VFIO and non-DMA devices

This proposal has been accepted as a session.


One Line Summary

This session proposes changes to vfio to remove a current limitation-- allowing the passthrough of non-DMA devices to user space.


vfio currently has an inherent assumption that devices passed through to user space do DMA and thus involves an IOMMU. A simple example would be something like a UART, but there are other potentially more interesting devices as well.

This topic covers:
-why it is potentially useful to pass-through devices that don’t do DMA
-why vfio is preferred to UIO for doing this
-a proposal for extending vfio to allow this