Advanced Operating Systems

This is the home page for the "Advanced OS" course. Here, you will find (in a badly-organised form) all the material, slides, and information needed to attend the course

For the previous edition of the course, check the old website.

Lessons:

• First lesson: 2019/04/11, 14:00 -> 16:30
• Second lesson: 2019/04/16, 14:00 -> 16:30
• Third lesson: 2019/05/02, 14:00 -> 16:30
• Fourth lesson: 2019/05/16, 14:00 -> 16:30
• Fifth lesson: 2019/06/06, 14:00 -> 16:30
• Sixth lesson: 2019/06/07, 9:30 -> 12:00
• Seventh lesson: 2019/06/13, 14:00 -> 16:30
• Eighth lesson: 2019/06/14, 9:30 -> 12:00
• Ninth lesson: 2019/06/20, 14:00 -> 16:30
• Tenth lesson: 2019/06/21, 9:30 -> 12:00
• Elevent lesson: 2019/06/27, 9:30 -> 12:00
• Tenth lesson: 2019/06/28, 9:30 -> 12:00

Project Ideas

Here are some ideas for possible projects for the exam. Remember to contact me when you chose one.

Slides and references:

• Introduction to the course
• Something about Real-Time OSs
• OS kernel and Abstract Machines
• Something more about the Kernel Latency
• Kernel architectures for low latency
• Resource Sharing in real-time theory
• uKernels vs Dual Kernels
• Implementing periodic tasks
• Using Xenomai
• Some details on u-kernels
• Nano-kernels, hypervisors and friends
• Something about CPU virtualization
• Hardware support for advanced CPU virtualization
• Quick introduction to unikernels
• Slides about the OSv unikernel
• Slides about unikernels
• Slides about unikernel hypervisors
• Slides about unikernels for nfv
• Introduction to containers
• Some references to scientific papers about the arguments described in the course

Source Code and Examples:

• Examples about periodic timers
• Some tests with Xenomai
• Simple l4re example, and its compiled version
• A more complex l4re example, similar to the Xenomai example
• A simple experiment with trap-and-emulate on Intel x86 (64). This simple "hypervisor" (executing in ring 0) just runs the "guest code" in ring 3... The guest executes a sensitive privileged instruction (mov cr0, edx) that is emulated, and a sensitive non privileged instruction (smswl eax) that cannot be trapped / emulated... Since in theory the two instructions should return the same value, the guest can easily understand that some kind of hypervisor is in action! This shows the need for VT-x.
• A half-working example about Intel VT-x. This Linux module tries to show how to use the Intel virtualization extensions; unfortunately, the Virtual Machine Control Structure is not setup in a 100% correct way (tries to copy the CPU state set up by the Linux kernel, but fails somewhere). So, it works only in some cases (do not use on real hw! Test only in a VM!!!). This is a log of a correctly working execution.
• Simple example about KVM
  • Try to handle different VM exit reasons as in this modified test.c (using this modified guest)
• Simple test about namespaces: try unshare -pmrf chroot _install/ /bin/sh, where "_install" is a directory containing a simple Linux-based OS... You can generate id by using BuildCore or similar tools...

Links:

• Some u-kernel based systems:
  • Google Zircon
  • Genode
  • L4 Runtime Environment (also see this)
  the family of L4 uKernels
• Paper comparing u-kernels and hypervisors
• Some references about lightweight virtualization:
  • Intel's cloud hypervisor
  • Amazon's Firecracker
  • The solo5's unikernel monitor: now called "hvt" (hardware virtualized tender), used to be "ukvm"