Without this argument, qemu will print an angry message about not being
able to connect to a display server if $DISPLAY is not set.  For me,
that breaks iotests.supported_formats() because it thus only sees
["Could", "not", "connect"] as the supported formats.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190819201851.24418-2-mreitz@redhat.com
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/check | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index c24874ff4a..a58232eefb 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -581,13 +581,13 @@ export QEMU_PROG="$(type -p "$QEMU_PROG")"
 
 case "$QEMU_PROG" in
     *qemu-system-arm|*qemu-system-aarch64)
-        export QEMU_OPTIONS="-nodefaults -machine virt,accel=qtest"
+        export QEMU_OPTIONS="-nodefaults -display none -machine virt,accel=qtest"
         ;;
     *qemu-system-tricore)
-        export QEMU_OPTIONS="-nodefaults -machine tricore_testboard,accel=qtest"
+        export QEMU_OPTIONS="-nodefaults -display none -machine tricore_testboard,accel=qtest"
         ;;
     *)
-        export QEMU_OPTIONS="-nodefaults -machine accel=qtest"
+        export QEMU_OPTIONS="-nodefaults -display none -machine accel=qtest"
         ;;
 esac
 
-- 
2.21.0