[Qemu-devel] Monitor multiplexing

[Jason Wessel]

I would like to submit the monitor multiplexing patch again.  It is 
ported against the latest CVS.

It allows adding monitor capabilities like stdio but with tcp for 
instance, and the escape character can be changed from the default.

signed-off-by: address@hidden

Index: monitor.c
===================================================================
RCS file: /sources/qemu/qemu/monitor.c,v
retrieving revision 1.64
diff -u -r1.64 monitor.c
--- monitor.c   5 Feb 2007 20:46:05 -0000       1.64
+++ monitor.c   5 Feb 2007 21:15:12 -0000
@@ -54,7 +54,8 @@
     const char *help;
 } term_cmd_t;
 
-static CharDriverState *monitor_hd;
+#define MAX_MON 4
+static CharDriverState *monitor_hd[MAX_MON];
 static int hide_banner;
 
 static term_cmd_t term_cmds[];
@@ -69,8 +70,11 @@
 
 void term_flush(void)
 {
+    int i;
     if (term_outbuf_index > 0) {
-        qemu_chr_write(monitor_hd, term_outbuf, term_outbuf_index);
+        for (i = 0; i < MAX_MON; i++)
+            if (monitor_hd[i] && monitor_hd[i]->focus == 0)
+                qemu_chr_write(monitor_hd[i], term_outbuf, term_outbuf_index);
         term_outbuf_index = 0;
     }
 }
@@ -2452,9 +2456,25 @@
     monitor_start_input();
 }
 
+static int is_first_init = 1;
+
 void monitor_init(CharDriverState *hd, int show_banner)
 {
-    monitor_hd = hd;
+    int i;
+
+    if (is_first_init) {
+        for (i = 0; i < MAX_MON; i++) {
+            monitor_hd[i] = NULL;
+        }
+        is_first_init = 0;
+    }
+    for (i = 0; i < MAX_MON; i++) {
+        if (monitor_hd[i] == NULL) {
+            monitor_hd[i] = hd;
+            break;
+        }
+    }
+
     hide_banner = !show_banner;
 
     qemu_chr_add_handlers(hd, term_can_read, term_read, term_event, NULL);
@@ -2475,8 +2495,12 @@
 void monitor_readline(const char *prompt, int is_password,
                       char *buf, int buf_size)
 {
+    int i;
+
     if (is_password) {
-        qemu_chr_send_event(monitor_hd, CHR_EVENT_FOCUS);
+        for (i = 0; i < MAX_MON; i++)
+            if (monitor_hd[i] && monitor_hd[i]->focus == 0)
+                qemu_chr_send_event(monitor_hd[i], CHR_EVENT_FOCUS);
     }
     readline_start(prompt, is_password, monitor_readline_cb, NULL);
     monitor_readline_buf = buf;
Index: qemu-doc.texi
===================================================================
RCS file: /sources/qemu/qemu/qemu-doc.texi,v
retrieving revision 1.128
diff -u -r1.128 qemu-doc.texi
--- qemu-doc.texi       5 Feb 2007 19:42:07 -0000       1.128
+++ qemu-doc.texi       5 Feb 2007 21:15:12 -0000
@@ -610,6 +610,18 @@
 same as if you had specified @code{-serial tcp} except the unix domain socket
 @var{path} is used for connections.
 
address@hidden mon:dev_string
+This is a special option to allow the monitor to be multiplexed onto
+another serial port.  The monitor is accessed with key sequence of
address@hidden and then pressing @key{c}. See monitor access
address@hidden in the -nographic section for more keys.
address@hidden should be any one of the serial devices specified
+above.  An example to multiplex the monitor onto a server telnet server
+listening on port 4444 would be:
address@hidden @code
address@hidden -serial mon:telnet::4444,server,nowait
address@hidden table
+
 @end table
 
 @item -parallel dev
@@ -629,6 +641,19 @@
 The default device is @code{vc} in graphical mode and @code{stdio} in
 non graphical mode.
 
