nixos/lib/qemu-flags: rename to qemu-common

The current name is misleading: it doesn't contain cli arguments,
but several constants and utility functions related to qemu.
This commit also removes the use of `with import ...` for clarity.

nixos/lib/build-vms.nix

@@ -4,15 +4,14 @@
 , # Ignored
   config ? null
 , # Nixpkgs, for qemu, lib and more
-  pkgs
+  pkgs, lib
 , # !!! See comment about args in lib/modules.nix
   specialArgs ? {}
 , # NixOS configuration to add to the VMs
   extraConfigurations ? []
 }:
 
-with pkgs.lib;
-with import ../lib/qemu-flags.nix { inherit pkgs; };
+with lib;
 
 rec {
 
@@ -93,8 +92,9 @@ rec {
                          "${config.networking.hostName}\n"));
 
                   virtualisation.qemu.options =
-                    flip concatMap interfacesNumbered
-                      ({ fst, snd }: qemuNICFlags snd fst m.snd);
+                    let qemu-common = import ../lib/qemu-common.nix { inherit lib pkgs; };
+                    in flip concatMap interfacesNumbered
+                      ({ fst, snd }: qemu-common.qemuNICFlags snd fst m.snd);
                 };
             }
           )

nixos/lib/qemu-common.nix

@@ -1,12 +1,12 @@
-# QEMU flags shared between various Nix expressions.
-{ pkgs }:
+# QEMU-related utilities shared between various Nix expressions.
+{ lib, pkgs }:
 
 let
   zeroPad = n:
-    pkgs.lib.optionalString (n < 16) "0" +
+    lib.optionalString (n < 16) "0" +
       (if n > 255
        then throw "Can't have more than 255 nets or nodes!"
-       else pkgs.lib.toHexString n);
+       else lib.toHexString n);
 in
 
 rec {

nixos/lib/testing-python.nix

@@ -217,7 +217,7 @@ rec {
       nodes = qemu_pkg:
         let
           build-vms = import ./build-vms.nix {
-            inherit system pkgs minimal specialArgs;
+            inherit system lib pkgs minimal specialArgs;
             extraConfigurations = extraConfigurations ++ [(
               {
                 virtualisation.qemu.package = qemu_pkg;
@@ -257,7 +257,6 @@ rec {
         inherit test driver driverInteractive nodes;
       };
 
-
   abortForFunction = functionName: abort ''The ${functionName} function was
     removed because it is not an essential part of the NixOS testing
     infrastructure. It had no usage in NixOS or Nixpkgs and it had no designated

nixos/modules/testing/test-instrumentation.nix

@@ -4,7 +4,10 @@
 { options, config, lib, pkgs, ... }:
 
 with lib;
-with import ../../lib/qemu-flags.nix { inherit pkgs; };
+
+let
+  qemu-common = import ../../lib/qemu-common.nix { inherit lib pkgs; };
+in
 
 {
 
@@ -12,8 +15,8 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
 
     systemd.services.backdoor =
       { wantedBy = [ "multi-user.target" ];
-        requires = [ "dev-hvc0.device" "dev-${qemuSerialDevice}.device" ];
-        after = [ "dev-hvc0.device" "dev-${qemuSerialDevice}.device" ];
+        requires = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
+        after = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
         script =
           ''
             export USER=root
@@ -30,7 +33,7 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
 
             cd /tmp
             exec < /dev/hvc0 > /dev/hvc0
-            while ! exec 2> /dev/${qemuSerialDevice}; do sleep 0.1; done
+            while ! exec 2> /dev/${qemu-common.qemuSerialDevice}; do sleep 0.1; done
             echo "connecting to host..." >&2
             stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion
             echo
@@ -42,7 +45,7 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
     # Prevent agetty from being instantiated on the serial device, since it
     # interferes with the backdoor (writes to it will randomly fail
     # with EIO).  Likewise for hvc0.
-    systemd.services."serial-getty@${qemuSerialDevice}".enable = false;
+    systemd.services."serial-getty@${qemu-common.qemuSerialDevice}".enable = false;
     systemd.services."serial-getty@hvc0".enable = false;
 
