qemu-iotests supports the -nocache option which makes the tests run with
cache=none. For blkdebug tests with qcow2 this means that we may see
test results that differ from cache=writethrough. This patch makes the
diff a bit smaller and therefore easier to review.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>