mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-12-27 08:04:14 +00:00
1152 lines
39 KiB
Nix
1152 lines
39 KiB
Nix
# This module creates a virtual machine from the NixOS configuration.
|
|
# Building the `config.system.build.vm' attribute gives you a command
|
|
# that starts a KVM/QEMU VM running the NixOS configuration defined in
|
|
# `config'. The Nix store is shared read-only with the host, which
|
|
# makes (re)building VMs very efficient. However, it also means you
|
|
# can't reconfigure the guest inside the guest - you need to rebuild
|
|
# the VM in the host. On the other hand, the root filesystem is a
|
|
# read/writable disk image persistent across VM reboots.
|
|
|
|
{ config, lib, pkgs, options, ... }:
|
|
|
|
with lib;
|
|
|
|
let
|
|
|
|
qemu-common = import ../../lib/qemu-common.nix { inherit lib pkgs; };
|
|
|
|
cfg = config.virtualisation;
|
|
|
|
opt = options.virtualisation;
|
|
|
|
qemu = cfg.qemu.package;
|
|
|
|
consoles = lib.concatMapStringsSep " " (c: "console=${c}") cfg.qemu.consoles;
|
|
|
|
driveOpts = { ... }: {
|
|
|
|
options = {
|
|
|
|
file = mkOption {
|
|
type = types.str;
|
|
description = lib.mdDoc "The file image used for this drive.";
|
|
};
|
|
|
|
driveExtraOpts = mkOption {
|
|
type = types.attrsOf types.str;
|
|
default = {};
|
|
description = lib.mdDoc "Extra options passed to drive flag.";
|
|
};
|
|
|
|
deviceExtraOpts = mkOption {
|
|
type = types.attrsOf types.str;
|
|
default = {};
|
|
description = lib.mdDoc "Extra options passed to device flag.";
|
|
};
|
|
|
|
name = mkOption {
|
|
type = types.nullOr types.str;
|
|
default = null;
|
|
description =
|
|
lib.mdDoc "A name for the drive. Must be unique in the drives list. Not passed to qemu.";
|
|
};
|
|
|
|
};
|
|
|
|
};
|
|
|
|
driveCmdline = idx: { file, driveExtraOpts, deviceExtraOpts, ... }:
|
|
let
|
|
drvId = "drive${toString idx}";
|
|
mkKeyValue = generators.mkKeyValueDefault {} "=";
|
|
mkOpts = opts: concatStringsSep "," (mapAttrsToList mkKeyValue opts);
|
|
driveOpts = mkOpts (driveExtraOpts // {
|
|
index = idx;
|
|
id = drvId;
|
|
"if" = "none";
|
|
inherit file;
|
|
});
|
|
deviceOpts = mkOpts (deviceExtraOpts // {
|
|
drive = drvId;
|
|
});
|
|
device =
|
|
if cfg.qemu.diskInterface == "scsi" then
|
|
"-device lsi53c895a -device scsi-hd,${deviceOpts}"
|
|
else
|
|
"-device virtio-blk-pci,${deviceOpts}";
|
|
in
|
|
"-drive ${driveOpts} ${device}";
|
|
|
|
drivesCmdLine = drives: concatStringsSep "\\\n " (imap1 driveCmdline drives);
|
|
|
|
|
|
# Creates a device name from a 1-based a numerical index, e.g.
|
|
# * `driveDeviceName 1` -> `/dev/vda`
|
|
# * `driveDeviceName 2` -> `/dev/vdb`
|
|
driveDeviceName = idx:
|
|
let letter = elemAt lowerChars (idx - 1);
|
|
in if cfg.qemu.diskInterface == "scsi" then
|
|
"/dev/sd${letter}"
|
|
else
|
|
"/dev/vd${letter}";
|
|
|
|
lookupDriveDeviceName = driveName: driveList:
|
|
(findSingle (drive: drive.name == driveName)
|
|
(throw "Drive ${driveName} not found")
|
|
(throw "Multiple drives named ${driveName}") driveList).device;
|
|
|
|
addDeviceNames =
|
|
imap1 (idx: drive: drive // { device = driveDeviceName idx; });
|
|
|
|
|
|
# Shell script to start the VM.
|
|
startVM =
|
|
''
|
|
#! ${cfg.host.pkgs.runtimeShell}
|
|
|
|
export PATH=${makeBinPath [ cfg.host.pkgs.coreutils ]}''${PATH:+:}$PATH
|
|
|
|
set -e
|
|
|
|
NIX_DISK_IMAGE=$(readlink -f "''${NIX_DISK_IMAGE:-${config.virtualisation.diskImage}}")
|
|
|
|
if ! test -e "$NIX_DISK_IMAGE"; then
|
|
${qemu}/bin/qemu-img create -f qcow2 "$NIX_DISK_IMAGE" \
|
|
${toString config.virtualisation.diskSize}M
|
|
fi
|
|
|
|
# Create a directory for storing temporary data of the running VM.
|
|
if [ -z "$TMPDIR" ] || [ -z "$USE_TMPDIR" ]; then
|
|
TMPDIR=$(mktemp -d nix-vm.XXXXXXXXXX --tmpdir)
|
|
fi
|
|
|
|
${lib.optionalString (cfg.useNixStoreImage)
|
|
(if cfg.writableStore
|
|
then ''
|
|
# Create a writable copy/snapshot of the store image.
|
|
${qemu}/bin/qemu-img create -f qcow2 -F qcow2 -b ${storeImage}/nixos.qcow2 "$TMPDIR"/store.img
|
|
''
|
|
else ''
|
|
(
|
|
cd ${builtins.storeDir}
|
|
${pkgs.erofs-utils}/bin/mkfs.erofs \
|
|
--force-uid=0 \
|
|
--force-gid=0 \
|
|
-U eb176051-bd15-49b7-9e6b-462e0b467019 \
|
|
-T 0 \
|
|
--exclude-regex="$(
|
|
<${pkgs.closureInfo { rootPaths = [ config.system.build.toplevel regInfo ]; }}/store-paths \
|
|
sed -e 's^.*/^^g' \
|
|
| cut -c -10 \
|
|
| ${pkgs.python3}/bin/python ${./includes-to-excludes.py} )" \
|
|
"$TMPDIR"/store.img \
|
|
. \
|
|
</dev/null >/dev/null
|
|
)
|
|
''
|
|
)
