char: allocate CharDriverState as a single object

Use a single allocation for CharDriverState, this avoids extra
allocations & pointers, and is a step towards more object-oriented
CharDriver.

Gtk console is a bit peculiar, gd_vc_chr_set_echo() used to have a
temporary VirtualConsole to save the echo bit. Instead now, we consider
whether vcd->console is set or not, and restore the echo bit saved in
VCDriverState when calling gd_vc_vte_init().

The casts added are temporary, they are replaced with QOM type-safe
macros in a later patch in this series.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

backends/baum.c

@@ -85,7 +85,7 @@
 #define BUF_SIZE 256
 
 typedef struct {
-    CharDriverState *chr;
+    CharDriverState parent;
 
     brlapi_handle_t *brlapi;
     int brlapi_fd;
@@ -255,7 +255,7 @@ static int baum_deferred_init(BaumDriverState *baum)
 /* The serial port can receive more of our data */
 static void baum_accept_input(struct CharDriverState *chr)
 {
-    BaumDriverState *baum = chr->opaque;
+    BaumDriverState *baum = (BaumDriverState *)chr;
     int room, first;
 
     if (!baum->out_buf_used)
@@ -281,22 +281,23 @@ static void baum_accept_input(struct CharDriverState *chr)
 /* We want to send a packet */
 static void baum_write_packet(BaumDriverState *baum, const uint8_t *buf, int len)
 {
+    CharDriverState *chr = (CharDriverState *)baum;
     uint8_t io_buf[1 + 2 * len], *cur = io_buf;
     int room;
     *cur++ = ESC;
     while (len--)
         if ((*cur++ = *buf++) == ESC)
             *cur++ = ESC;
-    room = qemu_chr_be_can_write(baum->chr);
+    room = qemu_chr_be_can_write(chr);
     len = cur - io_buf;
     if (len <= room) {
         /* Fits */
-        qemu_chr_be_write(baum->chr, io_buf, len);
+        qemu_chr_be_write(chr, io_buf, len);
     } else {
         int first;
         uint8_t out;
         /* Can't fit all, send what can be, and store the rest. */
-        qemu_chr_be_write(baum->chr, io_buf, room);
+        qemu_chr_be_write(chr, io_buf, room);
         len -= room;
         cur = io_buf + room;
         if (len > BUF_SIZE - baum->out_buf_used) {
@@ -471,7 +472,7 @@ static int baum_eat_packet(BaumDriverState *baum, const uint8_t *buf, int len)
 /* The other end is writing some data.  Store it and try to interpret */
 static int baum_write(CharDriverState *chr, const uint8_t *buf, int len)
 {
-    BaumDriverState *baum = chr->opaque;
+    BaumDriverState *baum = (BaumDriverState *)chr;
     int tocopy, cur, eaten, orig_len = len;
 
     if (!len)
@@ -612,14 +613,13 @@ static void baum_chr_read(void *opaque)
 
 static void baum_free(struct CharDriverState *chr)
 {
-    BaumDriverState *baum = chr->opaque;
+    BaumDriverState *baum = (BaumDriverState *)chr;
 
     timer_free(baum->cellCount_timer);
     if (baum->brlapi) {
         brlapi__closeConnection(baum->brlapi);
         g_free(baum->brlapi);
     }
-    g_free(baum);
 }
 
 static CharDriverState *chr_baum_init(const CharDriver *driver,
@@ -638,10 +638,7 @@ static CharDriverState *chr_baum_init(const CharDriver *driver,
     if (!chr) {
         return NULL;
     }
-    baum = g_malloc0(sizeof(BaumDriverState));
-    baum->chr = chr;
-
-    chr->opaque = baum;
+    baum = (BaumDriverState *)chr;
 
     handle = g_malloc0(brlapi_getHandleSize());
     baum->brlapi = handle;
@@ -663,13 +660,13 @@ static CharDriverState *chr_baum_init(const CharDriver *driver,
 fail_handle:
     g_free(handle);
     g_free(chr);
-    g_free(baum);
     return NULL;
 }
 
