module moving mostly done

systems/gerg-desktop/vfio.nix

@@ -0,0 +1,71 @@
+_: {
+  pkgs,
+  settings,
+  self,
+  ...
+}: {
+  boot = {
+    kernelParams = ["amd_iommu=on" "iommu=pt" "vfio_iommu_type1.allow_unsafe_interrupts=1" "kvm.ignore_msrs=1"];
+    kernelModules = ["kvm-amd" "vfio_virqfd" "vfio_pci" "vfio_iommu_type1" "vfio"];
+    initrd.kernelModules = ["vfio_virqfd" "vfio_pci" "vfio_iommu_type1" "vfio"];
+    extraModprobeConfig = ''
+      options vfio-pci ids=10de:228e,10de:2504
+    '';
+  };
+  virtualisation = {
+    libvirtd = {
+      enable = true;
+      qemu = {
+        runAsRoot = true;
+        ovmf.enable = true;
+        verbatimConfig = ''
+          user = "${settings.username}"
+          group = "kvm"
+          namespaces = []
+        '';
+      };
+    };
+  };
+  environment = {
+    systemPackages = [pkgs.virt-manager];
+    shellAliases = {
+      vm-start = "virsh start Windows";
+      vm-stop = "virsh shutdown Windows";
+    };
+  };
+
+  users.users."${settings.username}".extraGroups = ["kvm" "libvirtd"];
+
+  systemd.services.libvirtd.preStart = let
+    xml = pkgs.writeText "Windows.xml" (builtins.readFile "${self}/misc/Windows.xml");
+    qemuHook = pkgs.writeScript "qemu-hook" ''
+      #!${pkgs.stdenv.shell}
+      GUEST_NAME="$1"
+      OPERATION="$2"
+      SUB_OPERATION="$3"
+
+      if [ "$GUEST_NAME" == "Windows" ]; then
+        if [ "$OPERATION" == "start" ]; then
+          systemctl set-property --runtime -- user.slice AllowedCPUs=8-15,24-31
+          systemctl set-property --runtime -- system.slice AllowedCPUs=8-15,24-31
+          systemctl set-property --runtime -- init.scope AllowedCPUs=8-15,24-31
+        fi
+
+        if [ "$OPERATION" == "stopped" ]; then
+          systemctl set-property --runtime -- user.slice AllowedCPUs=0-31
+          systemctl set-property --runtime -- system.slice AllowedCPUs=0-31
+          systemctl set-property --runtime -- init.scope AllowedCPUs=0-31
+        fi
+      fi
+    '';
+  in ''
+    mkdir -p /var/lib/libvirt/hooks
+    chmod 755 /var/lib/libvirt/hooks
+
+    # Copy hook files
+    ln -sf ${qemuHook} /var/lib/libvirt/hooks/qemu
+
+    mkdir -p /var/lib/libvirt/qemu/
+    ln -sf ${xml} /var/lib/libvirt/qemu/Windows.xml
+  '';
+}