address@hidden -echr numeric_ascii_value
+Change the escape character used for switching to the monitor when using
+monitor and serial sharing.  The default is @code{0x01} when using the
address@hidden option.  @code{0x01} is equal to pressing
address@hidden  You can select a different character from the ascii
+control keys where 1 through 26 map to Control-a through Control-z.  For
+instance you could use the either of the following to change the escape
+character to Control-t.
address@hidden @code
address@hidden -echr 0x14
address@hidden -echr 20
address@hidden table
+
 @item -s
 Wait gdb connection to port 1234 (@pxref{gdb_usage}). 
 @item -p port
@@ -711,6 +736,8 @@
 Exit emulator
 @item Ctrl-a s    
 Save disk data back to file (if -snapshot)
address@hidden Ctrl-a t
+toggle console timestamps
 @item Ctrl-a b
 Send break (magic sysrq in Linux)
 @item Ctrl-a c
Index: vl.c
===================================================================
RCS file: /sources/qemu/qemu/vl.c,v
retrieving revision 1.248
diff -u -r1.248 vl.c
--- vl.c        5 Feb 2007 20:46:05 -0000       1.248
+++ vl.c        5 Feb 2007 21:15:13 -0000
@@ -1213,6 +1213,218 @@
     return chr;
 }
 
