29027fd1e1
Using pkgs.lib on the spine of module evaluation is problematic because the pkgs argument depends on the result of module evaluation. To prevent an infinite recursion, pkgs and some of the modules are evaluated twice, which is inefficient. Using ‘with lib’ prevents this problem.
91 lines
2.9 KiB
Nix
91 lines
2.9 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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{ config, lib, pkgs, ... }:
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with lib;
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let kernel = config.boot.kernelPackages.kernel; in
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{
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config = {
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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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source /etc/profile
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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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# 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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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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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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# 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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# 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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# 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=tty1" "console=ttyS0" "panic=1" "boot.panic_on_fail" ];
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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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# Log everything to the serial console.
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services.journald.console = "/dev/console";
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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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systemd.globalEnvironment.GCOV_PREFIX = "/tmp/xchg/coverage-data";
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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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}
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