If you encounter issues with graphics devices, you can try adding
option intel_iommu=igfx_off to turn off the integrated graphics engine.
+If it happens to be a PCI device included in the INCLUDE_ALL Engine,
+then try enabling CONFIG_DMAR_GFX_WA to setup a 1-1 map. We hear
+graphics drivers may be in process of using DMA api's in the near
+future and at that time this option can be yanked out.
+
Some exceptions to IOVA
-----------------------
Interrupt ranges are not address translated, (0xfee00000 - 0xfeefffff).