharDriverState *chr;
     WinCharState *s;
@@ -2154,7 +2183,7 @@ static CharDriverState *qemu_chr_open_pipe(ChardevHostdev *opts)
     chr->chr_write = win_chr_write;
     chr->chr_close = win_chr_close;
 
-    if (win_chr_pipe_init(chr, filename) < 0) {
+    if (win_chr_pipe_init(chr, filename, errp) < 0) {
         g_free(s);
         g_free(chr);
         return NULL;
@@ -2175,7 +2204,10 @@ static CharDriverState *qemu_chr_open_win_file(HANDLE fd_out)
     return chr;
 }
 
-static CharDriverState *qemu_chr_open_win_con(void)
+static CharDriverState *qemu_chr_open_win_con(const char *id,
+                                              ChardevBackend *backend,
+                                              ChardevReturn *ret,
+                                              Error **errp)
 {
     return qemu_chr_open_win_file(GetStdHandle(STD_OUTPUT_HANDLE));
 }
@@ -2316,7 +2348,10 @@ static void win_stdio_close(CharDriverState *chr)
     g_free(chr);
 }
 
-static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
+static CharDriverState *qemu_chr_open_stdio(const char *id,
+                                            ChardevBackend *backend,
+                                            ChardevReturn *ret,
+                                            Error **errp)
 {
     CharDriverState   *chr;
     WinStdioCharState *stdio;
@@ -2328,8 +2363,8 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
 
     stdio->hStdIn = GetStdHandle(STD_INPUT_HANDLE);
     if (stdio->hStdIn == INVALID_HANDLE_VALUE) {
-        fprintf(stderr, "cannot open stdio: invalid handle\n");
-        exit(1);
+        error_setg(errp, "cannot open stdio: invalid handle");
+        return NULL;
     }
 
     is_console = GetConsoleMode(stdio->hStdIn, &dwMode) != 0;
@@ -2341,25 +2376,30 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
     if (is_console) {
         if (qemu_add_wait_object(stdio->hStdIn,
                                  win_stdio_wait_func, chr)) {
-            fprintf(stderr, "qemu_add_wait_object: failed\n");
+            error_setg(errp, "qemu_add_wait_object: failed");
+            goto err1;
         }
     } else {
         DWORD   dwId;
             
         stdio->hInputReadyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
         stdio->hInputDoneEvent  = CreateEvent(NULL, FALSE, FALSE, NULL);
-        stdio->hInputThread     = CreateThread(NULL, 0, win_stdio_thread,
-                                               chr, 0, &dwId);
-
-        if (stdio->hInputThread == INVALID_HANDLE_VALUE
-            || stdio->hInputReadyEvent == INVALID_HANDLE_VALUE
+        if (stdio->hInputReadyEvent == INVALID_HANDLE_VALUE
             || stdio->hInputDoneEvent == INVALID_HANDLE_VALUE) {
-            fprintf(stderr, "cannot create stdio thread or event\n");
-            exit(1);
+            error_setg(errp, "cannot create event");
+            goto err2;
         }
         if (qemu_add_wait_object(stdio->hInputReadyEvent,
                                  win_stdio_thread_wait_func, chr)) {
-            fprintf(stderr, "qemu_add_wait_object: failed\n");
+            error_setg(errp, "qemu_add_wait_object: failed");
+            goto err2;
+        }
+        stdio->hInputThread     = CreateThread(NULL, 0, win_stdio_thread,
+                                               chr, 0, &dwId);
+
+        if (stdio->hInputThread == INVALID_HANDLE_VALUE) {
+            error_setg(errp, "cannot create stdio thread");
+            goto err3;
         }
     }
 
@@ -2377,6 +2417,15 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
     qemu_chr_fe_set_echo(chr, false);
 
     return chr;
+
+err3:
+    qemu_del_wait_object(stdio->hInputReadyEvent, NULL, NULL);
+err2:
+    CloseHandle(stdio->hInputReadyEvent);
+    CloseHandle(stdio->hInputDoneEvent);
+err1:
+    qemu_del_wait_object(stdio->hStdIn, NULL, NULL);
+    return NULL;
 }
 #endif /* !_WIN32 */
 
@@ -3173,9 +3222,12 @@ static void ringbuf_chr_close(struct CharDriverState *chr)
     chr->opaque = NULL;
 }
 
