When we were first adding Mac OS X guest support at ᴠᴍware, we had to inject some XML into the operating system during early boot so the kernel would load kexts we needed to support our existing virtual hardware (like the PS/2 driver, since I hadn’t finished writing the virtual USB keyboard yet). The year was 2009.

2019 comes around and I, along with many of my old coworkers, have moved on to Apple. One of them reaches out to me about a panic that’s only happening on virtual machines. Investigation has revealed some weird XML corruption in a system file, and he thought I might have some clues. Realizing immediately what was happening, I came over and confessed my sins to a group of suitably-horrified1 kernel engineers.

Luckily these shenanigans weren’t actually necessary anymore, so there are now some XML comments (containing a certain emoji) at specific offsets in that system file.

  1. And amused!