Refactor how display drivers are selected

My previous commit, f92f8afe,  broke -vnc (spotted by Glauber Costa).  This
is because it's necessary to tell when the no special display parameters have
been passed and default to SDL or VNC appropriately.

This refactors the display selection logic to be less complicated which has
the effect of fixing the regression mentioned above.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/fw_cfg.c

@@ -277,7 +277,7 @@ void *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
     }
     fw_cfg_add_bytes(s, FW_CFG_SIGNATURE, (uint8_t *)"QEMU", 4);
     fw_cfg_add_bytes(s, FW_CFG_UUID, qemu_uuid, 16);
-    fw_cfg_add_i16(s, FW_CFG_NOGRAPHIC, (uint16_t)nographic);
+    fw_cfg_add_i16(s, FW_CFG_NOGRAPHIC, (uint16_t)(display_type == DT_NOGRAPHIC));
     fw_cfg_add_i16(s, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
 
     register_savevm("fw_cfg", -1, 1, fw_cfg_save, fw_cfg_load, s);

hw/sun4m.c

@@ -505,7 +505,7 @@ static void sun4m_hw_init(const struct sun4m_hwdef *hwdef, ram_addr_t RAM_size,
                           slavio_cpu_irq, smp_cpus);
 
     slavio_serial_ms_kbd_init(hwdef->ms_kb_base, slavio_irq[hwdef->ms_kb_irq],
-                              nographic, ESCC_CLOCK, 1);
+                              display_type == DT_NOGRAPHIC, ESCC_CLOCK, 1);
     // Slavio TTYA (base+4, Linux ttyS0) is the first Qemu serial device
     // Slavio TTYB (base+0, Linux ttyS1) is the second Qemu serial device
     escc_init(hwdef->serial_base, slavio_irq[hwdef->ser_irq], slavio_irq[hwdef->ser_irq],
@@ -1273,7 +1273,7 @@ static void sun4d_hw_init(const struct sun4d_hwdef *hwdef, ram_addr_t RAM_size,
                           sbi_cpu_irq, smp_cpus);
 
     slavio_serial_ms_kbd_init(hwdef->ms_kb_base, sbi_irq[hwdef->ms_kb_irq],
-                              nographic, ESCC_CLOCK, 1);
+                              display_type == DT_NOGRAPHIC, ESCC_CLOCK, 1);
     // Slavio TTYA (base+4, Linux ttyS0) is the first Qemu serial device
     // Slavio TTYB (base+0, Linux ttyS1) is the second Qemu serial device
     escc_init(hwdef->serial_base, sbi_irq[hwdef->ser_irq], sbi_irq[hwdef->ser_irq],
@@ -1476,7 +1476,7 @@ static void sun4c_hw_init(const struct sun4c_hwdef *hwdef, ram_addr_t RAM_size,
                         hwdef->nvram_size, 2);
 
     slavio_serial_ms_kbd_init(hwdef->ms_kb_base, slavio_irq[hwdef->ms_kb_irq],
-                              nographic, ESCC_CLOCK, 1);
+                              display_type == DT_NOGRAPHIC, ESCC_CLOCK, 1);
     // Slavio TTYA (base+4, Linux ttyS0) is the first Qemu serial device
     // Slavio TTYB (base+0, Linux ttyS1) is the second Qemu serial device
     escc_init(hwdef->serial_base, slavio_irq[hwdef->ser_irq],

qemu-char.c

@@ -571,7 +571,7 @@ static void fd_chr_update_read_handler(CharDriverState *chr)
     FDCharDriver *s = chr->opaque;
 
     if (s->fd_in >= 0) {
-        if (nographic && s->fd_in == 0) {
+        if (display_type == DT_NOGRAPHIC && s->fd_in == 0) {
         } else {
             qemu_set_fd_handler2(s->fd_in, fd_chr_read_poll,
                                  fd_chr_read, NULL, chr);
@@ -584,7 +584,7 @@ static void fd_chr_close(struct CharDriverState *chr)
     FDCharDriver *s = chr->opaque;
 
     if (s->fd_in >= 0) {
-        if (nographic && s->fd_in == 0) {
+        if (display_type == DT_NOGRAPHIC && s->fd_in == 0) {
         } else {
             qemu_set_fd_handler2(s->fd_in, NULL, NULL, NULL, NULL);
         }
@@ -714,7 +714,7 @@ static void term_init(void)
     tty.c_oflag |= OPOST;
     tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
     /* if graphical mode, we allow Ctrl-C handling */
-    if (nographic)
+    if (display_type == DT_NOGRAPHIC)
         tty.c_lflag &= ~ISIG;
     tty.c_cflag &= ~(CSIZE|PARENB);
     tty.c_cflag |= CS8;

sysemu.h

@@ -86,6 +86,15 @@ int tap_win32_init(VLANState *vlan, const char *model,
 /* SLIRP */
 void do_info_slirp(Monitor *mon);
 
