A Low Overhead and Reliable Nested Virtualization VMM for Cloud Computing

Commodity operating systems have already gained functionality of virtual machine monitor. Nested virtualization is needed to run these commodity operating systems as virtual machines. Furthermore, with nested virtualization technology, users can run a self-configured virtual machine monitor (VMM) in Infrastructure as a Service (IaaS) cloud computing model, and live migration of VMM can be realized with the help of nested virtualization. In this paper, we present a new VMM nOSV, based on OSV VMM. nOSV is a lightweight VMM and can host multiple Xen VMMs, with little runtime overhead. Compared to traditional nested virtualization VMM, i) its performance overhead is significant low, ii) and with verified interfaces provided by OSV, nOSV is more robust and secure. The performance overhead of nOSV is less than 4%. With dedicated devices allocation policy, guest Xen VMM has a comparable network performance to Xen on bare metal.