 static void register_types(void)
 {
     static const CharDriver driver = {
+        .instance_size = sizeof(BaumDriverState),
         .kind = CHARDEV_BACKEND_KIND_BRAILLE,
         .create = chr_baum_init,
         .chr_write = baum_write,

backends/msmouse.c

@@ -31,7 +31,8 @@
 #define MSMOUSE_HI2(n) (((n) & 0xc0) >> 6)
 
 typedef struct {
-    CharDriverState *chr;
+    CharDriverState parent;
+
     QemuInputHandlerState *hs;
     int axis[INPUT_AXIS__MAX];
     bool btns[INPUT_BUTTON__MAX];
@@ -42,7 +43,7 @@ typedef struct {
 
 static void msmouse_chr_accept_input(CharDriverState *chr)
 {
-    MouseState *mouse = chr->opaque;
+    MouseState *mouse = (MouseState *)chr;
     int len;
 
     len = qemu_chr_be_can_write(chr);
@@ -122,9 +123,10 @@ static void msmouse_input_event(DeviceState *dev, QemuConsole *src,
 static void msmouse_input_sync(DeviceState *dev)
 {
     MouseState *mouse = (MouseState *)dev;
+    CharDriverState *chr = (CharDriverState *)dev;
 
     msmouse_queue_event(mouse);
-    msmouse_chr_accept_input(mouse->chr);
+    msmouse_chr_accept_input(chr);
 }
 
 static int msmouse_chr_write (struct CharDriverState *s, const uint8_t *buf, int len)
@@ -135,10 +137,9 @@ static int msmouse_chr_write (struct CharDriverState *s, const uint8_t *buf, int
 
 static void msmouse_chr_free(struct CharDriverState *chr)
 {
-    MouseState *mouse = chr->opaque;
+    MouseState *mouse = (MouseState *)chr;
 
     qemu_input_handler_unregister(mouse->hs);
-    g_free(mouse);
 }
 
 static QemuInputHandler msmouse_handler = {
@@ -165,12 +166,10 @@ static CharDriverState *qemu_chr_open_msmouse(const CharDriver *driver,
     }
     *be_opened = false;
 
-    mouse = g_new0(MouseState, 1);
+    mouse = (MouseState *)chr;
     mouse->hs = qemu_input_handler_register((DeviceState *)mouse,
                                             &msmouse_handler);
 
-    mouse->chr = chr;
-    chr->opaque = mouse;
 
     return chr;
 }
@@ -178,6 +177,7 @@ static CharDriverState *qemu_chr_open_msmouse(const CharDriver *driver,
 static void register_types(void)
 {
     static const CharDriver driver = {
+        .instance_size = sizeof(MouseState),
         .kind = CHARDEV_BACKEND_KIND_MSMOUSE,
         .create = qemu_chr_open_msmouse,
         .chr_write = msmouse_chr_write,

backends/testdev.c

@@ -30,7 +30,8 @@
 #define BUF_SIZE 32
 
 typedef struct {
-    CharDriverState *chr;
+    CharDriverState parent;
+
     uint8_t in_buf[32];
     int in_buf_used;
 } TestdevCharState;
@@ -79,7 +80,7 @@ static int testdev_eat_packet(TestdevCharState *testdev)
 /* The other end is writing some data.  Store it and try to interpret */
 static int testdev_write(CharDriverState *chr, const uint8_t *buf, int len)
 {
-    TestdevCharState *testdev = chr->opaque;
+    TestdevCharState *testdev = (TestdevCharState *)chr;
     int tocopy, eaten, orig_len = len;
 
     while (len) {
@@ -102,13 +103,6 @@ static int testdev_write(CharDriverState *chr, const uint8_t *buf, int len)
     return orig_len;
 }
 
