1. gksudo gedit /etc/default/grub
    2. edit the line that says GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash” and add iommu=soft Resulting in something like
      GRUB_CMDLINE_LINUX_DEFAULT=”quiet iommu=soft splash”
      if you haven’t changed kernel parameters previously

    The order of the parameters doesn’t matter, the spaces between them are however important.

    1. save the file
    2. Issue the command sudo update-grub
    3. Reboot