+/* MUX driver for serial I/O splitting */
+static int term_timestamps;
+static int64_t term_timestamps_start;
+#define MAX_MUX 2
+typedef struct {
+    IOCanRWHandler *chr_can_read[MAX_MUX];
+    IOReadHandler *chr_read[MAX_MUX];
+    IOEventHandler *chr_event[MAX_MUX];
+    void *ext_opaque[MAX_MUX];
+    CharDriverState *drv;
+    int mux_cnt;
+    int term_got_escape;
+    int max_size;
+} MuxDriver;
+
+
+static int mux_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
+{
+    MuxDriver *d = chr->opaque;
+    int ret;
+    if (!term_timestamps) {
+        ret = d->drv->chr_write(d->drv, buf, len);
+    } else {
+        int i;
+
+        ret = 0;
+        for(i = 0; i < len; i++) {
+            ret += d->drv->chr_write(d->drv, buf+i, 1);
+            if (buf[i] == '\n') {
+                char buf1[64];
+                int64_t ti;
+                int secs;
+
+                ti = get_clock();
+                if (term_timestamps_start == -1)
+                    term_timestamps_start = ti;
+                ti -= term_timestamps_start;
+                secs = ti / 1000000000;
+                snprintf(buf1, sizeof(buf1),
+                         "[%02d:%02d:%02d.%03d] ",
+                         secs / 3600,
+                         (secs / 60) % 60,
+                         secs % 60,
+                         (int)((ti / 1000000) % 1000));
+                d->drv->chr_write(d->drv, buf1, strlen(buf1));
+            }
+        }
+    }
+    return ret;
+}
+
+static char *mux_help[] = {
+    "% h    print this help\n\r",
+    "% x    exit emulator\n\r",
+    "% s    save disk data back to file (if -snapshot)\n\r",
+    "% t    toggle console timestamps\n\r"
+    "% b    send break (magic sysrq)\n\r",
+    "% c    switch between console and monitor\n\r",
+    "% %  sends %\n\r",
+    NULL
+};
+
+static int term_escape_char = 0x01; /* ctrl-a is used for escape */
+static void mux_print_help(CharDriverState *chr)
+{
+    int i, j;
+    char ebuf[15] = "Escape-Char";
+    char cbuf[50] = "\n\r";
+
+    if (term_escape_char > 0 && term_escape_char < 26) {
+        sprintf(cbuf,"\n\r");
+        sprintf(ebuf,"C-%c", term_escape_char - 1 + 'a');
+    } else {
+        sprintf(cbuf,"\n\rEscape-Char set to Ascii: 0x%02x\n\r\n\r", 
term_escape_char);
+    }
+    chr->chr_write(chr, cbuf, strlen(cbuf));
+    for (i = 0; mux_help[i] != NULL; i++) {
+        for (j=0; mux_help[i][j] != '\0'; j++) {
+            if (mux_help[i][j] == '%')
+                chr->chr_write(chr, ebuf, strlen(ebuf));
+            else
+                chr->chr_write(chr, &mux_help[i][j], 1);
+        }
+    }
+}
+
+static int mux_proc_byte(CharDriverState *chr, MuxDriver *d, int ch)
+{
+    if (d->term_got_escape) {
+        d->term_got_escape = 0;
+        if (ch == term_escape_char)
+            goto send_char;
+        switch(ch) {
+        case '?':
+        case 'h':
+            mux_print_help(chr);
+            break;
+        case 'x':
+            {
+                 char *term =  "QEMU: Terminated\n\r";
+                 chr->chr_write(chr,term,strlen(term));
+                 exit(0);
+                 break;
+            }
+        case 's':
+            {
+                int i;
+                for (i = 0; i < MAX_DISKS; i++) {
+                    if (bs_table[i])
+                        bdrv_commit(bs_table[i]);
+                }
+            }
+            break;
+        case 'b':
+            if (chr->chr_event)
+                chr->chr_event(chr->opaque, CHR_EVENT_BREAK);
+            break;
+        case 'c':
+            /* Switch to the next registered device */
+            chr->focus++;
+            if (chr->focus >= d->mux_cnt)
+                chr->focus = 0;
+            break;
+       case 't':
+           term_timestamps = !term_timestamps;
+           term_timestamps_start = -1;
+           break;
+        }
+    } else if (ch == term_escape_char) {
+        d->term_got_escape = 1;
+    } else {
+    send_char:
+        return 1;
+    }
+    return 0;
+}
+
+static int mux_chr_can_read(void *opaque)
+{
+    CharDriverState *chr = opaque;
+    MuxDriver *d = chr->opaque;
+    if (d->chr_can_read[chr->focus])
+       return d->chr_can_read[chr->focus](d->ext_opaque[chr->focus]);
+    return 0;
+}
+
+static void mux_chr_read(void *opaque, const uint8_t *buf, int size)
+{
+    CharDriverState *chr = opaque;
+    MuxDriver *d = chr->opaque;
+    int i;
+    for(i = 0; i < size; i++)
+        if (mux_proc_byte(chr, d, buf[i]))
+            d->chr_read[chr->focus](d->ext_opaque[chr->focus], &buf[i], 1);
+}
+
+static void mux_chr_event(void *opaque, int event)
+{
+    CharDriverState *chr = opaque;
+    MuxDriver *d = chr->opaque;
+    int i;
+
+    /* Send the event to all registered listeners */
+    for (i = 0; i < d->mux_cnt; i++)
+        if (d->chr_event[i])
+            d->chr_event[i](d->ext_opaque[i], event);
+}
+
+static void mux_chr_update_read_handler(CharDriverState *chr)
+{
+    MuxDriver *d = chr->opaque;
+
+    if (d->mux_cnt >= MAX_MUX) {
+        fprintf(stderr, "Cannot add I/O handlers, MUX array is full\n");
+        return;
+    }
+    d->ext_opaque[d->mux_cnt] = chr->handler_opaque;
+    d->chr_can_read[d->mux_cnt] = chr->chr_can_read;
+    d->chr_read[d->mux_cnt] = chr->chr_read;
+    d->chr_event[d->mux_cnt] = chr->chr_event;
+    /* Fix up the real driver with mux routines */
+    if (d->mux_cnt == 0) {
+        qemu_chr_add_handlers(d->drv, mux_chr_can_read, mux_chr_read,
+                              mux_chr_event, chr);
+    }
+    chr->focus = d->mux_cnt;
+    d->mux_cnt++;
+}
+
+CharDriverState *qemu_chr_open_mux(CharDriverState *drv)
+{
+    CharDriverState *chr;
+    MuxDriver *d;
+
+    chr = qemu_mallocz(sizeof(CharDriverState));
+    if (!chr)
+        return NULL;
+    d = qemu_mallocz(sizeof(MuxDriver));
+    if (!d) {
+        free(chr);
+        return NULL;
+    }
+
+    chr->opaque = d;
+    d->drv = drv;
+    chr->focus = -1;
+    chr->chr_write = mux_chr_write;
+    chr->chr_update_read_handler = mux_chr_update_read_handler;
+    return chr;
+}
+
+
 #ifdef _WIN32
 
