DMCA
Taming Hosted Hypervisors with (Mostly) Deprivileged Execution
| Citations: | 2 - 0 self |
BibTeX
@MISC{Wu_taminghosted,
author = {Chiachih Wu and Zhi Wang and Xuxian Jiang},
title = {Taming Hosted Hypervisors with (Mostly) Deprivileged Execution},
year = {}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
Recent years have witnessed increased adoption of hosted hypervisors in virtualized computer systems. By non-intrusively extending commodity OSs, hosted hypervi-sors can effectively take advantage of a variety of mature and stable features as well as the existing broad user base of commodity OSs. However, virtualizing a computer system is still a rather complex task. As a result, existing hosted hypervisors typically have a large code base (e.g., 33.6K SLOC for KVM), which inevitably introduces exploitable software bugs. Unfortunately, any compromised hosted hy-pervisor can immediately jeopardize the host system and subsequently affect all running guests in the same physical machine. In this paper, we present a system that aims to dramati-cally reduce the exposed attack surface of a hosted hypervi-sor by deprivileging its execution to user mode. In essence, by decoupling the hypervisor code from the host OS and deprivileging its execution, our system demotes the hyper-visor mostly as a user-level library, which not only substan-tially reduces the attack surface (with a much smaller TCB), but also brings additional benefits in allowing for better de-velopment and debugging as well as concurrent execution of multiple hypervisors in the same physical machine. To evaluate its effectiveness, we have developed a proof-of-concept prototype that successfully deprivileges ∼ 93.2% of the loadable KVM module code base in user mode while only adding a small TCB (2.3K SLOC) to the host OS ker-nel. Additional evaluation results with a number of bench-mark programs further demonstrate its practicality and ef-ficiency. 1
Keyphrases
commodity os physical machine exploitable software bug large code base hosted hypervisors host o user-level library complex task proof-of-concept prototype bench-mark program attack surface virtualized computer system computer system hypervisor code small tcb host o ker-nel stable feature host system loadable kvm module code base additional evaluation result exposed attack surface broad user base additional benefit user mode recent year concurrent execution multiple hypervisors
