[Qemu-devel] [0/13] RFC: Support for guest-visible IOMMUs

[David Gibson <david@gibson.dropbear.id.au>]

This patch series introduces a general DMA infrastructure which allows
the emulation of guest-visible IOMMUs.  That is, it provides a
framework by which an IOMMU device can be implemented, such that DMA
from other device emulations will be translated according to the
mappings provided by the IOMMU.

One example IOMMU implementation is included, for the para-virtualized
TCE tables specified by PAPR and used in the pseries machine for both
virtual IO and PCI devices.

This series is an updated and cleaned-up version of patches posted by
Eduard - Gabriel Munteanu some time ago.  Those prompted some
discussion at the time, but no resolution was reached.  These patches
are now pretty polished although I'd like to get some comment from
people working with other IOMMUs to make sure the infrastructure is
sufficient to cover those.

Specifically, Eduard - Gabriel, if you have an updated version of your
AMD IOMMU driver, it would be good to see if that can work with this
infrastructure.

The series also converts a number of existing device models to use the
new DMA infrastructure, so they can be used with IOMMUs.  Along with
the pci_dma_*() wrapper functions which are already in, this means
that with this series applied, essentially all PCI devices should work
with an emulated IOMMU, as well as pseries VIO devices.  Other types
of devices would need some further conversion to work with the new
framework, but that should be quite straightforward.