On Thu, 30 Apr 2020 16:33:59 +0200 Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> wrote: > Shared Virtual Addressing (SVA) allows to share process page tables > with devices using the IOMMU, PASIDs and I/O page faults. Add SVA > support to the Arm SMMUv3 driver. > > Since v5 [1]: > > * Added patches 1-3. Patch 1 adds a PASID field to mm_struct as > discussed in [1] and [2]. This is also needed for Intel ENQCMD. > Patch 2 adds refcounts to IOASID and patch 3 adds a couple of helpers > to allocate the PASID. > > * Dropped most of iommu-sva.c. After getting rid of io_mm following > review of v5, there wasn't enough generic code left to justify the > indirect branch overhead of io_mm_ops in the MMU notifiers. I ended > up with more glue than useful code, and couldn't find an easy way to > deal with domains in the SMMU driver (we keep PASID tables per domain, > while x86 keeps them per device). The direct approach in patch 17 is > nicer and a little easier to read. The SMMU driver only gained 160 > lines, while iommu-sva lost 470 lines. > > As a result I dropped the MMU notifier patch. > > Jacob, one upside of this rework is that we now free ioasids in > blocking context, which might help with your addition of notifiers > to ioasid.c > Thanks for the note. It does make notifier much easier, plus the refcount can alleviate the constraint on ordering. I guess we don't share mmu notifier code for now :) > * Simplified io-pgfault a bit, since flush() isn't called from mm exit > path anymore. > > * Fixed a bug in patch 17 (don't clear the stall bit when stall is > forced). > > You can find the latest version on https://jpbrucker.net/git/linux > branch sva/current, and sva/zip-devel for the Hisilicon zip > accelerator. > > [1] > https://lore.kernel.org/linux-iommu/20200414170252.714402-1-jean-philippe@xxxxxxxxxx/ > [2] > https://lore.kernel.org/linux-iommu/1585596788-193989-6-git-send-email-fenghua.yu@xxxxxxxxx/ > > Jean-Philippe Brucker (25): > mm: Add a PASID field to mm_struct > iommu/ioasid: Add ioasid references > iommu/sva: Add PASID helpers > iommu: Add a page fault handler > iommu/iopf: Handle mm faults > arm64: mm: Add asid_gen_match() helper > arm64: mm: Pin down ASIDs for sharing mm with devices > iommu/io-pgtable-arm: Move some definitions to a header > iommu/arm-smmu-v3: Manage ASIDs with xarray > arm64: cpufeature: Export symbol read_sanitised_ftr_reg() > iommu/arm-smmu-v3: Share process page tables > iommu/arm-smmu-v3: Seize private ASID > iommu/arm-smmu-v3: Add support for VHE > iommu/arm-smmu-v3: Enable broadcast TLB maintenance > iommu/arm-smmu-v3: Add SVA feature checking > iommu/arm-smmu-v3: Add SVA device feature > iommu/arm-smmu-v3: Implement iommu_sva_bind/unbind() > iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops > iommu/arm-smmu-v3: Add support for Hardware Translation Table Update > iommu/arm-smmu-v3: Maintain a SID->device structure > dt-bindings: document stall property for IOMMU masters > iommu/arm-smmu-v3: Add stall support for platform devices > PCI/ATS: Add PRI stubs > PCI/ATS: Export PRI functions > iommu/arm-smmu-v3: Add support for PRI > > drivers/iommu/Kconfig | 11 + > drivers/iommu/Makefile | 2 + > .../devicetree/bindings/iommu/iommu.txt | 18 + > arch/arm64/include/asm/mmu.h | 1 + > arch/arm64/include/asm/mmu_context.h | 11 +- > drivers/iommu/io-pgtable-arm.h | 30 + > drivers/iommu/iommu-sva.h | 15 + > include/linux/ioasid.h | 10 +- > include/linux/iommu.h | 53 + > include/linux/mm_types.h | 4 + > include/linux/pci-ats.h | 8 + > arch/arm64/kernel/cpufeature.c | 1 + > arch/arm64/mm/context.c | 103 +- > drivers/iommu/arm-smmu-v3.c | 1554 > +++++++++++++++-- drivers/iommu/io-pgfault.c | > 458 +++++ drivers/iommu/io-pgtable-arm.c | 27 +- > drivers/iommu/ioasid.c | 30 +- > drivers/iommu/iommu-sva.c | 85 + > drivers/iommu/of_iommu.c | 5 +- > drivers/pci/ats.c | 4 + > MAINTAINERS | 3 +- > 21 files changed, 2275 insertions(+), 158 deletions(-) > create mode 100644 drivers/iommu/io-pgtable-arm.h > create mode 100644 drivers/iommu/iommu-sva.h > create mode 100644 drivers/iommu/io-pgfault.c > create mode 100644 drivers/iommu/iommu-sva.c > [Jacob Pan]
