Hi Joerg and all,
Just wondering if you have more comments for this version. Since
the complete vSVA patchset is quite large, my hope is that we can make
incremental progress with smaller sets.
My plans are:
1. vSVA IOMMU APIs and VT-d support of PCI devices (this patchset)
2. Page request service
3. mdev support
4. code merge with Jean's generic sva_bind() APIs
For this set, we don't need PRS related patches (1-4). I included
them because they are in Jean's common API repo. Could you review 5-19
and consider for v5.4? This will make further submissions much easier.
Thanks,
Jacob
On Thu, 15 Aug 2019 13:13:06 -0700
Jacob Pan 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 |--|
> vv 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] Common APIs git://linux-arm.org/linux-jpb.git sva/api
>
> [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] with minor tweaks. With
> this patchset, guest SVA without page request works on VT-d. PRS
> patches will come next as we try to avoid large patchset that is hard
> to review. The patches for basic SVA support (w/o PRS) starts:
> [PATCH v5 05/19] iommu: Introduce attach/detach_pasid_table API
>
> 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:
> - V5
> Rebased on v5.3-rc4 which has some of the IOMMU fault APIs
> merged. Addressed v4 review comments from Eric Auger, Baolu Lu, and
> Jonathan Cameron. Specific changes are as follows:
> - Refined custom IOASID allocator to support multiple
> vIOMMU, hotplug cases.
> - Extracted vendor data from IOMMU guest PASID bind data,
> for VT-d will support all necessary guest PASID entry fields for PASID
> bind.
> - Support non-identity host-guest PASID mapping
> - Exception handling in various cases
>
> - V4
> - Redesigned IOASID allocator such that it can support
> custom allocators with shared helper functions. Use separate XArray
> to store IOASIDs per allocator. Took advice from Eric Auger
> to have default allocator use the generic allocator structure.
> Combined into one patch in
