phundrak
ba018ef841
Configuration is now held by the `.org` files. All `.nix` files are tangled from the org-mode files.
100 lines
2.5 KiB
Org Mode
100 lines
2.5 KiB
Org Mode
#+title: QEMU
|
||
#+setupfile: ../headers
|
||
|
||
* QEMU
|
||
On machines where I run virtual machines, I want =virt-manager=,
|
||
=libvirtd=, and a few supporting pieces set up together. Here’s the
|
||
skeleton of the =nixos.qemu= module.
|
||
#+begin_src nix :tangle yes
|
||
{
|
||
flake.modules.nixos.qemu = {
|
||
config,
|
||
lib,
|
||
pkgs,
|
||
...
|
||
}:
|
||
with lib; let
|
||
cfg = config.mySystem.dev.qemu;
|
||
in {
|
||
<<options>>
|
||
config = {
|
||
<<virt-manager>>
|
||
<<libvirtd-group>>
|
||
<<virtualisation>>
|
||
<<packages>>
|
||
<<firmware-tmpfiles>>
|
||
<<binfmt>>
|
||
};
|
||
};
|
||
}
|
||
#+end_src
|
||
|
||
** Declaring the Options
|
||
=users= lists which users get added to the =libvirtd= group, so they can
|
||
manage VMs without needing root. By default, I add myself to this
|
||
group.
|
||
#+name: options
|
||
#+begin_src nix
|
||
options.mySystem.dev.qemu.users = mkOption {
|
||
type = types.listOf types.str;
|
||
default = ["phundrak"];
|
||
example = ["user1" "user2"];
|
||
};
|
||
#+end_src
|
||
|
||
This option is then passed onto the standard NixOS option.
|
||
#+name: libvirtd-group
|
||
#+begin_src nix
|
||
users.groups.libvirtd.members = cfg.users;
|
||
#+end_src
|
||
|
||
** virt-manager
|
||
This pulls in the GUI I actually use to create and manage VMs.
|
||
#+name: virt-manager
|
||
#+begin_src nix
|
||
programs.virt-manager.enable = true;
|
||
#+end_src
|
||
|
||
** Virtualisation Backend
|
||
=libvirtd= is the daemon that actually runs and manages the VMs. SPICE
|
||
USB redirection lets me pass a USB device straight through to a guest
|
||
without unplugging it from the host first.
|
||
#+name: virtualisation
|
||
#+begin_src nix
|
||
virtualisation = {
|
||
libvirtd.enable = true;
|
||
spiceUSBRedirection.enable = true;
|
||
};
|
||
#+end_src
|
||
|
||
** Extra Packages
|
||
Besides =qemu= itself, =quickemu= lets me spin up a VM from a template in
|
||
one command, and =swtpm= provides the software TPM that guests like
|
||
Windows 11 insist on.
|
||
#+name: packages
|
||
#+begin_src nix
|
||
environment.systemPackages = with pkgs; [
|
||
qemu
|
||
quickemu
|
||
swtpm
|
||
];
|
||
#+end_src
|
||
|
||
** Firmware Lookup Path
|
||
=virt-manager= and friends expect to find UEFI firmware images under
|
||
=/var/lib/qemu/firmware=, so I symlink QEMU’s own copy there instead of
|
||
making every tool aware of the Nix store path.
|
||
#+name: firmware-tmpfiles
|
||
#+begin_src nix
|
||
systemd.tmpfiles.rules = ["L+ /var/lib/qemu/firmware - - - - ${pkgs.qemu}/share/qemu/firmware"];
|
||
#+end_src
|
||
|
||
** ARM Emulation
|
||
This lets me run (and build) =aarch64-linux= binaries transparently
|
||
through QEMU’s user-mode emulation, which comes in handy when working
|
||
on the PineTab2 without needing actual ARM hardware on hand.
|
||
#+name: binfmt
|
||
#+begin_src nix
|
||
boot.binfmt.emulatedSystems = ["aarch64-linux"];
|
||
#+end_src
|