-static void testdev_free(struct CharDriverState *chr)
-{
-    TestdevCharState *testdev = chr->opaque;
-
-    g_free(testdev);
-}
-
 static CharDriverState *chr_testdev_init(const CharDriver *driver,
                                          const char *id,
                                          ChardevBackend *backend,
@@ -116,14 +110,10 @@ static CharDriverState *chr_testdev_init(const CharDriver *driver,
                                          bool *be_opened,
                                          Error **errp)
 {
-    TestdevCharState *testdev;
-    CharDriverState *chr;
-
-    testdev = g_new0(TestdevCharState, 1);
-    testdev->chr = chr = g_new0(CharDriverState, 1);
+    TestdevCharState *testdev = g_new0(TestdevCharState, 1);;
+    CharDriverState *chr = (CharDriverState *)testdev;
 
     chr->driver = driver;
-    chr->opaque = testdev;
 
     return chr;
 }
@@ -131,10 +121,10 @@ static CharDriverState *chr_testdev_init(const CharDriver *driver,
 static void register_types(void)
 {
     static const CharDriver driver = {
+        .instance_size = sizeof(TestdevCharState),
         .kind = CHARDEV_BACKEND_KIND_TESTDEV,
         .create = chr_testdev_init,
         .chr_write = testdev_write,
-        .chr_free = testdev_free,
     };
     register_char_driver(&driver);
 }

gdbstub.c

@@ -1733,6 +1733,7 @@ int gdbserver_start(const char *device)
     CharDriverState *mon_chr;
     ChardevCommon common = { 0 };
     static const CharDriver driver = {
+        .instance_size = sizeof(CharDriverState),
         .kind = -1,
         .chr_write = gdb_monitor_write,
     };

hw/bt/hci-csr.c

@@ -28,11 +28,11 @@
 #include "hw/bt.h"
 
 struct csrhci_s {
+    CharDriverState chr;
     int enable;
     qemu_irq *pins;
     int pin_state;
     int modem_state;
-    CharDriverState chr;
 #define FIFO_LEN	4096
     int out_start;
     int out_len;
@@ -314,7 +314,7 @@ static void csrhci_ready_for_next_inpkt(struct csrhci_s *s)
 static int csrhci_write(struct CharDriverState *chr,
                 const uint8_t *buf, int len)
 {
-    struct csrhci_s *s = (struct csrhci_s *) chr->opaque;
+    struct csrhci_s *s = (struct csrhci_s *)chr;
     int total = 0;
 
     if (!s->enable)
@@ -387,7 +387,7 @@ static void csrhci_out_hci_packet_acl(void *opaque,
 static int csrhci_ioctl(struct CharDriverState *chr, int cmd, void *arg)
 {
     QEMUSerialSetParams *ssp;
-    struct csrhci_s *s = (struct csrhci_s *) chr->opaque;
+    struct csrhci_s *s = (struct csrhci_s *) chr;
     int prev_state = s->modem_state;
 
     switch (cmd) {
@@ -455,7 +455,7 @@ static void csrhci_pins(void *opaque, int line, int level)
 
 qemu_irq *csrhci_pins_get(CharDriverState *chr)
 {
-    struct csrhci_s *s = (struct csrhci_s *) chr->opaque;
+    struct csrhci_s *s = (struct csrhci_s *) chr;
 
     return s->pins;
 }
@@ -463,6 +463,7 @@ qemu_irq *csrhci_pins_get(CharDriverState *chr)
 CharDriverState *uart_hci_init(void)
 {
     static const CharDriver hci_driver = {
+        .instance_size = sizeof(struct csrhci_s),
         .kind = -1,
         .chr_write = csrhci_write,
         .chr_ioctl = csrhci_ioctl,
@@ -470,7 +471,6 @@ CharDriverState *uart_hci_init(void)
     struct csrhci_s *s = (struct csrhci_s *)
             g_malloc0(sizeof(struct csrhci_s));
 
-    s->chr.opaque = s;
     s->chr.driver = &hci_driver;
 
     s->hci = qemu_next_hci();

include/sysemu/char.h

@@ -93,7 +93,6 @@ struct CharDriverState {
     const CharDriver *driver;
     QemuMutex chr_write_lock;
     CharBackend *be;
-    void *opaque;
     char *label;
     char *filename;
     int logfd;
@@ -484,6 +483,7 @@ struct CharDriver {
                                ChardevBackend *backend,
                                ChardevReturn *ret, bool *be_opened,
                                Error **errp);
+    size_t instance_size;
 
     int (*chr_write)(struct CharDriverState *s, const uint8_t *buf, int len);
     int (*chr_sync_read)(struct CharDriverState *s,