-static CharDriverState *qemu_chr_open_ringbuf(ChardevRingbuf *opts,
+static CharDriverState *qemu_chr_open_ringbuf(const char *id,
+                                              ChardevBackend *backend,
+                                              ChardevReturn *ret,
                                               Error **errp)
 {
+    ChardevRingbuf *opts = backend->ringbuf;
     CharDriverState *chr;
     RingBufCharDriver *d;
 
@@ -3462,6 +3514,7 @@ static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
     backend->stdio->signal = qemu_opt_get_bool(opts, "signal", true);
 }
 
+#ifdef HAVE_CHARDEV_SERIAL
 static void qemu_chr_parse_serial(QemuOpts *opts, ChardevBackend *backend,
                                   Error **errp)
 {
@@ -3474,7 +3527,9 @@ static void qemu_chr_parse_serial(QemuOpts *opts, ChardevBackend *backend,
     backend->serial = g_new0(ChardevHostdev, 1);
     backend->serial->device = g_strdup(device);
 }
+#endif
 
+#ifdef HAVE_CHARDEV_PARPORT
 static void qemu_chr_parse_parallel(QemuOpts *opts, ChardevBackend *backend,
                                     Error **errp)
 {
@@ -3487,6 +3542,7 @@ static void qemu_chr_parse_parallel(QemuOpts *opts, ChardevBackend *backend,
     backend->parallel = g_new0(ChardevHostdev, 1);
     backend->parallel->device = g_strdup(device);
 }
+#endif
 
 static void qemu_chr_parse_pipe(QemuOpts *opts, ChardevBackend *backend,
                                 Error **errp)
@@ -3641,12 +3697,16 @@ typedef struct CharDriver {
     const char *name;
     ChardevBackendKind kind;
     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
+    CharDriverState *(*create)(const char *id, ChardevBackend *backend,
+                               ChardevReturn *ret, Error **errp);
 } CharDriver;
 
 static GSList *backends;
 
 void register_char_driver(const char *name, ChardevBackendKind kind,
-        void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp))
+        void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp),
+        CharDriverState *(*create)(const char *id, ChardevBackend *backend,
+                                   ChardevReturn *ret, Error **errp))
 {
     CharDriver *s;
 
@@ -3654,6 +3714,7 @@ void register_char_driver(const char *name, ChardevBackendKind kind,
     s->name = g_strdup(name);
     s->kind = kind;
     s->parse = parse;
+    s->create = create;
 
     backends = g_slist_append(backends, s);
 }
@@ -4002,8 +4063,12 @@ QemuOptsList qemu_chardev_opts = {
 
 #ifdef _WIN32
 
-static CharDriverState *qmp_chardev_open_file(ChardevFile *file, Error **errp)
+static CharDriverState *qmp_chardev_open_file(const char *id,
+                                              ChardevBackend *backend,
+                                              ChardevReturn *ret,
+                                              Error **errp)
 {
+    ChardevFile *file = backend->file;
     HANDLE out;
 
     if (file->has_in) {
@@ -4020,17 +4085,13 @@ static CharDriverState *qmp_chardev_open_file(ChardevFile *file, Error **errp)
     return qemu_chr_open_win_file(out);
 }
 
-static CharDriverState *qmp_chardev_open_serial(ChardevHostdev *serial,
+static CharDriverState *qmp_chardev_open_serial(const char *id,
+                                                ChardevBackend *backend,
+                                                ChardevReturn *ret,
                                                 Error **errp)
 {
-    return qemu_chr_open_win_path(serial->device);
-}
-
-static CharDriverState *qmp_chardev_open_parallel(ChardevHostdev *parallel,
-                                                  Error **errp)
-{
-    error_setg(errp, "character device backend type 'parallel' not supported");
-    return NULL;
+    ChardevHostdev *serial = backend->serial;
+    return qemu_chr_open_win_path(serial->device, errp);
 }
 
 #else /* WIN32 */
@@ -4047,8 +4108,12 @@ static int qmp_chardev_open_file_source(char *src, int flags,
     return fd;
 }
 
-static CharDriverState *qmp_chardev_open_file(ChardevFile *file, Error **errp)
+static CharDriverState *qmp_chardev_open_file(const char *id,
+                                              ChardevBackend *backend,
+                                              ChardevReturn *ret,
+                                              Error **errp)
 {
+    ChardevFile *file = backend->file;
     int flags, in = -1, out;
 
     flags = O_WRONLY | O_TRUNC | O_CREAT | O_BINARY;
@@ -4069,10 +4134,13 @@ static CharDriverState *qmp_chardev_open_file(ChardevFile *file, Error **errp)
     return qemu_chr_open_fd(in, out);
 }
 
