Script / tooling around HYPERCALL_KAFL_LOCK to snapshot a VM

[Wenzel]

raised by @hyjun0407 in https://github.com/IntelLabs/kAFL/issues/224#issuecomment-1712412473

The Lock hypercall is difficult to use since it's main use case are applicable when the desired VM state is very hard to automate (GUI installer for example, user interactions, non determinism).

Providing some tooling to trigger this hypercall at will would be beneficial.