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Diffstat (limited to 'nixos/modules/virtualisation/kvmgt.nix')
-rw-r--r-- | nixos/modules/virtualisation/kvmgt.nix | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/nixos/modules/virtualisation/kvmgt.nix b/nixos/modules/virtualisation/kvmgt.nix new file mode 100644 index 00000000000..5e7a73bec90 --- /dev/null +++ b/nixos/modules/virtualisation/kvmgt.nix @@ -0,0 +1,86 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + cfg = config.virtualisation.kvmgt; + + kernelPackages = config.boot.kernelPackages; + + vgpuOptions = { + uuid = mkOption { + type = with types; listOf str; + description = "UUID(s) of VGPU device. You can generate one with <package>libossp_uuid</package>."; + }; + }; + +in { + options = { + virtualisation.kvmgt = { + enable = mkEnableOption '' + KVMGT (iGVT-g) VGPU support. Allows Qemu/KVM guests to share host's Intel integrated graphics card. + Currently only one graphical device can be shared. To allow users to access the device without root add them + to the kvm group: <literal>users.extraUsers.<yourusername>.extraGroups = [ "kvm" ];</literal> + ''; + # multi GPU support is under the question + device = mkOption { + type = types.str; + default = "0000:00:02.0"; + description = "PCI ID of graphics card. You can figure it with <command>ls /sys/class/mdev_bus</command>."; + }; + vgpus = mkOption { + default = {}; + type = with types; attrsOf (submodule [ { options = vgpuOptions; } ]); + description = '' + Virtual GPUs to be used in Qemu. You can find devices via <command>ls /sys/bus/pci/devices/*/mdev_supported_types</command> + and find info about device via <command>cat /sys/bus/pci/devices/*/mdev_supported_types/i915-GVTg_V5_4/description</command> + ''; + example = { + i915-GVTg_V5_8.uuid = [ "a297db4a-f4c2-11e6-90f6-d3b88d6c9525" ]; + }; + }; + }; + }; + + config = mkIf cfg.enable { + assertions = singleton { + assertion = versionAtLeast kernelPackages.kernel.version "4.16"; + message = "KVMGT is not properly supported for kernels older than 4.16"; + }; + + boot.kernelModules = [ "kvmgt" ]; + boot.kernelParams = [ "i915.enable_gvt=1" ]; + + services.udev.extraRules = '' + SUBSYSTEM=="vfio", OWNER="root", GROUP="kvm" + ''; + + systemd = let + vgpus = listToAttrs (flatten (mapAttrsToList + (mdev: opt: map (id: nameValuePair "kvmgt-${id}" { inherit mdev; uuid = id; }) opt.uuid) + cfg.vgpus)); + in { + paths = mapAttrs (_: opt: + { + description = "KVMGT VGPU ${opt.uuid} path"; + wantedBy = [ "multi-user.target" ]; + pathConfig = { + PathExists = "/sys/bus/pci/devices/${cfg.device}/mdev_supported_types/${opt.mdev}/create"; + }; + }) vgpus; + + services = mapAttrs (_: opt: + { + description = "KVMGT VGPU ${opt.uuid}"; + serviceConfig = { + Type = "oneshot"; + RemainAfterExit = true; + ExecStart = "${pkgs.runtimeShell} -c 'echo ${opt.uuid} > /sys/bus/pci/devices/${cfg.device}/mdev_supported_types/${opt.mdev}/create'"; + ExecStop = "${pkgs.runtimeShell} -c 'echo 1 > /sys/bus/pci/devices/${cfg.device}/${opt.uuid}/remove'"; + }; + }) vgpus; + }; + }; + + meta.maintainers = with maintainers; [ patryk27 ]; +} |