-static CharDriverState *qmp_chardev_open_serial(ChardevHostdev *serial,
+#ifdef HAVE_CHARDEV_SERIAL
+static CharDriverState *qmp_chardev_open_serial(const char *id,
+                                                ChardevBackend *backend,
+                                                ChardevReturn *ret,
                                                 Error **errp)
 {
-#ifdef HAVE_CHARDEV_TTY
+    ChardevHostdev *serial = backend->serial;
     int fd;
 
     fd = qmp_chardev_open_file_source(serial->device, O_RDWR, errp);
@@ -4081,28 +4149,25 @@ static CharDriverState *qmp_chardev_open_serial(ChardevHostdev *serial,
     }
     qemu_set_nonblock(fd);
     return qemu_chr_open_tty_fd(fd);
-#else
-    error_setg(errp, "character device backend type 'serial' not supported");
-    return NULL;
-#endif
 }
+#endif
 
-static CharDriverState *qmp_chardev_open_parallel(ChardevHostdev *parallel,
+#ifdef HAVE_CHARDEV_PARPORT
+static CharDriverState *qmp_chardev_open_parallel(const char *id,
+                                                  ChardevBackend *backend,
+                                                  ChardevReturn *ret,
                                                   Error **errp)
 {
-#ifdef HAVE_CHARDEV_PARPORT
+    ChardevHostdev *parallel = backend->parallel;
     int fd;
 
     fd = qmp_chardev_open_file_source(parallel->device, O_RDWR, errp);
     if (fd < 0) {
         return NULL;
     }
-    return qemu_chr_open_pp_fd(fd);
-#else
-    error_setg(errp, "character device backend type 'parallel' not supported");
-    return NULL;
-#endif
+    return qemu_chr_open_pp_fd(fd, errp);
 }
+#endif
 
 #endif /* WIN32 */
 
@@ -4131,11 +4196,14 @@ static gboolean socket_reconnect_timeout(gpointer opaque)
     return false;
 }
 
-static CharDriverState *qmp_chardev_open_socket(ChardevSocket *sock,
+static CharDriverState *qmp_chardev_open_socket(const char *id,
+                                                ChardevBackend *backend,
+                                                ChardevReturn *ret,
                                                 Error **errp)
 {
     CharDriverState *chr;
     TCPCharDriver *s;
+    ChardevSocket *sock = backend->socket;
     SocketAddress *addr = sock->addr;
     bool do_nodelay     = sock->has_nodelay ? sock->nodelay : false;
     bool is_listen      = sock->has_server  ? sock->server  : true;
@@ -4197,9 +4265,12 @@ static CharDriverState *qmp_chardev_open_socket(ChardevSocket *sock,
     return chr;
 }
 
-static CharDriverState *qmp_chardev_open_udp(ChardevUdp *udp,
+static CharDriverState *qmp_chardev_open_udp(const char *id,
+                                             ChardevBackend *backend,
+                                             ChardevReturn *ret,
                                              Error **errp)
 {
+    ChardevUdp *udp = backend->udp;
     int fd;
 
     fd = socket_dgram(udp->remote, udp->local, errp);
@@ -4213,7 +4284,10 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
                                Error **errp)
 {
     ChardevReturn *ret = g_new0(ChardevReturn, 1);
-    CharDriverState *base, *chr = NULL;
+    CharDriverState *chr = NULL;
+    Error *local_err = NULL;
+    GSList *i;
+    CharDriver *cd;
 
     chr = qemu_chr_find(id);
     if (chr) {
@@ -4222,106 +4296,40 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
         return NULL;
     }
 