 static void socket_cleanup(void)
@@ -1304,10 +1516,8 @@
     int max_size;
 } FDCharDriver;
 
-#define STDIO_MAX_CLIENTS 2
-
-static int stdio_nb_clients;
-static CharDriverState *stdio_clients[STDIO_MAX_CLIENTS];
+#define STDIO_MAX_CLIENTS 1
+static int stdio_nb_clients = 0;
 
 static int fd_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
 {
@@ -1420,162 +1630,45 @@
 /* for STDIO, we handle the case where several clients use it
    (nographic mode) */
 
-#define TERM_ESCAPE 0x01 /* ctrl-a is used for escape */
-
 #define TERM_FIFO_MAX_SIZE 1
 
-static int term_got_escape, client_index;
 static uint8_t term_fifo[TERM_FIFO_MAX_SIZE];
 static int term_fifo_size;
-static int term_timestamps;
-static int64_t term_timestamps_start;
-
-void term_print_help(void)
-{
-    printf("\n"
-           "C-a h    print this help\n"
-           "C-a x    exit emulator\n"
-           "C-a s    save disk data back to file (if -snapshot)\n"
-           "C-a b    send break (magic sysrq)\n"
-           "C-a t    toggle console timestamps\n"
-           "C-a c    switch between console and monitor\n"
-           "C-a C-a  send C-a\n"
-           );
-}
-
-/* called when a char is received */
-static void stdio_received_byte(int ch)
-{
-    if (term_got_escape) {
-        term_got_escape = 0;
-        switch(ch) {
-        case 'h':
-            term_print_help();
-            break;
-        case 'x':
-            exit(0);
-            break;
-        case 's': 
-            {
-                int i;
-                for (i = 0; i < MAX_DISKS; i++) {
-                    if (bs_table[i])
-                        bdrv_commit(bs_table[i]);
-                }
-            }
-            break;
-        case 'b':
-            if (client_index < stdio_nb_clients) {
-                CharDriverState *chr;
-                FDCharDriver *s;
-
-                chr = stdio_clients[client_index];
-                s = chr->opaque;
-                qemu_chr_event(chr, CHR_EVENT_BREAK);
-            }
-            break;
-        case 'c':
-            client_index++;
-            if (client_index >= stdio_nb_clients)
-                client_index = 0;
-            if (client_index == 0) {
-                /* send a new line in the monitor to get the prompt */
-                ch = '\r';
-                goto send_char;
-            }
-            break;
-        case 't':
-            term_timestamps = !term_timestamps;
-            term_timestamps_start = -1;
-            break;
-        case TERM_ESCAPE:
-            goto send_char;
-        }
-    } else if (ch == TERM_ESCAPE) {
-        term_got_escape = 1;
-    } else {
-    send_char:
-        if (client_index < stdio_nb_clients) {
-            uint8_t buf[1];
-            CharDriverState *chr;
-            
-            chr = stdio_clients[client_index];
-            if (qemu_chr_can_read(chr) > 0) {
-                buf[0] = ch;
-                qemu_chr_read(chr, buf, 1);
-            } else if (term_fifo_size == 0) {
-                term_fifo[term_fifo_size++] = ch;
-            }
-        }
-    }
-}
 
 static int stdio_read_poll(void *opaque)
 {
-    CharDriverState *chr;
+    CharDriverState *chr = opaque;
 
