Add vfio stuff for win10

Add a whole bunch of stuff to start/stop displays for the win10 vm
Hopefully this will allow win10 to directly use the same GPU in passthru
mode

pkgs/default.nix

@@ -13,7 +13,10 @@ in
   inject-darwin = c ./inject-darwin.nix { };
   inject = c ./inject.nix { };
   hms = c ./hms { };
+  qemu-hook = c ./qemu-hook.nix { };
   setup-ssh = c ./setup-ssh { };
   upgrade-pg-cluster = c ./upgrade-pg-cluster.nix { };
+  vfio_startup = c ./vfio_startup.nix { };
+  vfio_shutdown = c ./vfio_shutdown.nix { };
   zim = c ./zim.nix { };
 }

pkgs/qemu-hook.nix

@@ -0,0 +1,31 @@
+{
+  writeShellApplication,
+  vfio_shutdown,
+  vfio_startup,
+}:
+
+writeShellApplication {
+  name = "qemu_hook";
+  runtimeInputs = [
+    vfio_shutdown
+    vfio_startup
+  ];
+
+  text = ''
+    OBJECT="''${1}"
+    OPERATION="''${2}"
+
+    if [[ "''${OBJECT}" == "win10" ]]; then
+      case "''${OPERATION}" in
+        "prepare")
+          systemctl start libvirt-nosleep@"''${OBJECT}".service
+          systemctl start bluetooth.service
+          vfio_startup 2>&1 | tee -a /var/log/qemu_hook.log
+          ;;
+        "release")
+          systemctl stop libvirt-nosleep@"''${OBJECT}".service
+          vfio_shutdown 2>&1 | tee -a /var/log/qemu_hook.log
+      esac
+    fi
+  '';
+}

pkgs/vfio_shutdown.nix

@@ -0,0 +1,32 @@
+{
+  writeShellApplication,
+  coreutils,
+  kmod,
+  systemd,
+}:
+
+writeShellApplication {
+  name = "vfio_shutdown";
+  runtimeInputs = [
+    coreutils
+    kmod
+    systemd
+  ];
+  text = ''
+    echo "Removing vfio modules..."
+    modprobe -r vfio_pci
+    modprobe -r vfio_iommu_type1
+    modprobe -r vfio
+
+    echo "Reload the GPU modules..."
+    modprobe nvidia
+    modprobe nvidia_modeset
+    modprobe nvidia_drm
+    modprobe nvidia_uvm
+
+    echo "Starting the display manager..."
+    systemctl start display-manager.service
+
+    echo "All done!"
+  '';
+}

pkgs/vfio_startup.nix

@@ -0,0 +1,33 @@
+{
+  writeShellApplication,
+  kmod,
+  systemd,
+}:
+
+writeShellApplication {
+  name = "vfio_startup";
+  runtimeInputs = [
+    kmod
+    systemd
+  ];
+  text = ''
+    # Stop the service that uses the GPU
+    echo "Stopping the display manager..."
+    systemctl stop display-manager.service
+
+    # Unload the GPU modules
+    echo "Unloading the GPU modules..."
+    modprobe -r nvidia_uvm
+    modprobe -r nvidia_drm
+    modprobe -r nvidia_modeset
+    modprobe -r nvidia
+
+    # Insert the vfio modules
+    echo "Inserting the vfio modules..."
+    modprobe vfio
+    modprobe vfio_pci
+    modprobe vfio_iommu_type1
+
+    echo "Aaaand... off you go!"
+  '';
+}