spice-qemu-char.c

@@ -7,7 +7,8 @@
 
 
 typedef struct SpiceCharDriver {
-    CharDriverState*      chr;
+    CharDriverState       parent;
+
     SpiceCharDeviceInstance     sin;
     bool                  active;
     bool                  blocked;
@@ -27,17 +28,18 @@ static QLIST_HEAD(, SpiceCharDriver) spice_chars =
 static int vmc_write(SpiceCharDeviceInstance *sin, const uint8_t *buf, int len)
 {
     SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
+    CharDriverState *chr = (CharDriverState *)scd;
     ssize_t out = 0;
     ssize_t last_out;
     uint8_t* p = (uint8_t*)buf;
 
     while (len > 0) {
-        int can_write = qemu_chr_be_can_write(scd->chr);
+        int can_write = qemu_chr_be_can_write(chr);
         last_out = MIN(len, can_write);
         if (last_out <= 0) {
             break;
         }
-        qemu_chr_be_write(scd->chr, p, last_out);
+        qemu_chr_be_write(chr, p, last_out);
         out += last_out;
         len -= last_out;
         p += last_out;
@@ -70,6 +72,7 @@ static int vmc_read(SpiceCharDeviceInstance *sin, uint8_t *buf, int len)
 static void vmc_event(SpiceCharDeviceInstance *sin, uint8_t event)
 {
     SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
+    CharDriverState *chr = (CharDriverState *)scd;
     int chr_event;
 
     switch (event) {
@@ -81,20 +84,21 @@ static void vmc_event(SpiceCharDeviceInstance *sin, uint8_t event)
     }
 
     trace_spice_vmc_event(chr_event);
-    qemu_chr_be_event(scd->chr, chr_event);
+    qemu_chr_be_event(chr, chr_event);
 }
 #endif
 
 static void vmc_state(SpiceCharDeviceInstance *sin, int connected)
 {
     SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
+    CharDriverState *chr = (CharDriverState *)scd;
 
-    if ((scd->chr->be_open && connected) ||
-        (!scd->chr->be_open && !connected)) {
+    if ((chr->be_open && connected) ||
+        (!chr->be_open && !connected)) {
         return;
     }
 
-    qemu_chr_be_event(scd->chr,
+    qemu_chr_be_event(chr,
                       connected ? CHR_EVENT_OPENED : CHR_EVENT_CLOSED);
 }
 
@@ -168,7 +172,7 @@ static GSourceFuncs SpiceCharSourceFuncs = {
 
 static GSource *spice_chr_add_watch(CharDriverState *chr, GIOCondition cond)
 {
-    SpiceCharDriver *scd = chr->opaque;
+    SpiceCharDriver *scd = (SpiceCharDriver *)chr;
     SpiceCharSource *src;
 
     assert(cond & G_IO_OUT);
@@ -182,7 +186,7 @@ static GSource *spice_chr_add_watch(CharDriverState *chr, GIOCondition cond)
 
 static int spice_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
 {
-    SpiceCharDriver *s = chr->opaque;
+    SpiceCharDriver *s = (SpiceCharDriver *)chr;
     int read_bytes;
 
     assert(s->datalen == 0);
@@ -201,7 +205,7 @@ static int spice_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
 
 static void spice_chr_free(struct CharDriverState *chr)
 {
-    SpiceCharDriver *s = chr->opaque;
+    SpiceCharDriver *s = (SpiceCharDriver *)chr;
 
     vmc_unregister_interface(s);
     QLIST_REMOVE(s, next);
@@ -210,12 +214,11 @@ static void spice_chr_free(struct CharDriverState *chr)
 #if SPICE_SERVER_VERSION >= 0x000c02
     g_free((char *)s->sin.portname);
 #endif
-    g_free(s);
 }
 
 static void spice_vmc_set_fe_open(struct CharDriverState *chr, int fe_open)
 {
-    SpiceCharDriver *s = chr->opaque;
+    SpiceCharDriver *s = (SpiceCharDriver *)chr;
     if (fe_open) {
         vmc_register_interface(s);
     } else {
@@ -226,7 +229,7 @@ static void spice_vmc_set_fe_open(struct CharDriverState *chr, int fe_open)
 static void spice_port_set_fe_open(struct CharDriverState *chr, int fe_open)
 {
 #if SPICE_SERVER_VERSION >= 0x000c02
-    SpiceCharDriver *s = chr->opaque;
+    SpiceCharDriver *s = (SpiceCharDriver *)chr;
 
