nixos/waydroid: enable kernel psi interface if required

nixos/modules/virtualisation/waydroid.nix

@@ -18,7 +18,8 @@ let
     /dev/hwbinder = hidl
   '';
 
-in {
+in
+{
 
   options.virtualisation.waydroid = {
     enable = mkEnableOption "Waydroid";
@@ -36,6 +37,12 @@ in {
       (isEnabled "ASHMEM")
     ];
 
+    /* NOTE: we always enable this flag even if CONFIG_PSI_DEFAULT_DISABLED is not on
+      as reading the kernel config is not always possible and on kernels where it's
+      already on it will be no-op
+    */
+    boot.kernelParams = [ "psi=1" ];
+
     environment.etc."gbinder.d/waydroid.conf".source = waydroidGbinderConf;
 
     environment.systemPackages = with pkgs; [ waydroid ];