GPU passthrough via VFIO

I always needed both Windows and Linux operating systems for various reasons since the beginning of University.

GNU/Linux offers tiling window managers, theming, native Emacs support, and a wonderful ecosystem of terminals, providing comfortable developement environments. It's not the most polished place when you first install it, but you can pretty much customize it to look like anything you want. The only downside is gaming (as of 2021, although Proton is changing the field rapidly) and it's limited integration with popular commercial and academic software.

Windows, on the other hand, is more polished on the surface but just never felt like home. It has intrusive promotions/ads and bundled software/games, aggressive telemetry, and forced updates. However, it works well in organisations such as hospitals and universities with its software ecosystem such as Office, Endnote and other proprietary software. And did I mention that gaming just works?

I tried dual booting on my laptop for a while, but it's never been a satisfying experience. For example, switching between the 2 systems requires a full reboot. Not only it takes time to shut down (and sometimes install updates) but also requires me to close all the apps and files I have opened. This means I have to think twice before switching over each time.

After I started working, I quickly assembled two desktops towers, one runs Windows and the other Linux. This has been a big step up from dual boot, because I can now switch between the two systems easily. The only catch is switching between keyboard and mous. But that was relieved by the built-in KVM in my Dell monitor.

There are still minor issues, though. For example, there's a bug with the windows box, that the KVM constantly disconnects and reconnects my USB hub after each switching from Linux. Also, having two boxes under the desk can be quite noisy, espcially when the Windows box was a few years older (couldn't afford good fans initially).

Then I tried virtual machines with solutions such as Virtualbox and VMware. They are really good CPU-wise, except for the heavy graphics performance penalty with emulated GPU.

There is one last solution I have yet to try, that is called "VFIO GPU passthrough". It is where the guest operating system runs in a virtual machine, but with the graphics performance of a native computer. I actually first attempted this with a single GPU (a second hand Radeon HD 7950 with a broken fan) in 2016 on Arch Linux, but failed despite multiple weekends of tinkering.

I reckon it's worth giving it another try 5 years later, when the documentation and technology support is far more mature.

• Seamless switching between Linux and Windows
• High graphics performance on Windows, enough for gaming
• Single computer with minimal interruption to switch