Finally switch to flakes.

nixos/services/virtualisation.nix

@@ -0,0 +1,36 @@
+{
+  config,
+  pkgs,
+  ...
+}: {
+  # Enable virtualization
+  virtualisation = {
+    libvirtd = {
+      enable = true;
+      onBoot = "ignore";
+      onShutdown = "shutdown";
+      qemu = {
+        ovmf = {
+          enable = true;
+          packages = [pkgs.OVMFFull.fd];
+        };
+        swtpm.enable = true;
+      };
+    };
+    spiceUSBRedirection.enable = true;
+  };
+
+  # Install programs system-wide
+  environment.systemPackages = with pkgs; [
+    virt-manager
+    virtiofsd
+    dnsmasq
+    spice-vdagent
+    looking-glass-client
+  ];
+
+  # Allow Looking-Glass permissions
+  systemd.tmpfiles.rules = [
+    "f /dev/shm/looking-glass 0660 jimbo libvirtd -"
+  ];
+}