Support identity domains, allowing to only enable IOMMU protection for a subset of endpoints (those assigned to userspace, for example). Users may enable identity domains at compile time (CONFIG_IOMMU_DEFAULT_PASSTHROUGH), boot time (iommu.passthrough=1) or runtime (/sys/kernel/iommu_groups/*/type = identity).
Since v2 [1] I fixed the padding in patch 1 and a rebase error in patch 5, reported by Eric. Patches 1-2 support identity domains using the optional VIRTIO_IOMMU_F_BYPASS_CONFIG feature, which was accepted into the spec [2]. Patches 3-5 add a fallback to identity mappings, when the feature is not supported. QEMU patches are on my virtio-iommu/bypass branch [3], and depend on the UAPI update. [1] https://lore.kernel.org/linux-iommu/20211123155301.1047943-1-jean-phili...@linaro.org/ [2] https://github.com/oasis-tcs/virtio-spec/issues/119 [3] https://jpbrucker.net/git/qemu/log/?h=virtio-iommu/bypass Jean-Philippe Brucker (5): iommu/virtio: Add definitions for VIRTIO_IOMMU_F_BYPASS_CONFIG iommu/virtio: Support bypass domains iommu/virtio: Sort reserved regions iommu/virtio: Pass end address to viommu_add_mapping() iommu/virtio: Support identity-mapped domains include/uapi/linux/virtio_iommu.h | 8 ++- drivers/iommu/virtio-iommu.c | 113 +++++++++++++++++++++++++----- 2 files changed, 101 insertions(+), 20 deletions(-) -- 2.34.0 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
