http://libvirt.org/ is a foundation stone of many virtualization capabilities and where really interesting features are being added to cloud and virtualization.
for one area, it is where software defined storage (SDS) inserts itself, for example, ceph provides software defined storage and makes it available to OpenStack as a swift interface. Underneath, it is not part of OpenStack but so tightly integrates with OpenStack and works underneath, that tenants will never know nor detect any difference in their access to storage.
another, VMQoS examines the QoS (quality of service) issues internal to a complex service like OpenStack. Conventional QoS talks about external connectivity (communications QoS), but what about the internal movement of data between compute and storage (through the network linking them)? How is that measured and what assurances can be established, and corrected when the performance deviates beyond set limits?
it can also be an interesting attack surface for malicious actors since so much depends on libvirt
