The canonical mechanism for running amd64 Linux processes appears to be to virtualise aarch64 and use binfmt-misc with Rosetta 2 to get emulation working.
It does make a certain amount of sense that Apple would have hardware virtualisation support for native VMs but not for emulated VMs. I can imagine (but I've not checked) that support for emulation of the VT extensions is lacking.
As a random person on the Internet, I'm obviously overqualified to suggest that you use native virtualisation to run aarch64 Linux, then use Rosetta within that Linux VM to run whatever amd64 software virtualisation tool you prefer. This is quite similar to what containerisation tooling does -- Docker (and similar) on aarch64 runs an ARM VM, then uses Rosetta inside that VM to run containers. You don't get a native amd64 kernel that way, but even without nested virtualisation you get a complete (namespaced) amd64 userspace.
It does make a certain amount of sense that Apple would have hardware virtualisation support for native VMs but not for emulated VMs. I can imagine (but I've not checked) that support for emulation of the VT extensions is lacking.
As a random person on the Internet, I'm obviously overqualified to suggest that you use native virtualisation to run aarch64 Linux, then use Rosetta within that Linux VM to run whatever amd64 software virtualisation tool you prefer. This is quite similar to what containerisation tooling does -- Docker (and similar) on aarch64 runs an ARM VM, then uses Rosetta inside that VM to run containers. You don't get a native amd64 kernel that way, but even without nested virtualisation you get a complete (namespaced) amd64 userspace.