Set default console to virtio on S390x

All "normal" system emulation targets in qemu I'm aware of display
output on either VGA or serial output.

Our S390x virtio machine doesn't have such kind of legacy hardware. So
instead we need to default to a virtio console.

Add flags to QEMUMachine to indicate which kind of default devices make
sense for the machine in question.  Use it for S390x: enable virtcon,
disable serial, parallel and vga.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit 986c5f78543bdbd696664447ecdd08cf6d935370)

1 files changed, 18 insertions, 1 deletions

diff --git a/vl.c b/vl.c
index b4138be0e..d02893173 100644
--- a/vl.c
+++ b/vl.c
@@ -270,7 +270,7 @@ static void *boot_set_opaque;
 
 static int default_serial = 1;
 static int default_parallel = 1;
-static int default_virtcon = 0;
+static int default_virtcon = 1;
 static int default_monitor = 1;
 static int default_vga = 1;
 static int default_drive = 1;
@@ -5629,14 +5629,31 @@ int main(int argc, char **argv, char **envp)
 
     qemu_opts_foreach(&qemu_device_opts, default_driver_check, NULL, 0);
 
+    if (machine->no_serial) {
+        default_serial = 0;
+    }
+    if (machine->no_parallel) {
+        default_parallel = 0;
+    }
+    if (!machine->use_virtcon) {
+        default_virtcon = 0;
+    }
+    if (machine->no_vga) {
+        default_vga = 0;
+    }
+
     if (display_type == DT_NOGRAPHIC) {
         if (default_parallel)
             add_device_config(DEV_PARALLEL, "null");
         if (default_serial && default_monitor) {
             add_device_config(DEV_SERIAL, "mon:stdio");
+        } else if (default_virtcon && default_monitor) {
+            add_device_config(DEV_VIRTCON, "mon:stdio");
         } else {
             if (default_serial)
                 add_device_config(DEV_SERIAL, "stdio");
+            if (default_virtcon)
+                add_device_config(DEV_VIRTCON, "stdio");
             if (default_monitor)
                 monitor_parse("stdio", "readline");
         }