Towards Scalable and High Performance I/O Virtualization – A Case

Abstract. I/O Virtualization provides a convenient way of device sharing among guest domains in a virtualized platform (e.g. Xen). However, with the ever-increasing number and variety of devices, the current model of a centralized driver domain is in question. For example, any optimization in the centralized driver domain for a particular kind of device may not satisfy the conflicting needs of other devices and their usage patterns. This paper has tried to use IO Virtual Machines (IOVMs) as a solution to this problem, specifically to deliver scalable network performance on a multi-core platform. Xen 3 has been extended to support IOVMs for networking and then optimized for a minimal driver domain. Performance comparisons show that by moving the network stack into a separate domain, and optimizing that domain, better efficiency is achieved. Further experiments on different configurations show the flexibility of scheduling across IOVMs and guests to achieve better performance. For example, multiple single-core IOVMs have shown promise as a scalable solution to network virtualization.