Today I updated my Arch Linux and got kernel 5.6.3. DKMS complained that it can't rebuild Parallel Tools, so I investigated. In kernel 5.6 there was a major change to the procfs interface (https://patchwork.kernel.org/patch/11363867/). Long story short, the attached file is a patch against Parallel Tools 18.104.22.168123 to make that version compile on kernels above 5.6. I tested it on 5.6.3 and it seems fine (I am currently writing this from a VM that runs 5.6.3). The patch is hacky - I wanted to introduce support as fast as I could since I have other things to do, but should be OK until Parallels release a proper update.