|
|
}
|
|
|
|
# Create a directory for exchanging data with the VM.
|
|
mkdir -p "$TMPDIR/xchg"
|
|
|
|
${lib.optionalString cfg.useBootLoader
|
|
''
|
|
# Create a writable copy/snapshot of the boot disk.
|
|
# A writable boot disk can be booted from automatically.
|
|
${qemu}/bin/qemu-img create -f qcow2 -F qcow2 -b ${bootDisk}/disk.img "$TMPDIR/disk.img"
|
|
|
|
NIX_EFI_VARS=$(readlink -f "''${NIX_EFI_VARS:-${cfg.efiVars}}")
|
|
|
|
${lib.optionalString cfg.useEFIBoot
|
|
''
|
|
# VM needs writable EFI vars
|
|
if ! test -e "$NIX_EFI_VARS"; then
|
|
cp ${bootDisk}/efi-vars.fd "$NIX_EFI_VARS"
|
|
chmod 0644 "$NIX_EFI_VARS"
|
|
fi
|
|
''}
|
|
''}
|
|
|
|
cd "$TMPDIR"
|
|
|
|
${lib.optionalString (cfg.emptyDiskImages != []) "idx=0"}
|
|
${flip concatMapStrings cfg.emptyDiskImages (size: ''
|
|
if ! test -e "empty$idx.qcow2"; then
|
|
${qemu}/bin/qemu-img create -f qcow2 "empty$idx.qcow2" "${toString size}M"
|
|
fi
|
|
idx=$((idx + 1))
|
|
'')}
|
|
|
|
# Start QEMU.
|
|
exec ${qemu-common.qemuBinary qemu} \
|
|
-name ${config.system.name} \
|
|
-m ${toString config.virtualisation.memorySize} \
|
|
-smp ${toString config.virtualisation.cores} \
|
|
-device virtio-rng-pci \
|
|
${concatStringsSep " " config.virtualisation.qemu.networkingOptions} \
|
|
${concatStringsSep " \\\n "
|
|
(mapAttrsToList
|
|
(tag: share: "-virtfs local,path=${share.source},security_model=none,mount_tag=${tag}")
|
|
config.virtualisation.sharedDirectories)} \
|
|
${drivesCmdLine config.virtualisation.qemu.drives} \
|
|
${concatStringsSep " \\\n " config.virtualisation.qemu.options} \
|
|
$QEMU_OPTS \
|
|
"$@"
|
|
'';
|
|
|
|
|
|
regInfo = pkgs.closureInfo { rootPaths = config.virtualisation.additionalPaths; };
|
|
|
|
|
|
# Generate a hard disk image containing a /boot partition and GRUB
|
|
# in the MBR. Used when the `useBootLoader' option is set.
|
|
# Uses `runInLinuxVM` to create the image in a throwaway VM.
|
|
# See note [Disk layout with `useBootLoader`].
|
|
# FIXME: use nixos/lib/make-disk-image.nix.
|
|
bootDisk =
|
|
pkgs.vmTools.runInLinuxVM (
|
|
pkgs.runCommand "nixos-boot-disk"
|
|
{ preVM =
|
|
''
|
|
mkdir $out
|
|
diskImage=$out/disk.img
|
|
${qemu}/bin/qemu-img create -f qcow2 $diskImage "60M"
|
|
${if cfg.useEFIBoot then ''
|
|
efiVars=$out/efi-vars.fd
|
|
cp ${cfg.efi.variables} $efiVars
|
|
chmod 0644 $efiVars
|
|
'' else ""}
|
|
'';
|
|
buildInputs = [ pkgs.util-linux ];
|
|
QEMU_OPTS = "-nographic -serial stdio -monitor none"
|
|
+ lib.optionalString cfg.useEFIBoot (
|
|
" -drive if=pflash,format=raw,unit=0,readonly=on,file=${cfg.efi.firmware}"
|
|
+ " -drive if=pflash,format=raw,unit=1,file=$efiVars");
|
|
}
|
|
''
|
|
# Create a /boot EFI partition with 60M and arbitrary but fixed GUIDs for reproducibility
|
|
${pkgs.gptfdisk}/bin/sgdisk \
|
|
--set-alignment=1 --new=1:34:2047 --change-name=1:BIOSBootPartition --typecode=1:ef02 \
|
|
--set-alignment=512 --largest-new=2 --change-name=2:EFISystem --typecode=2:ef00 \
|
|
--attributes=1:set:1 \
|
|
--attributes=2:set:2 \
|
|
--disk-guid=97FD5997-D90B-4AA3-8D16-C1723AEA73C1 \
|
|
--partition-guid=1:1C06F03B-704E-4657-B9CD-681A087A2FDC \
|
|
--partition-guid=2:970C694F-AFD0-4B99-B750-CDB7A329AB6F \
|
|
--hybrid 2 \
|
|
--recompute-chs /dev/vda
|
|
|
|
${optionalString (config.boot.loader.grub.device != "/dev/vda")
|
|
# In this throwaway VM, we only have the /dev/vda disk, but the
|
|
# actual VM described by `config` (used by `switch-to-configuration`
|
|
# below) may set `boot.loader.grub.device` to a different device
|
|
# that's nonexistent in the throwaway VM.
|
|
# Create a symlink for that device, so that the `grub-install`
|
|
# by `switch-to-configuration` will hit /dev/vda anyway.
|
|
''
|
|
ln -s /dev/vda ${config.boot.loader.grub.device}
|
|
''
