Re: [PATCH v3 00/16] Shared virtual address IOMMU and VT-d support

Jacob Pan
2019-05-15T16:28:23Z

Hi all,
Just wondering if you have any more feedbacks other than the cache
invalidate API change for archid?
I plan to do the next version on top of Jean's sva/api branch (common
iommu APIs) with minor tweak to support non-identity guest-host PASID
mapping. It would be great if I can address additional comments
together.

Thanks!

Jacob

On Fri, 3 May 2019 15:32:01 -0700
Jacob Pan <jacob.jun.pan@linux.intel.com> wrote:

> Shared virtual address (SVA), a.k.a, Shared virtual memory (SVM) on
> Intel platforms allow address space sharing between device DMA and
> applications. SVA can reduce programming complexity and enhance
> security. This series is intended to enable SVA virtualization, i.e.
> shared guest application address space and physical device DMA
> address. Only IOMMU portion of the changes are included in this
> series. Additional support is needed in VFIO and QEMU (will be
> submitted separately) to complete this functionality.
>
> To make incremental changes and reduce the size of each patchset.
> This series does not inlcude support for page request services.
>
> In VT-d implementation, PASID table is per device and maintained in
> the host. Guest PASID table is shadowed in VMM where virtual IOMMU is
> emulated.
>
> .-------------. .---------------------------.
> | vIOMMU | | Guest process CR3, FL only|
> | | '---------------------------'
> .----------------/
> | PASID Entry |--- PASID cache flush -
> '-------------' |
> | | V
> | | CR3 in GPA
> '-------------'
> Guest
> ------| Shadow |--------------------------|--------
> v v v
> Host
> .-------------. .----------------------.
> | pIOMMU | | Bind FL for GVA-GPA |
> | | '----------------------'
> .----------------/ |
> | PASID Entry | V (Nested xlate)
> '----------------\.------------------------------.
> | | |SL for GPA-HPA, default domain|
> | | '------------------------------'
> '-------------'
> Where:
> - FL = First level/stage one page tables
> - SL = Second level/stage two page tables
>
>
> This work is based on collaboration with other developers on the IOMMU
> mailing list. Notably,
>
> [1] [PATCH v6 00/22] SMMUv3 Nested Stage Setup by Eric Auger
> https://lkml.org/lkml/2019/3/17/124
>
> [2] [RFC PATCH 2/6] drivers core: Add I/O ASID allocator by
> Jean-Philippe Brucker
> https://www.spinics.net/lists/iommu/msg30639.html
>
> [3] [RFC PATCH 0/5] iommu: APIs for paravirtual PASID allocation by
> Lu Baolu https://lkml.org/lkml/2018/11/12/1921
>
> [4] [PATCH v5 00/23] IOMMU and VT-d driver support for Shared Virtual
> Address (SVA)
> https://lwn.net/Articles/754331/
>
> There are roughly three parts:
> 1. Generic PASID allocator [1] with extension to support custom
> allocator 2. IOMMU cache invalidation passdown from guest to host
> 3. Guest PASID bind for nested translation
>
> All generic IOMMU APIs are reused from [1], which has a v7 just
> published with no real impact to the patches used here. It is worth
> noting that unlike sMMU nested stage setup, where PASID table is
> owned by the guest, VT-d PASID table is owned by the host, individual
> PASIDs are bound instead of the PASID table.
>
> This series is based on the new VT-d 3.0 Specification
> (https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf).
> This is different than the older series in [4] which was based on the
> older specification that does not have scalable mode.
>
>
> ChangeLog:
> - V3
> - Addressed thorough review comments from Eric Auger (Thank
> you!)
> - Moved IOASID allocator from driver core to IOMMU code per
> suggestion by Christoph Hellwig
> (https://lkml.org/lkml/2019/4/26/462)
> - Rebased on top of Jean's SVA API branch and Eric's v7[1]
> (git://linux-arm.org/linux-jpb.git sva/api)
> - All IOMMU APIs are unmodified (except the new bind guest
> PASID call in patch 9/16)
>
> - V2
> - Rebased on Joerg's IOMMU x86/vt-d branch v5.1-rc4
> - Integrated with Eric Auger's new v7 series for common APIs
> (https://github.com/eauger/linux/tree/v5.1-rc3-2stage-v7)
> - Addressed review comments from Andy Shevchenko and Alex
> Williamson on IOASID custom allocator.
> - Support multiple custom IOASID allocators (vIOMMUs) and
> dynamic registration.
>
>
> Jacob Pan (13):
> iommu: Introduce attach/detach_pasid_table API
> ioasid: Add custom IOASID allocator
> iommu/vt-d: Add custom allocator for IOASID
> iommu/vtd: Optimize tlb invalidation for vIOMMU
> iommu/vt-d: Replace Intel specific PASID allocator with IOASID
> iommu: Introduce guest PASID bind function
> iommu/vt-d: Move domain helper to header
> iommu/vt-d: Avoid duplicated code for PASID setup
> iommu/vt-d: Add nested translation helper function
> iommu/vt-d: Clean up for SVM device list
> iommu/vt-d: Add bind guest PASID support
> iommu/vt-d: Support flushing more translation cache types
> iommu/vt-d: Add svm/sva invalidate function
>
> Jean-Philippe Brucker (1):
> iommu: Add I/O ASID allocator
>
> Liu, Yi L (1):
> iommu: Introduce cache_invalidate API
>
> Lu Baolu (1):
> iommu/vt-d: Enlightened PASID allocation
>
> drivers/iommu/Kconfig | 7 ++
> drivers/iommu/Makefile | 1 +
> drivers/iommu/dmar.c | 50 ++++++++
> drivers/iommu/intel-iommu.c | 241
> ++++++++++++++++++++++++++++++++++-- drivers/iommu/intel-pasid.c |
> 223 +++++++++++++++++++++++++-------- drivers/iommu/intel-pasid.h |
> 24 +++- drivers/iommu/intel-svm.c | 293
> +++++++++++++++++++++++++++++++++++---------
> drivers/iommu/ioasid.c | 265
> +++++++++++++++++++++++++++++++++++++++ drivers/iommu/iommu.c
> | 53 ++++++++ include/linux/intel-iommu.h | 41 ++++++-
> include/linux/intel-svm.h | 7 ++ include/linux/ioasid.h |
> 67 ++++++++++ include/linux/iommu.h | 43 ++++++-
> include/uapi/linux/iommu.h | 140 +++++++++++++++++++++
> 14 files changed, 1328 insertions(+), 127 deletions(-)
> create mode 100644 drivers/iommu/ioasid.c
> create mode 100644 include/linux/ioasid.h
>

[Jacob Pan]