     # Only set these settings when the options exist. Some tests (e.g. those
@@ -57,7 +60,7 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
         #       we avoid defining consoles if not possible.
         # TODO: refactor such that test-instrumentation can import qemu-vm
         #       or declare virtualisation.qemu.console option in a module that's always imported
-        consoles = [ qemuSerialDevice ];
+        consoles = [ qemu-common.qemuSerialDevice ];
         package  = lib.mkDefault pkgs.qemu_test;
       };
     };
@@ -88,7 +91,7 @@ with import ../../lib/qemu-flags.nix { inherit pkgs; };
     # Panic if an error occurs in stage 1 (rather than waiting for
     # user intervention).
     boot.kernelParams =
-      [ "console=${qemuSerialDevice}" "panic=1" "boot.panic_on_fail" ];
+      [ "console=${qemu-common.qemuSerialDevice}" "panic=1" "boot.panic_on_fail" ];
 
     # `xwininfo' is used by the test driver to query open windows.
     environment.systemPackages = [ pkgs.xorg.xwininfo ];

nixos/modules/virtualisation/qemu-vm.nix

@@ -10,10 +10,10 @@
 { config, lib, pkgs, options, ... }:
 
 with lib;
-with import ../../lib/qemu-flags.nix { inherit pkgs; };
 
 let
 
+  qemu-common = import ../../lib/qemu-common.nix { inherit lib pkgs; };
 
   cfg = config.virtualisation;
 
@@ -152,7 +152,7 @@ let
       '')}
 
       # Start QEMU.
-      exec ${qemuBinary qemu} \
+      exec ${qemu-common.qemuBinary qemu} \
           -name ${config.system.name} \
           -m ${toString config.virtualisation.memorySize} \
           -smp ${toString config.virtualisation.cores} \
@@ -549,7 +549,7 @@ in
       consoles = mkOption {
         type = types.listOf types.str;
         default = let
-          consoles = [ "${qemu-flags.qemuSerialDevice},115200n8" "tty0" ];
+          consoles = [ "${qemu-common.qemuSerialDevice},115200n8" "tty0" ];
         in if cfg.graphics then consoles else reverseList consoles;
         example = [ "console=tty1" ];
         description = ''

nixos/tests/networking.nix

@@ -8,7 +8,7 @@ with import ../lib/testing-python.nix { inherit system pkgs; };
 with pkgs.lib;
 
 let
-  qemu-flags = import ../lib/qemu-flags.nix { inherit pkgs; };
+  qemu-common = import ../lib/qemu-common.nix { inherit (pkgs) lib pkgs; };
 
   router = { config, pkgs, lib, ... }:
     with pkgs.lib;
@@ -42,7 +42,7 @@ let
         machines = flip map vlanIfs (vlan:
           {
             hostName = "client${toString vlan}";
-            ethernetAddress = qemu-flags.qemuNicMac vlan 1;
+            ethernetAddress = qemu-common.qemuNicMac vlan 1;
             ipAddress = "192.168.${toString vlan}.2";
           }
         );

pkgs/build-support/vm/default.nix

@@ -9,9 +9,9 @@
 }:
 
 with pkgs;
-with import ../../../nixos/lib/qemu-flags.nix { inherit pkgs; };
 
 rec {
+  qemu-common = import ../../../nixos/lib/qemu-common.nix { inherit lib pkgs; };
 
   qemu = pkgs.qemu_kvm;
 
@@ -192,13 +192,13 @@ rec {
       export PATH=/bin:/usr/bin:${coreutils}/bin
       echo "Starting interactive shell..."
       echo "(To run the original builder: \$origBuilder \$origArgs)"
-      exec ${busybox}/bin/setsid ${bashInteractive}/bin/bash < /dev/${qemuSerialDevice} &> /dev/${qemuSerialDevice}
+      exec ${busybox}/bin/setsid ${bashInteractive}/bin/bash < /dev/${qemu-common.qemuSerialDevice} &> /dev/${qemu-common.qemuSerialDevice}
     fi
   '';
 
 
   qemuCommandLinux = ''
-    ${qemuBinary qemu} \
+    ${qemu-common.qemuBinary qemu} \
       -nographic -no-reboot \
       -device virtio-rng-pci \
       -virtfs local,path=${storeDir},security_model=none,mount_tag=store \
@@ -206,7 +206,7 @@ rec {
       ''${diskImage:+-drive file=$diskImage,if=virtio,cache=unsafe,werror=report} \
       -kernel ${kernel}/${img} \
       -initrd ${initrd}/initrd \
-      -append "console=${qemuSerialDevice} panic=1 command=${stage2Init} out=$out mountDisk=$mountDisk loglevel=4" \
+      -append "console=${qemu-common.qemuSerialDevice} panic=1 command=${stage2Init} out=$out mountDisk=$mountDisk loglevel=4" \
       $QEMU_OPTS
   '';