From 25208eeaba9e009a8248d1f720d1d5cc130dd05a Mon Sep 17 00:00:00 2001
From: Alyssa Ross <hi@alyssa.is>
Date: Sun, 4 Apr 2021 14:55:56 +0000
Subject: [PATCH] linux: remove xen_dom0 feature entirely

Xen is now enabled unconditionally on kernels that support it, so the
xen_dom0 feature doesn't do anything.  The isXen attribute will now
produce a deprecation warning and unconditionally return true.
Passing in a custom value for isXen is no longer supported.
---
 nixos/modules/virtualisation/xen-dom0.nix       | 3 ---
 pkgs/os-specific/linux/kernel/generic.nix       | 5 ++---
 pkgs/os-specific/linux/kernel/manual-config.nix | 4 ++--
 pkgs/top-level/all-packages.nix                 | 2 +-
 4 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/nixos/modules/virtualisation/xen-dom0.nix b/nixos/modules/virtualisation/xen-dom0.nix
index 5b57ca860da..b649d64be3c 100644
--- a/nixos/modules/virtualisation/xen-dom0.nix
+++ b/nixos/modules/virtualisation/xen-dom0.nix
@@ -161,9 +161,6 @@ in
 
     environment.systemPackages = [ cfg.package ];
 
-    # Make sure Domain 0 gets the required configuration
-    #boot.kernelPackages = pkgs.boot.kernelPackages.override { features={xen_dom0=true;}; };
-
     boot.kernelModules =
       [ "xen-evtchn" "xen-gntdev" "xen-gntalloc" "xen-blkback" "xen-netback"
         "xen-pciback" "evtchn" "gntdev" "netbk" "blkbk" "xen-scsibk"
diff --git a/pkgs/os-specific/linux/kernel/generic.nix b/pkgs/os-specific/linux/kernel/generic.nix
index ac9d6fbb2b5..4518b5a336b 100644
--- a/pkgs/os-specific/linux/kernel/generic.nix
+++ b/pkgs/os-specific/linux/kernel/generic.nix
@@ -46,7 +46,6 @@
                        stdenv.hostPlatform != stdenv.buildPlatform
 , extraMeta ? {}
 
-, isXen      ? features.xen_dom0 or false
 , isZen      ? false
 , isLibre    ? false
 , isHardened ? false
@@ -74,7 +73,6 @@ let
     needsCifsUtils = true;
     netfilterRPFilter = true;
     grsecurity = false;
-    xen_dom0 = false;
     ia32Emulation = true;
   } // features) kernelPatches;
 
@@ -178,7 +176,8 @@ let
 
   passthru = {
     features = kernelFeatures;
-    inherit commonStructuredConfig isXen isZen isHardened isLibre;
+    inherit commonStructuredConfig isZen isHardened isLibre;
+    isXen = lib.warn "The isXen attribute is deprecated. All Nixpkgs kernels that support it now have Xen enabled." true;
     kernelOlder = lib.versionOlder version;
     kernelAtLeast = lib.versionAtLeast version;
     passthru = kernel.passthru // (removeAttrs passthru [ "passthru" ]);
diff --git a/pkgs/os-specific/linux/kernel/manual-config.nix b/pkgs/os-specific/linux/kernel/manual-config.nix
index 2fc63322f5b..e45b21ff35f 100644
--- a/pkgs/os-specific/linux/kernel/manual-config.nix
+++ b/pkgs/os-specific/linux/kernel/manual-config.nix
@@ -37,7 +37,6 @@ in {
   extraMeta ? {},
 
   # for module compatibility
-  isXen      ? features.xen_dom0 or false,
   isZen      ? false,
   isLibre    ? false,
   isHardened ? false,
@@ -94,7 +93,8 @@ let
       passthru = {
         inherit version modDirVersion config kernelPatches configfile
           moduleBuildDependencies stdenv;
-        inherit isXen isZen isHardened isLibre;
+        inherit isZen isHardened isLibre;
+        isXen = lib.warn "The isXen attribute is deprecated. All Nixpkgs kernels that support it now have Xen enabled." true;
         kernelOlder = lib.versionOlder version;
         kernelAtLeast = lib.versionAtLeast version;
       };
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 2ca19cb30c0..4fab58b566b 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -19777,7 +19777,7 @@ in
     inherit (kernel) stdenv; # in particular, use the same compiler by default
 
     # to help determine module compatibility
-    inherit (kernel) isXen isZen isHardened isLibre;
+    inherit (kernel) isZen isHardened isLibre;
     inherit (kernel) kernelOlder kernelAtLeast;
 
     # Obsolete aliases (these packages do not depend on the kernel).