I suggest we can have just two variables (names slightly changed from the above):

* `SNABB_TEST_VHOST_USER_SOCKET` filename of the vhost_user socket file.
* `SNABB_TEST_INTEL10G_PCI_ID` PCI ID of an Intel 82599 network device.

... which contain information that needs to be supplied by the developer to make the tests meaningful (otherwise they are better skipped).

I don't think that we need to have configuration options for the /proc and /sys paths (?) that should be consistent for Linux hosts.