|
|
}
|
|
|
|
${pkgs.dosfstools}/bin/mkfs.fat -F16 /dev/vda2
|
|
export MTOOLS_SKIP_CHECK=1
|
|
${pkgs.mtools}/bin/mlabel -i /dev/vda2 ::boot
|
|
|
|
# Mount /boot; load necessary modules first.
|
|
${pkgs.kmod}/bin/insmod ${pkgs.linux}/lib/modules/*/kernel/fs/nls/nls_cp437.ko.xz || true
|
|
${pkgs.kmod}/bin/insmod ${pkgs.linux}/lib/modules/*/kernel/fs/nls/nls_iso8859-1.ko.xz || true
|
|
${pkgs.kmod}/bin/insmod ${pkgs.linux}/lib/modules/*/kernel/fs/fat/fat.ko.xz || true
|
|
${pkgs.kmod}/bin/insmod ${pkgs.linux}/lib/modules/*/kernel/fs/fat/vfat.ko.xz || true
|
|
${pkgs.kmod}/bin/insmod ${pkgs.linux}/lib/modules/*/kernel/fs/efivarfs/efivarfs.ko.xz || true
|
|
mkdir /boot
|
|
mount /dev/vda2 /boot
|
|
|
|
${optionalString config.boot.loader.efi.canTouchEfiVariables ''
|
|
mount -t efivarfs efivarfs /sys/firmware/efi/efivars
|
|
''}
|
|
|
|
# This is needed for GRUB 0.97, which doesn't know about virtio devices.
|
|
mkdir /boot/grub
|
|
echo '(hd0) /dev/vda' > /boot/grub/device.map
|
|
|
|
# This is needed for systemd-boot to find ESP, and udev is not available here to create this
|
|
mkdir -p /dev/block
|
|
ln -s /dev/vda2 /dev/block/254:2
|
|
|
|
# Set up system profile (normally done by nixos-rebuild / nix-env --set)
|
|
mkdir -p /nix/var/nix/profiles
|
|
ln -s ${config.system.build.toplevel} /nix/var/nix/profiles/system-1-link
|
|
ln -s /nix/var/nix/profiles/system-1-link /nix/var/nix/profiles/system
|
|
|
|
# Install bootloader
|
|
touch /etc/NIXOS
|
|
export NIXOS_INSTALL_BOOTLOADER=1
|
|
${config.system.build.toplevel}/bin/switch-to-configuration boot
|
|
|
|
umount /boot
|
|
'' # */
|
|
);
|
|
|
|
storeImage = import ../../lib/make-disk-image.nix {
|
|
inherit pkgs config lib;
|
|
additionalPaths = [ regInfo ];
|
|
format = "qcow2";
|
|
onlyNixStore = true;
|
|
partitionTableType = "none";
|
|
installBootLoader = false;
|
|
diskSize = "auto";
|
|
additionalSpace = "0M";
|
|
copyChannel = false;
|
|
};
|
|
|
|
in
|
|
|
|
{
|
|
imports = [
|
|
../profiles/qemu-guest.nix
|
|
(mkRenamedOptionModule [ "virtualisation" "pathsInNixDB" ] [ "virtualisation" "additionalPaths" ])
|
|
];
|
|
|
|
options = {
|
|
|
|
virtualisation.fileSystems = options.fileSystems;
|
|
|
|
virtualisation.memorySize =
|
|
mkOption {
|
|
type = types.ints.positive;
|
|
default = 1024;
|
|
description =
|
|
lib.mdDoc ''
|
|
The memory size in megabytes of the virtual machine.
|
|
'';
|
|
};
|
|
|
|
virtualisation.msize =
|
|
mkOption {
|
|
type = types.ints.positive;
|
|
default = 16384;
|
|
description =
|
|
lib.mdDoc ''
|
|
The msize (maximum packet size) option passed to 9p file systems, in
|
|
bytes. Increasing this should increase performance significantly,
|
|
at the cost of higher RAM usage.
|
|
'';
|
|
};
|
|
|
|
virtualisation.diskSize =
|
|
mkOption {
|
|
type = types.nullOr types.ints.positive;
|
|
default = 1024;
|
|
description =
|
|
lib.mdDoc ''
|
|
The disk size in megabytes of the virtual machine.
|
|
'';
|
|
};
|
|
|
|
virtualisation.diskImage =
|
|
mkOption {
|
|
type = types.str;
|
|
default = "./${config.system.name}.qcow2";
|
|
defaultText = literalExpression ''"./''${config.system.name}.qcow2"'';
|
|
description =
|
|
lib.mdDoc ''
|
|
Path to the disk image containing the root filesystem.
|
|
The image will be created on startup if it does not
|
|
exist.
|
|
'';
|
|
};
|
|
|
|
virtualisation.bootDevice =
|
|
mkOption {
|
|
type = types.path;
|
|
example = "/dev/vda";
|
|
description =
|
|
lib.mdDoc ''
|
|
The disk to be used for the root filesystem.
|
|
'';
|
|
};
|
|
|
|
virtualisation.emptyDiskImages =
|
|
mkOption {
|
|
type = types.listOf types.ints.positive;
|
|
default = [];
|
|
description =
|
|
lib.mdDoc ''
|
|
Additional disk images to provide to the VM. The value is
|
|
a list of size in megabytes of each disk. These disks are
|
|
writeable by the VM.
|
|
'';
|
|
};
|
|
|
|
virtualisation.graphics =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = true;
|
|
description =
|
|
lib.mdDoc ''
|
|
Whether to run QEMU with a graphics window, or in nographic mode.
|
|
Serial console will be enabled on both settings, but this will
|
|
change the preferred console.
|
|
'';
|
|
};
|
|
|
|
virtualisation.resolution =
|
|
mkOption {
|
|
type = options.services.xserver.resolutions.type.nestedTypes.elemType;
|
|
default = { x = 1024; y = 768; };
|
|
description =
|
|
lib.mdDoc ''
|
|
The resolution of the virtual machine display.
|
|
'';
|
|
};
|
|
|
|
virtualisation.cores =
|
|
mkOption {
|
|
type = types.ints.positive;
|
|
default = 1;
|
|
description =
|
|
lib.mdDoc ''
|
|
Specify the number of cores the guest is permitted to use.
|
|
The number can be higher than the available cores on the
|
|
host system.
