This is a preparatory series for IOMMUFD v2 patches. It enforces error code -EMEDIUMTYPE in iommu_attach_device() and iommu_attach_group() when an IOMMU domain and a device/group are incompatible. It also drops the useless domain->ops check since it won't fail in current environment.
These allow VFIO iommu code to simplify its group attachment routine, by avoiding the extra IOMMU domain allocations and attach/detach sequences of the old code. Worths mentioning the exact match for enforce_cache_coherency is removed with this series, since there's very less value in doing that since KVM won't be able to take advantage of it -- this just wastes domain memory. Instead, we rely on Intel IOMMU driver taking care of that internally. This is on github: https://github.com/nicolinc/iommufd/commits/vfio_iommu_attach Changelog v3: * Dropped all dev_err since -EMEDIUMTYPE clearly indicates what error. * Updated commit message of enforce_cache_coherency removing patch. * Updated commit message of domain->ops removing patch. * Replaced "goto out_unlock" with simply mutex_unlock() and return. * Added a line of comments for -EMEDIUMTYPE return check. * Moved iommu_get_msi_cookie() into alloc_attach_domain() as a cookie should be logically tied to the lifetime of a domain itself. * Added Kevin's "Reviewed-by". v2: https://lore.kernel.org/kvm/20220616000304.23890-1-nicol...@nvidia.com/ * Added -EMEDIUMTYPE to more IOMMU drivers that fit the category. * Changed dev_err to dev_dbg for -EMEDIUMTYPE to avoid kernel log spam. * Dropped iommu_ops patch, and removed domain->ops in VFIO directly, since there's no mixed-driver use case that would fail the sanity. * Updated commit log of the patch removing enforce_cache_coherency. * Fixed a misplace of "num_non_pinned_groups--" in detach_group patch. * Moved "num_non_pinned_groups++" in PATCH-5 to the common path between domain-reusing and new-domain pathways, like the code previously did. * Fixed a typo in EMEDIUMTYPE patch. v1: https://lore.kernel.org/kvm/20220606061927.26049-1-nicol...@nvidia.com/ Jason Gunthorpe (1): vfio/iommu_type1: Prefer to reuse domains vs match enforced cache coherency Nicolin Chen (4): iommu: Return -EMEDIUMTYPE for incompatible domain and device/group vfio/iommu_type1: Remove the domain->ops comparison vfio/iommu_type1: Clean up update_dirty_scope in detach_group() vfio/iommu_type1: Simplify group attachment drivers/iommu/amd/iommu.c | 2 +- drivers/iommu/apple-dart.c | 4 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 +- drivers/iommu/arm/arm-smmu/arm-smmu.c | 6 +- drivers/iommu/arm/arm-smmu/qcom_iommu.c | 9 +- drivers/iommu/intel/iommu.c | 10 +- drivers/iommu/iommu.c | 28 ++ drivers/iommu/ipmmu-vmsa.c | 4 +- drivers/iommu/mtk_iommu_v1.c | 2 +- drivers/iommu/omap-iommu.c | 3 +- drivers/iommu/s390-iommu.c | 2 +- drivers/iommu/sprd-iommu.c | 6 +- drivers/iommu/tegra-gart.c | 2 +- drivers/iommu/virtio-iommu.c | 3 +- drivers/vfio/vfio_iommu_type1.c | 340 ++++++++++---------- 15 files changed, 225 insertions(+), 211 deletions(-) -- 2.17.1 _______________________________________________ iommu mailing list email@example.com https://lists.linuxfoundation.org/mailman/listinfo/iommu