On 2024/5/29 13:32, Lu Baolu wrote:
The IOMMU subsystem has undergone some changes, including the removal of iommu_ops from the bus structure. Consequently, the existing domain allocation interface, which relies on a bus type argument, is no longer relevant: struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) This series is designed to refactor the use of this interface. It proposes two new interfaces to replace iommu_domain_alloc(): - iommu_user_domain_alloc(): This interface is intended for allocating iommu domains managed by userspace for device passthrough scenarios, such as those used by iommufd, vfio, and vdpa. It clearly indicates that the domain is for user-managed device DMA.
user paging domain? It looks to me user domain includes the nested domains as well.
If an IOMMU driver does not implement iommu_ops->domain_alloc_user, this interface will rollback to the generic paging domain allocation. - iommu_paging_domain_alloc(): This interface is for allocating iommu domains managed by kernel drivers for kernel DMA purposes. It takes a device pointer as a parameter, which better reflects the current design of the IOMMU subsystem. The majority of device drivers currently using iommu_domain_alloc() do so to allocate a domain for a specific device and then attach that domain to the device. These cases can be straightforwardly migrated to the new interfaces. However, there are some drivers with more complex use cases that do not fit neatly into this new scheme. For example: $ git grep "= iommu_domain_alloc" arch/arm/mm/dma-mapping.c: mapping->domain = iommu_domain_alloc(bus); drivers/gpu/drm/rockchip/rockchip_drm_drv.c: private->domain = iommu_domain_alloc(private->iommu_dev->bus); drivers/gpu/drm/tegra/drm.c: tegra->domain = iommu_domain_alloc(&platform_bus_type); drivers/infiniband/hw/usnic/usnic_uiom.c: pd->domain = domain = iommu_domain_alloc(dev->bus); This series leave those cases unchanged and keep iommu_domain_alloc() for their usage. But new drivers should not use it anymore.
does it mean there is still domains allocated via iommu_domain_alloc() on VT-d platform?
The whole series is also available on GitHub: https://github.com/LuBaolu/intel-iommu/commits/iommu-domain-allocation-refactor-v1 Lu Baolu (20): iommu: Add iommu_user_domain_alloc() interface iommufd: Use iommu_user_domain_alloc() vfio/type1: Use iommu_paging_domain_alloc() vhost-vdpa: Use iommu_user_domain_alloc() iommu: Add iommu_paging_domain_alloc() interface drm/msm: Use iommu_paging_domain_alloc() drm/nouveau/tegra: Use iommu_paging_domain_alloc() gpu: host1x: Use iommu_paging_domain_alloc() media: nvidia: tegra: Use iommu_paging_domain_alloc() media: venus: firmware: Use iommu_paging_domain_alloc() ath10k: Use iommu_paging_domain_alloc() wifi: ath11k: Use iommu_paging_domain_alloc() remoteproc: Use iommu_paging_domain_alloc() soc/fsl/qbman: Use iommu_paging_domain_alloc() iommu/vt-d: Add helper to allocate paging domain iommu/vt-d: Add domain_alloc_paging support iommu/vt-d: Simplify compatibility check for identity domain iommu/vt-d: Enhance compatibility check for paging domain attach iommu/vt-d: Remove domain_update_iommu_cap() iommu/vt-d: Remove domain_update_iommu_superpage() include/linux/iommu.h | 12 + drivers/gpu/drm/msm/msm_iommu.c | 8 +- .../drm/nouveau/nvkm/engine/device/tegra.c | 4 +- drivers/gpu/host1x/dev.c | 6 +- drivers/iommu/intel/iommu.c | 319 ++++++++---------- drivers/iommu/intel/pasid.c | 28 +- drivers/iommu/iommu.c | 62 ++++ drivers/iommu/iommufd/hw_pagetable.c | 20 +- .../media/platform/nvidia/tegra-vde/iommu.c | 6 +- drivers/media/platform/qcom/venus/firmware.c | 6 +- drivers/net/wireless/ath/ath10k/snoc.c | 6 +- drivers/net/wireless/ath/ath11k/ahb.c | 6 +- drivers/remoteproc/remoteproc_core.c | 6 +- drivers/soc/fsl/qbman/qman_portal.c | 4 +- drivers/vfio/vfio_iommu_type1.c | 7 +- drivers/vhost/vdpa.c | 11 +- 16 files changed, 253 insertions(+), 258 deletions(-)
-- Regards, Yi Liu