Re: [PATCH v9 0/7] IOMMU user API enhancement
Hi Joerg, On Fri, 18 Sep 2020 12:02:36 +0200, Joerg Roedel wrote: > Hi Jacob, > > On Fri, Sep 11, 2020 at 02:57:49PM -0700, Jacob Pan wrote: > > IOMMU user API header was introduced to support nested DMA translation > > and related fault handling. The current UAPI data structures consist of > > three areas that cover the interactions between host kernel and guest: > > - fault handling > > - cache invalidation > > - bind guest page tables, i.e. guest PASID > > > > Future extensions are likely to support more architectures and vIOMMU > > features. > > > > In the previous discussion, using user-filled data size and feature > > flags is made a preferred approach over a unified version number. > > https://lkml.org/lkml/2020/1/29/45 > > > > In addition to introduce argsz field to data structures, this patchset > > is also trying to document the UAPI design, usage, and extension rules. > > VT-d driver changes to utilize the new argsz field is included, VFIO > > usage is to follow. > > > > This set is available at: > > https://github.com/jacobpan/linux.git vsva_v5.9_uapi_v9 > > This changes user visible structs in incompatible ways, are you sure > those are not used yet anywhere? > These structs are not used yet in that IOMMU UAPI does not provide direct user IOCTLs. For guest SVA of assigned devices, VFIO is used. Yi's companion patches are here. https://lore.kernel.org/linux-iommu/5dd95fbf-054c-3bbc-e76b-2d5636214...@redhat.com/T/#t These user structs can also be used by other framework in the future, such as vDPA. > Please address Randy's comments on patch 1 and my comment about the > build-time checking and repost with linux-...@vger.kernel.org on Cc. > Will do. > Regards, > > Joerg Thanks, Jacob ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v9 0/7] IOMMU user API enhancement
Hi Jacob, On Fri, Sep 11, 2020 at 02:57:49PM -0700, Jacob Pan wrote: > IOMMU user API header was introduced to support nested DMA translation and > related fault handling. The current UAPI data structures consist of three > areas that cover the interactions between host kernel and guest: > - fault handling > - cache invalidation > - bind guest page tables, i.e. guest PASID > > Future extensions are likely to support more architectures and vIOMMU > features. > > In the previous discussion, using user-filled data size and feature flags is > made a preferred approach over a unified version number. > https://lkml.org/lkml/2020/1/29/45 > > In addition to introduce argsz field to data structures, this patchset is also > trying to document the UAPI design, usage, and extension rules. VT-d driver > changes to utilize the new argsz field is included, VFIO usage is to follow. > > This set is available at: > https://github.com/jacobpan/linux.git vsva_v5.9_uapi_v9 This changes user visible structs in incompatible ways, are you sure those are not used yet anywhere? Please address Randy's comments on patch 1 and my comment about the build-time checking and repost with linux-...@vger.kernel.org on Cc. Regards, Joerg ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
[PATCH v9 0/7] IOMMU user API enhancement
IOMMU user API header was introduced to support nested DMA translation and related fault handling. The current UAPI data structures consist of three areas that cover the interactions between host kernel and guest: - fault handling - cache invalidation - bind guest page tables, i.e. guest PASID Future extensions are likely to support more architectures and vIOMMU features. In the previous discussion, using user-filled data size and feature flags is made a preferred approach over a unified version number. https://lkml.org/lkml/2020/1/29/45 In addition to introduce argsz field to data structures, this patchset is also trying to document the UAPI design, usage, and extension rules. VT-d driver changes to utilize the new argsz field is included, VFIO usage is to follow. This set is available at: https://github.com/jacobpan/linux.git vsva_v5.9_uapi_v9 Thanks, Jacob Changelog: v9 - Directly pass PASID value to iommu_sva_unbind_gpasid() without the superfluous data in struct iommu_gpasid_bind_data. v8 - Rebased to v5.9-rc2 - Addressed review comments from Eric Auger 1. added a check for the unused vendor flags 2. commit message improvements v7 - Added PASID data format enum for range checking - Tidy up based on reviews from Alex W. - Removed doc section for vIOMMU fault handling v6 - Renamed all UAPI functions with iommu_uapi_ prefix - Replaced argsz maxsz checking with flag specific size checks - Documentation improvements based on suggestions by Eric Auger Replaced example code with a pointer to the actual code - Added more checks for illegal flags combinations - Added doc file to MAINTAINERS v5 - Addjusted paddings in UAPI data to be 8 byte aligned - Do not clobber argsz in IOMMU core before passing on to vendor driver - Removed pr_warn_ for invalid UAPI data check, just return -EINVAL - Clarified VFIO responsibility in UAPI data handling - Use iommu_uapi prefix to differentiate APIs has in-kernel caller - Added comment for unchecked flags of invalidation granularity - Added example in doc to show vendor data checking v4 - Added checks of UAPI data for reserved fields, version, and flags. - Removed version check from vendor driver (vt-d) - Relaxed argsz check to match the UAPI struct size instead of variable union size - Updated documentation v3: - Rewrote backward compatibility rule to support existing code re-compiled with newer kernel UAPI header that runs on older kernel. Based on review comment from Alex W. https://lore.kernel.org/linux-iommu/20200611094741.6d118...@w520.home/ - Take user pointer directly in UAPI functions. Perform argsz check and copy_from_user() in IOMMU driver. Eliminate the need for VFIO or other upper layer to parse IOMMU data. - Create wrapper function for in-kernel users of UAPI functions v2: - Removed unified API version and helper - Introduced argsz for each UAPI data - Introduced UAPI doc Jacob Pan (7): docs: IOMMU user API iommu/uapi: Add argsz for user filled data iommu/uapi: Introduce enum type for PASID data format iommu/uapi: Use named union for user data iommu/uapi: Rename uapi functions iommu/uapi: Handle data and argsz filled by users iommu/vt-d: Check UAPI data processed by IOMMU core Documentation/userspace-api/iommu.rst | 211 ++ MAINTAINERS | 1 + drivers/iommu/intel/iommu.c | 25 ++-- drivers/iommu/intel/svm.c | 13 ++- drivers/iommu/iommu.c | 201 ++-- include/linux/iommu.h | 35 -- include/uapi/linux/iommu.h| 25 ++-- 7 files changed, 468 insertions(+), 43 deletions(-) create mode 100644 Documentation/userspace-api/iommu.rst -- 2.7.4 ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
