It's worth noting if you are using this on an arm device, this isn't a "virtualization VM" any more, as you are using the emulator backend, so this is far closer to a traditional emulator then anything else.
While the term virtual machine is extremely poorly defined, it could still apply.
also TCG is as slow as molasses, it's a good demo, not actually usable for much, at least unless it's a super beefy phone.
Looks like it's an x86_64 kernel though? So this is a VM - it's not running as a paravirtualised system, it's having to emulate everything from the CPU up?
Interesting running it in QEMU. If possible, it might be better to use a container if the host kernel supports this because performance and resource consumption should both be significantly improved.
However, an emulator provides great flexibility I'll give you that.
It is pretty cool! QEMU can do all kinds of interesting things, although I do wish it had better performance. High performance doesn't appear to be a primary goal for QEMU outside of using KVM.