234 lines
8 KiB
Nix
234 lines
8 KiB
Nix
# 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;
|
|
|
|
let
|
|
cfg = config.testing;
|
|
|
|
qemu-common = import ../../lib/qemu-common.nix { inherit lib pkgs; };
|
|
|
|
backdoorService = {
|
|
requires = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
|
|
after = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
|
|
script =
|
|
''
|
|
export USER=root
|
|
export HOME=/root
|
|
export DISPLAY=:0.0
|
|
|
|
if [[ -e /etc/profile ]]; then
|
|
source /etc/profile
|
|
fi
|
|
|
|
# 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/${qemu-common.qemuSerialDevice}; do sleep 0.1; done
|
|
echo "connecting to host..." >&2
|
|
stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion
|
|
# The following line is essential since it signals to
|
|
# the test driver that the shell is ready.
|
|
# See: the connect method in the Machine class.
|
|
echo "Spawning backdoor root shell..."
|
|
# Passing the terminal device makes bash run non-interactively.
|
|
# Otherwise we get errors on the terminal because bash tries to
|
|
# setup things like job control.
|
|
# Note: calling bash explicitly here instead of sh makes sure that
|
|
# we can also run non-NixOS guests during tests. This, however, is
|
|
# mostly futureproofing as the test instrumentation is still very
|
|
# tightly coupled to NixOS.
|
|
PS1= exec ${pkgs.coreutils}/bin/env bash --norc /dev/hvc0
|
|
'';
|
|
serviceConfig.KillSignal = "SIGHUP";
|
|
};
|
|
|
|
in
|
|
|
|
{
|
|
|
|
options.testing = {
|
|
|
|
initrdBackdoor = lib.mkEnableOption ''
|
|
backdoor.service in initrd. Requires
|
|
boot.initrd.systemd.enable to be enabled. Boot will pause in
|
|
stage 1 at initrd.target, and will listen for commands from the
|
|
Machine python interface, just like stage 2 normally does. This
|
|
enables commands to be sent to test and debug stage 1. Use
|
|
machine.switch_root() to leave stage 1 and proceed to stage 2
|
|
'';
|
|
|
|
};
|
|
|
|
config = {
|
|
|
|
assertions = [
|
|
{
|
|
assertion = cfg.initrdBackdoor -> config.boot.initrd.systemd.enable;
|
|
message = ''
|
|
testing.initrdBackdoor requires boot.initrd.systemd.enable to be enabled.
|
|
'';
|
|
}
|
|
];
|
|
|
|
systemd.services.backdoor = lib.mkMerge [
|
|
backdoorService
|
|
{
|
|
wantedBy = [ "multi-user.target" ];
|
|
}
|
|
];
|
|
|
|
boot.initrd.systemd = lib.mkMerge [
|
|
{
|
|
contents."/etc/systemd/journald.conf".text = ''
|
|
[Journal]
|
|
ForwardToConsole=yes
|
|
TTYPath=/dev/${qemu-common.qemuSerialDevice}
|
|
MaxLevelConsole=debug
|
|
'';
|
|
|
|
extraConfig = config.systemd.extraConfig;
|
|
}
|
|
|
|
(lib.mkIf cfg.initrdBackdoor {
|
|
# Implemented in machine.switch_root(). Suppress the unit by
|
|
# making it a noop without removing it, which would break
|
|
# initrd-parse-etc.service
|
|
services.initrd-cleanup.serviceConfig.ExecStart = [
|
|
# Reset
|
|
""
|
|
# noop
|
|
"/bin/true"
|
|
];
