中文摘要：

I／O的性能是许多从事虚拟化研究的学者致力于解决的难题之一。单根I／O虚拟化SR—IOV（Single Root I／O Virtualiza—tion）技术规范的提出，使得I／O虚拟化的性能得到了较大改善。但由于客户域单独占有虚拟功能（VF），而相关设备的VF数目及网络设备带宽有限，影响了其可扩展性和客户域I／O性能。针对这种现状，提出一种扩展的VF分配模型。基于Xen，通过在主域（Dom0）SR—IOV管理器（IOVM）中增加虚拟功能管理模块（VFM），来实现多个客户域虚拟独占拥有较大带宽的VF。采用Netperf工具进行测试，实验结果表明，该模型能够较好地解决VF不足和VF增加带宽迅速下降的问题。

英文摘要：

I/O performance is one of the difficulties to be solved committed by many scholars engaging in virtualisation research. The performance of I/O virtualisation has been greatly improved with the presentation of the technology specification in single root I/O virtualisation （SR-IOV）. However, due to the mechanism that guest domains access virtual function （VF） exclusively, and the numbers of VF of correlated device and the bandwidth of network device are limited, the scalability and I/O performance of guest domains are impacted. In view of this situation, an extended VFs allocation model is proposed. Based on Xen, virtual function management module （VFM） is added to the SR-IOV manager of main domain （ Dom 0）, in this way it is achieved that muhiple guest domains could own a VF with larger bandwidth virtual exclusively. Netperf tool is used in test, and the experimental result shows that this model can well solve the problems of insufficiency in VF numbers and the bandwidth of VF declines rapidly while the number of VF is expanding.