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Using Intel VT-d PCI Devices in Parallels Virtual Machines

If your computer has an Intel VT-d chipset, you can set the physical PCI Express (PCIe) devices connected to the physical computer to be directly assigned to your virtual machine. The virtual machine will directly access the PCIe devices without using the resources of the primary OS.

You can connect up to eight PCIe devices of any of the supported types to a single virtual machine.

To connect a PCIe device to a virtual machine

  1. Assign the device to your virtual machines in the Intel VT-d pane of Parallels Workstation Extreme Preferences.

    Note: You are recommended to have at least two adapters of the same type (video or network adapters): if you reassign one adapter to your virtual machines, the other adapter will be left to the physical computer. Keep in mind that if you assign your video or network adapter to a virtual machine, this adapter will be invisible to your primary OS.

  2. Add the device to the virtual machine configuration. For more information, refer to the Adding a Network Adapter, Adding a Video Adapter, and Adding Intel VT-d PCI Devices subsections.


In Windows-based virtual machines, if the pass-through driver cannot be installed automatically after a PCIe device has been assigned to virtual machines in Preferences, install it manually by doing the following:

  1. Go to Start > Control Panel > System > Hardware and open the Device Manager.
  2. In the Device Manager, locate the appropriate PCIe device, right-click it and choose Update Driver from the context menu.
  3. In the Hardware Update wizard, choose to install the driver from the specific location.
  4. Choose to specify the driver yourself.
  5. In the next window, select the Have Disk option and specify the following path to the driver's location: C:\Program Files\Parallels\Parallels Workstation\Drivers\prl_vtdvideo.inf or C:\Program Files\Parallels\Parallels Workstation\Drivers\prl_vtdnet.inf and click Open.
  6. Follow the wizard's instructions to complete the installation of the driver.
  7. Restart the host computer.

In rare cases you cannot boot the primary Linux operating system after a PCIe device is added to the configuration of a virtual machine. To work around the issue, do the following:

  1. In the grub loader splash screen, with your primary operating system selected in the list, press e on the keyboard to display the boot parameters.
  2. Select the line starting with "kernel" by pressing the down arrow on the keyboard.
  3. Press e to launch an editor for the selected line.
  4. At the end of the line, add


  5. Press Enter to return to the boot parameters screen.
  6. Press b to boot the kernel.
  7. In the command line window, mount the root partition in read-write mode by entering

    mount /dev/root / -oremount,rw

    Note: If you want your root partition to be mounted to a different location, replace root with this location in the command above.

  8. Type the following command and press Enter:

    echo -n "" > /etc/parallels/vtd.hook

  9. Type the following command and press Enter:

    mount /dev/root / -oremount,ro

  10. Type the following command and press Enter:


This procedure will make your primary Linux operating system boot normally.