3 Jakub Szefer Ruby B. Lee 2011 A Case for Hardware Protection of Guest VMs from Compromised Hypervisors in Cloud Computing in Proceedings of the Second International Workshop on Security and Privacy in Cloud Computing (SPCC) June 20-24, 2011 Cloud computing, enabled by virtualization technologies, is becoming a mainstream computing model. Many companies are starting to utilize the infrastructure-as-a-service (IaaS) cloud computing model, leasing guest virtual machines (VMs) from the infrastructure providers for economic reasons: to reduce their operating costs and to increase the flexibility of their own infrastructures. Yet, many companies may be hesitant to move to cloud computing due to security concerns. An integral part of any virtualization technology is the all-powerful hypervisor. A hypervisor is a system management software layer which can access all resources of the platform. Much research has been done on using hypervisors to monitor guest VMs for malicious code and on hardening hypervisors to make them more secure. There is, however, another threat which has not been addressed by researchers â that of compromised or malicious hypervisors that can extract sensitive or confidential data from guest VMs. Consequently, we propose that a new research direction needs to be undertaken to tackle this threat. We further propose that new hardware mechanisms in the multicore microprocessors are a viable way of providing protections for the guest VMs from the hypervisor, while still allowing the hypervisor to flexibly manage the resources of the physical platform.