This series allows a virtualizer to program the nested stage mode. This is useful when both the host and the guest are exposed with an SMMUv3 and a PCI device is assigned to the guest using VFIO. In this mode, the physical IOMMU must be programmed to translate the two stages: the one set up by the guest (IOVA -> GPA) and the one set up by the host VFIO driver as part of the assignment process (GPA -> HPA). On Intel, this is traditionnaly achieved by combining the 2 stages into a single physical stage. However this relies on the capability to trap on each guest translation structure update. This is possible by using the VTD Caching Mode. Unfortunately the ARM SMMUv3 does not offer a similar mechanism. However, the ARM SMMUv3 architecture supports 2 physical stages! Those were devised exactly with that use case in mind. Assuming the HW implements both stages (optional), the guest now can use stage 1 while the host uses stage 2. This assumes the virtualizer has means to propagate guest settings to the host SMMUv3 driver. This series brings this VFIO/IOMMU infrastructure. Those services are: - bind the guest stage 1 configuration to the stream table entry - propagate guest TLB invalidations - bind MSI IOVAs This series largely reuses the infrastructure devised for SVA/SVM and patches submitted by Jacob and Liu in [1] and [2] and Jean-Philippe [3], with some generalizations to adapt to this use case. At the moment, this series does not implement fault reporting to the guest. This will be added later on. Best Regards Eric This series can be found at: https://github.com/eauger/linux/tree/v4.18-2stage-rfc This was tested on Qualcomm HW featuring SMMUv3 and with adapted QEMU vSMMUv3. References: [1] [PATCH v5 00/23] IOMMU and VT-d driver support for Shared Virtual Address (SVA) https://lwn.net/Articles/754331/ [2] [RFC PATCH 0/8] Shared Virtual Memory virtualization for VT-d (VFIO part) https://lists.linuxfoundation.org/pipermail/iommu/2017-April/021475.html [3] [v2,17/40] iommu/arm-smmu-v3: Link domains and devices https://patchwork.kernel.org/patch/10395187/ Eric Auger (8): iommu: Introduce bind_guest_msi vfio: VFIO_IOMMU_BIND_MSI vfio: Document nested stage control iommu/smmuv3: Get prepared for nested stage support iommu/smmuv3: Implement bind_guest_stage iommu/smmuv3: Implement tlb_invalidate dma-iommu: Implement NESTED_MSI cookie iommu/smmuv3: Implement bind_guest_msi Jacob Pan (1): iommu: Introduce bind_guest_stage API Jean-Philippe Brucker (1): iommu/arm-smmu-v3: Link domains and devices Liu, Yi L (3): iommu: Introduce tlb_invalidate API vfio: VFIO_IOMMU_BIND_GUEST_STAGE vfio: VFIO_IOMMU_TLB_INVALIDATE Documentation/vfio.txt | 45 ++++++++++ drivers/iommu/arm-smmu-v3.c | 179 ++++++++++++++++++++++++++++++++++++++-- drivers/iommu/dma-iommu.c | 88 +++++++++++++++++++- drivers/iommu/iommu.c | 43 ++++++++++ drivers/vfio/vfio_iommu_type1.c | 110 ++++++++++++++++++++++++ include/linux/dma-iommu.h | 11 +++ include/linux/iommu.h | 48 +++++++++++ include/uapi/linux/iommu.h | 157 +++++++++++++++++++++++++++++++++++ include/uapi/linux/vfio.h | 22 +++++ 9 files changed, 692 insertions(+), 11 deletions(-) create mode 100644 include/uapi/linux/iommu.h -- 2.5.5 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
