The majority of code will never be hit in QEMU or any testing in general, because 56%+ lines are in drivers. https://unix.stackexchange.com/a/223763/29119

With 16%+ lines in all 24 architectures combined, you're not going to reach more than one of them at a time.

10% is going to be an extremely happy case. If we can test 5-10% that's a great achievement. To get past that you need to start booting real hardware with specific configurations.