NixOS · Jan 29, 2021 · Jan 29, 2021
Showing with 71 additions and 9 deletions.

+71 −9 nixos/modules/hardware/video/nvidia.nix
diff --git a/nixos/modules/hardware/video/nvidia.nix b/nixos/modules/hardware/video/nvidia.nix
@@ -63,6 +63,15 @@ in
       '';
     };
 
+    hardware.nvidia.powerManagement.finegrained = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Experimental power management of PRIME offload. For more information, see
+        the NVIDIA docs, chapter 22. PCI-Express runtime power management.
+      '';
+    };
+
     hardware.nvidia.modesetting.enable = mkOption {
       type = types.bool;
       default = false;
@@ -96,6 +105,16 @@ in
       '';
     };
 
+    hardware.nvidia.prime.amdgpuBusId = mkOption {
+      type = types.str;
+      default = "";
+      example = "PCI:4:0:0";
+      description = ''
+        Bus ID of the AMD APU. You can find it using lspci; for example if lspci
+	shows the AMD APU at "04:00.0", set this option to "PCI:4:0:0".
+      '';
+    };
+
     hardware.nvidia.prime.sync.enable = mkOption {
       type = types.bool;
       default = false;
@@ -153,15 +172,24 @@ in
     };
   };
 
-  config = mkIf enabled {
+  config = let
+      igpuDriver = if pCfg.intelBusId != "" then "modesetting" else "amdgpu";
+      igpuBusId = if pCfg.intelBusId != "" then pCfg.intelBusId else pCfg.amdgpuBusId;
+  in mkIf enabled {
     assertions = [
       {
         assertion = with config.services.xserver.displayManager; gdm.nvidiaWayland -> cfg.modesetting.enable;
         message = "You cannot use wayland with GDM without modesetting enabled for NVIDIA drivers, set `hardware.nvidia.modesetting.enable = true`";
       }
 
       {
-        assertion = primeEnabled -> pCfg.nvidiaBusId != "" && pCfg.intelBusId != "";
+        assertion = primeEnabled -> pCfg.intelBusId == "" || pCfg.amdgpuBusId == "";
+        message = ''
+          You cannot configure both an Intel iGPU and an AMD APU. Pick the one corresponding to your processor.
+        '';
+      }
+      {
+        assertion = primeEnabled -> pCfg.nvidiaBusId != "" && (pCfg.intelBusId != "" || pCfg.amdgpuBusId != "");
         message = ''
           When NVIDIA PRIME is enabled, the GPU bus IDs must configured.
         '';
@@ -174,6 +202,14 @@ in
         assertion = !(syncCfg.enable && offloadCfg.enable);
         message = "Only one NVIDIA PRIME solution may be used at a time.";
       }
+      {
+        assertion = !(syncCfg.enable && cfg.powerManagement.finegrained);
+        message = "Sync precludes powering down the NVIDIA GPU.";
+      }
+      {
+        assertion = cfg.powerManagement.enable -> offloadCfg.enable;
+        message = "Fine-grained power management requires offload to be enabled.";
+      }
     ];
 
     # If Optimus/PRIME is enabled, we:
@@ -183,18 +219,22 @@ in
     #   "nvidia" driver, in order to allow the X server to start without any outputs.
     # - Add a separate Device section for the Intel GPU, using the "modesetting"
     #   driver and with the configured BusID.
+    # - OR add a separate Device section for the AMD APU, using the "amdgpu"
+    #   driver and with the configures BusID.
     # - Reference that Device section from the ServerLayout section as an inactive
     #   device.
     # - Configure the display manager to run specific `xrandr` commands which will
-    #   configure/enable displays connected to the Intel GPU.
+    #   configure/enable displays connected to the Intel iGPU / AMD APU.
 
     services.xserver.useGlamor = mkDefault offloadCfg.enable;
 
