Prof. Dr. Frank Bellosa
Dr. Marc Rittinghaus

Abstract
Modern operating systems fix a set of protection and isolation mechanisms at design time, making changes to those mechanisms costly in terms of engineering effort. Flexible isolation, as pursued by the FlexOS project, seeks to allow specialisation of operating systems in the dimension of security by allowing users to flexibly define protection domains at the level of individual libraries while also giving users the choice over the mechanism by which isolation between these domains is enforced.
This thesis explores the use of high-guarantee isolation mechanisms for compartmentalisation at the granularity of individual libraries. For this purpose, we perform a systematic analysis of existing isolation mechanisms, motivate for VM-based isolation, before designing, implementing, and evaluating a prototype in the FlexOS framework. We show that, while VM-based isolation comes with significant performance overhead compared to lightweight isolation mechanisms when considering raw domain crossing costs, our prototype achieves reasonable slowdown with real-world workloads (for SQLite roughly 50% compared to lightweight isolation and comparable to Linux), making it a practicable mechanism when security is the primary
concern.

BibTex:

@masterthesis{rauch22EPT based Isolation for FlexOS,
  author = {Sebastian Rauch},
  title = {VM/EPT: A Virtualisation-based Isolation Backend for FlexOS},
  type = {Master Thesis},
  year = 2022,
  month = feb # "28",
  school = {Operating Systems Group, Karlsruhe Institute of Technology (KIT), Germany}
  }