Breaking up is hard to do
Patrick Colp, Mihir Nanavati, Jun Zhu, William A. Aiello, George Coker, Tim Deegan, Peter A. Loscocco, Andrew Warfield · 2011
Cloud computing uses virtualization to lease small slices of large-scale datacenter facilities to individual paying customers. These multi-tenant environments, on which numerous large and popular web-based applications run today, are founded on the belief that the virtualization platform is sufficiently secure to prevent breaches of isolation between different users who are co-located on the same host. Hypervisors are believed to be trustworthy in this role because of their small size and narrow interfaces.