-    services.xserver.drivers = optional primeEnabled {
-      name = "modesetting";
+    services.xserver.drivers = let
+    in optional primeEnabled {
+      name = igpuDriver;
       display = offloadCfg.enable;
+      modules = optional (igpuDriver == "amdgpu") [ pkgs.xorg.xf86videoamdgpu ];
       deviceSection = ''
-        BusID "${pCfg.intelBusId}"
+        BusID "${igpuBusId}"
         ${optionalString syncCfg.enable ''Option "AccelMethod" "none"''}
       '';
     } ++ singleton {
@@ -205,6 +245,7 @@ in
         ''
           BusID "${pCfg.nvidiaBusId}"
           ${optionalString syncCfg.allowExternalGpu "Option \"AllowExternalGpus\""}
+          ${optionalString cfg.powerManagement.finegrained "Option \"NVreg_DynamicPowerManagement=0x02\""}
         '';
       screenSection =
         ''
@@ -214,14 +255,14 @@ in
     };
 
     services.xserver.serverLayoutSection = optionalString syncCfg.enable ''
-      Inactive "Device-modesetting[0]"
+      Inactive "Device-${igpuDriver}[0]"
     '' + optionalString offloadCfg.enable ''
       Option "AllowNVIDIAGPUScreens"
     '';
 
     services.xserver.displayManager.setupCommands = optionalString syncCfg.enable ''
       # Added by nvidia configuration module for Optimus/PRIME.
-      ${pkgs.xorg.xrandr}/bin/xrandr --setprovideroutputsource modesetting NVIDIA-0
+      ${pkgs.xorg.xrandr}/bin/xrandr --setprovideroutputsource ${igpuDriver} NVIDIA-0
       ${pkgs.xorg.xrandr}/bin/xrandr --auto
     '';
 
@@ -292,16 +333,37 @@ in
     boot.kernelParams = optional (offloadCfg.enable || cfg.modesetting.enable) "nvidia-drm.modeset=1"
       ++ optional cfg.powerManagement.enable "nvidia.NVreg_PreserveVideoMemoryAllocations=1";
 
-    # Create /dev/nvidia-uvm when the nvidia-uvm module is loaded.
     services.udev.extraRules =
       ''
+        # Create /dev/nvidia-uvm when the nvidia-uvm module is loaded.
         KERNEL=="nvidia", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidiactl c $$(grep nvidia-frontend /proc/devices | cut -d \  -f 1) 255'"
         KERNEL=="nvidia_modeset", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-modeset c $$(grep nvidia-frontend /proc/devices | cut -d \  -f 1) 254'"
         KERNEL=="card*", SUBSYSTEM=="drm", DRIVERS=="nvidia", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia%n c $$(grep nvidia-frontend /proc/devices | cut -d \  -f 1) %n'"
         KERNEL=="nvidia_uvm", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-uvm c $$(grep nvidia-uvm /proc/devices | cut -d \  -f 1) 0'"
         KERNEL=="nvidia_uvm", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-uvm-tools c $$(grep nvidia-uvm /proc/devices | cut -d \  -f 1) 0'"
+      '' + optionalString cfg.powerManagement.finegrained ''
+        # Remove NVIDIA USB xHCI Host Controller devices, if present
+        ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c0330", ATTR{remove}="1"
+
+        # Remove NVIDIA USB Type-C UCSI devices, if present
+        ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c8000", ATTR{remove}="1"
+
+        # Remove NVIDIA Audio devices, if present
+        ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x040300", ATTR{remove}="1"
+
+        # Enable runtime PM for NVIDIA VGA/3D controller devices on driver bind
+        ACTION=="bind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030000", TEST=="power/control", ATTR{power/control}="auto"
+        ACTION=="bind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030200", TEST=="power/control", ATTR{power/control}="auto"
+
+        # Disable runtime PM for NVIDIA VGA/3D controller devices on driver unbind
+        ACTION=="unbind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030000", TEST=="power/control", ATTR{power/control}="on"
+        ACTION=="unbind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030200", TEST=="power/control", ATTR{power/control}="on"
       '';
 
+    boot.extraModprobeConfig = mkIf cfg.powerManagement.finegrained ''
+      options nvidia "NVreg_DynamicPowerManagement=0x02"
+    '';
+
     boot.blacklistedKernelModules = [ "nouveau" "nvidiafb" ];
 
     services.acpid.enable = true;