[PATCH v4 00/22] Shared virtual address IOMMU and VT-d support

From: Jacob Pan
Date: Sun Jun 09 2019 - 09:47:07 EST


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:
- 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 that the default allocator is just
"another" allocator now. Can be built as a module in case of
driver use without IOMMU.
- Extended bind guest PASID data to support SMMU and non-identity
guest to host PASID mapping https://lkml.org/lkml/2019/5/21/802
- Rebased on Jean's sva/api common tree, new patches starts with
[PATCH v4 10/22]

- 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 (17):
driver core: Add per device iommu param
iommu: Introduce device fault data
iommu: Introduce device fault report API
iommu: Add a timeout parameter for PRQ response
iommu: Use device fault trace event
iommu: Introduce attach/detach_pasid_table API
iommu: Fix compile error without IOMMU_API
iommu: Introduce guest PASID bind function
iommu/vt-d: Add custom allocator for IOASID
iommu/vt-d: Replace Intel specific PASID allocator with IOASID
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 (3):
iommu: Add recoverable fault reporting
trace/iommu: Add sva trace events
iommu: Add I/O ASID allocator

Liu Yi L (1):
iommu: Introduce cache_invalidate API

Lu Baolu (1):
iommu/vt-d: Enlightened PASID allocation

Documentation/admin-guide/kernel-parameters.txt | 8 +
drivers/iommu/Kconfig | 9 +
drivers/iommu/Makefile | 1 +
drivers/iommu/dmar.c | 50 +++
drivers/iommu/intel-iommu.c | 251 +++++++++++++-
drivers/iommu/intel-pasid.c | 223 ++++++++++---
drivers/iommu/intel-pasid.h | 24 +-
drivers/iommu/intel-svm.c | 301 ++++++++++++++---
drivers/iommu/ioasid.c | 427 ++++++++++++++++++++++++
drivers/iommu/iommu.c | 282 +++++++++++++++-
include/linux/device.h | 3 +
include/linux/intel-iommu.h | 44 ++-
include/linux/intel-svm.h | 17 +
include/linux/ioasid.h | 74 ++++
include/linux/iommu.h | 178 +++++++++-
include/trace/events/iommu.h | 87 +++++
include/uapi/linux/iommu.h | 338 +++++++++++++++++++
17 files changed, 2190 insertions(+), 127 deletions(-)
create mode 100644 drivers/iommu/ioasid.c
create mode 100644 include/linux/ioasid.h
create mode 100644 include/uapi/linux/iommu.h

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2.7.4