nixos/qemu-vm: add opengl hardware acceleration option

nixos/modules/virtualisation/qemu-vm.nix

@@ -450,6 +450,16 @@ in
           '';
       };
 
+    virtualisation.opengl =
+      mkOption {
+        type = types.bool;
+        default = false;
+        description =
+          lib.mdDoc ''
+            Whether or not to run QEMU with OpenGL hardware acceleration.
+          '';
+      };
+
     virtualisation.cores =
       mkOption {
         type = types.ints.positive;
@@ -1153,12 +1163,17 @@ in
       (mkIf cfg.qemu.virtioKeyboard [
         "-device virtio-keyboard"
       ])
-      (mkIf pkgs.stdenv.hostPlatform.isx86 [
-        "-usb" "-device usb-tablet,bus=usb-bus.0"
-      ])
-      (mkIf pkgs.stdenv.hostPlatform.isAarch [
-        "-device virtio-gpu-pci" "-device usb-ehci,id=usb0" "-device usb-kbd" "-device usb-tablet"
-      ])
+      (mkIf pkgs.stdenv.hostPlatform.isx86 (mkMerge [
+        [ "-usb" "-device usb-tablet,bus=usb-bus.0" ]
+        (mkIf cfg.opengl [ "-vga none" "-device virtio-gpu-gl-pci" ])
+        # Use software rendering when opengl is required, but hardware acceleration is disabled
+        (mkIf (!cfg.opengl && config.hardware.opengl.enable) [ "-vga none" "-device virtio-gpu-pci" ])
+      ]))
+      (mkIf pkgs.stdenv.hostPlatform.isAarch (mkMerge [
+        [ "-device usb-ehci,id=usb0" "-device usb-kbd" "-device usb-tablet" ]
+        (mkIf cfg.opengl [ "-device virtio-gpu-gl-pci" ])
+        (mkIf (!cfg.opengl) [ "-device virtio-gpu-pci" ])
+      ]))
       (let
         alphaNumericChars = lowerChars ++ upperChars ++ (map toString (range 0 9));
         # Replace all non-alphanumeric characters with underscores
@@ -1175,9 +1190,13 @@ in
       (mkIf (cfg.bios != null) [
         "-bios ${cfg.bios}/bios.bin"
       ])
-      (mkIf (!cfg.graphics) [
-        "-nographic"
+      (mkIf cfg.graphics [
+        "-display default${lib.optionalString cfg.opengl ",gl=on"}"
       ])
+      (mkIf (!cfg.graphics) (mkMerge [
+        [ "-nographic" ]
+        (mkIf cfg.opengl [ "-display egl-headless" ])
+      ]))
       (mkIf (cfg.tpm.enable) [
         "-chardev socket,id=chrtpm,path=\"$NIX_SWTPM_DIR\"/socket"
         "-tpmdev emulator,id=tpm_dev_0,chardev=chrtpm"

nixos/tests/cage.nix

@@ -18,9 +18,10 @@ import ./make-test-python.nix ({ pkgs, ...} :
       user = "alice";
       program = "${pkgs.xterm}/bin/xterm";
     };
+  };
 
-    # Need to switch to a different GPU driver than the default one (-vga std) so that Cage can launch:
-    virtualisation.qemu.options = [ "-vga none -device virtio-gpu-pci" ];
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
   };
 
   enableOCR = true;

nixos/tests/cagebreak.nix

@@ -35,9 +35,10 @@ in
     programs.xwayland.enable = true;
     security.polkit.enable = true;
     environment.systemPackages = [ pkgs.cagebreak pkgs.wayland-utils ];
+  };
 
-    # Need to switch to a different GPU driver than the default one (-vga std) so that Cagebreak can launch:
-    virtualisation.qemu.options = [ "-vga none -device virtio-gpu-pci" ];
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
   };
 
   enableOCR = true;

nixos/tests/gnome-extensions.nix

@@ -50,9 +50,12 @@ import ./make-test-python.nix (
           };
         };
       };
-
     };
 
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
+  };
+
   testScript = { nodes, ... }: let
     # Keep line widths somewhat manageable
     user = nodes.machine.users.users.alice;

nixos/tests/gnome-xorg.nix

@@ -7,7 +7,6 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
   nodes.machine = { nodes, ... }: let
     user = nodes.machine.users.users.alice;
   in
-
     { imports = [ ./common/user-account.nix ];
 
       services.xserver.enable = true;
@@ -39,9 +38,12 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
           };
         };
       };
-
     };
 
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
+  };
+
   testScript = { nodes, ... }: let
     user = nodes.machine.users.users.alice;
     uid = toString user.uid;

nixos/tests/gnome.nix

@@ -35,9 +35,12 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
           };
         };
       };
-
     };
 