     if (fe_open) {
         spice_server_port_event(&s->sin, SPICE_PORT_EVENT_OPENED);
@@ -255,7 +258,7 @@ static void print_allowed_subtypes(void)
 
 static void spice_chr_accept_input(struct CharDriverState *chr)
 {
-    SpiceCharDriver *s = chr->opaque;
+    SpiceCharDriver *s = (SpiceCharDriver *)chr;
 
     spice_server_char_device_wakeup(&s->sin);
 }
@@ -272,11 +275,9 @@ static CharDriverState *chr_open(const CharDriver *driver,
     if (!chr) {
         return NULL;
     }
-    s = g_malloc0(sizeof(SpiceCharDriver));
-    s->chr = chr;
+    s = (SpiceCharDriver *)chr;
     s->active = false;
     s->sin.subtype = g_strdup(subtype);
-    chr->opaque = s;
 
     QLIST_INSERT_HEAD(&spice_chars, s, next);
 
@@ -334,7 +335,7 @@ static CharDriverState *qemu_chr_open_spice_port(const CharDriver *driver,
         return NULL;
     }
     *be_opened = false;
-    s = chr->opaque;
+    s = (SpiceCharDriver *)chr;
     s->sin.portname = g_strdup(name);
 
     return chr;
@@ -386,6 +387,7 @@ static void qemu_chr_parse_spice_port(QemuOpts *opts, ChardevBackend *backend,
 static void register_types(void)
 {
     static const CharDriver vmc_driver = {
+        .instance_size = sizeof(SpiceCharDriver),
         .kind = CHARDEV_BACKEND_KIND_SPICEVMC,
         .parse = qemu_chr_parse_spice_vmc,
         .create = qemu_chr_open_spice_vmc,
@@ -396,6 +398,7 @@ static void register_types(void)
         .chr_free = spice_chr_free,
     };
     static const CharDriver port_driver = {
+        .instance_size = sizeof(SpiceCharDriver),
         .kind = CHARDEV_BACKEND_KIND_SPICEPORT,
         .parse = qemu_chr_parse_spice_port,
         .create = qemu_chr_open_spice_port,

ui/console.c

@@ -1046,9 +1046,15 @@ void console_select(unsigned int index)
     }
 }
 
+typedef struct VCDriverState {
+    CharDriverState parent;
+    QemuConsole *console;
+} VCDriverState;
+
 static int console_puts(CharDriverState *chr, const uint8_t *buf, int len)
 {
-    QemuConsole *s = chr->opaque;
+    VCDriverState *drv = (VCDriverState *)chr;
+    QemuConsole *s = drv->console;
     int i;
 
     if (!s->ds) {
@@ -1958,7 +1964,8 @@ int qemu_console_get_height(QemuConsole *con, int fallback)
 
 static void text_console_set_echo(CharDriverState *chr, bool echo)
 {
-    QemuConsole *s = chr->opaque;
+    VCDriverState *drv = (VCDriverState *)chr;
+    QemuConsole *s = drv->console;
 
     s->echo = echo;
 }
@@ -1998,12 +2005,11 @@ static const GraphicHwOps text_console_ops = {
 
 static void text_console_do_init(CharDriverState *chr, DisplayState *ds)
 {
-    QemuConsole *s;
+    VCDriverState *drv = (VCDriverState *)chr;
+    QemuConsole *s = drv->console;
     int g_width = 80 * FONT_WIDTH;
     int g_height = 24 * FONT_HEIGHT;
 
