From 07880405bb6be41717fa9e646bb045f9cd404771 Mon Sep 17 00:00:00 2001
From: ooonea <35407790+ooonea@users.noreply.github.com>
Date: Thu, 15 Oct 2026 22:08:05 +0200
Subject: [PATCH] nixos/nvidia: use nvidia-modprobe to create device nodes

Use the native helper to handle existing nodes and driver device-file parameters, including stale UVM major numbers. Create the reverse-link directory before the module add handlers, keep GPU minor enumeration, and do not recreate nodes on remove events. Backport the independently prepared helper fix for concurrent device creation.

Assisted-by: OpenAI Codex (gpt-6.1-sol)
---
 nixos/modules/hardware/video/nvidia.nix     | 12 ++++++------
 pkgs/by-name/nv/nvidia-modprobe/package.nix |  8 ++++++++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/nixos/modules/hardware/video/nvidia.nix b/nixos/modules/hardware/video/nvidia.nix
index 91424fbb643d..77461de17ca5 100644
--- a/nixos/modules/hardware/video/nvidia.nix
+++ b/nixos/modules/hardware/video/nvidia.nix
@@ -456,12 +456,12 @@ in
             "L+ /run/nvidia-docker/bin - - - - ${nvidia_x11.bin}/origBin"
           ];
           services.udev.extraRules = ''
-            # Create /dev/nvidia-uvm when the nvidia-uvm module is loaded.
-            KERNEL=="nvidia", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidiactl c 195 255'"
-            KERNEL=="nvidia", RUN+="${pkgs.runtimeShell} -c 'for i in $$(cat /proc/driver/nvidia/gpus/*/information | grep Minor | cut -d \  -f 4); do mknod -m 666 /dev/nvidia$${i} c 195 $${i}; done'"
-            KERNEL=="nvidia_modeset", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-modeset c 195 254'"
-            KERNEL=="nvidia_uvm", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-uvm c $$(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 $$(grep nvidia-uvm /proc/devices | cut -d \  -f 1) 1'"
+            # nvidia-modprobe honors the driver's device-file parameters.
+            ACTION=="add", SUBSYSTEM=="module", KERNEL=="nvidia|nvidia_modeset|nvidia_uvm", RUN+="${pkgs.coreutils}/bin/mkdir -m 755 -p /dev/char"
+            ACTION=="add", SUBSYSTEM=="module", KERNEL=="nvidia", RUN+="${pkgs.nvidia-modprobe}/bin/nvidia-modprobe -c 255"
+            ACTION=="add", SUBSYSTEM=="module", KERNEL=="nvidia", RUN+="${pkgs.runtimeShell} -c 'for i in $$(cat /proc/driver/nvidia/gpus/*/information | grep Minor | cut -d \  -f 4); do ${pkgs.nvidia-modprobe}/bin/nvidia-modprobe -c $${i} || exit; done'"
+            ACTION=="add", SUBSYSTEM=="module", KERNEL=="nvidia_modeset", RUN+="${pkgs.nvidia-modprobe}/bin/nvidia-modprobe -m"
+            ACTION=="add", SUBSYSTEM=="module", KERNEL=="nvidia_uvm", RUN+="${pkgs.nvidia-modprobe}/bin/nvidia-modprobe -u -c 0"
           '';
           hardware.graphics =
             let
diff --git a/pkgs/by-name/nv/nvidia-modprobe/package.nix b/pkgs/by-name/nv/nvidia-modprobe/package.nix
index b1c9c7f9c0d9..84ed230b36c1 100644
--- a/pkgs/by-name/nv/nvidia-modprobe/package.nix
+++ b/pkgs/by-name/nv/nvidia-modprobe/package.nix
@@ -2,6 +2,7 @@
   stdenv,
   lib,
   fetchFromGitHub,
+  fetchpatch,
   gnum4,
 }:
 stdenv.mkDerivation (finalAttrs: {
@@ -15,6 +16,13 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-XVWvnUZkEqEh3UjPIU6DaZuYU9DvjfIMsWbLJ78jJWs=";
   };
 
+  patches = [
+    (fetchpatch {
+      url = "https://github.com/ooonea/nvidia-modprobe/commit/450f0c15ad9229fe5f4d3f80ae4d95e42d9c038e.patch";
+      hash = "sha256-SKJqt2MJDQxzRnfGcgB9oJHyt6Rwrm4hLh9zgIPEv/0=";
+    })
+  ];
+
   nativeBuildInputs = [ gnum4 ];
 
   postPatch = ''