This is a follow-on series to "vfio-pci: Block user access to disabled device MMIO"[1], which extends user access blocking of disabled MMIO ranges to include unmapping the ranges from the IOMMU. The first patch adds an invalidation callback path, allowing vfio bus drivers to signal the IOMMU backend to unmap ranges with vma level granularity. This signaling is done both when the MMIO range becomes inaccessible due to memory disabling, as well as when a vma is closed, making up for the lack of tracking or pinning for non-page backed vmas. The second patch adds registration and testing interfaces such that the IOMMU backend driver can test whether a given PFNMAP vma is provided by a vfio bus driver supporting invalidation. We can then implement more restricted semantics to only allow PFNMAP DMA mappings when we have such support, which becomes the new default. Jason, if you'd like Suggested-by credit for the ideas here I'd be glad to add it. Thanks, Alex [1]https://lore.kernel.org/kvm/158871401328.15589.17598154478222071285.stgit@xxxxxxxxxx/ --- Alex Williamson (2): vfio: Introduce bus driver to IOMMU invalidation interface vfio: Introduce strict PFNMAP mappings drivers/vfio/pci/vfio_pci.c | 41 ++++++++++- drivers/vfio/pci/vfio_pci_private.h | 1 drivers/vfio/vfio.c | 76 ++++++++++++++++++++ drivers/vfio/vfio_iommu_type1.c | 130 +++++++++++++++++++++++++++-------- include/linux/vfio.h | 9 ++ 5 files changed, 222 insertions(+), 35 deletions(-)
