Messages in this thread | | | From | Jacob Pan <> | Subject | [PATCH 0/2] Replace Intel SVM with IOMMU SVA APIs | Date | Mon, 24 Feb 2020 15:26:34 -0800 |
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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]. 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
Jacob Pan (2): iommu/vt-d: Report SVA feature with generic flag iommu/vt-d: Replace intel SVM APIs with generic SVA APIs
drivers/iommu/intel-iommu.c | 8 +++ drivers/iommu/intel-svm.c | 123 ++++++++++++++++++++++++-------------------- include/linux/intel-iommu.h | 7 +++ include/linux/intel-svm.h | 85 ------------------------------ 4 files changed, 83 insertions(+), 140 deletions(-)
-- 2.7.4
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