libvirt users - May 2015 - SELinux for separate shared folders

How can I enforce SELinux separation between the shared folders 
belonging to different VMs running with sVirt's SELinux dynamic labels?

I want to create a permanent exception for VM 'A' to only be able to 
read and write to shared folder 'A' and the same for VM 'B' and
shared
folder 'B'

svirt_image_t permits access to a shared folder but for all VMs.