a driver issue maybe

hosts/mpl/disk-config.nix

@@ -30,7 +30,6 @@
                   allowDiscards = true;
                   bypassWorkqueues = true;
                 };
-                initrdUnlock = true;
                 passwordFile = "/tmp/luks-pw";
                 content = {
                   type = "btrfs";

hosts/mpl/hardware.nix

@@ -6,6 +6,7 @@
 }: {
   imports = [
     (modulesPath + "/installer/scan/not-detected.nix")
+    (modulesPath + "/profiles/qemu-guest.nix")
   ];
 
   boot = {
@@ -15,6 +16,7 @@
     };
     kernelModules = ["kvm-amd"];
     extraModulePackages = [];
+    supportedFilesystems = ["ext4" "btrfs"];
   };
 
   hardware.enableAllFirmware = true;