Public bug reported: Description: Shared virtual address (SVA) capable accelerator device drivers on Intel platform are required to call VT-d driver directly to bind a device with a given address space. It is conceptually incorrect with the following reasons:
A device driver is bypassing IOMMU generic layer Device driver cannot be reused across architectures Opens a door to duplicated code Generic SVA APIs was introduced[1] and partially merged upstream which created a common ground for vendor IOMMU driver to consolidate SVA code. On the other hand, Uacce (Unified/User-space-access-intended Accelerator Framework) [2] is emerging to be a generic user-kernel interface for SVA capable devices. IOMMU generic SVA APIs are used by Uacce. Therefore, replacing VT-d SVM code with IOMMU SVA APIs are required by device drivers want to use Uacce. The features below will continue to work but are not included in this patch in that they are handled mostly within the IOMMU subsystem. IO page fault mmu notifier Consolidation of the above will come after generic IOMMU sva code[1]. This will be a second phase and under difference JIRA feature. There should not be any changes needed for accelerator device drivers during this time. References: [1] http://jpbrucker.net/sva/ [2] https://lkml.org/lkml/2020/1/15/604 Target Release: 20.10 Target Kernel: 5.8 ** Affects: intel Importance: Undecided Status: New ** Affects: ubuntu Importance: Undecided Status: New ** Tags: intel-kernel-20.10 ** Also affects: ubuntu Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1880160 Title: [EGS] Replace Intel SVM with IOMMU SVA APIs To manage notifications about this bug go to: https://bugs.launchpad.net/intel/+bug/1880160/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
