QEMU: Difference between revisions
→Setup: : Cleanup odd wording and add the Evaluate template. |
→Emulate different architecture: Adjusted the build to not rely on reaily set up binfmt/remote builders anymore. Fixed some other problems I had during experiments. Still I was unable to actually see the started VM in virt-man or similar or connect to it, additional info needed! |
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[https://www.qemu.org/ QEMU] is a generic and open source machine emulator and virtualizer. | [https://www.qemu.org/ QEMU] is a generic and open source machine emulator and virtualizer. | ||
For running virtual machines as a services see [[Libvirt]]. | |||
== Setup == | == Setup == | ||
| Line 23: | Line 25: | ||
== Configuration == | == Configuration == | ||
=== | === UEFI firmware support === | ||
To | To enable UEFI firmware support in Virt-Manager, Libvirt, Gnome-Boxes etc. add following snippet to your system configuration and apply it<syntaxhighlight lang="nix"> | ||
systemd.tmpfiles.rules = [ "L+ /var/lib/qemu/firmware - - - - ${pkgs.qemu}/share/qemu/firmware" ]; | |||
<syntaxhighlight lang=nix> | |||
</syntaxhighlight> | </syntaxhighlight> | ||
=== Run binaries of different architecture === | === Run binaries of different architecture === | ||
| Line 65: | Line 53: | ||
outputs = { self, nixpkgs }: | outputs = { self, nixpkgs }: | ||
let | let | ||
# Put your actual system of your machine here. In VM terms it is the "HOST" | |||
buildPlatform = "x86_64-linux"; | |||
# Put the system you want to emulate here. In VM terms it is the "GUEST" | |||
hostPlatform = "aarch64-linux"; | |||
pkgs = import nixpkgs { system = buildPlatform; }; | |||
vmConfig = (pkgs.nixos { | |||
imports = [ "${nixpkgs}/nixos/modules/installer/cd-dvd/installation-cd-base.nix" ]; | imports = [ "${nixpkgs}/nixos/modules/installer/cd-dvd/installation-cd-base.nix" ]; | ||
}).config.system.build.isoImage; | nixpkgs = { inherit buildPlatform hostPlatform; }; | ||
}); | |||
vmIso = vmConfig.config.system.build.isoImage; | |||
vmPkgs = vmConfig.pkgs; | |||
vmScript = pkgs. | vmScript = pkgs.writeShellScriptBin "run-nixos-vm" '' | ||
${pkgs.qemu}/bin/qemu-system-aarch64 \ | ${pkgs.qemu}/bin/qemu-system-aarch64 \ | ||
-machine virt,gic-version=max \ | -machine virt,gic-version=max \ | ||
| Line 79: | Line 74: | ||
-m 2G \ | -m 2G \ | ||
-smp 4 \ | -smp 4 \ | ||
-drive file=$(echo ${ | -drive file=$(echo ${vmIso}/iso/*.iso),format=raw,readonly=on \ | ||
-nographic \ | -nographic \ | ||
-bios ${ | -bios ${vmPkgs.OVMF.fd}/FV/OVMF.fd | ||
''; | ''; | ||
in { | in { | ||
packages.x86_64-linux.default = vmScript; | |||
}; | }; | ||
} | } | ||
</syntaxhighlight>Alternatively a different iso file can be specified in the drive-parameter, for example for Ubuntu Server ARM64. | |||
</syntaxhighlight> | |||
Alternatively a different iso file can be specified in the drive-parameter, for example for Ubuntu Server ARM64. | |||
Make sure to adjust the 2 toplevel variables to set up the cross compilation correctly. If your target is not AARCH64, you have to use the correct qemu binay in the start script. | |||
[[Category:Virtualization]] | [[Category:Virtualization]] | ||
Latest revision as of 12:29, 28 January 2026
QEMU is a generic and open source machine emulator and virtualizer.
For running virtual machines as a services see Libvirt.
Setup
To install the main QEMU program system-wide, add the following to your configuration.nix:
environment = {
systemPackages = [ pkgs.qemu ];
};
🟆︎
Tip: In order to affect your NixOS system by your nix-language-specific changes you must first evaluate it:
$ nixos-rebuild switch --sudo
Quick EMU
Quickly create and run highly optimised desktop virtual machines for Linux, macOS and Windows; with just two commands.
https://github.com/quickemu-project/quickemu
quickget windows 11
quickemu --vm windows-11.conf
Configuration
UEFI firmware support
To enable UEFI firmware support in Virt-Manager, Libvirt, Gnome-Boxes etc. add following snippet to your system configuration and apply it
systemd.tmpfiles.rules = [ "L+ /var/lib/qemu/firmware - - - - ${pkgs.qemu}/share/qemu/firmware" ];
Run binaries of different architecture
Following configuration will enable the emulation of different architectures. For example to run aarch64 and riscv64 binaries on an native x86_64 host, add following part to your system configuration, apply it and reboot your system.
boot.binfmt.emulatedSystems = [
"aarch64-linux"
"riscv64-linux"
];
Tips and tricks
Emulate different architecture
The following Flake file constructs and executes a NixOS virtual machine with an architecture distinct from that of the host system; in this example, it utilizes aarch64.
Save the snippet as flake.nix and run nix run in the same directory to bootup the VM.
{
description = "Nix flake to build and run a NixOS VM for aarch64";
inputs = {
nixpkgs.url = "nixpkgs/nixos-24.05";
};
outputs = { self, nixpkgs }:
let
# Put your actual system of your machine here. In VM terms it is the "HOST"
buildPlatform = "x86_64-linux";
# Put the system you want to emulate here. In VM terms it is the "GUEST"
hostPlatform = "aarch64-linux";
pkgs = import nixpkgs { system = buildPlatform; };
vmConfig = (pkgs.nixos {
imports = [ "${nixpkgs}/nixos/modules/installer/cd-dvd/installation-cd-base.nix" ];
nixpkgs = { inherit buildPlatform hostPlatform; };
});
vmIso = vmConfig.config.system.build.isoImage;
vmPkgs = vmConfig.pkgs;
vmScript = pkgs.writeShellScriptBin "run-nixos-vm" ''
${pkgs.qemu}/bin/qemu-system-aarch64 \
-machine virt,gic-version=max \
-cpu max \
-m 2G \
-smp 4 \
-drive file=$(echo ${vmIso}/iso/*.iso),format=raw,readonly=on \
-nographic \
-bios ${vmPkgs.OVMF.fd}/FV/OVMF.fd
'';
in {
packages.x86_64-linux.default = vmScript;
};
}
Alternatively a different iso file can be specified in the drive-parameter, for example for Ubuntu Server ARM64.
Make sure to adjust the 2 toplevel variables to set up the cross compilation correctly. If your target is not AARCH64, you have to use the correct qemu binay in the start script.