monitor: Command-line flag to enable control mode

This commit adds a flag called 'control' to the '-monitor'
command-line option. This flag enables control mode.

The syntax is:

qemu [...] -monitor control,<device>

Where <device> is a chardev (excluding 'vc', for obvious reasons).

For example:

$ qemu [...] -monitor control,tcp:localhost:4444,server

Will run QEMU in control mode, waiting for a client TCP connection
on localhost port 4444.

NOTE: I've tried using QemuOpts for this, but turns out that it
will try to parse the device part, which should be untouched.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/monitor.c b/monitor.c
index 6733022a16..1dda8cdedb 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3535,6 +3535,24 @@ static void monitor_event(void *opaque, int event)
  * End:
  */
 
+const char *monitor_cmdline_parse(const char *cmdline, int *flags)
+{
+    const char *dev;
+
+    if (strstart(cmdline, "control,", &dev)) {
+        if (strstart(dev, "vc", NULL)) {
+            fprintf(stderr, "qemu: control mode is for low-level interaction ");
+            fprintf(stderr, "cannot be used with device 'vc'\n");
+            exit(1);
+        }
+        *flags &= ~MONITOR_USE_READLINE;
+        *flags |= MONITOR_USE_CONTROL;
+        return dev;
+    }
+
+    return cmdline;
+}
+
 void monitor_init(CharDriverState *chr, int flags)
 {
     static int is_first_init = 1;