-    switch (backend->kind) {
-    case CHARDEV_BACKEND_KIND_FILE:
-        chr = qmp_chardev_open_file(backend->file, errp);
-        break;
-    case CHARDEV_BACKEND_KIND_SERIAL:
-        chr = qmp_chardev_open_serial(backend->serial, errp);
-        break;
-    case CHARDEV_BACKEND_KIND_PARALLEL:
-        chr = qmp_chardev_open_parallel(backend->parallel, errp);
-        break;
-    case CHARDEV_BACKEND_KIND_PIPE:
-        chr = qemu_chr_open_pipe(backend->pipe);
-        break;
-    case CHARDEV_BACKEND_KIND_SOCKET:
-        chr = qmp_chardev_open_socket(backend->socket, errp);
-        break;
-    case CHARDEV_BACKEND_KIND_UDP:
-        chr = qmp_chardev_open_udp(backend->udp, errp);
-        break;
-#ifdef HAVE_CHARDEV_TTY
-    case CHARDEV_BACKEND_KIND_PTY:
-        chr = qemu_chr_open_pty(id, ret);
-        break;
-#endif
-    case CHARDEV_BACKEND_KIND_NULL:
-        chr = qemu_chr_open_null();
-        break;
-    case CHARDEV_BACKEND_KIND_MUX:
-        base = qemu_chr_find(backend->mux->chardev);
-        if (base == NULL) {
-            error_setg(errp, "mux: base chardev %s not found",
-                       backend->mux->chardev);
+    for (i = backends; i; i = i->next) {
+        cd = i->data;
+
+        if (cd->kind == backend->kind) {
+            chr = cd->create(id, backend, ret, &local_err);
+            if (local_err) {
+                error_propagate(errp, local_err);
+                goto out_error;
+            }
             break;
         }
-        chr = qemu_chr_open_mux(base);
-        break;
-    case CHARDEV_BACKEND_KIND_MSMOUSE:
-        chr = qemu_chr_open_msmouse();
-        break;
-#ifdef CONFIG_BRLAPI
-    case CHARDEV_BACKEND_KIND_BRAILLE:
-        chr = chr_baum_init();
-        break;
-#endif
-    case CHARDEV_BACKEND_KIND_TESTDEV:
-        chr = chr_testdev_init();
-        break;
-    case CHARDEV_BACKEND_KIND_STDIO:
-        chr = qemu_chr_open_stdio(backend->stdio);
-        break;
-#ifdef _WIN32
-    case CHARDEV_BACKEND_KIND_CONSOLE:
-        chr = qemu_chr_open_win_con();
-        break;
-#endif
-#ifdef CONFIG_SPICE
-    case CHARDEV_BACKEND_KIND_SPICEVMC:
-        chr = qemu_chr_open_spice_vmc(backend->spicevmc->type);
-        break;
-    case CHARDEV_BACKEND_KIND_SPICEPORT:
-        chr = qemu_chr_open_spice_port(backend->spiceport->fqdn);
-        break;
-#endif
-    case CHARDEV_BACKEND_KIND_VC:
-        chr = vc_init(backend->vc);
-        break;
-    case CHARDEV_BACKEND_KIND_RINGBUF:
-    case CHARDEV_BACKEND_KIND_MEMORY:
-        chr = qemu_chr_open_ringbuf(backend->ringbuf, errp);
-        break;
-    default:
-        error_setg(errp, "unknown chardev backend (%d)", backend->kind);
-        break;
     }
 
-    /*
-     * Character backend open hasn't been fully converted to the Error
-     * API.  Some opens fail without setting an error.  Set a generic
-     * error then.
-     * TODO full conversion to Error API
-     */
-    if (chr == NULL && errp && !*errp) {
-        error_setg(errp, "Failed to create chardev");
+    if (chr == NULL) {
+        assert(!i);
+        error_setg(errp, "chardev backend not available");
+        goto out_error;
     }
-    if (chr) {
-        chr->label = g_strdup(id);
-        chr->avail_connections =
-            (backend->kind == CHARDEV_BACKEND_KIND_MUX) ? MAX_MUX : 1;
-        if (!chr->filename) {
-            chr->filename = g_strdup(ChardevBackendKind_lookup[backend->kind]);
-        }
-        if (!chr->explicit_be_open) {
-            qemu_chr_be_event(chr, CHR_EVENT_OPENED);
-        }
-        QTAILQ_INSERT_TAIL(&chardevs, chr, next);
-        return ret;
-    } else {
-        g_free(ret);
-        return NULL;
+
+    chr->label = g_strdup(id);
+    chr->avail_connections =
+        (backend->kind == CHARDEV_BACKEND_KIND_MUX) ? MAX_MUX : 1;
+    if (!chr->filename) {
+        chr->filename = g_strdup(ChardevBackendKind_lookup[backend->kind]);
+    }
+    if (!chr->explicit_be_open) {
+        qemu_chr_be_event(chr, CHR_EVENT_OPENED);
     }
+    QTAILQ_INSERT_TAIL(&chardevs, chr, next);
+    return ret;
+
+out_error:
+    g_free(ret);
+    return NULL;
 }
 
