With the public release of Monterey, this guide is now obsolete, please use my new installation guide instead
This tutorial for installing macOS Monterey Developer Beta has been adapted for Proxmox from Kholia’s OSX-KVM project and Leoyzen’s OpenCore configuration for KVM. You can get the full sourcecode of my OpenCore release on my GitHub here.
Requirements
Since Monterey is still in closed Developer Beta, you need to be an Apple Developer and have access to a Mac (or Mac VM) to download it.
Your Proxmox host computer’s CPU must support SSE 4.2, so for Intel your CPU must be at least as new as Nehalem, which was the first CPU generation to bear the “Core” i5/i7 branding. Older CPUs will cause Illegal Instruction crashes when apps/extensions attempt to use these missing instructions.
Modern AMD CPUs also support SSE 4.2 and will work with this guide.