TwinDrivers

Abstract

In a virtualized environment, device drivers are often run inside a virtual machine (VM) rather than in the hypervisor, for reasons of safety and reduction in software engineering effort. Unfortunately, this approach results in poor performance for I/O-intensive devices such as network cards. The alternative approach of running device drivers directly in the hypervisor yields better performance, but results in the loss of safety guarantees for the hypervisor and incurs additional software engineering costs.