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