nixpkgs/modules/testing/test-instrumentation.nix
Eelco Dolstra ae4e94d9ac Rename ‘boot.systemd’ to ‘systemd’
Suggested by Mathijs Kwik.  ‘boot.systemd’ is a misnomer because
systemd affects more than just booting.  And it saves some typing.
2013-01-16 12:33:18 +01:00

90 lines
2.9 KiB
Nix

# This module allows the test driver to connect to the virtual machine
# via a root shell attached to port 514.
{ config, pkgs, ... }:
with pkgs.lib;
let kernel = config.boot.kernelPackages.kernel; in
{
config = {
systemd.services.backdoor =
{ wantedBy = [ "multi-user.target" ];
requires = [ "dev-hvc0.device" "dev-ttyS0.device" ];
after = [ "dev-hvc0.device" "dev-ttyS0.device" ];
script =
''
export USER=root
export HOME=/root
export DISPLAY=:0.0
source /etc/profile
cd /tmp
exec < /dev/hvc0 > /dev/hvc0 2> /dev/ttyS0
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 ttyS0, since it
# interferes with the backdoor (writes to ttyS0 will randomly fail
# with EIO). Likewise for hvc0.
systemd.services."serial-getty@ttyS0".enable = false;
systemd.services."serial-getty@hvc0".enable = false;
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=tty1" "console=ttyS0" "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.console = "/dev/console";
# 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")
];
};
}