|
|
'';
|
|
};
|
|
|
|
virtualisation.sharedDirectories =
|
|
mkOption {
|
|
type = types.attrsOf
|
|
(types.submodule {
|
|
options.source = mkOption {
|
|
type = types.str;
|
|
description = lib.mdDoc "The path of the directory to share, can be a shell variable";
|
|
};
|
|
options.target = mkOption {
|
|
type = types.path;
|
|
description = lib.mdDoc "The mount point of the directory inside the virtual machine";
|
|
};
|
|
});
|
|
default = { };
|
|
example = {
|
|
my-share = { source = "/path/to/be/shared"; target = "/mnt/shared"; };
|
|
};
|
|
description =
|
|
lib.mdDoc ''
|
|
An attributes set of directories that will be shared with the
|
|
virtual machine using VirtFS (9P filesystem over VirtIO).
|
|
The attribute name will be used as the 9P mount tag.
|
|
'';
|
|
};
|
|
|
|
virtualisation.additionalPaths =
|
|
mkOption {
|
|
type = types.listOf types.path;
|
|
default = [];
|
|
description =
|
|
lib.mdDoc ''
|
|
A list of paths whose closure should be made available to
|
|
the VM.
|
|
|
|
When 9p is used, the closure is registered in the Nix
|
|
database in the VM. All other paths in the host Nix store
|
|
appear in the guest Nix store as well, but are considered
|
|
garbage (because they are not registered in the Nix
|
|
database of the guest).
|
|
|
|
When {option}`virtualisation.useNixStoreImage` is
|
|
set, the closure is copied to the Nix store image.
|
|
'';
|
|
};
|
|
|
|
virtualisation.forwardPorts = mkOption {
|
|
type = types.listOf
|
|
(types.submodule {
|
|
options.from = mkOption {
|
|
type = types.enum [ "host" "guest" ];
|
|
default = "host";
|
|
description =
|
|
lib.mdDoc ''
|
|
Controls the direction in which the ports are mapped:
|
|
|
|
- `"host"` means traffic from the host ports
|
|
is forwarded to the given guest port.
|
|
- `"guest"` means traffic from the guest ports
|
|
is forwarded to the given host port.
|
|
'';
|
|
};
|
|
options.proto = mkOption {
|
|
type = types.enum [ "tcp" "udp" ];
|
|
default = "tcp";
|
|
description = lib.mdDoc "The protocol to forward.";
|
|
};
|
|
options.host.address = mkOption {
|
|
type = types.str;
|
|
default = "";
|
|
description = lib.mdDoc "The IPv4 address of the host.";
|
|
};
|
|
options.host.port = mkOption {
|
|
type = types.port;
|
|
description = lib.mdDoc "The host port to be mapped.";
|
|
};
|
|
options.guest.address = mkOption {
|
|
type = types.str;
|
|
default = "";
|
|
description = lib.mdDoc "The IPv4 address on the guest VLAN.";
|
|
};
|
|
options.guest.port = mkOption {
|
|
type = types.port;
|
|
description = lib.mdDoc "The guest port to be mapped.";
|
|
};
|
|
});
|
|
default = [];
|
|
example = lib.literalExpression
|
|
''
|
|
[ # forward local port 2222 -> 22, to ssh into the VM
|
|
{ from = "host"; host.port = 2222; guest.port = 22; }
|
|
|
|
# forward local port 80 -> 10.0.2.10:80 in the VLAN
|
|
{ from = "guest";
|
|
guest.address = "10.0.2.10"; guest.port = 80;
|
|
host.address = "127.0.0.1"; host.port = 80;
|
|
}
|
|
]
|
|
'';
|
|
description =
|
|
lib.mdDoc ''
|
|
When using the SLiRP user networking (default), this option allows to
|
|
forward ports to/from the host/guest.
|
|
|
|
::: {.warning}
|
|
If the NixOS firewall on the virtual machine is enabled, you also
|
|
have to open the guest ports to enable the traffic between host and
|
|
guest.
|
|
:::
|
|
|
|
::: {.note}
|
|
Currently QEMU supports only IPv4 forwarding.
|
|
:::
|
|
'';
|
|
};
|
|
|
|
virtualisation.vlans =
|
|
mkOption {
|
|
type = types.listOf types.ints.unsigned;
|
|
default = [ 1 ];
|
|
example = [ 1 2 ];
|
|
description =
|
|
lib.mdDoc ''
|
|
Virtual networks to which the VM is connected. Each
|
|
number «N» in this list causes
|
|
the VM to have a virtual Ethernet interface attached to a
|
|
separate virtual network on which it will be assigned IP
|
|
address
|
|
`192.168.«N».«M»`,
|
|
where «M» is the index of this VM
|
|
in the list of VMs.
|
|
'';
|
|
};
|
|
|
|
virtualisation.writableStore =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = true; # FIXME
|
|
description =
|
|
lib.mdDoc ''
|
|
If enabled, the Nix store in the VM is made writable by
|
|
layering an overlay filesystem on top of the host's Nix
|
|
store.
|
|
'';
|
|
};
|
|
|
|
virtualisation.writableStoreUseTmpfs =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = true;
|
|
description =
|
|
lib.mdDoc ''
|
|
Use a tmpfs for the writable store instead of writing to the VM's
|
|
own filesystem.
|
|
'';
|
|
};
|
|
|
|
networking.primaryIPAddress =
|
|
mkOption {
|
|
type = types.str;
|
|
default = "";
|
|
internal = true;
|
|
description = lib.mdDoc "Primary IP address used in /etc/hosts.";
|
|
};
|
|
|
|
virtualisation.host.pkgs = mkOption {
|
|
type = options.nixpkgs.pkgs.type;
|
|
default = pkgs;
|
|
defaultText = literalExpression "pkgs";
|
|
example = literalExpression ''
|
|
import pkgs.path { system = "x86_64-darwin"; }
|
|
'';
|
|
description = lib.mdDoc ''
|
|
pkgs set to use for the host-specific packages of the vm runner.
|
|
Changing this to e.g. a Darwin package set allows running NixOS VMs on Darwin.