|
|
|
|
services.backdoor = lib.mkMerge [
|
|
backdoorService
|
|
{
|
|
# TODO: Both stage 1 and stage 2 should use these same
|
|
# settings. But a lot of existing tests rely on
|
|
# backdoor.service having default orderings,
|
|
# e.g. systemd-boot.update relies on /boot being mounted
|
|
# as soon as backdoor starts. But it can be useful for
|
|
# backdoor to start even earlier.
|
|
wantedBy = [ "sysinit.target" ];
|
|
unitConfig.DefaultDependencies = false;
|
|
conflicts = [ "shutdown.target" "initrd-switch-root.target" ];
|
|
before = [ "shutdown.target" "initrd-switch-root.target" ];
|
|
}
|
|
];
|
|
|
|
storePaths = [
|
|
"${pkgs.coreutils}/bin/env"
|
|
];
|
|
})
|
|
];
|
|
|
|
# Prevent agetty from being instantiated on the serial device, since it
|
|
# interferes with the backdoor (writes to it will randomly fail
|
|
# with EIO). Likewise for hvc0.
|
|
systemd.services."serial-getty@${qemu-common.qemuSerialDevice}".enable = false;
|
|
systemd.services."serial-getty@hvc0".enable = false;
|
|
|
|
# Only set these settings when the options exist. Some tests (e.g. those
|
|
# that do not specify any nodes, or an empty attr set as nodes) will not
|
|
# have the QEMU module loaded and thuse these options can't and should not
|
|
# be set.
|
|
virtualisation = lib.optionalAttrs (options ? virtualisation.qemu) {
|
|
qemu = {
|
|
# 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
|
|
consoles = [ qemu-common.qemuSerialDevice ];
|
|
package = lib.mkDefault pkgs.qemu_test;
|
|
};
|
|
};
|
|
|
|
boot.kernel.sysctl = {
|
|
"kernel.hung_task_timeout_secs" = 600;
|
|
# 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.
|
|
"vm.panic_on_oom" = lib.mkDefault 2;
|
|
};
|
|
|
|
boot.kernelParams = [
|
|
"console=${qemu-common.qemuSerialDevice}"
|
|
"console=tty0"
|
|
# Panic if an error occurs in stage 1 (rather than waiting for
|
|
# user intervention).
|
|
"panic=1" "boot.panic_on_fail"
|
|
# Using acpi_pm as a clock source causes the guest clock to
|
|
# slow down under high host load. This is usually a bad
|
|
# thing, but for VM tests it should provide a bit more
|
|
# determinism (e.g. if the VM runs at lower speed, then
|
|
# timeouts in the VM should also be delayed).
|
|
"clocksource=acpi_pm"
|
|
];
|
|
|
|
# `xwininfo' is used by the test driver to query open windows.
|
|
environment.systemPackages = [ pkgs.xorg.xwininfo ];
|
|
|
|
# Log everything to the serial console.
|
|
services.journald.extraConfig =
|
|
''
|
|
ForwardToConsole=yes
|
|
TTYPath=/dev/${qemu-common.qemuSerialDevice}
|
|
MaxLevelConsole=debug
|
|
'';
|
|
|
|
systemd.extraConfig = ''
|
|
# Don't clobber the console with duplicate systemd messages.
|
|
ShowStatus=no
|
|
# Allow very slow start
|
|
DefaultTimeoutStartSec=300
|
|
DefaultDeviceTimeoutSec=300
|
|
'';
|
|
systemd.user.extraConfig = ''
|
|
# Allow very slow start
|
|
DefaultTimeoutStartSec=300
|
|
DefaultDeviceTimeoutSec=300
|
|
'';
|
|
|
|
boot.consoleLogLevel = 7;
|
|
|
|
# Prevent tests from accessing the Internet.
|
|
networking.defaultGateway = mkOverride 150 null;
|
|
networking.nameservers = mkOverride 150 [ ];
|
|
|
|
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.
|
|
# This needs to be a file because of a quirk in systemd credentials,
|
|
# where you cannot specify an empty string as a value. systemd-sysusers
|
|
# uses credentials to set passwords on users.
|
|
users.users.root.hashedPasswordFile = mkOverride 150 "${pkgs.writeText "hashed-password.root" ""}";
|
|
|
|
services.displayManager.logToJournal = true;
|
|
|
|
services.logrotate.enable = mkOverride 150 false;
|
|
|
|
# Make sure we use the Guest Agent from the QEMU package for testing
|
|
# to reduce the closure size required for the tests.
|
|
services.qemuGuest.package = pkgs.qemu_test.ga;
|
|
|
|
# Squelch warning about unset system.stateVersion
|
|
system.stateVersion = lib.mkDefault lib.trivial.release;
|
|
};
|
|
|
|
}
|