Commits
Will Deacon committed c02607aad2f
iommu: introduce domain attribute for nesting IOMMUs Some IOMMUs, such as the ARM SMMU, support two stages of translation. The idea behind such a scheme is to allow a guest operating system to use the IOMMU for DMA mappings in the first stage of translation, with the hypervisor then installing mappings in the second stage to provide isolation of the DMA to the physical range assigned to that virtual machine. In order to allow IOMMU domains to be used for second-stage translation, this patch adds a new iommu_attr (IOMMU_ATTR_NESTING) for setting second-stage domains prior to device attach. The attribute can also be queried to see if a domain is actually making use of nesting. Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>