[PATCH v3 27/49] monitor: reject readline monitor when HMP is disabled

When QEMU is built without HMP support, reject '-monitor' (which
requests readline/HMP mode) early in monitor_new_opts() with a
clear error message directing users to '-qmp' instead.

Signed-off-by: Marc-Andre Lureau <[email protected]>
---
 monitor/monitor.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/monitor/monitor.c b/monitor/monitor.c
index 6d6ffbb0f78a..8528af6f79b8 100644
--- a/monitor/monitor.c
+++ b/monitor/monitor.c
@@ -776,6 +776,16 @@ int monitor_new_opts(QemuOpts *opts, Error **errp)
     MonitorOptions *options;
     int ret;
 
+#ifndef CONFIG_HMP
+    const char *mode = qemu_opt_get(opts, "mode");
+    /* readline is HMP..  */
+    if (mode && g_str_equal(mode, "readline")) {
+        error_setg(errp, "HMP monitor is not available,"
+                   " use '-qmp' instead of '-monitor'");
+        return -1;
+    }
+#endif
+
     v = opts_visitor_new(opts);
     visit_type_MonitorOptions(v, NULL, &options, errp);
     visit_free(v);

-- 
2.55.0.543.g5ebe2ebe4ea8