diff options
Diffstat (limited to 'nixpkgs/nixos/modules/virtualisation/libvirtd.nix')
| -rw-r--r-- | nixpkgs/nixos/modules/virtualisation/libvirtd.nix | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/virtualisation/libvirtd.nix b/nixpkgs/nixos/modules/virtualisation/libvirtd.nix new file mode 100644 index 00000000000..52d852894ce --- /dev/null +++ b/nixpkgs/nixos/modules/virtualisation/libvirtd.nix @@ -0,0 +1,270 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + + cfg = config.virtualisation.libvirtd; + vswitch = config.virtualisation.vswitch; + configFile = pkgs.writeText "libvirtd.conf" '' + unix_sock_group = "libvirtd" + unix_sock_rw_perms = "0770" + auth_unix_ro = "none" + auth_unix_rw = "none" + ${cfg.extraConfig} + ''; + qemuConfigFile = pkgs.writeText "qemu.conf" '' + ${optionalString cfg.qemuOvmf '' + nvram = ["/run/libvirt/nix-ovmf/OVMF_CODE.fd:/run/libvirt/nix-ovmf/OVMF_VARS.fd"] + ''} + ${optionalString (!cfg.qemuRunAsRoot) '' + user = "qemu-libvirtd" + group = "qemu-libvirtd" + ''} + ${cfg.qemuVerbatimConfig} + ''; + dirName = "libvirt"; + subDirs = list: [ dirName ] ++ map (e: "${dirName}/${e}") list; + +in { + + imports = [ + (mkRemovedOptionModule [ "virtualisation" "libvirtd" "enableKVM" ] + "Set the option `virtualisation.libvirtd.qemuPackage' instead.") + ]; + + ###### interface + + options.virtualisation.libvirtd = { + + enable = mkOption { + type = types.bool; + default = false; + description = '' + This option enables libvirtd, a daemon that manages + virtual machines. Users in the "libvirtd" group can interact with + the daemon (e.g. to start or stop VMs) using the + <command>virsh</command> command line tool, among others. + ''; + }; + + qemuPackage = mkOption { + type = types.package; + default = pkgs.qemu; + description = '' + Qemu package to use with libvirt. + `pkgs.qemu` can emulate alien architectures (e.g. aarch64 on x86) + `pkgs.qemu_kvm` saves disk space allowing to emulate only host architectures. + ''; + }; + + extraConfig = mkOption { + type = types.lines; + default = ""; + description = '' + Extra contents appended to the libvirtd configuration file, + libvirtd.conf. + ''; + }; + + qemuRunAsRoot = mkOption { + type = types.bool; + default = true; + description = '' + If true, libvirtd runs qemu as root. + If false, libvirtd runs qemu as unprivileged user qemu-libvirtd. + Changing this option to false may cause file permission issues + for existing guests. To fix these, manually change ownership + of affected files in /var/lib/libvirt/qemu to qemu-libvirtd. + ''; + }; + + qemuVerbatimConfig = mkOption { + type = types.lines; + default = '' + namespaces = [] + ''; + description = '' + Contents written to the qemu configuration file, qemu.conf. + Make sure to include a proper namespace configuration when + supplying custom configuration. + ''; + }; + + qemuOvmf = mkOption { + type = types.bool; + default = true; + description = '' + Allows libvirtd to take advantage of OVMF when creating new + QEMU VMs with UEFI boot. + ''; + }; + + extraOptions = mkOption { + type = types.listOf types.str; + default = [ ]; + example = [ "--verbose" ]; + description = '' + Extra command line arguments passed to libvirtd on startup. + ''; + }; + + onBoot = mkOption { + type = types.enum ["start" "ignore" ]; + default = "start"; + description = '' + Specifies the action to be done to / on the guests when the host boots. + The "start" option starts all guests that were running prior to shutdown + regardless of their autostart settings. The "ignore" option will not + start the formally running guest on boot. However, any guest marked as + autostart will still be automatically started by libvirtd. + ''; + }; + + onShutdown = mkOption { + type = types.enum ["shutdown" "suspend" ]; + default = "suspend"; + description = '' + When shutting down / restarting the host what method should + be used to gracefully halt the guests. Setting to "shutdown" + will cause an ACPI shutdown of each guest. "suspend" will + attempt to save the state of the guests ready to restore on boot. + ''; + }; + + allowedBridges = mkOption { + type = types.listOf types.str; + default = [ "virbr0" ]; + description = '' + List of bridge devices that can be used by qemu:///session + ''; + }; + + }; + + + ###### implementation + + config = mkIf cfg.enable { + + environment = { + # this file is expected in /etc/qemu and not sysconfdir (/var/lib) + etc."qemu/bridge.conf".text = lib.concatMapStringsSep "\n" (e: + "allow ${e}") cfg.allowedBridges; + systemPackages = with pkgs; [ libvirt libressl.nc iptables cfg.qemuPackage ]; + etc.ethertypes.source = "${pkgs.iptables}/etc/ethertypes"; + }; + + boot.kernelModules = [ "tun" ]; + + users.groups.libvirtd.gid = config.ids.gids.libvirtd; + + # libvirtd runs qemu as this user and group by default + users.extraGroups.qemu-libvirtd.gid = config.ids.gids.qemu-libvirtd; + users.extraUsers.qemu-libvirtd = { + uid = config.ids.uids.qemu-libvirtd; + isNormalUser = false; + group = "qemu-libvirtd"; + }; + + security.wrappers.qemu-bridge-helper = { + source = "/run/${dirName}/nix-helpers/qemu-bridge-helper"; + }; + + systemd.packages = [ pkgs.libvirt ]; + + systemd.services.libvirtd-config = { + description = "Libvirt Virtual Machine Management Daemon - configuration"; + script = '' + # Copy default libvirt network config .xml files to /var/lib + # Files modified by the user will not be overwritten + for i in $(cd ${pkgs.libvirt}/var/lib && echo \ + libvirt/qemu/networks/*.xml libvirt/qemu/networks/autostart/*.xml \ + libvirt/nwfilter/*.xml ); + do + mkdir -p /var/lib/$(dirname $i) -m 755 + cp -npd ${pkgs.libvirt}/var/lib/$i /var/lib/$i + done + + # Copy generated qemu config to libvirt directory + cp -f ${qemuConfigFile} /var/lib/${dirName}/qemu.conf + + # stable (not GC'able as in /nix/store) paths for using in <emulator> section of xml configs + for emulator in ${pkgs.libvirt}/libexec/libvirt_lxc ${cfg.qemuPackage}/bin/qemu-kvm ${cfg.qemuPackage}/bin/qemu-system-*; do + ln -s --force "$emulator" /run/${dirName}/nix-emulators/ + done + + for helper in libexec/qemu-bridge-helper bin/qemu-pr-helper; do + ln -s --force ${cfg.qemuPackage}/$helper /run/${dirName}/nix-helpers/ + done + + ${optionalString cfg.qemuOvmf '' + ln -s --force ${pkgs.OVMF.fd}/FV/OVMF_CODE.fd /run/${dirName}/nix-ovmf/ + ln -s --force ${pkgs.OVMF.fd}/FV/OVMF_VARS.fd /run/${dirName}/nix-ovmf/ + ''} + ''; + + serviceConfig = { + Type = "oneshot"; + RuntimeDirectoryPreserve = "yes"; + LogsDirectory = subDirs [ "qemu" ]; + RuntimeDirectory = subDirs [ "nix-emulators" "nix-helpers" "nix-ovmf" ]; + StateDirectory = subDirs [ "dnsmasq" ]; + }; + }; + + systemd.services.libvirtd = { + description = "Libvirt Virtual Machine Management Daemon"; + + wantedBy = [ "multi-user.target" ]; + requires = [ "libvirtd-config.service" ]; + after = [ "systemd-udev-settle.service" "libvirtd-config.service" ] + ++ optional vswitch.enable "vswitchd.service"; + + environment.LIBVIRTD_ARGS = ''--config "${configFile}" ${concatStringsSep " " cfg.extraOptions}''; + + path = [ cfg.qemuPackage ] # libvirtd requires qemu-img to manage disk images + ++ optional vswitch.enable vswitch.package; + + serviceConfig = { + Type = "notify"; + KillMode = "process"; # when stopping, leave the VMs alone + Restart = "no"; + }; + restartIfChanged = false; + }; + + systemd.services.libvirt-guests = { + wantedBy = [ "multi-user.target" ]; + path = with pkgs; [ coreutils libvirt gawk ]; + restartIfChanged = false; + + environment.ON_BOOT = "${cfg.onBoot}"; + environment.ON_SHUTDOWN = "${cfg.onShutdown}"; + }; + + systemd.sockets.virtlogd = { + description = "Virtual machine log manager socket"; + wantedBy = [ "sockets.target" ]; + listenStreams = [ "/run/${dirName}/virtlogd-sock" ]; + }; + + systemd.services.virtlogd = { + description = "Virtual machine log manager"; + serviceConfig.ExecStart = "@${pkgs.libvirt}/sbin/virtlogd virtlogd"; + restartIfChanged = false; + }; + + systemd.sockets.virtlockd = { + description = "Virtual machine lock manager socket"; + wantedBy = [ "sockets.target" ]; + listenStreams = [ "/run/${dirName}/virtlockd-sock" ]; + }; + + systemd.services.virtlockd = { + description = "Virtual machine lock manager"; + serviceConfig.ExecStart = "@${pkgs.libvirt}/sbin/virtlockd virtlockd"; + restartIfChanged = false; + }; + }; +} |