|
|
'';
|
|
};
|
|
|
|
virtualisation.qemu = {
|
|
package =
|
|
mkOption {
|
|
type = types.package;
|
|
default = cfg.host.pkgs.qemu_kvm;
|
|
defaultText = literalExpression "config.virtualisation.host.pkgs.qemu_kvm";
|
|
example = literalExpression "pkgs.qemu_test";
|
|
description = lib.mdDoc "QEMU package to use.";
|
|
};
|
|
|
|
options =
|
|
mkOption {
|
|
type = types.listOf types.str;
|
|
default = [];
|
|
example = [ "-vga std" ];
|
|
description = lib.mdDoc "Options passed to QEMU.";
|
|
};
|
|
|
|
consoles = mkOption {
|
|
type = types.listOf types.str;
|
|
default = let
|
|
consoles = [ "${qemu-common.qemuSerialDevice},115200n8" "tty0" ];
|
|
in if cfg.graphics then consoles else reverseList consoles;
|
|
example = [ "console=tty1" ];
|
|
description = lib.mdDoc ''
|
|
The output console devices to pass to the kernel command line via the
|
|
`console` parameter, the primary console is the last
|
|
item of this list.
|
|
|
|
By default it enables both serial console and
|
|
`tty0`. The preferred console (last one) is based on
|
|
the value of {option}`virtualisation.graphics`.
|
|
'';
|
|
};
|
|
|
|
networkingOptions =
|
|
mkOption {
|
|
type = types.listOf types.str;
|
|
default = [ ];
|
|
example = [
|
|
"-net nic,netdev=user.0,model=virtio"
|
|
"-netdev user,id=user.0,\${QEMU_NET_OPTS:+,$QEMU_NET_OPTS}"
|
|
];
|
|
description = lib.mdDoc ''
|
|
Networking-related command-line options that should be passed to qemu.
|
|
The default is to use userspace networking (SLiRP).
|
|
|
|
If you override this option, be advised to keep
|
|
''${QEMU_NET_OPTS:+,$QEMU_NET_OPTS} (as seen in the example)
|
|
to keep the default runtime behaviour.
|
|
'';
|
|
};
|
|
|
|
drives =
|
|
mkOption {
|
|
type = types.listOf (types.submodule driveOpts);
|
|
description = lib.mdDoc "Drives passed to qemu.";
|
|
apply = addDeviceNames;
|
|
};
|
|
|
|
diskInterface =
|
|
mkOption {
|
|
type = types.enum [ "virtio" "scsi" "ide" ];
|
|
default = "virtio";
|
|
example = "scsi";
|
|
description = lib.mdDoc "The interface used for the virtual hard disks.";
|
|
};
|
|
|
|
guestAgent.enable =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = true;
|
|
description = lib.mdDoc ''
|
|
Enable the Qemu guest agent.
|
|
'';
|
|
};
|
|
|
|
virtioKeyboard =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = true;
|
|
description = lib.mdDoc ''
|
|
Enable the virtio-keyboard device.
|
|
'';
|
|
};
|
|
};
|
|
|
|
virtualisation.useNixStoreImage =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = false;
|
|
description = lib.mdDoc ''
|
|
Build and use a disk image for the Nix store, instead of
|
|
accessing the host's one through 9p.
|
|
|
|
For applications which do a lot of reads from the store,
|
|
this can drastically improve performance, but at the cost of
|
|
disk space and image build time.
|
|
'';
|
|
};
|
|
|
|
virtualisation.useBootLoader =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = false;
|
|
description =
|
|
lib.mdDoc ''
|
|
If enabled, the virtual machine will be booted using the
|
|
regular boot loader (i.e., GRUB 1 or 2). This allows
|
|
testing of the boot loader. If
|
|
disabled (the default), the VM directly boots the NixOS
|
|
kernel and initial ramdisk, bypassing the boot loader
|
|
altogether.
|
|
'';
|
|
};
|
|
|
|
virtualisation.useEFIBoot =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = false;
|
|
description =
|
|
lib.mdDoc ''
|
|
If enabled, the virtual machine will provide a EFI boot
|
|
manager.
|
|
useEFIBoot is ignored if useBootLoader == false.
|
|
'';
|
|
};
|
|
|
|
virtualisation.efi = {
|
|
firmware = mkOption {
|
|
type = types.path;
|
|
default = pkgs.OVMF.firmware;
|
|
defaultText = literalExpression "pkgs.OVMF.firmware";
|
|
description =
|
|
lib.mdDoc ''
|
|
Firmware binary for EFI implementation, defaults to OVMF.
|
|
'';
|
|
};
|
|
|
|
variables = mkOption {
|
|
type = types.path;
|
|
default = pkgs.OVMF.variables;
|
|
defaultText = literalExpression "pkgs.OVMF.variables";
|
|
description =
|
|
lib.mdDoc ''
|
|
Platform-specific flash binary for EFI variables, implementation-dependent to the EFI firmware.
|
|
Defaults to OVMF.
|
|
'';
|
|
};
|
|
};
|
|
|
|
virtualisation.useDefaultFilesystems =
|
|
mkOption {
|
|
type = types.bool;
|
|
default = true;
|
|
description =
|
|
lib.mdDoc ''
|
|
If enabled, the boot disk of the virtual machine will be
|
|
formatted and mounted with the default filesystems for
|
|
testing. Swap devices and LUKS will be disabled.
|
|
|
|
If disabled, a root filesystem has to be specified and
|
|
formatted (for example in the initial ramdisk).
|
|
'';
|
|
};
|
|
|
|
virtualisation.efiVars =
|
|
mkOption {
|
|
type = types.str;
|
|
default = "./${config.system.name}-efi-vars.fd";
|
|
defaultText = literalExpression ''"./''${config.system.name}-efi-vars.fd"'';
|
|
description =
|
|
lib.mdDoc ''
|
|
Path to nvram image containing UEFI variables. The will be created
|
|
on startup if it does not exist.
|
|
'';
|
|
};
|
|
|
|
virtualisation.bios =
|
|
mkOption {
|
|
type = types.nullOr types.package;
|
|
default = null;
|
|
description =
|
|
lib.mdDoc ''
|
|
An alternate BIOS (such as `qboot`) with which to start the VM.
|
|
Should contain a file named `bios.bin`.
|
|
If `null`, QEMU's builtin SeaBIOS will be used.
