A Multi-hypervisor Virtual Machine (VM) in which a single VM can simultaneously run on multiple hypervisors.
Span provides a Multi-hypervisor VM in which a single VM can simultaneously run on multiple hypervisors, which permits a VM to benefit from different services provided by multiple hypervisors that co-exist on a single physical machine. Span allows (a) the memory footprint of the VM to be shared across two hypervisors, and (b) the responsibility for CPU and I/O scheduling to be distributed among the two hypervisors. Span VMs can achieve performance comparable to traditional (single-hypervisor) nested VMs for common benchmarks
Users can run their own hypervisors in IaaS clouds.
Live migration of hypervisors + guest VMs as a single entity.
Hypervisor-level intrusion detection/prevention.