1 files changed, 7 insertions, 20 deletions
diff --git a/nixpkgs/nixos/modules/testing/test-instrumentation.nix b/nixpkgs/nixos/modules/testing/test-instrumentation.nix
index 1baeab53b0c..c0ec76e8a3a 100644
--- a/nixpkgs/nixos/modules/testing/test-instrumentation.nix
+++ b/nixpkgs/nixos/modules/testing/test-instrumentation.nix
@@ -1,22 +1,13 @@
 # This module allows the test driver to connect to the virtual machine
 # via a root shell attached to port 514.
 
-{ config, lib, pkgs, ... }:
+{ options, config, lib, pkgs, ... }:
 
 with lib;
 with import ../../lib/qemu-flags.nix { inherit pkgs; };
 
 {
 
-  # This option is a dummy that if used in conjunction with
-  # modules/virtualisation/qemu-vm.nix gets merged with the same option defined
-  # there and only is declared here because some modules use
-  # test-instrumentation.nix but not qemu-vm.nix.
-  #
-  # One particular example are the boot tests where we want instrumentation
-  # within the images but not other stuff like setting up 9p filesystems.
-  options.virtualisation.qemu = { };
-
   config = {
 
     systemd.services.backdoor =
@@ -55,7 +46,12 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
     systemd.services."serial-getty@hvc0".enable = false;
 
     # Only use a serial console, no TTY.
-    virtualisation.qemu.consoles = [ qemuSerialDevice ];
+    # NOTE: optionalAttrs
+    #       test-instrumentation.nix appears to be used without qemu-vm.nix, so
+    #       we avoid defining consoles if not possible.
+    # TODO: refactor such that test-instrumentation can import qemu-vm
+    #       or declare virtualisation.qemu.console option in a module that's always imported
+    virtualisation = lib.optionalAttrs (options ? virtualisation.qemu.consoles) { qemu.consoles = [ qemuSerialDevice ]; };
 
     boot.initrd.preDeviceCommands =
       ''
@@ -78,15 +74,8 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
         # OOM killer randomly get rid of processes, since this leads
         # to failures that are hard to diagnose.
         echo 2 > /proc/sys/vm/panic_on_oom
-
-        # Coverage data is written into /tmp/coverage-data.
-        mkdir -p /tmp/xchg/coverage-data
       '';
 
-    # If the kernel has been built with coverage instrumentation, make
-    # it available under /proc/gcov.
-    boot.kernelModules = [ "gcov-proc" ];
-
     # Panic if an error occurs in stage 1 (rather than waiting for
     # user intervention).
     boot.kernelParams =
@@ -115,8 +104,6 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
     networking.defaultGateway = mkOverride 150 "";
     networking.nameservers = mkOverride 150 [ ];
 
-    systemd.globalEnvironment.GCOV_PREFIX = "/tmp/xchg/coverage-data";
-
     system.requiredKernelConfig = with config.lib.kernelConfig; [
       (isYes "SERIAL_8250_CONSOLE")
       (isYes "SERIAL_8250")