|
|
'';
|
|
};
|
|
|
|
};
|
|
|
|
config = {
|
|
|
|
assertions =
|
|
lib.concatLists (lib.flip lib.imap cfg.forwardPorts (i: rule:
|
|
[
|
|
{ assertion = rule.from == "guest" -> rule.proto == "tcp";
|
|
message =
|
|
''
|
|
Invalid virtualisation.forwardPorts.<entry ${toString i}>.proto:
|
|
Guest forwarding supports only TCP connections.
|
|
'';
|
|
}
|
|
{ assertion = rule.from == "guest" -> lib.hasPrefix "10.0.2." rule.guest.address;
|
|
message =
|
|
''
|
|
Invalid virtualisation.forwardPorts.<entry ${toString i}>.guest.address:
|
|
The address must be in the default VLAN (10.0.2.0/24).
|
|
'';
|
|
}
|
|
]));
|
|
|
|
warnings =
|
|
optional (
|
|
cfg.writableStore &&
|
|
cfg.useNixStoreImage &&
|
|
opt.writableStore.highestPrio > lib.modules.defaultOverridePriority)
|
|
''
|
|
You have enabled ${opt.useNixStoreImage} = true,
|
|
without setting ${opt.writableStore} = false.
|
|
|
|
This causes a store image to be written to the store, which is
|
|
costly, especially for the binary cache, and because of the need
|
|
for more frequent garbage collection.
|
|
|
|
If you really need this combination, you can set ${opt.writableStore}
|
|
explicitly to true, incur the cost and make this warning go away.
|
|
Otherwise, we recommend
|
|
|
|
${opt.writableStore} = false;
|
|
'';
|
|
|
|
# Note [Disk layout with `useBootLoader`]
|
|
#
|
|
# If `useBootLoader = true`, we configure 2 drives:
|
|
# `/dev/?da` for the root disk, and `/dev/?db` for the boot disk
|
|
# which has the `/boot` partition and the boot loader.
|
|
# Concretely:
|
|
#
|
|
# * The second drive's image `disk.img` is created in `bootDisk = ...`
|
|
# using a throwaway VM. Note that there the disk is always `/dev/vda`,
|
|
# even though in the final VM it will be at `/dev/*b`.
|
|
# * The disks are attached in `virtualisation.qemu.drives`.
|
|
# Their order makes them appear as devices `a`, `b`, etc.
|
|
# * `fileSystems."/boot"` is adjusted to be on device `b`.
|
|
|
|
# If `useBootLoader`, GRUB goes to the second disk, see
|
|
# note [Disk layout with `useBootLoader`].
|
|
boot.loader.grub.device = mkVMOverride (
|
|
if cfg.useBootLoader
|
|
then driveDeviceName 2 # second disk
|
|
else cfg.bootDevice
|
|
);
|
|
boot.loader.grub.gfxmodeBios = with cfg.resolution; "${toString x}x${toString y}";
|
|
|
|
boot.initrd.kernelModules = optionals (cfg.useNixStoreImage && !cfg.writableStore) [ "erofs" ];
|
|
|
|
boot.initrd.extraUtilsCommands = lib.mkIf (cfg.useDefaultFilesystems && !config.boot.initrd.systemd.enable)
|
|
''
|
|
# We need mke2fs in the initrd.
|
|
copy_bin_and_libs ${pkgs.e2fsprogs}/bin/mke2fs
|
|
'';
|
|
|
|
boot.initrd.postDeviceCommands = lib.mkIf (cfg.useDefaultFilesystems && !config.boot.initrd.systemd.enable)
|
|
''
|
|
# If the disk image appears to be empty, run mke2fs to
|
|
# initialise.
|
|
FSTYPE=$(blkid -o value -s TYPE ${cfg.bootDevice} || true)
|
|
PARTTYPE=$(blkid -o value -s PTTYPE ${cfg.bootDevice} || true)
|
|
if test -z "$FSTYPE" -a -z "$PARTTYPE"; then
|
|
mke2fs -t ext4 ${cfg.bootDevice}
|
|
fi
|
|
'';
|
|
|
|
boot.initrd.postMountCommands = lib.mkIf (!config.boot.initrd.systemd.enable)
|
|
''
|
|
# Mark this as a NixOS machine.
|
|
mkdir -p $targetRoot/etc
|
|
echo -n > $targetRoot/etc/NIXOS
|
|
|
|
# Fix the permissions on /tmp.
|
|
chmod 1777 $targetRoot/tmp
|
|
|
|
mkdir -p $targetRoot/boot
|
|
|
|
${optionalString cfg.writableStore ''
|
|
echo "mounting overlay filesystem on /nix/store..."
|
|
mkdir -p 0755 $targetRoot/nix/.rw-store/store $targetRoot/nix/.rw-store/work $targetRoot/nix/store
|
|
mount -t overlay overlay $targetRoot/nix/store \
|
|
-o lowerdir=$targetRoot/nix/.ro-store,upperdir=$targetRoot/nix/.rw-store/store,workdir=$targetRoot/nix/.rw-store/work || fail
|
|
''}
|
|
'';
|
|
|
|
systemd.tmpfiles.rules = lib.mkIf config.boot.initrd.systemd.enable [
|
|
"f /etc/NIXOS 0644 root root -"
|
|
"d /boot 0644 root root -"
|
|
];