+typedef enum DisplayType
+{
+    DT_DEFAULT,
+    DT_CURSES,
+    DT_SDL,
+    DT_VNC,
+    DT_NOGRAPHIC,
+} DisplayType;
+
 extern int bios_size;
 extern int cirrus_vga_enabled;
 extern int std_vga_enabled;
@@ -94,7 +103,7 @@ extern int xenfb_enabled;
 extern int graphic_width;
 extern int graphic_height;
 extern int graphic_depth;
-extern int nographic;
+extern DisplayType display_type;
 extern const char *keyboard_layout;
 extern int win2k_install_hack;
 extern int rtc_td_hack;

vl.c

@@ -201,9 +201,7 @@ DriveInfo drives_table[MAX_DRIVES+1];
 int nb_drives;
 enum vga_retrace_method vga_retrace_method = VGA_RETRACE_DUMB;
 static DisplayState *display_state;
-int nographic;
-static int curses;
-static int sdl = 1;
+DisplayType display_type = DT_DEFAULT;
 const char* keyboard_layout = NULL;
 int64_t ticks_per_sec;
 ram_addr_t ram_size;
@@ -4842,6 +4840,7 @@ int main(int argc, char **argv, char **envp)
     const char *run_as = NULL;
 #endif
     CPUState *env;
+    int show_vnc_port = 0;
 
     qemu_cache_utils_init(envp);
 
@@ -4882,8 +4881,6 @@ int main(int argc, char **argv, char **envp)
     initrd_filename = NULL;
     ram_size = 0;
     snapshot = 0;
-    nographic = 0;
-    curses = 0;
     kernel_filename = NULL;
     kernel_cmdline = "";
     cyls = heads = secs = 0;
@@ -5075,11 +5072,11 @@ int main(int argc, char **argv, char **envp)
                 numa_add(optarg);
                 break;
             case QEMU_OPTION_nographic:
-                nographic = 1;
+                display_type = DT_NOGRAPHIC;
                 break;
 #ifdef CONFIG_CURSES
             case QEMU_OPTION_curses:
-                curses = 1;
+                display_type = DT_CURSES;
                 break;
 #endif
             case QEMU_OPTION_portrait:
@@ -5358,7 +5355,7 @@ int main(int argc, char **argv, char **envp)
                 no_quit = 1;
                 break;
             case QEMU_OPTION_sdl:
-                sdl = 1;
+                display_type = DT_SDL;
                 break;
 #endif
             case QEMU_OPTION_pidfile:
@@ -5420,6 +5417,7 @@ int main(int argc, char **argv, char **envp)
                 }
                 break;
 	    case QEMU_OPTION_vnc:
+                display_type = DT_VNC;
 		vnc_display = optarg;
 		break;
 #ifdef TARGET_I386
@@ -5578,7 +5576,7 @@ int main(int argc, char **argv, char **envp)
         exit(1);
     }
 
-    if (nographic) {
+    if (display_type == DT_NOGRAPHIC) {
        if (serial_device_index == 0)
            serial_devices[0] = "stdio";
        if (parallel_device_index == 0)
@@ -5944,44 +5942,46 @@ int main(int argc, char **argv, char **envp)
         dumb_display_init();
     /* just use the first displaystate for the moment */
     ds = display_state;
-    /* terminal init */
-    if (nographic) {
-        if (curses) {
-            fprintf(stderr, "fatal: -nographic can't be used with -curses\n");
-            exit(1);
-        }
-    } else { 
+
+    if (display_type == DT_DEFAULT) {
+#if defined(CONFIG_SDL) || defined(CONFIG_COCOA)
+        display_type = DT_SDL;
+#else
+        display_type = DT_VNC;
+        vnc_display = "localhost:0,to=99";
+        show_vnc_port = 1;
+#endif
+    }
+        
+
+    switch (display_type) {
+    case DT_NOGRAPHIC:
+        break;
 #if defined(CONFIG_CURSES)
-        if (curses) {
-            /* At the moment curses cannot be used with other displays */
-            curses_display_init(ds, full_screen);
-        } else
+    case DT_CURSES:
+        curses_display_init(ds, full_screen);
+        break;
 #endif
-#if defined(CONFIG_SDL) || defined(CONFIG_COCOA)
-        if (sdl) {
 #if defined(CONFIG_SDL)
-            sdl_display_init(ds, full_screen, no_frame);
+    case DT_SDL:
+        sdl_display_init(ds, full_screen, no_frame);
+        break;
 #elif defined(CONFIG_COCOA)
-            cocoa_display_init(ds, full_screen);
-#endif
-        } else
+    case DT_SDL:
+        cocoa_display_init(ds, full_screen);
+        break;
 #endif
-        {
-            int print_port = 0;
-
-            if (vnc_display == NULL) {
-                vnc_display = "localhost:0,to=99";
-                print_port = 1;
-            }
-
-            vnc_display_init(ds);
-            if (vnc_display_open(ds, vnc_display) < 0)
-                exit(1);
+    case DT_VNC:
+        vnc_display_init(ds);
+        if (vnc_display_open(ds, vnc_display) < 0)
+            exit(1);
 
-            if (print_port) {
-                printf("VNC server running on `%s'\n", vnc_display_local_addr(ds));
-            }
+        if (show_vnc_port) {
+            printf("VNC server running on `%s'\n", vnc_display_local_addr(ds));
         }
+        break;
+    default:
+        break;
     }
     dpy_resize(ds);
 
@@ -5994,7 +5994,7 @@ int main(int argc, char **argv, char **envp)
         dcl = dcl->next;
     }
 
-    if (nographic || (vnc_display && !sdl)) {
+    if (display_type == DT_NOGRAPHIC || display_type == DT_VNC) {
         nographic_timer = qemu_new_timer(rt_clock, nographic_update, NULL);
         qemu_mod_timer(nographic_timer, qemu_get_clock(rt_clock));
     }