摘要
影子页表作为内存虚拟化地址转换问题的解决方案之一,其性能开销主要源于客户机页表和影子页表不一致造成的缺页异常。实验发现:在使用影子页表技术的虚拟机中,缺页异常引起的虚拟机陷入占所有虚拟机陷入的70%以上;这些缺页异常中,30%的缺页异常由客户机页表本身引起,从而造成不必要的虚拟机陷入。客户机的不必要陷入可以通过结合类虚拟化思想和硬件虚拟化条件优化技术并调整影子页表的缺页异常处理流程来解决。为验证上述方法的有效性,设计并实现了AccSP原型系统。实验结果表明,AccSP能够使得系统性能得以稳定提升。
Shadow paging is one of the solutions of address translation in memory virtualization.Most of shadow paging overhead comes from the page fault due to the difference between shadow page table and guest page table.The experiment shows that more than 70%of all the VM-Exits are incurred by page faults,and about 30%of all the page faults are occurred on the guest page ta-ble,which leads to unnecessary VM-Exits.The page fault handler mechanism of shadow paging is promoted to avoid unnecessary VM-Exits,by introducing the hardware-assisted conditional optimization and para-virtualization method.A prototype,named as AccSP,is designed and implemented,which improves system performance stably.
出处
《中国科技论文》
CAS
北大核心
2014年第7期774-778,793,共6页
China Sciencepaper
基金
国家高技术研究发展计划(863计划)资助项目(2011AA01A203)
关键词
影子页表
内存虚拟化
缺页异常
类虚拟化
shadow page
memory virtualization
page fault
paravirtualization
