First, let me say that the guide from Spaceinvader One is thorough and well explained.
Second, I am either experiencing difficulties with hardware or configuration. I have gone through the process 4 times and have difficulties every time. I change only the items that need to be changed at the appropriate step. I can get through the install process of Big Sur but, once complete, I cannot get the vm to consistently boot correctly and, once it does boot into BigSur, I am unable to login with my apple id.
At one point, after complete installation, I got an error that the machine had been used too many times to complete the appleid login. You might ask if I verified that I had an invalid serial number when checking coverage in Opencore Configurator. The answer is yes, I made sure I had an invalid serial number. So, not sure what any of this means but not sure I will try again.
I have a 2017 macbook air but my hope was that I could have the vm run in the background from my Windows machine to have iMessage and other apps available. I have not added any real specifics about my issue because I am no longer trying to get this working. Maybe I will try again in a few weeks.
Good luck to you guys who are getting it figured out.
I run a dual xeon 5630 system with 20GB of ram.