A simple test which checks if the device is visible there at all.
Device set with QUBES_TEST_PCIDEV env variable is used - it should be
some unimportant device which can be freely detached from dom0.
QubesOS/qubes-issues#1659
SystemTestsMixin.prepare_hvm_system_linux creates minimal Linux
installation necessary to launch simple shell script. It installs:
- grub2
- kernel from dom0 (the same as the running one)
- dracut based initramfs, with provided script set as pre-pivot hook
Done in preparation for QubesOS/qubes-issues#1659 test