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
+  };
+
   testScript = { nodes, ... }: let
     # Keep line widths somewhat manageable
     user = nodes.machine.users.users.alice;

nixos/tests/mate-wayland.nix

@@ -21,9 +21,10 @@ import ./make-test-python.nix ({ pkgs, lib, ... }: {
     services.xserver.desktopManager.mate.enableWaylandSession = true;
 
     hardware.pulseaudio.enable = true;
+  };
 
-    # Need to switch to a different GPU driver than the default one (-vga std) so that wayfire can launch:
-    virtualisation.qemu.options = [ "-vga none -device virtio-gpu-pci" ];
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
   };
 
   enableOCR = true;

nixos/tests/mate.nix

@@ -27,6 +27,10 @@ import ./make-test-python.nix ({ pkgs, lib, ... }: {
     hardware.pulseaudio.enable = true;
   };
 
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
+  };
+
   enableOCR = true;
 
   testScript = { nodes, ... }:

nixos/tests/phosh.nix

@@ -1,4 +1,4 @@
-import ./make-test-python.nix ({ pkgs, ...}: let
+import ./make-test-python.nix ({ pkgs, ... }: let
   pin = "1234";
 in {
   name = "phosh";
@@ -25,18 +25,14 @@ in {
         };
       };
 
-      systemd.services.phosh = {
-        environment = {
-          # Accelerated graphics fail on phoc 0.20 (wlroots 0.15)
-          "WLR_RENDERER" = "pixman";
-        };
-      };
-
       virtualisation.resolution = { x = 720; y = 1440; };
-      virtualisation.qemu.options = [ "-vga none -device virtio-gpu-pci,xres=720,yres=1440" ];
     };
   };
 
+  interactive.nodes.phone = {
+    virtualisation.opengl = true;
+  };
+
   enableOCR = true;
 
   testScript = ''

nixos/tests/plasma5.nix

@@ -7,7 +7,6 @@ import ./make-test-python.nix ({ pkgs, ...} :
   };
 
   nodes.machine = { ... }:
-
   {
     imports = [ ./common/user-account.nix ];
     services.xserver.enable = true;
@@ -22,6 +21,10 @@ import ./make-test-python.nix ({ pkgs, ...} :
     hardware.pulseaudio.enable = true; # needed for the factl test, /dev/snd/* exists without them but udev doesn't care then
   };
 
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
+  };
+
   testScript = { nodes, ... }: let
     user = nodes.machine.users.users.alice;
     xdo = "${pkgs.xdotool}/bin/xdotool";

nixos/tests/seatd.nix

@@ -40,10 +40,13 @@ in
     '';
 
     hardware.opengl.enable = true;
-    virtualisation.qemu.options = [ "-vga none -device virtio-gpu-pci" ];
     services.seatd.enable = true;
   };
 
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
+  };
+
   testScript = ''
     machine.wait_for_file("/tmp/foot_started")
     machine.succeed("test $(seatd-client-pid) = $(pgrep dwl)")

nixos/tests/sway.nix

@@ -19,15 +19,7 @@ import ./make-test-python.nix ({ pkgs, lib, ... }: {
       # For glinfo and wayland-info:
       systemPackages = with pkgs; [ mesa-demos wayland-utils alacritty ];
       # Use a fixed SWAYSOCK path (for swaymsg):
-      variables = {
-        "SWAYSOCK" = "/tmp/sway-ipc.sock";
-        # TODO: Investigate if we can get hardware acceleration to work (via
-        # virtio-gpu and Virgil). We currently have to use the Pixman software
-        # renderer since the GLES2 renderer doesn't work inside the VM (even
-        # with WLR_RENDERER_ALLOW_SOFTWARE):
-        # "WLR_RENDERER_ALLOW_SOFTWARE" = "1";
-        "WLR_RENDERER" = "pixman";
-      };
+      variables."SWAYSOCK" = "/tmp/sway-ipc.sock";
       # For convenience:
       shellAliases = {
         test-x11 = "glinfo | tee /tmp/test-x11.out && touch /tmp/test-x11-exit-ok";
@@ -70,9 +62,10 @@ import ./make-test-python.nix ({ pkgs, lib, ... }: {
 
     # To test pinentry via gpg-agent:
     programs.gnupg.agent.enable = true;
+  };
 
-    # Need to switch to a different GPU driver than the default one (-vga std) so that Sway can launch:
-    virtualisation.qemu.options = [ "-vga none -device virtio-gpu-pci" ];
+  interactive.nodes.machine = {
+    virtualisation.opengl = true;
   };
 
   testScript = { nodes, ... }: ''

nixos/tests/tinywl.nix

@@ -29,9 +29,10 @@ import ./make-test-python.nix ({ pkgs, lib, ... }:
           touch /tmp/tinywl-exit-ok
         fi
       '';
+    };
 
-      # Switch to a different GPU driver (default: -vga std), otherwise TinyWL segfaults:
-      virtualisation.qemu.options = [ "-vga none -device virtio-gpu-pci" ];
+    interactive.nodes.machine = {
+      virtualisation.opengl = true;
     };
 
     testScript = { nodes, ... }: ''