VFIO No-IOMMU support


Linux Kernel Configuration
└─>Device Drivers
└─>VFIO Non-Privileged userspace driver framework
└─>VFIO No-IOMMU support
In linux kernel since version 3.10 (release Date: 2013-06-30)  
VFIO is built on the ability to isolate devices using the IOMMU.
Only with an IOMMU can userspace access to DMA capable devices be
considered secure. VFIO No-IOMMU mode enables IOMMU groups for
devices without IOMMU backing for the purpose of re-using the VFIO
infrastructure in a non-secure mode. Use of this mode will result
in an unsupportable kernel and will therefore taint the kernel.
Device assignment to virtual machines is also not possible with
this mode since there is no IOMMU to provide DMA translation.

If you don't know what to do here, say N.