4 files changed, 21 insertions, 14 deletions
diff --git a/tests/qemu-iotests/026 b/tests/qemu-iotests/026
index ebe29d0168..c9c5f83936 100755
--- a/tests/qemu-iotests/026
+++ b/tests/qemu-iotests/026
@@ -44,7 +44,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto generic
 _supported_os Linux
-
+_default_cache_mode "writethrough"
+_supported_cache_modes "writethrough" "none"
 
 echo "Errors while writing 128 kB"
 echo
diff --git a/tests/qemu-iotests/039 b/tests/qemu-iotests/039
index 8bade92a80..6abf47267f 100755
--- a/tests/qemu-iotests/039
+++ b/tests/qemu-iotests/039
@@ -44,7 +44,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto generic
 _supported_os Linux
-_unsupported_qemu_io_options --nocache
+_default_cache_mode "writethrough"
+_supported_cache_modes "writethrough"
 
 size=128M
 
diff --git a/tests/qemu-iotests/052 b/tests/qemu-iotests/052
index f5f9683e68..4d4e411339 100755
--- a/tests/qemu-iotests/052
+++ b/tests/qemu-iotests/052
@@ -41,8 +41,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt generic
 _supported_proto generic
 _supported_os Linux
-_unsupported_qemu_io_options --nocache
-
+_default_cache_mode "writethrough"
+_supported_cache_modes "writethrough"
 
 size=128M
 _make_test_img $size
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index 7f6245770a..47cef6dbe4 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -387,18 +387,23 @@ _supported_os()
     _notrun "not suitable for this OS: $HOSTOS"
 }
 
-_unsupported_qemu_io_options()
+_supported_cache_modes()
 {
-    for bad_opt
-    do
-        for opt in $QEMU_IO_OPTIONS
-        do
-            if [ "$bad_opt" = "$opt" ]
-            then
-                _notrun "not suitable for qemu-io option: $bad_opt"
-            fi
-        done
+    for mode; do
+        if [ "$mode" = "$CACHEMODE" ]; then
+            return
+        fi
     done
+    _notrun "not suitable for cache mode: $CACHEMODE"
+}
+
+_default_cache_mode()
+{
+    if $CACHEMODE_IS_DEFAULT; then
+        CACHEMODE="$1"
+        QEMU_IO="$QEMU_IO --cache $1"
+        return
+    fi
 }
 
 # this test requires that a specified command (executable) exists