Open Stack

Hi,
I am developing a security driver of libvirt , I want to test the new "security driver" of libvirt 
using OpenStack , I encounter some problem:

I have known the back-end of OpenStack compute-node is libvirt (but they are independent modules) , I use 
DevStack to deploy the OpenStack . I notice that it automatically install "All packages" including "libvirt",
so I decide to uninstall the "libvirt packages" ,then compile and install libvirt , but all after, 
when I use the OpenStack dashboard to create Instance , the Task state keep "scheduling" ,no forwarding.

Is the problem in lacking proper libvirt configuration ?
Is there other method to "integrate" libvirt to Openstack from src ? or How to deploy and test libvirt using OpenStack ?

Thanks

H Changyao