|
|
|
|
# After booting, register the closure of the paths in
|
|
# `virtualisation.additionalPaths' in the Nix database in the VM. This
|
|
# allows Nix operations to work in the VM. The path to the
|
|
# registration file is passed through the kernel command line to
|
|
# allow `system.build.toplevel' to be included. (If we had a direct
|
|
# reference to ${regInfo} here, then we would get a cyclic
|
|
# dependency.)
|
|
boot.postBootCommands = lib.mkIf config.nix.enable
|
|
''
|
|
if [[ "$(cat /proc/cmdline)" =~ regInfo=([^ ]*) ]]; then
|
|
${config.nix.package.out}/bin/nix-store --load-db < ''${BASH_REMATCH[1]}
|
|
fi
|
|
'';
|
|
|
|
boot.initrd.availableKernelModules =
|
|
optional cfg.writableStore "overlay"
|
|
++ optional (cfg.qemu.diskInterface == "scsi") "sym53c8xx";
|
|
|
|
virtualisation.bootDevice = mkDefault (driveDeviceName 1);
|
|
|
|
virtualisation.additionalPaths = [ config.system.build.toplevel ];
|
|
|
|
virtualisation.sharedDirectories = {
|
|
nix-store = mkIf (!cfg.useNixStoreImage) {
|
|
source = builtins.storeDir;
|
|
target = "/nix/store";
|
|
};
|
|
xchg = {
|
|
source = ''"$TMPDIR"/xchg'';
|
|
target = "/tmp/xchg";
|
|
};
|
|
shared = {
|
|
source = ''"''${SHARED_DIR:-$TMPDIR/xchg}"'';
|
|
target = "/tmp/shared";
|
|
};
|
|
};
|
|
|
|
virtualisation.qemu.networkingOptions =
|
|
let
|
|
forwardingOptions = flip concatMapStrings cfg.forwardPorts
|
|
({ proto, from, host, guest }:
|
|
if from == "host"
|
|
then "hostfwd=${proto}:${host.address}:${toString host.port}-" +
|
|
"${guest.address}:${toString guest.port},"
|
|
else "'guestfwd=${proto}:${guest.address}:${toString guest.port}-" +
|
|
"cmd:${pkgs.netcat}/bin/nc ${host.address} ${toString host.port}',"
|
|
);
|
|
in
|
|
[
|
|
"-net nic,netdev=user.0,model=virtio"
|
|
"-netdev user,id=user.0,${forwardingOptions}\"$QEMU_NET_OPTS\""
|
|
];
|
|
|
|
# FIXME: Consolidate this one day.
|
|
virtualisation.qemu.options = mkMerge [
|
|
(mkIf cfg.qemu.virtioKeyboard [
|
|
"-device virtio-keyboard"
|
|
])
|
|
(mkIf pkgs.stdenv.hostPlatform.isx86 [
|
|
"-usb" "-device usb-tablet,bus=usb-bus.0"
|
|
])
|
|
(mkIf pkgs.stdenv.hostPlatform.isAarch [
|
|
"-device virtio-gpu-pci" "-device usb-ehci,id=usb0" "-device usb-kbd" "-device usb-tablet"
|
|
])
|
|
(let
|
|
alphaNumericChars = lowerChars ++ upperChars ++ (map toString (range 0 9));
|
|
# Replace all non-alphanumeric characters with underscores
|
|
sanitizeShellIdent = s: concatMapStrings (c: if builtins.elem c alphaNumericChars then c else "_") (stringToCharacters s);
|
|
in mkIf (!cfg.useBootLoader) [
|
|
"-kernel \${NIXPKGS_QEMU_KERNEL_${sanitizeShellIdent config.system.name}:-${config.system.build.toplevel}/kernel}"
|
|
"-initrd ${config.system.build.toplevel}/initrd"
|
|
''-append "$(cat ${config.system.build.toplevel}/kernel-params) init=${config.system.build.toplevel}/init regInfo=${regInfo}/registration ${consoles} $QEMU_KERNEL_PARAMS"''
|
|
])
|
|
(mkIf cfg.useEFIBoot [
|
|
"-drive if=pflash,format=raw,unit=0,readonly=on,file=${cfg.efi.firmware}"
|
|
"-drive if=pflash,format=raw,unit=1,file=$NIX_EFI_VARS"
|
|
])
|
|
(mkIf (cfg.bios != null) [
|
|
"-bios ${cfg.bios}/bios.bin"
|
|
])
|
|
(mkIf (!cfg.graphics) [
|
|
"-nographic"
|
|
])
|
|
];
|
|
|
|
virtualisation.qemu.drives = mkMerge [
|
|
[{
|
|
name = "root";
|
|
file = ''"$NIX_DISK_IMAGE"'';
|
|
driveExtraOpts.cache = "writeback";
|
|
driveExtraOpts.werror = "report";
|
|
}]
|
|
(mkIf cfg.useNixStoreImage [{
|
|
name = "nix-store";
|
|
file = ''"$TMPDIR"/store.img'';
|
|
deviceExtraOpts.bootindex = if cfg.useBootLoader then "3" else "2";
|
|
driveExtraOpts.format = if cfg.writableStore then "qcow2" else "raw";
|
|
}])
|
|
(mkIf cfg.useBootLoader [
|
|
# The order of this list determines the device names, see
|
|
# note [Disk layout with `useBootLoader`].
|
|
{
|
|
name = "boot";
|
|
file = ''"$TMPDIR"/disk.img'';
|
|
driveExtraOpts.media = "disk";
|
|
deviceExtraOpts.bootindex = "1";
|
|
}
|
|
])
|
|
(imap0 (idx: _: {
|
|
file = "$(pwd)/empty${toString idx}.qcow2";
|
|
driveExtraOpts.werror = "report";
|
|
}) cfg.emptyDiskImages)
|
|
];
