These tests will create some other format of image, so the
options for qcow3 would affect them.
To make these cases still work with qcow3 format, reset the
'image_extra_params' parameter in them.
Signed-off-by: NQingtang Zhou <qzhou@redhat.com>

This patch creates a series of sub functions for device add
action in different version of qemu.
Signed-off-by: NQingtang Zhou <qzhou@redhat.com>

We've only spot this mistake now :(
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

In order to have self describing tests, split the original
subtests.cfg in several per test files, and create subtests.cfg
out from this information.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>