 void qmp_chardev_remove(const char *id, Error **errp)
@@ -4343,32 +4351,45 @@ void qmp_chardev_remove(const char *id, Error **errp)
 
 static void register_types(void)
 {
-    register_char_driver("null", CHARDEV_BACKEND_KIND_NULL, NULL);
+    register_char_driver("null", CHARDEV_BACKEND_KIND_NULL, NULL,
+                         qemu_chr_open_null);
     register_char_driver("socket", CHARDEV_BACKEND_KIND_SOCKET,
-                         qemu_chr_parse_socket);
-    register_char_driver("udp", CHARDEV_BACKEND_KIND_UDP, qemu_chr_parse_udp);
+                         qemu_chr_parse_socket, qmp_chardev_open_socket);
+    register_char_driver("udp", CHARDEV_BACKEND_KIND_UDP, qemu_chr_parse_udp,
+                         qmp_chardev_open_udp);
     register_char_driver("ringbuf", CHARDEV_BACKEND_KIND_RINGBUF,
-                         qemu_chr_parse_ringbuf);
+                         qemu_chr_parse_ringbuf, qemu_chr_open_ringbuf);
     register_char_driver("file", CHARDEV_BACKEND_KIND_FILE,
-                         qemu_chr_parse_file_out);
+                         qemu_chr_parse_file_out, qmp_chardev_open_file);
     register_char_driver("stdio", CHARDEV_BACKEND_KIND_STDIO,
-                         qemu_chr_parse_stdio);
+                         qemu_chr_parse_stdio, qemu_chr_open_stdio);
+#if defined HAVE_CHARDEV_SERIAL
     register_char_driver("serial", CHARDEV_BACKEND_KIND_SERIAL,
-                         qemu_chr_parse_serial);
+                         qemu_chr_parse_serial, qmp_chardev_open_serial);
     register_char_driver("tty", CHARDEV_BACKEND_KIND_SERIAL,
-                         qemu_chr_parse_serial);
+                         qemu_chr_parse_serial, qmp_chardev_open_serial);
+#endif
+#ifdef HAVE_CHARDEV_PARPORT
     register_char_driver("parallel", CHARDEV_BACKEND_KIND_PARALLEL,
-                         qemu_chr_parse_parallel);
+                         qemu_chr_parse_parallel, qmp_chardev_open_parallel);
     register_char_driver("parport", CHARDEV_BACKEND_KIND_PARALLEL,
-                         qemu_chr_parse_parallel);
-    register_char_driver("pty", CHARDEV_BACKEND_KIND_PTY, NULL);
-    register_char_driver("console", CHARDEV_BACKEND_KIND_CONSOLE, NULL);
+                         qemu_chr_parse_parallel, qmp_chardev_open_parallel);
+#endif
+#ifdef HAVE_CHARDEV_PTY
+    register_char_driver("pty", CHARDEV_BACKEND_KIND_PTY, NULL,
+                         qemu_chr_open_pty);
+#endif
+#ifdef _WIN32
+    register_char_driver("console", CHARDEV_BACKEND_KIND_CONSOLE, NULL,
+                         qemu_chr_open_win_con);
+#endif
     register_char_driver("pipe", CHARDEV_BACKEND_KIND_PIPE,
-                         qemu_chr_parse_pipe);
-    register_char_driver("mux", CHARDEV_BACKEND_KIND_MUX, qemu_chr_parse_mux);
+                         qemu_chr_parse_pipe, qemu_chr_open_pipe);
+    register_char_driver("mux", CHARDEV_BACKEND_KIND_MUX, qemu_chr_parse_mux,
+                         qemu_chr_open_mux);
     /* Bug-compatibility: */
     register_char_driver("memory", CHARDEV_BACKEND_KIND_MEMORY,
-                         qemu_chr_parse_ringbuf);
+                         qemu_chr_parse_ringbuf, qemu_chr_open_ringbuf);
     /* this must be done after machine init, since we register FEs with muxes
      * as part of realize functions like serial_isa_realizefn when -nographic
      * is specified