Karl Taht's Research Paper Blog

Authors: Adam Belay, Andrea Bittau, Ali Mashtizadeh, David Terei, David Mazieres, Christos Kozyrakis Venue: OSDI 2012 Dune uses virtualization hardware to provide the abstraction of a userspace process, but with safe access to hardware features. The Dune process runs as VMX non-root (aka guest ring 0). This enables virtual access to hardware features, such as exception handling and virtual memory. Because the system is built utilizing hardware support, performance is maintained (e.g. normal system call invocations do not cause a VM exit). Furthermore, a Dune process in guest ring 0 can run untrusted code in guest ring 3, and intercept any unwanted behavior, such as unauthorized systems calls. Without getting into more details, what is important is that Dune effectively enables kernel bypass, and sets the stage future work such as Shinjuku.

Authors: Ravi Iyer, Ramesh Illikkal, Omesh Tickoo, Li Zhao, Padma Apparo, Don Newell Venue:   Computer Networks 2009 The authors of this paper seek to understand the importance of resource allocation in a VM/cloud environment. At the time of publishing, only time-multiplexing and core allocation isolated VMs from a performance standpoint, which they refer to as a Virtual Platform Architecture (VPA) . The authors suggest that cache space, memory, bandwidth and power equally need to be virtualized as well. They focus on memory bandwidth and cache allocation. They motivate the problem by performing measurements and effects of resource contention and show significant performance degradation. Then then show that a simplistic model can perform fairly accurate predictions of cache occupancy, MPI, and cache contention. Perhaps the most elegant part of the paper is the description of the cache and memory bandwidth monitoring and allocation technology, which I assume laid foundatio...