In reply to @eljamm:matrix.org
Hello, can someone please help test this program? the executable seems to be working, but I have no clue how to test the module.

Thanks, I'm looking into doing this right now with this NixOS test. Things are a bit cursed, because I had to enable binfmt for riscv64-linux in my system to get the test to even start, but inside that I'm also supposed to test Linux emulation for RISC-V 😅

Now, the test is just hanging here:

machine: Guest root shell did not produce any data yet...
machine:   To debug, enter the VM and run 'systemctl status backdoor.service'.
machine: Guest root shell did not produce any data yet...
machine:   To debug, enter the VM and run 'systemctl status backdoor.service'.

Thanks, I'm looking into doing this right now with this NixOS test. Things are a bit cursed, because I had to enable binfmt for riscv64-linux in my system to get the test to even start, but inside that I'm also supposed to test Linux emulation for RISC-V 😅

This said, the test is just hanging here:

machine: Guest root shell did not produce any data yet...
machine:   To debug, enter the VM and run 'systemctl status backdoor.service'.
machine: Guest root shell did not produce any data yet...
machine:   To debug, enter the VM and run 'systemctl status backdoor.service'.

That's not a good sign.
The backdoor service that the test driver uses to control the VM is not printing the sentinel value that the test driver recognises as "VM is ready". There are a number of ways for this to go wrong, none of which are easy to identify without logs.
It might not be writing system logs to a visible location.

Can you try adding this to the VM's system configuration?

boot.kernelParams = [ "console=ttyS0" "console=hvc0" ];

One of these console options might allow you to see kernel and early userspace logs.

Is anyone able to build the latest Nixpkgs natively?
My build is failing during xgcc.

checking for suffix of object files... configure: error: in `/build/build/riscv64-unknown-linux-gnu/libgcc':
configure: error: cannot compute suffix of object files: cannot compile

Oh so you are getting kernel logs even without setting console=....
One of the annoying things about systemd is that it doesn't log anything useful during boot.
Btw the console=... isn't really helping, even if it no longer prints warnings about backdoor.service, because it's still unable to send commands to the VM.

You could I guess try building the driverInteractive version of the test, then inside the interactive prompt run machine.shell_interact() to get a prompt (assuming this doesn't require the backdoor service, which it might).

It's also pretty slow.

I think that's because you're emulating RISC-V using binfmt emulation to run a riscv64-linux build of qEMU to run the test? That sounds to me like you have qEMU running under qEMU.