-    if (client_index < stdio_nb_clients) {
-        chr = stdio_clients[client_index];
-        /* try to flush the queue if needed */
-        if (term_fifo_size != 0 && qemu_chr_can_read(chr) > 0) {
-            qemu_chr_read(chr, term_fifo, 1);
-            term_fifo_size = 0;
-        }
-        /* see if we can absorb more chars */
-        if (term_fifo_size == 0)
-            return 1;
-        else
-            return 0;
-    } else {
-        return 1;
+    /* try to flush the queue if needed */
+    if (term_fifo_size != 0 && qemu_chr_can_read(chr) > 0) {
+        qemu_chr_read(chr, term_fifo, 1);
+        term_fifo_size = 0;
     }
+    /* see if we can absorb more chars */
+    if (term_fifo_size == 0)
+        return 1;
+    else
+        return 0;
 }
 
 static void stdio_read(void *opaque)
 {
     int size;
     uint8_t buf[1];
-    
+    CharDriverState *chr = opaque;
+
     size = read(0, buf, 1);
     if (size == 0) {
         /* stdin has been closed. Remove it from the active list.  */
         qemu_set_fd_handler2(0, NULL, NULL, NULL, NULL);
         return;
     }
-    if (size > 0)
-        stdio_received_byte(buf[0]);
-}
-
-static int stdio_write(CharDriverState *chr, const uint8_t *buf, int len)
-{
-    FDCharDriver *s = chr->opaque;
-    if (!term_timestamps) {
-        return unix_write(s->fd_out, buf, len);
-    } else {
-        int i;
-        char buf1[64];
-
-        for(i = 0; i < len; i++) {
-            unix_write(s->fd_out, buf + i, 1);
-            if (buf[i] == '\n') {
-                int64_t ti;
-                int secs;
-
-                ti = get_clock();
-                if (term_timestamps_start == -1)
-                    term_timestamps_start = ti;
-                ti -= term_timestamps_start;
-                secs = ti / 1000000000;
-                snprintf(buf1, sizeof(buf1), 
-                         "[%02d:%02d:%02d.%03d] ",
-                         secs / 3600,
-                         (secs / 60) % 60,
-                         secs % 60,
-                         (int)((ti / 1000000) % 1000));
-                unix_write(s->fd_out, buf1, strlen(buf1));
-            }
+    if (size > 0) {
+        if (qemu_chr_can_read(chr) > 0) {
+            qemu_chr_read(chr, buf, 1);
+        } else if (term_fifo_size == 0) {
+            term_fifo[term_fifo_size++] = buf[0];
         }
-        return len;
     }
 }
 
@@ -1620,24 +1713,13 @@
 {
     CharDriverState *chr;
 
-    if (nographic) {
-        if (stdio_nb_clients >= STDIO_MAX_CLIENTS)
-            return NULL;
-        chr = qemu_chr_open_fd(0, 1);
-        chr->chr_write = stdio_write;
-        if (stdio_nb_clients == 0)
-            qemu_set_fd_handler2(0, stdio_read_poll, stdio_read, NULL, NULL);
-        client_index = stdio_nb_clients;
-    } else {
-        if (stdio_nb_clients != 0)
-            return NULL;
-        chr = qemu_chr_open_fd(0, 1);
-    }
-    stdio_clients[stdio_nb_clients++] = chr;
-    if (stdio_nb_clients == 1) {
-        /* set the terminal in raw mode */
-        term_init();
-    }
+    if (stdio_nb_clients >= STDIO_MAX_CLIENTS)
+        return NULL;
+    chr = qemu_chr_open_fd(0, 1);
+    qemu_set_fd_handler2(0, stdio_read_poll, stdio_read, NULL, chr);
+    stdio_nb_clients++;
+    term_init();
+
     return chr;
 }
 
