Information from VMTN's Virtually There

In the latest edition of Steve Herrod's Blog postings, Virtually There sends us to an interesting write up by two of VMware's engineers, Keith Adams and Ole Agesen.  Their paper was accepted for presentation at the upcoming ASPLOS XII conference. According to Steve, "It's exciting to see that this conference starts with a dedicated virtualization session and that Keith and Ole's paper kicks off the whole thing."

Their paper, "A Comparison of Software and Hardware Techniques for x86 Virtualization," is the most detailed description of VMware's virtual machine monitor (vmm) available. It also examines the vmm implementation trade-offs as the CPU vendors directly support x86 virtualization with architectural extensions.

From the paper's abstract:

We find that the hardware support fails to provide an unambiguous performance advantage for two primary reasons: first, it offers no support for MMU virtualization; second, it fails to co-exist with existing software techniques for MMU virtualization. We look ahead to emerging techniques for addressing this MMU virtualization problem in the context of hardware-assisted virtualization.

You can download the paper here.