iommu/dma: Add IOMMU op to choose lazy domain type

With two flush queue variants add an IOMMU operation that allows the
IOMMU driver to choose its preferred flush queue variant on a per device
basis. For s390 use this callback to choose the single queue variant
whenever the device requires explicit IOTLB flushes on map indicating
that we're running in a paged memory guest with expensive IOTLB flushes.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
3 files changed