ITEC -  Operating Systems Group

Improving Virtualization on L4

  • Subject:L4Ka
  • Type:Diploma Thesis
  • Date:14.02.2007
  • Supervisor:

    Prof. Dr. Frank Bellosa, Joshua LeVasseur

  • Graduand:Thomas Blattmann
  • Links:PDF
  • Abstract:

    A variety of classes of hypervisors run virtual machines. One approach is to use specialized, thin kernels as a base for virtual machine construction. A second approach is to build virtual machines on the higher-level abstractions offered by platform-independent operating system APIs. Virtual machines have also been successfully set up on top of µ-kernels. A µ-kernel is a thin hypervisor with a minimally trusted computing base. Unlike pure hypervisors, however, it is not specialized to one specific purpose. Instead, common µ-kernels are designed to perform well as generic platforms upon which many and various systems can be built. This generality, on the downside, allows pure hypervisors to outperform µ-kernels in their virtualization specific application area.

    This work investigates L4, a second generation µ-kernel, with respect to virtual machine construction. It identifies several L4 characteristics that complicate virtual machine construction and cause a performance overhead, respectively. Also, it proposes µ-kernel extensions that are well suited to the usage patterns of a virtual machine but still conform to L4's design philosophy. Finally, the thesis provides a reference implementation that demonstrates the new L4 interface extensions. It reveals that many challenges can be overcome.

    BibTex:

    @diplomathesis{blattmann07improvingl4vm,
      author = {Thomas Blattmann},
      title = {Improving Virtualization on L4},
      type = {Diploma Thesis},
      address = {System Architecture Group, University of Karlsruhe, Germany},
      month = feb # "~14",
      year = 2007,
      url = {http://i30www.ira.uka.de/teaching/theses/pasttheses/}
    }