Le 11/04/2021 à 02:27, Haren Myneni a écrit :

This patch series enables VAS / NX-GZIP on powerVM which allows
the user space to do copy/paste with the same existing interface
that is available on powerNV.

Can you explain (here and in patch 1 at least) what VAS and NX means ?
Is that Vector Addition System ? Is that Virtual Address Space ?

VAS Enablement:
- Get all VAS capabilities using H_QUERY_VAS_CAPABILITIES that are
   available in the hypervisor. These capabilities tells OS which
   type of features (credit types such as Default and Quality of
   Service (QoS)). Also gives specific capabilities for each credit
   type: Maximum window credits, Maximum LPAR credits, Target credits
   in that parition (varies from max LPAR credits based DLPAR
   operation), whether supports user mode COPY/PASTE and etc.
- Register LPAR VAS operations such as open window. get paste
   address and close window with the current VAS user space API.
- Open window operation - Use H_ALLOCATE_VAS_WINDOW HCALL to open
   window and H_MODIFY_VAS_WINDOW HCALL to setup the window with LPAR
   PID and etc.
- mmap to paste address returned in H_ALLOCATE_VAS_WINDOW HCALL
- To close window, H_DEALLOCATE_VAS_WINDOW HCALL is used to close in
   the hypervisor.

NX Enablement:
- Get NX capabilities from the the hypervisor which provides Maximum
   buffer length in a single GZIP request, recommended minimum
   compression / decompression lengths.
- Register to VAS to enable user space VAS API

Main feature differences with powerNV implementation:
- Each VAS window will be configured with a number of credits which
   means that many requests can be issues simultaniously on that
   window. On powerNV, 1K credits are configured per window.
   Whereas on powerVM, the hypervisor allows 1 credit per window
   at present.
- The hypervisor introduced 2 different types of credits: Default -
   Uses normal priority FIFO and Quality of Service (QoS) - Uses high
   priority FIFO. On powerVM, VAS/NX HW resources are shared across
   LPARs. The total number of credits available on a system depends
   on cores configured. We may see more credits are assigned across
   the system than the NX HW resources can handle. So to avoid NX HW
   contention, pHyp introduced QoS credits which can be configured
   by system administration with HMC API. Then the total number of
   available default credits on LPAR varies based on QoS credits
- On powerNV, windows are allocated on a specific VAS instance
   and the user space can select VAS instance with the open window
   ioctl. Since VAS instances can be shared across partitions on
   powerVM, the hypervisor manages window allocations on different
   VAS instances. So H_ALLOCATE_VAS_WINDOW allows to select by domain
   indentifiers (H_HOME_NODE_ASSOCIATIVITY values by cpu). By default
   the hypervisor selects VAS instance closer to CPU resources that the
   parition uses. So vas_id in ioctl interface is ignored on powerVM
   except vas_id=-1 which is used to allocate window based on CPU that
   the process is executing. This option is needed for process affinity
   to NUMA node.

   The existing applications that linked with libnxz should work as
   long as the job request length is restricted to

   Tested the following patches on P10 successfully with test cases
   given: https://github.com/libnxz/power-gzip

   Note: The hypervisor supports user mode NX from p10 onwards. Linux
        supports user mode VAS/NX on P10 only with radix page tables.

Patches 1- 4:   Make the code that is needed for both powerNV and
                 powerVM to powerpc platform independent.
Patch5:         Modify vas-window struct to support both and the
                 related changes.
Patch 6:        Define HCALL and the related VAS/NXGZIP specific
Patch 7:        Define QoS credit flag in window open ioctl
Patch 8:        Implement Allocate, Modify and Deallocate HCALLs
Patch 9:        Retrieve VAS capabilities from the hypervisor
Patch 10;       Implement window operations and integrate with API
Patch 11:       Setup IRQ and NX fault handling
Patch 12;       Add sysfs interface to expose VAS capabilities
Patch 13 - 14:  Make the code common to add NX-GZIP enablement
Patch 15:       Get NX capabilities from the hypervisor
patch 16;       Add sysfs interface to expose NX capabilities

Haren Myneni (16):
   powerpc/powernv/vas: Rename register/unregister functions
   powerpc/vas: Make VAS API powerpc platform independent
   powerpc/vas: Create take/drop task reference functions
   powerpc/vas: Move update_csb/dump_crb to platform independent
   powerpc/vas:  Define and use common vas_window struct
   powerpc/pseries/vas: Define VAS/NXGZIP HCALLs and structs
   powerpc/vas: Define QoS credit flag to allocate window
   powerpc/pseries/vas: Implement allocate/modify/deallocate HCALLS
   powerpc/pseries/vas: Implement to get all capabilities
   powerpc/pseries/vas: Integrate API with open/close windows
   powerpc/pseries/vas: Setup IRQ and fault handling
   powerpc/pseries/vas: sysfs interface to export capabilities
   crypto/nx: Rename nx-842-pseries file name to nx-common-pseries
   crypto/nx: Register and unregister VAS interface
   crypto/nx: Get NX capabilities for GZIP coprocessor type
   crypto/nx: sysfs interface to export NX capabilities

  arch/powerpc/Kconfig                          |  15 +
  arch/powerpc/include/asm/hvcall.h             |   7 +
  arch/powerpc/include/asm/vas.h                | 122 +++-
  arch/powerpc/include/uapi/asm/vas-api.h       |   6 +-
  arch/powerpc/kernel/Makefile                  |   1 +
  arch/powerpc/kernel/vas-api.c                 | 485 +++++++++++++
  arch/powerpc/platforms/powernv/Kconfig        |  14 -
  arch/powerpc/platforms/powernv/Makefile       |   2 +-
  arch/powerpc/platforms/powernv/vas-api.c      | 278 --------
  arch/powerpc/platforms/powernv/vas-debug.c    |  12 +-
  arch/powerpc/platforms/powernv/vas-fault.c    | 155 +---
  arch/powerpc/platforms/powernv/vas-trace.h    |   6 +-
  arch/powerpc/platforms/powernv/vas-window.c   | 250 ++++---
  arch/powerpc/platforms/powernv/vas.h          |  42 +-
  arch/powerpc/platforms/pseries/Makefile       |   1 +
  arch/powerpc/platforms/pseries/vas-sysfs.c    | 173 +++++
  arch/powerpc/platforms/pseries/vas.c          | 674 ++++++++++++++++++
  arch/powerpc/platforms/pseries/vas.h          |  98 +++
  drivers/crypto/nx/Makefile                    |   2 +-
  drivers/crypto/nx/nx-common-powernv.c         |   6 +-
  .../{nx-842-pseries.c => nx-common-pseries.c} | 135 ++++
  21 files changed, 1885 insertions(+), 599 deletions(-)
  create mode 100644 arch/powerpc/kernel/vas-api.c
  delete mode 100644 arch/powerpc/platforms/powernv/vas-api.c
  create mode 100644 arch/powerpc/platforms/pseries/vas-sysfs.c
  create mode 100644 arch/powerpc/platforms/pseries/vas.c
  create mode 100644 arch/powerpc/platforms/pseries/vas.h
  rename drivers/crypto/nx/{nx-842-pseries.c => nx-common-pseries.c} (90%)

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