Auger Eric
2021-Jan-19 09:03 UTC
[PATCH RFC v1 00/15] iommu/virtio: Nested stage support with Arm
Hi Vivek, On 1/15/21 1:13 PM, Vivek Gautam wrote:> This patch-series aims at enabling Nested stage translation in guests > using virtio-iommu as the paravirtualized iommu. The backend is supported > with Arm SMMU-v3 that provides nested stage-1 and stage-2 translation. > > This series derives its purpose from various efforts happening to add > support for Shared Virtual Addressing (SVA) in host and guest. On Arm, > most of the support for SVA has already landed. The support for nested > stage translation and fault reporting to guest has been proposed [1]. > The related changes required in VFIO [2] framework have also been put > forward. > > This series proposes changes in virtio-iommu to program PASID tables > and related stage-1 page tables. A simple iommu-pasid-table library > is added for this purpose that interacts with vendor drivers to > allocate and populate PASID tables. > In Arm SMMUv3 we propose to pull the Context Descriptor (CD) management > code out of the arm-smmu-v3 driver and add that as a glue vendor layer > to support allocating CD tables, and populating them with right values. > These CD tables are essentially the PASID tables and contain stage-1 > page table configurations too. > A request to setup these CD tables come from virtio-iommu driver using > the iommu-pasid-table library when running on Arm. The virtio-iommu > then pass these PASID tables to the host using the right virtio backend > and support in VMM. > > For testing we have added necessary support in kvmtool. The changes in > kvmtool are based on virtio-iommu development branch by Jean-Philippe > Brucker [3]. > > The tested kernel branch contains following in the order bottom to top > on the git hash - > a) v5.11-rc3 > b) arm-smmu-v3 [1] and vfio [2] changes from Eric to add nested page > table support for Arm. > c) Smmu test engine patches from Jean-Philippe's branch [4] > d) This series > e) Domain nesting info patches [5][6][7]. > f) Changes to add arm-smmu-v3 specific nesting info (to be sent to > the list). > > This kernel is tested on Neoverse reference software stack with > Fixed virtual platform. Public version of the software stack and > FVP is available here[8][9]. > > A big thanks to Jean-Philippe for his contributions towards this work > and for his valuable guidance. > > [1] https://lore.kernel.org/linux-iommu/20201118112151.25412-1-eric.auger at redhat.com/T/ > [2] https://lore.kernel.org/kvmarm/20201116110030.32335-12-eric.auger at redhat.com/T/ > [3] https://jpbrucker.net/git/kvmtool/log/?h=virtio-iommu/devel > [4] https://jpbrucker.net/git/linux/log/?h=sva/smmute > [5] https://lore.kernel.org/kvm/1599734733-6431-2-git-send-email-yi.l.liu at intel.com/ > [6] https://lore.kernel.org/kvm/1599734733-6431-3-git-send-email-yi.l.liu at intel.com/ > [7] https://lore.kernel.org/kvm/1599734733-6431-4-git-send-email-yi.l.liu at intel.com/ > [8] https://developer.arm.com/tools-and-software/open-source-software/arm-platforms-software/arm-ecosystem-fvps > [9] https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms.git/about/docs/rdn1edge/user-guide.rstCould you share a public branch where we could find all the kernel pieces. Thank you in advance Best Regards Eric> > Jean-Philippe Brucker (6): > iommu/virtio: Add headers for table format probing > iommu/virtio: Add table format probing > iommu/virtio: Add headers for binding pasid table in iommu > iommu/virtio: Add support for INVALIDATE request > iommu/virtio: Attach Arm PASID tables when available > iommu/virtio: Add support for Arm LPAE page table format > > Vivek Gautam (9): > iommu/arm-smmu-v3: Create a Context Descriptor library > iommu: Add a simple PASID table library > iommu/arm-smmu-v3: Update drivers to work with iommu-pasid-table > iommu/arm-smmu-v3: Update CD base address info for user-space > iommu/arm-smmu-v3: Set sync op from consumer driver of cd-lib > iommu: Add asid_bits to arm smmu-v3 stage1 table info > iommu/virtio: Update table format probing header > iommu/virtio: Prepare to add attach pasid table infrastructure > iommu/virtio: Update fault type and reason info for viommu fault > > drivers/iommu/arm/arm-smmu-v3/Makefile | 2 +- > .../arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c | 283 +++++++ > .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 16 +- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 268 +------ > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 4 +- > drivers/iommu/iommu-pasid-table.h | 140 ++++ > drivers/iommu/virtio-iommu.c | 692 +++++++++++++++++- > include/uapi/linux/iommu.h | 2 +- > include/uapi/linux/virtio_iommu.h | 158 +++- > 9 files changed, 1303 insertions(+), 262 deletions(-) > create mode 100644 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c > create mode 100644 drivers/iommu/iommu-pasid-table.h >