Don't represent vm status via cpu type

hosts/vbox_nix/default.nix

@@ -24,7 +24,8 @@
       username = "itsdrike";
     };
     device = {
-      cpu.type = "vm-amd";
+      virtual-machine = true;
+      cpu.type = "amd";
     };
   };
 }

options/device/hardware.nix

@@ -3,14 +3,21 @@ in
 {
   options.myOptions.device = {
     cpu.type = mkOption {
-      type = with types; nullOr (enum [ "intel" "vm-intel" "amd" "vm-amd" ]);
+      type = with types; nullOr (enum [ "intel" "amd" ]);
       default = null;
       description = ''
         The manifaturer/type of the primary system CPU.
 
         Determines which ucode services will be enabled and provides additional kernel packages.
-        If running in a virtual machine with forwarded/shared cores, use the `vm-` prefix.
+        If running in a virtual machine with forwarded/shared cores (CPU passthrough), use the
+        cpu type of the host machine.
       '';
     };
+
+    virtual-machine = mkOption {
+      type = lib.types.bool;
+      default = false;
+      description = "Is this system a virtual machine?";
+    };
   };
 }

system/hardware/cpu/amd.nix

@@ -3,7 +3,7 @@ let
   dev = config.myOptions.device;
 in
 {
-  config = lib.mkIf (builtins.elem dev.cpu.type [ "amd" "vm-amd" ]) {
+  config = lib.mkIf (dev.cpu.type == "amd") {
     hardware.cpu.amd.updateMicrocode = true;
   };
 }

system/hardware/cpu/intel.nix

@@ -3,7 +3,7 @@ let
   dev = config.myOptions.device;
 in
 {
-  config = lib.mkIf (builtins.elem dev.cpu.type [ "intel" "vm-intel" ]) {
+  config = lib.mkIf (dev.cpu.type == "intel") {
     hardware.cpu.intel.updateMicrocode = true;
   };
 }