Index

`virtualisation.additionalPaths`

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.

Type: list of path

Default

[ ]

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.bios`

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.

Type: null or package

Default

null

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.bootLoaderDevice`

The path (inside th VM) to the device to boot from when legacy booting.

Type: path

Default

/dev/disk/by-id/virtio-root

Example

"/dev/disk/by-id/virtio-boot-loader-device"

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.bootPartition`

The path (inside the VM) to the device containing the EFI System Partition (ESP).

If you are not booting from a UEFI firmware, this value is, by default, null. The ESP is mounted to boot.loader.efi.efiSysMountpoint.

Type: null or path

Default

if cfg.useEFIBoot then "/dev/disk/by-label/ESP" else null

Example

"/dev/disk/by-label/esp"

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.cores`

Specify the number of cores the guest is permitted to use. The number can be higher than the available cores on the host system.

Type: positive integer, meaning >0

Default

1

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.diskImage`

Path to the disk image containing the root filesystem. The image will be created on startup if it does not exist.

If null, a tmpfs will be used as the root filesystem and the VM's state will not be persistent.

Type: null or string

Default

"./${config.system.name}.qcow2"

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.diskSize`

The disk size in megabytes of the virtual machine.

Type: null or (positive integer, meaning >0)

Default

1024

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.emptyDiskImages`

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.

Type: list of (positive integer, meaning >0)

Default

[ ]

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.fileSystems`

The file systems to be mounted. It must include an entry for the root directory (mountPoint = "/"). Each entry in the list is an attribute set with the following fields: mountPoint, device, fsType (a file system type recognised by {command}mount; defaults to "auto"), and options (the mount options passed to {command}mount using the {option}-o flag; defaults to [ "defaults" ]).

Instead of specifying device, you can also specify a volume label (label) for file systems that support it, such as ext2/ext3 (see {command}mke2fs -L).

Type: attribute set of (submodule)

Default

{ }

Example

{"/".device = "/dev/hda1";"/data" = {device = "/dev/hda2";fsType = "ext3";options = [ "data=journal" ];};"/bigdisk".label = "bigdisk";}

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.forwardPorts`

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. :::

Type: list of (submodule)

Default

[ ]

Example

`#!nix [ # forward local port 2222 -> 22, to ssh into the VM

# 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; } ] `

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.graphics`

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.

Type: boolean

Default

true

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.interfaces`

Network interfaces to add to the VM.

Type: attribute set of (submodule)

Default

{ }

Example

{enp1s0 = {vlan = 1;};}

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.memorySize`

The memory size in megabytes of the virtual machine.

Type: positive integer, meaning >0

Default

1024

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.mountHostNixStore`

Mount the host Nix store as a 9p mount.

Type: boolean

Default

!cfg.useNixStoreImage && !cfg.useBootLoader

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.msize`

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.

Type: positive integer, meaning >0

Default

16384

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.resolution`

The resolution of the virtual machine display.

Type: attribute set

Default

{x = 1024;y = 768;}

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.restrictNetwork`

If this option is enabled, the guest will be isolated, i.e. it will not be able to contact the host and no guest IP packets will be routed over the host to the outside. This option does not affect any explicitly set forwarding rules.

Type: boolean

Default

false

Example

true

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.rootDevice`

The path (inside the VM) to the device containing the root filesystem.

Type: null or path

Default

/dev/disk/by-label/nixos

Example

"/dev/disk/by-label/nixos"

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.sharedDirectories`

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.

Type: attribute set of (submodule)

Default

{ }

Example

{my-share = {source = "/path/to/be/shared";target = "/mnt/shared";};}

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.useBootLoader`

Use a boot loader to boot the system. This allows, among other things, testing the boot loader.

If disabled, the kernel and initrd are directly booted, forgoing any bootloader.

Check the documentation on {option}virtualisation.directBoot.enable for details.

Type: boolean

Default

false

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.useDefaultFilesystems`

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).

Type: boolean

Default

true

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.useEFIBoot`

If enabled, the virtual machine will provide a EFI boot manager. useEFIBoot is ignored if useBootLoader == false.

Type: boolean

Default

false

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.useHostCerts`

If enabled, when NIX_SSL_CERT_FILE is set on the host, pass the CA certificates from the host to the VM.

Type: boolean

Default

false

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.useNixStoreImage`

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.

The Nix store image is built just-in-time right before the VM is started. Because it does not produce another derivation, the image is not cached between invocations and never lands in the store or binary cache.

If you want a full disk image with a partition table and a root filesystem instead of only a store image, enable {option}virtualisation.useBootLoader instead.

Type: boolean

Default

false

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.useSecureBoot`

Enable Secure Boot support in the EFI firmware.

Type: boolean

Default

false

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.vlans`

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.

Type: list of (unsigned integer, meaning >=0)

Default

if config.virtualisation.interfaces == {} then [ 1 ] else [ ]

Example

[12]

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.vmVariant`

Machine configuration to be added for the vm script produced by nixos-rebuild build-vm.

Type: submodule

Default

{ }

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/build-vm.nix

`virtualisation.vmVariantWithBootLoader`

Machine configuration to be added for the vm script produced by nixos-rebuild build-vm-with-bootloader.

Type: submodule

Default

{ }

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/build-vm.nix

`virtualisation.writableStore`

If enabled, the Nix store in the VM is made writable by layering an overlay filesystem on top of the host's Nix store.

By default, this is enabled if you mount a host Nix store.

Type: boolean

Default

cfg.mountHostNixStore

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix

`virtualisation.writableStoreUseTmpfs`

Use a tmpfs for the writable store instead of writing to the VM's own filesystem.

Type: boolean

Default

true

Declared by: https://github.com/nixos/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix