In case there were options set in the default config file, print
a warning so users can update their scripts.

If somebody wants to keep the config file as-is, avoid the
warning and use a command-line that will work in future QEMU
versions, they can use:

 $QEMU -nodefconfig -readconfig /etc/qemu/qemu.conf

I was going to add an additional message suggesting it as a
solution, but I thought it could make it more confusing. The
solution can be documented in the QEMU 2.9 ChangeLog.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 vl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/vl.c b/vl.c
index 7f1644a2be..dae86fd4a8 100644
--- a/vl.c
+++ b/vl.c
@@ -2939,6 +2939,12 @@ static int qemu_read_default_config_file(void)
         return ret;
     }
 
+    if (ret > 0) {
+        loc_set_none();
+        error_report("Warning: Future QEMU versions won't load %s automatically",
+                     CONFIG_QEMU_CONFDIR "/qemu.conf");
+    }
+
     return 0;
 }
 
-- 
2.11.0.259.g40922b1