A paravirtualized file system for accelerating file I/O

摘要

With several new virtualization technologies, a virtual machine has gradually achieved higher performance. However, I/O-intensive workloads still suffer from performance deg-radation due to CPU mode switching and duplicated I/O stacks. In this paper, we propose a framework for improving file I/O performance in a virtualized environment, which consists of a paravirtualized file system, a shared queue, and an I/O-dedicated thread. The key idea is to make file I/O requests handled without mode switching and to bypass a guest I/O stack. We implemented a prototype and measured its performance. The results show that our framework gives 1.2–1.6 times better performance than virtio, and most of vmexits are eliminated.