[Qemu-devel] [PATCH 5/5] HMP: Introduce console command

[Lei Li <lilei@linux.vnet.ibm.com>]

Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
---
 hmp-commands.hx |   23 +++++++++++++++++++++++
 hmp.c           |   53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 hmp.h           |    1 +
 monitor.c       |   15 +++++++++++++++
 monitor.h       |    3 +++
 5 files changed, 95 insertions(+), 0 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 5f91428..f862a53 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -868,7 +868,30 @@ char device and return @var{size} of the data.
 that specifies behavior when the queue is full/empty. By default is
 'drop'. Note that the 'block' option is not supported now.
         -b for 'block' option. None for 'drop' option.
+ETEXI
+
+    {
+        .name       = "console",
+        .args_type  = "chardev:s",
+        .params     = "chardev",
+        .help       = "Connect to the serial console from within the"
+                      "monitor, allow to write data to memchardev"
+                      "'chardev'. Exit from the console and return back"
+                      "to monitor by typing 'ctrl-]'",
+        .mhandler.cmd = hmp_console,
+    },
 
+STEXI
+@item console @var{device}
+@findex console
+
+Connect to the serial console from within the monitor, allow to write data
+to memchardev @var{chardev}. Exit from the console and return back to
+monitor by typing 'ctrl-]'.
+@example
+(qemu) console foo
+foo: data string...
+@end example
 ETEXI
 
     {
diff --git a/hmp.c b/hmp.c
index fa858c4..bc245f4 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1245,3 +1245,56 @@ void hmp_screen_dump(Monitor *mon, const QDict *qdict)
     qmp_screendump(filename, &err);
     hmp_handle_error(mon, &err);
 }
+
+enum escape_char
+{
+    ESCAPE_CHAR_CTRL_GS = 0x1d  /* ctrl-] used for escape */
+};
+
+static void hmp_read_console(Monitor *mon, const char *data,
+                             void *opaque)
+{
+    CharDriverState *chr = opaque;
+    uint32_t size = strlen(data);
+    enum DataFormat format = DATA_FORMAT_UTF8;
+    enum CongestionControl control = CONGESTION_CONTROL_DROP;
+    enum escape_char console_escape = ESCAPE_CHAR_CTRL_GS;
+
+    Error *err = NULL;
+
+    if (*data == console_escape) {
+        monitor_resume(mon);
+        return;
+    }
+
+    qmp_memchar_write(chr->label, size, data, 0, format,
+                      0, control, &err);
+    if (err) {
+        monitor_printf(mon, "%s\n", error_get_pretty(err));
+        error_free(err);
+        return;
+    }
+
+    monitor_read_command(mon, 1);
+}
+
+void hmp_console(Monitor *mon, const QDict *qdict)
+{
+    const char *device = qdict_get_str(qdict, "chardev");
+    CharDriverState *chr;
+    Error *err = NULL;
+
+    chr = qemu_chr_find(device);
+
+    if (!chr) {
+        error_set(&err, QERR_DEVICE_NOT_FOUND, device);
+        goto out;
+    }
+
+    if (monitor_read_console(mon, device, hmp_read_console, chr) < 0) {
+        monitor_printf(mon, "Connect to console %s failed\n", device);
+    }
+
+out:
+    hmp_handle_error(mon, &err);
+}
diff --git a/hmp.h b/hmp.h
index a5a0cfe..5b54a79 100644
--- a/hmp.h
+++ b/hmp.h
@@ -77,5 +77,6 @@ void hmp_getfd(Monitor *mon, const QDict *qdict);
 void hmp_closefd(Monitor *mon, const QDict *qdict);
 void hmp_send_key(Monitor *mon, const QDict *qdict);
 void hmp_screen_dump(Monitor *mon, const QDict *qdict);
+void hmp_console(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/monitor.c b/monitor.c
index 131b325..453c084 100644
--- a/monitor.c
+++ b/monitor.c
@@ -256,6 +256,21 @@ int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
     }
 }
 
+int monitor_read_console(Monitor *mon, const char *device,
+                         ReadLineFunc *readline_func, void *opaque)
+{
+    char prompt[60];
+
+    if (!mon->rs) {
+        return -1;
+    }
+
+    snprintf(prompt, sizeof(prompt), "%s: ", device);
+    readline_start(mon->rs, prompt, 0, readline_func, opaque);
+
+    return 0;
+}
+
 void monitor_flush(Monitor *mon)
 {
     if (mon && mon->outbuf_index != 0 && !mon->mux_out) {
diff --git a/monitor.h b/monitor.h
index b6e7d95..735bd1b 100644
--- a/monitor.h
+++ b/monitor.h
@@ -86,6 +86,9 @@ ReadLineState *monitor_get_rs(Monitor *mon);
 int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
                           void *opaque);
 
+int monitor_read_console(Monitor *mon, const char *device,
+                         ReadLineFunc *readline_func, void *opaque);
+
 int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret);
 
 int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret);
-- 
1.7.7.6