-    s = chr->opaque;
-
     s->out_fifo.buf = s->out_fifo_buf;
     s->out_fifo.buf_size = sizeof(s->out_fifo_buf);
     s->kbd_timer = timer_new_ms(QEMU_CLOCK_REALTIME, kbd_send_chars, s);
@@ -2056,6 +2062,7 @@ static CharDriverState *text_console_init(ChardevVC *vc, Error **errp)
 {
     ChardevCommon *common = qapi_ChardevVC_base(vc);
     CharDriverState *chr;
+    VCDriverState *drv;
     QemuConsole *s;
     unsigned width = 0;
     unsigned height = 0;
@@ -2092,7 +2099,8 @@ static CharDriverState *text_console_init(ChardevVC *vc, Error **errp)
     }
 
     s->chr = chr;
-    chr->opaque = s;
+    drv = (VCDriverState *)chr;
+    drv->console = s;
 
     if (display_state) {
         text_console_do_init(chr, display_state);
@@ -2196,6 +2204,7 @@ static const TypeInfo qemu_console_info = {
 };
 
 static const CharDriver vc_driver = {
+    .instance_size = sizeof(VCDriverState),
     .kind = CHARDEV_BACKEND_KIND_VC,
     .parse = qemu_chr_parse_vc,
     .create = vc_init,

ui/gtk.c

@@ -181,6 +181,12 @@ struct GtkDisplayState {
     bool ignore_keys;
 };
 
+typedef struct VCDriverState {
+    CharDriverState parent;
+    VirtualConsole *console;
+    bool echo;
+} VCDriverState;
+
 static void gd_grab_pointer(VirtualConsole *vc, const char *reason);
 static void gd_ungrab_pointer(GtkDisplayState *s);
 static void gd_grab_keyboard(VirtualConsole *vc, const char *reason);
@@ -1685,7 +1691,8 @@ static void gd_vc_adjustment_changed(GtkAdjustment *adjustment, void *opaque)
 
 static int gd_vc_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
 {
-    VirtualConsole *vc = chr->opaque;
+    VCDriverState *vcd = (VCDriverState *)chr;
+    VirtualConsole *vc = vcd->console;
 
     vte_terminal_feed(VTE_TERMINAL(vc->vte.terminal), (const char *)buf, len);
     return len;
@@ -1693,9 +1700,14 @@ static int gd_vc_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
 
 static void gd_vc_chr_set_echo(CharDriverState *chr, bool echo)
 {
-    VirtualConsole *vc = chr->opaque;
+    VCDriverState *vcd = (VCDriverState *)chr;
+    VirtualConsole *vc = vcd->console;
 
-    vc->vte.echo = echo;
+    if (vc) {
+        vc->vte.echo = echo;
+    } else {
+        vcd->echo = echo;
+    }
 }
 
 static int nb_vcs;
@@ -1704,6 +1716,7 @@ static CharDriverState *vcs[MAX_VCS];
 static CharDriverState *gd_vc_handler(ChardevVC *vc, Error **errp)
 {
     static const CharDriver gd_vc_driver = {
+        .instance_size = sizeof(VCDriverState),
         .kind = CHARDEV_BACKEND_KIND_VC,
         .chr_write = gd_vc_chr_write,
         .chr_set_echo = gd_vc_chr_set_echo,
@@ -1722,9 +1735,6 @@ static CharDriverState *gd_vc_handler(ChardevVC *vc, Error **errp)
         return NULL;
     }
 
-    /* Temporary, until gd_vc_vte_init runs.  */
-    chr->opaque = g_new0(VirtualConsole, 1);
-
     vcs[nb_vcs++] = chr;
 
     return chr;
@@ -1765,14 +1775,12 @@ static GSList *gd_vc_vte_init(GtkDisplayState *s, VirtualConsole *vc,
     GtkWidget *box;
     GtkWidget *scrollbar;
     GtkAdjustment *vadjustment;
-    VirtualConsole *tmp_vc = chr->opaque;
+    VCDriverState *vcd = (VCDriverState *)chr;
 
     vc->s = s;
-    vc->vte.echo = tmp_vc->vte.echo;
-
+    vc->vte.echo = vcd->echo;
     vc->vte.chr = chr;
-    chr->opaque = vc;
-    g_free(tmp_vc);
+    vcd->console = vc;
 
     snprintf(buffer, sizeof(buffer), "vc%d", idx);
     vc->label = g_strdup_printf("%s", vc->vte.chr->label