iotests: fix 197 for vpc

VPC has some difficulty creating geometries of particular size.
However, we can indeed force it to use a literal one, so let's
do that for the sake of test 197, which is testing some specific
offsets.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Lukáš Doktor <ldoktor@redhat.com>
diff --git a/tests/qemu-iotests/197 b/tests/qemu-iotests/197
index 887eb4f..5e869fe 100755
--- a/tests/qemu-iotests/197
+++ b/tests/qemu-iotests/197
@@ -60,6 +60,10 @@
 echo
 
 # Prep the images
+# VPC rounds image sizes to a specific geometry, force a specific size.
+if [ "$IMGFMT" = "vpc" ]; then
+    IMGOPTS=$(_optstr_add "$IMGOPTS" "force_size")
+fi
 _make_test_img 4G
 $QEMU_IO -c "write -P 55 3G 1k" "$TEST_IMG" | _filter_qemu_io
 IMGPROTO=file IMGFMT=qcow2 IMGOPTS= TEST_IMG_FILE="$TEST_WRAP" \