# This module allows the test driver to connect to the virtual machine # via a root shell attached to port 514. { config, lib, pkgs, ... }: with lib; let kernel = config.boot.kernelPackages.kernel; # FIXME: figure out a common place for this instead of copy pasting serialDevice = if pkgs.stdenv.isi686 || pkgs.stdenv.isx86_64 then "ttyS0" else if pkgs.stdenv.isArm || pkgs.stdenv.isAarch64 then "ttyAMA0" else throw "Unknown QEMU serial device for system '${pkgs.stdenv.system}'"; in { # This option is a dummy that if used in conjunction with # modules/virtualisation/qemu-vm.nix gets merged with the same option defined # there and only is declared here because some modules use # test-instrumentation.nix but not qemu-vm.nix. # # One particular example are the boot tests where we want instrumentation # within the images but not other stuff like setting up 9p filesystems. options.virtualisation.qemu.program = mkOption { type = types.path; }; config = { systemd.services.backdoor = { wantedBy = [ "multi-user.target" ]; requires = [ "dev-hvc0.device" "dev-${serialDevice}.device" ]; after = [ "dev-hvc0.device" "dev-${serialDevice}.device" ]; script = '' export USER=root export HOME=/root export DISPLAY=:0.0 source /etc/profile # Don't use a pager when executing backdoor # actions. Because we use a tty, commands like systemctl # or nix-store get confused into thinking they're running # interactively. export PAGER= cd /tmp exec < /dev/hvc0 > /dev/hvc0 while ! exec 2> /dev/${serialDevice}; do sleep 0.1; done echo "connecting to host..." >&2 stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion echo PS1= exec /bin/sh ''; serviceConfig.KillSignal = "SIGHUP"; }; # Prevent agetty from being instantiated on ${serialDevice}, since it # interferes with the backdoor (writes to ${serialDevice} will randomly fail # with EIO). Likewise for hvc0. systemd.services."serial-getty@${serialDevice}".enable = false; systemd.services."serial-getty@hvc0".enable = false; boot.initrd.preDeviceCommands = '' echo 600 > /proc/sys/kernel/hung_task_timeout_secs ''; boot.initrd.postDeviceCommands = '' # Using acpi_pm as a clock source causes the guest clock to # slow down under high host load. This is usually a bad # thing, but for VM tests it should provide a bit more # determinism (e.g. if the VM runs at lower speed, then # timeouts in the VM should also be delayed). echo acpi_pm > /sys/devices/system/clocksource/clocksource0/current_clocksource ''; boot.postBootCommands = '' # Panic on out-of-memory conditions rather than letting the # 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 = [ "console=${serialDevice}" "panic=1" "boot.panic_on_fail" ]; # `xwininfo' is used by the test driver to query open windows. environment.systemPackages = [ pkgs.xorg.xwininfo ]; # Log everything to the serial console. services.journald.extraConfig = '' ForwardToConsole=yes MaxLevelConsole=debug ''; # Don't clobber the console with duplicate systemd messages. systemd.extraConfig = "ShowStatus=no"; boot.consoleLogLevel = 7; # Prevent tests from accessing the Internet. 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") (isEnabled "VIRTIO_CONSOLE") ]; networking.usePredictableInterfaceNames = false; # Make it easy to log in as root when running the test interactively. users.extraUsers.root.initialHashedPassword = mkOverride 150 ""; services.xserver.displayManager.logToJournal = true; }; }