129 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			Nix
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			Nix
		
	
	
	
	
	
| # This module allows the test driver to connect to the virtual machine
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| # via a root shell attached to port 514.
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| 
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| { config, lib, pkgs, ... }:
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| 
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| with lib;
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| 
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| let kernel = config.boot.kernelPackages.kernel; in
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| 
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| {
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| 
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|   config = {
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| 
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|     systemd.services.backdoor =
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|       { wantedBy = [ "multi-user.target" ];
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|         requires = [ "dev-hvc0.device" "dev-ttyS0.device" ];
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|         after = [ "dev-hvc0.device" "dev-ttyS0.device" ];
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|         script =
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|           ''
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|             export USER=root
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|             export HOME=/root
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|             export DISPLAY=:0.0
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| 
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|             source /etc/profile
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| 
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|             # Don't use a pager when executing backdoor
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|             # actions. Because we use a tty, commands like systemctl
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|             # or nix-store get confused into thinking they're running
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|             # interactively.
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|             export PAGER=
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| 
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|             cd /tmp
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|             exec < /dev/hvc0 > /dev/hvc0
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|             while ! exec 2> /dev/ttyS0; do sleep 0.1; done
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|             echo "connecting to host..." >&2
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|             stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion
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|             echo
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|             PS1= exec /bin/sh
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|           '';
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|         serviceConfig.KillSignal = "SIGHUP";
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|       };
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| 
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|     # Prevent agetty from being instantiated on ttyS0, since it
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|     # interferes with the backdoor (writes to ttyS0 will randomly fail
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|     # with EIO).  Likewise for hvc0.
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|     systemd.services."serial-getty@ttyS0".enable = false;
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|     systemd.services."serial-getty@hvc0".enable = false;
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| 
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|     boot.initrd.preDeviceCommands =
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|       ''
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|         echo 600 > /proc/sys/kernel/hung_task_timeout_secs
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|       '';
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| 
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|     boot.initrd.postDeviceCommands =
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|       ''
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|         # Using acpi_pm as a clock source causes the guest clock to
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|         # slow down under high host load.  This is usually a bad
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|         # thing, but for VM tests it should provide a bit more
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|         # determinism (e.g. if the VM runs at lower speed, then
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|         # timeouts in the VM should also be delayed).
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|         echo acpi_pm > /sys/devices/system/clocksource/clocksource0/current_clocksource
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|       '';
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| 
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|     boot.postBootCommands =
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|       ''
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|         # Panic on out-of-memory conditions rather than letting the
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|         # OOM killer randomly get rid of processes, since this leads
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|         # to failures that are hard to diagnose.
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|         echo 2 > /proc/sys/vm/panic_on_oom
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| 
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|         # Coverage data is written into /tmp/coverage-data.
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|         mkdir -p /tmp/xchg/coverage-data
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|       '';
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| 
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|     # If the kernel has been built with coverage instrumentation, make
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|     # it available under /proc/gcov.
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|     boot.kernelModules = [ "gcov-proc" ];
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| 
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|     # Panic if an error occurs in stage 1 (rather than waiting for
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|     # user intervention).
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|     boot.kernelParams =
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|       [ "console=ttyS0" "panic=1" "boot.panic_on_fail" ];
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| 
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|     # `xwininfo' is used by the test driver to query open windows.
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|     environment.systemPackages = [ pkgs.xorg.xwininfo ];
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| 
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|     # Log everything to the serial console.
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|     services.journald.extraConfig =
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|       ''
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|         ForwardToConsole=yes
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|         MaxLevelConsole=debug
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|       '';
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| 
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|     # Don't clobber the console with duplicate systemd messages.
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|     systemd.extraConfig = "ShowStatus=no";
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| 
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|     boot.consoleLogLevel = 7;
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| 
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|     # Prevent tests from accessing the Internet.
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|     networking.defaultGateway = mkOverride 150 "";
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|     networking.nameservers = mkOverride 150 [ ];
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| 
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|     systemd.globalEnvironment.GCOV_PREFIX = "/tmp/xchg/coverage-data";
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| 
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|     system.requiredKernelConfig = with config.lib.kernelConfig; [
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|       (isYes "SERIAL_8250_CONSOLE")
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|       (isYes "SERIAL_8250")
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|       (isEnabled "VIRTIO_CONSOLE")
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|     ];
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| 
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|     networking.usePredictableInterfaceNames = false;
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| 
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|     # Make it easy to log in as root when running the test interactively.
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|     users.extraUsers.root.initialHashedPassword = mkOverride 150 "";
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| 
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|     services.xserver.displayManager.logToJournal = true;
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| 
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|     # Bump kdm's X server start timeout to account for heavily loaded
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|     # VM host systems.
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|     services.xserver.displayManager.kdm.extraConfig =
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|       ''
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|         [X-:*-Core]
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|         ServerTimeout=240
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|       '';
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| 
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|   };
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| 
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| }
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