Regression introduced by d4468bedb5.
No systemd messages are shown anymore during VM test runs, which is not
very helpful if you want to find out about failures.
There is a bit of a conflict between testing and the change that
introduced the regression. While the mentioned commit makes sure that
the primary console is tty0 for virtualisation.graphics = false, our VM
tests need to have the serial console as primary console.
So in order to support both, I added a new virtualisation.qemu.consoles
option, which allows to specify those options using the module system.
The default of this option is to use the changes that were introduced
and in test-instrumentation.nix we use only the serial console the same
way as before.
For test-instrumentation.nix I didn't add a baudrate to the serial
console because I can't find a reason on top of my head why it should
need it. There also wasn't a reason stated when that was introduced in
7499e4a5b9.
Signed-off-by: aszlig <aszlig@nix.build>
Cc: @flokli, @dezgeg, @edolstra