libvirt: expose libvirt qemu configuration file

fixes #22823

1 files changed, 18 insertions, 0 deletions

diff --git a/nixos/modules/virtualisation/libvirtd.nix b/nixos/modules/virtualisation/libvirtd.nix
index 5f669dee7545..101ea9a4f51b 100644
--- a/nixos/modules/virtualisation/libvirtd.nix
+++ b/nixos/modules/virtualisation/libvirtd.nix
@@ -13,6 +13,9 @@ let
     auth_unix_rw = "none"
     ${cfg.extraConfig}
   '';
+  qemuConfigFile = pkgs.writeText "qemu.conf" ''
+    ${cfg.qemuVerbatimConfig}
+  '';
 
 in {
 
@@ -48,6 +51,18 @@ in {
       '';
     };
 
+    virtualisation.libvirtd.qemuVerbatimConfig = mkOption {
+      type = types.lines;
+      default = ''
+        namespaces = []
+      '';
+      description = ''
+        Contents written to the qemu configuration file, qemu.conf.
+        Make sure to include a proper namespace configuration when
+        supplying custom configuration.
+      '';
+    };
+
     virtualisation.libvirtd.extraOptions = mkOption {
       type = types.listOf types.str;
       default = [ ];
@@ -119,6 +134,9 @@ in {
             cp -npd ${pkgs.libvirt}/var/lib/$i /var/lib/$i
         done
 
+        # Copy generated qemu config to libvirt directory
+        cp -f ${qemuConfigFile} /var/lib/libvirt/qemu.conf
+
         # libvirtd puts the full path of the emulator binary in the machine
         # config file. But this path can unfortunately be garbage collected
         # while still being used by the virtual machine. So update the