full: Starts several OSes and checks if they boot correctly. This is the most useful test.
qemu: Builds a Linux binary, which tests many CPU features. Needs to be manually put on a Linux image and run in the emulator. This test is contained in the linux.iso image and automatically run in the full test.
perf-irhydra: Manual performance test. Probably not interesting for you.
perf: Very simple performance test. Probably not interesting for you.