From b04d39b01c8c84cb435de125f2fecf8952646bbc Mon Sep 17 00:00:00 2001
From: June Stepp <git@junestepp.me>
Date: Fri, 19 Sep 2025 15:15:55 -0500
Subject: [PATCH] nixos/virtualbox-host: fix for kernels >= 6.12

A change in Linux 6.12 broke VirtualBox without an added kernel
parameter. VirtualBox version 7.2.2 has a fix, but it only works
for kernels >= 6.16.
---
 nixos/modules/virtualisation/virtualbox-host.nix | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/nixos/modules/virtualisation/virtualbox-host.nix b/nixos/modules/virtualisation/virtualbox-host.nix
index d5b2949b762f..56ba741dc2e4 100644
--- a/nixos/modules/virtualisation/virtualbox-host.nix
+++ b/nixos/modules/virtualisation/virtualbox-host.nix
@@ -164,6 +164,16 @@ in
           "vboxnetflt"
         ];
         boot.extraModulePackages = [ kernelModules ];
+        # See https://github.com/VirtualBox/virtualbox/issues/188
+        boot.kernelParams =
+          lib.mkIf
+            (
+              lib.versionAtLeast config.boot.kernelPackages.kernel.version "6.12"
+              && lib.versionOlder config.boot.kernelPackages.kernel.version "6.16"
+            )
+            [
+              "kvm.enable_virt_at_load=0"
+            ];
 
         services.udev.extraRules = ''
           KERNEL=="vboxdrv",    OWNER="root", GROUP="vboxusers", MODE="0660", TAG+="systemd"