[Qemu-devel] [PATCH] -nographic sometimes adds an extra chardev for stdio

[Mike Day]

When the deprecated -nographic option is used with the -mon option in
readline mode, qemu will create a second character device for stdio
and place it over the stdio chardev put into place by the -mon
option. This causes the terminal to stop echoeing characters upon exit
from Qemu.

Fix by checking for the existing chardev before adding another.
Signed-off-by: Mike Day <address@hidden>

---

To reproduce, use -mon and -nographic together. I was able to
reproduce it using

# qemu-system-x86_64 -enable-kvm -m 1G  -chardev stdio,id=mon0 \
# -mon chardev=mon0,mode=readline -nographic



---
 vl.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/vl.c b/vl.c
index 236f95e..3104b20 100644
--- a/vl.c
+++ b/vl.c
@@ -93,6 +93,7 @@ int main(int argc, char **argv)
 #include "sysemu/kvm.h"
 #include "qapi/qmp/qjson.h"
 #include "qemu/option.h"
+#include "qemu/option_int.h"
 #include "qemu/config-file.h"
 #include "qemu-options.h"
 #include "qmp-commands.h"
@@ -524,6 +525,20 @@ static QemuOptsList qemu_mem_opts = {
     },
 };
 
+static int qemu_opts_loopfun(QemuOpts *opts, void *opaque)
+{
+    QemuOpt *opt;
+
+    if (!strncmp(((QemuOpt *)opts->list)->name, "mon", 3)) {
+        QTAILQ_FOREACH(opt, &opts->head, next) {
+            if (!strncmp(opt->name, "chardev", 7)) {
+                return 1;
+            }
+        }
+    }
+    return 0;
+}
+
 /**
  * Get machine options
  *
@@ -4113,6 +4128,11 @@ int main(int argc, char **argv, char **envp)
     }
 
     if (display_type == DT_NOGRAPHIC) {
+        int have_stdio = 0;
+        QemuOptsList *opts = qemu_find_opts("mon");
+        if (opts) {
+            have_stdio = qemu_opts_foreach(opts, qemu_opts_loopfun, NULL, 0);
+        }
         if (default_parallel)
             add_device_config(DEV_PARALLEL, "null");
         if (default_serial && default_monitor) {
@@ -4122,7 +4142,7 @@ int main(int argc, char **argv, char **envp)
         } else if (default_sclp && default_monitor) {
             add_device_config(DEV_SCLP, "mon:stdio");
         } else {
-            if (default_serial)
+            if (default_serial && !have_stdio)
                 add_device_config(DEV_SERIAL, "stdio");
             if (default_virtcon)
                 add_device_config(DEV_VIRTCON, "stdio");
-- 
1.9.0