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|
# This module allows the test driver to connect to the virtual machine
# via a root shell attached to port 514.
{ options, config, lib, pkgs, ... }:
with lib;
with import ../../lib/qemu-flags.nix { inherit pkgs; };
{
config = {
systemd.services.backdoor =
{ wantedBy = [ "multi-user.target" ];
requires = [ "dev-hvc0.device" "dev-${qemuSerialDevice}.device" ];
after = [ "dev-hvc0.device" "dev-${qemuSerialDevice}.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/${qemuSerialDevice}; do sleep 0.1; done
echo "connecting to host..." >&2
stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion
echo
PS1= exec /bin/sh
'';
serviceConfig.KillSignal = "SIGHUP";
};
# Prevent agetty from being instantiated on the serial device, since it
# interferes with the backdoor (writes to it will randomly fail
# with EIO). Likewise for hvc0.
systemd.services."serial-getty@${qemuSerialDevice}".enable = false;
systemd.services."serial-getty@hvc0".enable = false;
# Only use a serial console, no TTY.
# 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 =
''
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=${qemuSerialDevice}" "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
'';
systemd.extraConfig = ''
# Don't clobber the console with duplicate systemd messages.
ShowStatus=no
# Allow very slow start
DefaultTimeoutStartSec=300
'';
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.users.root.initialHashedPassword = mkOverride 150 "";
services.xserver.displayManager.job.logToJournal = true;
};
}
|