[PATCH 0/2] A General Accelerator Framework, WarpDrive

[Zhangfei Gao]

*WarpDrive* is a general accelerator framework for the user application to
access the hardware without going through the kernel in data path.

WarpDrive is the name for the whole framework. The component in kernel
is called uacce, meaning "Unified/User-space-access-intended Accelerator
Framework". It makes use of the capability of IOMMU to maintain a
unified virtual address space between the hardware and the process.

WarpDrive is intended to be used with Jean Philippe Brucker's SVA
patchset[1], which enables IO side page fault and PASID support. 
We have keep verifying with Jean's sva/current [2]
We also keep verifying with Eric's SMMUv3 Nested Stage patch [3]

This series and related zip & qm driver as well as dummy driver for qemu test:
https://github.com/Linaro/linux-kernel-warpdrive/tree/5.3-rc1-warpdrive-v1
zip driver already been upstreamed.
zip supporting uacce will be the next step.

The library and user application:
https://github.com/Linaro/warpdrive/tree/wdprd-v1-current

Change History:
v4 changed from V3
1. Rebase to 5.3-rc1
2. Build on iommu interface
3. Verifying with Jean's sva and Eric's nested mode iommu.
4. User library has developed a lot: support zlib, openssl etc.
5. Move to misc first

V3 changed from V2:
https://lkml.org/lkml/2018/11/12/1951
1. Build uacce from original IOMMU interface. V2 is built on VFIO.
   But the VFIO way locking the user memory in place will not
   work properly if the process fork a child. Because the
   copy-on-write strategy will make the parent process lost its
   page. This is not acceptable to accelerator user.
2. The kernel component is renamed to uacce from sdmdev accordingly
3. Document is updated for the new design. The Static Shared
   Virtual Memory concept is introduced to replace the User
	Memory Sharing concept.
4. Rebase to the lastest kernel (4.20.0-rc1)
5. As an RFC, this version is tested only with "test-to-pass"
   test case and not tested with Jean's SVA patch.

V2 changed from V1:
https://lwn.net/Articles/763990/
1. Change kernel framework name from SPIMDEV (Share Parent IOMMU
   Mdev) to SDMDEV (Share Domain Mdev).
2. Allocate Hardware Resource when a new mdev is created (While
   it is allocated when the mdev is openned)
3. Unmap pages from the shared domain when the sdmdev iommu group is
   detached. (This procedure is necessary, but missed in V1)
4. Update document accordingly.
5. Rebase to the latest kernel (4.19.0-rc1)

References:
[1] http://jpbrucker.net/sva/
[2] http://www.linux-arm.org/git?p=linux-jpb.git;a=shortlog;h=refs/heads/sva/current
[3] https://github.com/eauger/linux/tree/v5.3.0-rc0-2stage-v9

Kenneth Lee (2):
  uacce: Add documents for WarpDrive/uacce
  uacce: add uacce module

 Documentation/misc-devices/warpdrive.rst |  351 +++++++++
 drivers/misc/Kconfig                     |    1 +
 drivers/misc/Makefile                    |    1 +
 drivers/misc/uacce/Kconfig               |   13 +
 drivers/misc/uacce/Makefile              |    2 +
 drivers/misc/uacce/uacce.c               | 1186 ++++++++++++++++++++++++++++++
 include/linux/uacce.h                    |  109 +++
 include/uapi/misc/uacce.h                |   44 ++
 8 files changed, 1707 insertions(+)
 create mode 100644 Documentation/misc-devices/warpdrive.rst
 create mode 100644 drivers/misc/uacce/Kconfig
 create mode 100644 drivers/misc/uacce/Makefile
 create mode 100644 drivers/misc/uacce/uacce.c
 create mode 100644 include/linux/uacce.h
 create mode 100644 include/uapi/misc/uacce.h

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