@@ -2719,6 +2801,16 @@
     if (strstart(filename, "udp:", &p)) {
         return qemu_chr_open_udp(p);
     } else
+    if (strstart(filename, "mon:", &p)) {
+        CharDriverState *drv = qemu_chr_open(p);
+        if (drv) {
+            drv = qemu_chr_open_mux(drv);
+            monitor_init(drv, !nographic);
+            return drv;
+        }
+        printf("Unable to open driver: %s\n", p);
+        return 0;
+    } else
 #ifndef _WIN32
     if (strstart(filename, "unix:", &p)) {
        return qemu_chr_open_tcp(p, 0, 1);
@@ -6187,6 +6279,7 @@
     QEMU_OPTION_cirrusvga,
     QEMU_OPTION_g,
     QEMU_OPTION_std_vga,
+    QEMU_OPTION_echr,
     QEMU_OPTION_monitor,
     QEMU_OPTION_serial,
     QEMU_OPTION_parallel,
@@ -6268,6 +6361,7 @@
 #endif
     { "localtime", 0, QEMU_OPTION_localtime },
     { "std-vga", 0, QEMU_OPTION_std_vga },
+    { "echr", 1, QEMU_OPTION_echr },
     { "monitor", 1, QEMU_OPTION_monitor },
     { "serial", 1, QEMU_OPTION_serial },
     { "parallel", 1, QEMU_OPTION_parallel },
@@ -6704,8 +6798,8 @@
                 }
                 break;
             case QEMU_OPTION_nographic:
-                pstrcpy(monitor_device, sizeof(monitor_device), "stdio");
                 pstrcpy(serial_devices[0], sizeof(serial_devices[0]), "stdio");
+                pstrcpy(monitor_device, sizeof(monitor_device), "stdio");
                 nographic = 1;
                 break;
             case QEMU_OPTION_kernel:
@@ -6866,6 +6960,14 @@
                     graphic_depth = depth;
                 }
                 break;
+            case QEMU_OPTION_echr:
+                {
+                    char *r;
+                    term_escape_char = strtol(optarg, &r, 0);
+                    if (r == optarg)
+                        printf("Bad argument to echr\n");
+                    break;
+                }
             case QEMU_OPTION_monitor:
                 pstrcpy(monitor_device, sizeof(monitor_device), optarg);
                 break;
@@ -7165,12 +7267,27 @@
 #endif
     }
 
-    monitor_hd = qemu_chr_open(monitor_device);
-    if (!monitor_hd) {
-        fprintf(stderr, "qemu: could not open monitor device '%s'\n", 
monitor_device);
-        exit(1);
+    /* Maintain compatibility with multiple stdio monitors */
+    if (!strcmp(monitor_device,"stdio")) {
+        for (i = 0; i < MAX_SERIAL_PORTS; i++) {
+            if (!strcmp(serial_devices[i],"mon:stdio")) {
+                monitor_device[0] = '\0';
+                break;
+            } else if (!strcmp(serial_devices[i],"stdio")) {
+                monitor_device[0] = '\0';
+                pstrcpy(serial_devices[0], sizeof(serial_devices[0]), 
"mon:stdio");
+                break;
+            }
+        }
+    }
+    if (monitor_device[0] != '\0') {
+        monitor_hd = qemu_chr_open(monitor_device);
+        if (!monitor_hd) {
+            fprintf(stderr, "qemu: could not open monitor device '%s'\n", 
monitor_device);
+            exit(1);
+        }
+        monitor_init(monitor_hd, !nographic);
     }
-    monitor_init(monitor_hd, !nographic);
 
     for(i = 0; i < MAX_SERIAL_PORTS; i++) {
         const char *devname = serial_devices[i];
Index: vl.h
===================================================================
RCS file: /sources/qemu/qemu/vl.h,v
retrieving revision 1.184
diff -u -r1.184 vl.h
--- vl.h        5 Feb 2007 20:20:30 -0000       1.184
+++ vl.h        5 Feb 2007 21:15:13 -0000
@@ -300,6 +300,7 @@
     void (*chr_send_event)(struct CharDriverState *chr, int event);
     void (*chr_close)(struct CharDriverState *chr);
     void *opaque;
+    int focus;
     QEMUBH *bh;
 } CharDriverState;