Commits
Will Deacon committed f5c9ecebaf2
vfio/iommu_type1: add new VFIO_TYPE1_NESTING_IOMMU IOMMU type VFIO allows devices to be safely handed off to userspace by putting them behind an IOMMU configured to ensure DMA and interrupt isolation. This enables userspace KVM clients, such as kvmtool and qemu, to further map the device into a virtual machine. With IOMMUs such as the ARM SMMU, it is then possible to provide SMMU translation services to the guest operating system, which are nested with the existing translation installed by VFIO. However, enabling this feature means that the IOMMU driver must be informed that the VFIO domain is being created for the purposes of nested translation. This patch adds a new IOMMU type (VFIO_TYPE1_NESTING_IOMMU) to the VFIO type-1 driver. The new IOMMU type acts identically to the VFIO_TYPE1v2_IOMMU type, but additionally sets the DOMAIN_ATTR_NESTING attribute on its IOMMU domains. Cc: Joerg Roedel <joro@8bytes.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>