Performance Evaluation of MMU-Virtualized CPU

对2006年A Comparison of Software and Hardware Techniques for x86 Virtualization-ASPLOS 2006 论文后的最新进展。
      从2009年3月Vmware公司发布的白皮书来看，硬件方案已经占据绝对上风。可以认为硬件的出现给了其他公司机会减少与Vmware技术的差距。问题思考：adaptive BT还有用途吗？如果修改页表多次，HVMM如何处理？


AMD 的 MMU virtualization 称为 Rapid Virtualization Indexing (RVI).
We evaluated RVI performance by comparing it to the performance of our software-only shadow page table technique on an RVI-enabled AMD system. From our studies we conclude that RVI-enabled systems can improve performance compared to using shadow paging for MMU virtualization. RVI provides performance gains of up to 42% for MMU-intensive benchmarks and up to 500% for MMU-intensive microbenchmarks. We have also observed that although RVI increases memory access latencies for a few workloads, this cost can be reduced by effectively using large pages in the guest and the hypervisor.


Intel 的 MMU virtualization称为Extended Page Tables (EPT).
We evaluated EPT performance by comparing it to the performance of our software-only shadow page table technique on an EPT-enabled Intel system. From our studies we conclude that EPT-enabled systems can improve performance compared to using shadow paging for MMU virtualization. EPT provides performance gains of up to 48% for MMU-intensive benchmarks and up to 600% for MMU-intensive microbenchmarks. We have also observed that although EPT increases memory access latencies for a few workloads, this cost can be reduced by effectively using large pages in the guest and the hypervisor.