Reference: bnc#885380
Allow Xen based VMs to default to using qcow2
Index: virt-manager-3.0.0/virtinst/support.py
===================================================================
--- virt-manager-3.0.0.orig/virtinst/support.py
+++ virt-manager-3.0.0/virtinst/support.py
@@ -242,7 +242,7 @@ class SupportCache:
     # This is an arbitrary check to say whether it's a good idea to
     # default to qcow2. It might be fine for xen or qemu older than the versions
     # here, but until someone tests things I'm going to be a bit conservative.
-    conn_default_qcow2 = _make(hv_version={"qemu": "1.2.0", "test": 0})
+    conn_default_qcow2 = _make(hv_version={"qemu": "1.2.0", "all": 0})
     conn_autosocket = _make(hv_libvirt_version={"qemu": "1.0.6"})
     conn_pm_disable = _make(hv_version={"qemu": "1.2.0", "test": 0})
     conn_qcow2_lazy_refcounts = _make(