graphics: Enable gpu passthrough

Pass "x-igd-opregion=on" deviceExtraArgs to graphics
pci device which helps to enable opregion which in-turn
enable access to video bios table (VBT) to gui-vm.
So qemu will have access to display parameters which
are needed in Link training for the Gen 12 eDP panel.

Signed-off-by: Vunny Sodhi <vunny.sodhi@unikie.com>

Author: vunnyso

modules/hardware/common/devices.nix

@@ -52,7 +52,7 @@ in
         microvm.devices = mkForce (
           builtins.map (d: {
             bus = "pci";
-            inherit (d) path;
+            inherit (d) path qemu;
           }) config.ghaf.hardware.definition.gpu.pciDevices
         );
         ghaf.hardware.definition.gpu.pciDevices = config.ghaf.hardware.definition.gpu.pciDevices;

modules/hardware/definition.nix

@@ -41,6 +41,13 @@ in
               PCI device name (optional)
             '';
           };
+          qemu.deviceExtraArgs = mkOption {
+            type = types.nullOr types.str;
+            default = null;
+            description = ''
+              Device additional arguments (optional)
+            '';
+          };
         };
       };
 
@@ -255,6 +262,7 @@ in
               path = "0000:00:02.0";
               vendorId = "8086";
               productId = "a7a1";
+              qemu.deviceExtraArgs = "x-igd-opregion=on"
             }]
           '';
         };

modules/reference/hardware/lenovo-x1/definitions/x1-gen12.nix

@@ -78,6 +78,7 @@
         path = "0000:00:02.0";
         vendorId = "8086";
         productId = "7d45";
+        qemu.deviceExtraArgs = "x-igd-opregion=on";
       }
       {
         # Communication controller [0780]: Intel Corporation Device [8086:7e70] (rev 20)