|
|
|
|
# Mount the host filesystem via 9P, and bind-mount the Nix store
|
|
# of the host into our own filesystem. We use mkVMOverride to
|
|
# allow this module to be applied to "normal" NixOS system
|
|
# configuration, where the regular value for the `fileSystems'
|
|
# attribute should be disregarded for the purpose of building a VM
|
|
# test image (since those filesystems don't exist in the VM).
|
|
fileSystems =
|
|
let
|
|
mkSharedDir = tag: share:
|
|
{
|
|
name =
|
|
if tag == "nix-store" && cfg.writableStore
|
|
then "/nix/.ro-store"
|
|
else share.target;
|
|
value.device = tag;
|
|
value.fsType = "9p";
|
|
value.neededForBoot = true;
|
|
value.options =
|
|
[ "trans=virtio" "version=9p2000.L" "msize=${toString cfg.msize}" ]
|
|
++ lib.optional (tag == "nix-store") "cache=loose";
|
|
};
|
|
in
|
|
mkVMOverride (cfg.fileSystems //
|
|
optionalAttrs cfg.useDefaultFilesystems {
|
|
"/".device = cfg.bootDevice;
|
|
"/".fsType = "ext4";
|
|
"/".autoFormat = true;
|
|
} //
|
|
optionalAttrs config.boot.tmpOnTmpfs {
|
|
"/tmp" = {
|
|
device = "tmpfs";
|
|
fsType = "tmpfs";
|
|
neededForBoot = true;
|
|
# Sync with systemd's tmp.mount;
|
|
options = [ "mode=1777" "strictatime" "nosuid" "nodev" "size=${toString config.boot.tmpOnTmpfsSize}" ];
|
|
};
|
|
} //
|
|
optionalAttrs cfg.useNixStoreImage {
|
|
"/nix/${if cfg.writableStore then ".ro-store" else "store"}" = {
|
|
device = "${lookupDriveDeviceName "nix-store" cfg.qemu.drives}";
|
|
neededForBoot = true;
|
|
options = [ "ro" ];
|
|
};
|
|
} //
|
|
optionalAttrs (cfg.writableStore && cfg.writableStoreUseTmpfs) {
|
|
"/nix/.rw-store" = {
|
|
fsType = "tmpfs";
|
|
options = [ "mode=0755" ];
|
|
neededForBoot = true;
|
|
};
|
|
} //
|
|
optionalAttrs cfg.useBootLoader {
|
|
# see note [Disk layout with `useBootLoader`]
|
|
"/boot" = {
|
|
device = "${lookupDriveDeviceName "boot" cfg.qemu.drives}2"; # 2 for e.g. `vdb2`, as created in `bootDisk`
|
|
fsType = "vfat";
|
|
noCheck = true; # fsck fails on a r/o filesystem
|
|
};
|
|
} // lib.mapAttrs' mkSharedDir cfg.sharedDirectories);
|
|
|
|
boot.initrd.systemd = lib.mkIf (config.boot.initrd.systemd.enable && cfg.writableStore) {
|
|
mounts = [{
|
|
where = "/sysroot/nix/store";
|
|
what = "overlay";
|
|
type = "overlay";
|
|
options = "lowerdir=/sysroot/nix/.ro-store,upperdir=/sysroot/nix/.rw-store/store,workdir=/sysroot/nix/.rw-store/work";
|
|
wantedBy = ["local-fs.target"];
|
|
before = ["local-fs.target"];
|
|
requires = ["sysroot-nix-.ro\\x2dstore.mount" "sysroot-nix-.rw\\x2dstore.mount" "rw-store.service"];
|
|
after = ["sysroot-nix-.ro\\x2dstore.mount" "sysroot-nix-.rw\\x2dstore.mount" "rw-store.service"];
|
|
unitConfig.IgnoreOnIsolate = true;
|
|
}];
|
|
services.rw-store = {
|
|
after = ["sysroot-nix-.rw\\x2dstore.mount"];
|
|
unitConfig.DefaultDependencies = false;
|
|
serviceConfig = {
|
|
Type = "oneshot";
|
|
ExecStart = "/bin/mkdir -p 0755 /sysroot/nix/.rw-store/store /sysroot/nix/.rw-store/work /sysroot/nix/store";
|
|
};
|
|
};
|
|
};
|
|
|
|
swapDevices = (if cfg.useDefaultFilesystems then mkVMOverride else mkDefault) [ ];
|
|
boot.initrd.luks.devices = (if cfg.useDefaultFilesystems then mkVMOverride else mkDefault) {};
|
|
|
|
# Don't run ntpd in the guest. It should get the correct time from KVM.
|
|
services.timesyncd.enable = false;
|
|
|
|
services.qemuGuest.enable = cfg.qemu.guestAgent.enable;
|
|
|
|
system.build.vm = cfg.host.pkgs.runCommand "nixos-vm" {
|
|
preferLocalBuild = true;
|
|
meta.mainProgram = "run-${config.system.name}-vm";
|
|
}
|
|
''
|
|
mkdir -p $out/bin
|
|
ln -s ${config.system.build.toplevel} $out/system
|
|
ln -s ${cfg.host.pkgs.writeScript "run-nixos-vm" startVM} $out/bin/run-${config.system.name}-vm
|
|
'';
|
|
|
|
# When building a regular system configuration, override whatever
|
|
# video driver the host uses.
|
|
services.xserver.videoDrivers = mkVMOverride [ "modesetting" ];
|
|
services.xserver.defaultDepth = mkVMOverride 0;
|
|
services.xserver.resolutions = mkVMOverride [ cfg.resolution ];
|
|
services.xserver.monitorSection =
|
|
''
|
|
# Set a higher refresh rate so that resolutions > 800x600 work.
|
|
HorizSync 30-140
|
|
VertRefresh 50-160
|
|
'';
|
|
|
|
# Wireless won't work in the VM.
|
|
networking.wireless.enable = mkVMOverride false;
|
|
services.connman.enable = mkVMOverride false;
|
|
|
|
# Speed up booting by not waiting for ARP.
|
|
networking.dhcpcd.extraConfig = "noarp";
|
|
|
|
networking.usePredictableInterfaceNames = false;
|
|
|
|
system.requiredKernelConfig = with config.lib.kernelConfig;
|
|
[ (isEnabled "VIRTIO_BLK")
|
|
(isEnabled "VIRTIO_PCI")
|
|
(isEnabled "VIRTIO_NET")
|
|
(isEnabled "EXT4_FS")
|
|
(isEnabled "NET_9P_VIRTIO")
|
|
(isEnabled "9P_FS")
|
|
(isYes "BLK_DEV")
|
|
(isYes "PCI")
|
|
(isYes "NETDEVICES")
|
|
(isYes "NET_CORE")
|
|
(isYes "INET")
|
|
(isYes "NETWORK_FILESYSTEMS")
|
|
] ++ optionals (!cfg.graphics) [
|
|
(isYes "SERIAL_8250_CONSOLE")
|
|
(isYes "SERIAL_8250")
|
|
] ++ optionals (cfg.writableStore) [
|
|
(isEnabled "OVERLAY_FS")
|
|
];
|
|
|
|
};
|
|
|
|
# uses types of services/x11/xserver.nix
|
|
meta.buildDocsInSandbox = false;
|
|
}
|