针对传统的同构内存虚拟化方法缺乏平台扩展性,在非X86处理器平台上性能较差的问题,研究了影响虚拟机内存性能的几个因素,并基于MIPS架构处理器提出了异构内存虚拟化方法,在不增加软件复杂度的前提下,提高了内存虚拟化性能。该方法基于对同构内存虚拟化的性能瓶颈的分析,通过修改虚拟机内存管理单元(MMU)降低软件维护开销;采用宿主机与客户机共享页表的方法提升访存的异常处理速度。该方法在龙芯3号处理器的系统虚拟机KVM-LOONGSON上得到实现。测试结果表明,该方法可以显著提升各类应用程序的性能,相比同构内存虚拟化方法,性能可以提升50%到700%,达到本地执行性能的71%~97%。
In consideration of the problem that the traditional isomorphic memory virtualization (IMV)method lacks plat- form scalability and performs poorly on the platforms of non X86 processors, the factors influencing the performance of virtual memories were investigated, and a heterogeneous memory virtualization (HMV) method based on the MIPS architecture,was presented to improve the performance of memories' virtualization while without increasing the software complerity. The HMV method can reduce the software maintenance overhead by modifying the structure of the virtual machine' s memory management unit, and enhance the speed of memory access exception handling by sharing page tables between host and guest OS. This model was implemented on the Loongson_3 processor virtual ma- chine KVM-LOONGSON. The test results show that the method can greatly enhance the performance of the various types of applications. Comparing to the IMV method, the performance of the HMV method can increase from 50% to 700% ,and approache 71% to 97% of the performance of the native implementation.