diff --git a/block/amend.c b/block/amend.c
index f4612dcf08..392df9ef83 100644
--- a/block/amend.c
+++ b/block/amend.c
@@ -69,8 +69,12 @@ void qmp_x_blockdev_amend(const char *job_id,
     BlockdevAmendJob *s;
     const char *fmt = BlockdevDriver_str(options->driver);
     BlockDriver *drv = bdrv_find_format(fmt);
-    BlockDriverState *bs = bdrv_find_node(node_name);
+    BlockDriverState *bs;
 
+    bs = bdrv_lookup_bs(NULL, node_name, errp);
+    if (!bs) {
+        return;
+    }
 
     if (!drv) {
         error_setg(errp, "Block driver '%s' not found or not supported", fmt);
diff --git a/tests/qemu-iotests/197 b/tests/qemu-iotests/197
index 95f05b0e34..121959a09c 100755
--- a/tests/qemu-iotests/197
+++ b/tests/qemu-iotests/197
@@ -112,7 +112,9 @@ echo
 echo '=== Partial final cluster ==='
 echo
 
-_make_test_img 1024
+# Force compat=1.1, because writing zeroes on a v2 image without a
+# backing file would just result in an unallocated cluster
+_make_test_img -o compat=1.1 1024
 $QEMU_IO -f $IMGFMT -C -c 'read 0 1024' "$TEST_IMG" | _filter_qemu_io
 $QEMU_IO -f $IMGFMT -c map "$TEST_IMG"
 _check_test_img
diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index e0d8049012..0657f7286c 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -595,15 +595,19 @@ then
 fi
 export QEMU_PROG="$(type -p "$QEMU_PROG")"
 
+export QEMU_OPTIONS="-nodefaults -display none -accel qtest"
 case "$QEMU_PROG" in
     *qemu-system-arm|*qemu-system-aarch64)
-        export QEMU_OPTIONS="-nodefaults -display none -machine virt -accel qtest"
+        export QEMU_OPTIONS="$QEMU_OPTIONS -machine virt"
+        ;;
+    *qemu-system-avr)
+        export QEMU_OPTIONS="$QEMU_OPTIONS -machine mega2560"
+        ;;
+    *qemu-system-rx)
+        export QEMU_OPTIONS="$QEMU_OPTIONS -machine gdbsim-r5f562n8"
         ;;
     *qemu-system-tricore)
-        export QEMU_OPTIONS="-nodefaults -display none -machine tricore_testboard -accel qtest"
-        ;;
-    *)
-        export QEMU_OPTIONS="-nodefaults -display none -accel qtest"
+        export QEMU_OPTIONS="-$QEMU_OPTIONS -machine tricore_testboard"
         ;;
 esac