This course provides students the skills and knowledge to develop their thin hypervisors as UEFI modules using Intel VT-x. This is a hands-on heavy class and will spend about half of the time with excesses.
This class is geared towards software developers, security researchers and others with an interest in expanding knowledge of Intel VT-x, the x86_64 system architecture, and/or UEFI.
Recommended pre-class learning materials will be introduced about prior to the class.
At the end of the class, students will gain enough knowledge and skills to start developing their pass-through UEFI-based hypervisors. Knowledge-wise, this includes but not limited to the understanding of:
1. UEFI and Hypervisors
2. Basics of VT-x
3. OS Boot
4. Extended Page Tables (EPT)
5. Multi-processors Support
6. Control Register Shadowing
7. Demos and References
Contents may change in a way that does not impact the learning objectives.
A hypervisor is a critical component in both security and cloud computing. There is also an increasing interest in applying virtualization technologies in the area of security engineering and analysis. How can hypervisors be used to secure the existing systems? How to write custom hypervisors to perform reverse engineering and fuzzing more efficiently?
In this class, the students will learn the foundations to answer those questions, that is, the basic skills and knowledge to develop hypervisors. The class is designed in a way such that everything is built from scratch and optimized for learning. This allows students to better understand the building blocks and expand the knowledge acquired in the course by themselves afterward. Topics include UEFI architecture and programming, VT-x/EPT configuration, debugging tools, comparison of hypervisor designs, application of the technologies, and more.
This is a hands-on-oriented class. We believe that the students can learn and retain concepts and skills the best by working with those concepts by themselves and not by being taught; hence gaining the greatest value. With this philosophy, the class is designed for lab activities as the primary learning opportunities, and lectures are to explain backgrounds and the motivations for those. We will spend about half of the time for hands-on.
At the beginning of the class, students will receive skeleton implementations of our hypervisors and incrementally update them through the exercises with a clear understanding of motivations and design choices.
At the end of the class, students will also receive a full version of our hypervisor. This includes implementation of advanced concepts, such as stealth-hooking hypercall, use of VT-d, guest hardening (like HyperGuard if you are familiar with it), host hardening through CET, SMAP, UMIP, etc, handling of uncommon events like microcode update, NMI, and so on. This version can be used to complement your understanding of advanced topics and as a reference to explore more topics as you wish.
Additionally, a proof-of-concept implementation of taking and reverting to snapshots for fast full-system fuzzing will be shared as well.
The students are expected to have the following hardware and software:
The newer versions of the operating systems and other software are supported. Another Linux distro may be workable but unsupported. Other hypervisors such as KVM, Hyper-V, or VirtualBox cannot be used.
The host system can also be a cloud-provided machine if the host machine cannot be arranged locally. Those are confirmed to be usable:
The students are expected to complete the setup instructions that will be sent by the instructor before the class.
Satoshi Tanda (@standa_t) is a system software engineer and a security researcher with more than a decade of experience. His experience spans over the areas of UEFI- and Windows kernel-module programming and reverse engineering, vulnerability discovery and exploitation, malware analysis, and teaching them to professionals and school students. He open-sourced multiple hypervisors for security researchers, including type-1 and type-2 hypervisors on Intel and AMD processors. He currently works at CrowdStrike.