Virtual Accelerator Switchboard (VAS) allows kernel subsystems and user space processes to directly access the Nest Accelerator (NX) engines which provides HW compression. The true user mode VAS/NX support on PowerNV is already included in Linux. Whereas PowerVM support is available from P10 onwards.
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. 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, the hypervisor 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 configured. - 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 req_max_processed_len. 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. Patch 1: Fix to release reference to tgid during window close Patches 2- 6: Move the code that is needed for both PowerNV and PowerVM to powerpc book3s platform directory Patch 7: Modify vas-window struct to support both platforms and the related changes. Patch 8: Define HCALL and the related VAS/NXGZIP specific structs. Patch 9: Define QoS credit flag in window open ioctl Patch 10: Implement Allocate, Modify and Deallocate HCALLs Patch 11: Retrieve VAS capabilities from the hypervisor Patch 12; Implement window operations and integrate with API Patch 13: Setup IRQ and NX fault handling Patch 14 - 15: Make the code common to add NX-GZIP enablement Patch 16: Get NX capabilities from the hypervisor patch 17; Add sysfs interface to expose NX capabilities Changes in v2: - Rebase on 5.12-rc6 - Moved VAS Kconfig changes to arch/powerpc/platform as suggested by Christophe Leroy - build fix with allyesconfig (reported by kernel test build) Changes in v3: - Rebase on 5.12-rc7 - Moved vas-api.c and VAS Kconfig changes to arch/powerpc/platform/book3s as Michael Ellerman suggested Changes in v4: - Rebase on 5.13-rc2 - Changes based on review comments from Nicholas Piggin - Add seperate patch to define user window operations - Drop "sysfs interface to export VAS capabilities" patch This interface is mainly needed for DLPAR operations and this patch will be included when DLPAR/LPM support is added. - Other cleanup changes Changes in v5: - Rebase on 5.13-rc5 - Changes based on review comments from Nicholas Piggin and Michael Ellerman: - Add new patch to fix tgid reference release. This fix should be also included in stable 5.8+ - Define platform specific VAS window structs - Define helper functions to take and release pid, tgid and mm references - Other cleanup suggestions Haren Myneni (17): powerpc/powernv/vas: Release reference to tgid during window close powerpc/vas: Move VAS API to book3s common platform powerpc/powernv/vas: Rename register/unregister functions powerpc/vas: Add platform specific user window operations powerpc/vas: Create take/drop pid and mm reference functions powerpc/vas: Move update_csb/dump_crb to common book3s platform 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: Add hcall wrappers for VAS handling powerpc/pseries/vas: Implement getting capabilities from hypervisor powerpc/pseries/vas: Integrate API with open/close windows powerpc/pseries/vas: Setup IRQ and fault handling crypto/nx: Rename nx-842-pseries file name to nx-common-pseries crypto/nx: Register and unregister VAS interface on PowerVM crypto/nx: Get NX capabilities for GZIP coprocessor type crypto/nx: Add sysfs interface to export NX capabilities arch/powerpc/include/asm/hvcall.h | 7 + arch/powerpc/include/asm/vas.h | 109 ++- arch/powerpc/include/uapi/asm/vas-api.h | 6 +- arch/powerpc/platforms/Kconfig | 1 + arch/powerpc/platforms/Makefile | 1 + arch/powerpc/platforms/book3s/Kconfig | 15 + arch/powerpc/platforms/book3s/Makefile | 2 + arch/powerpc/platforms/book3s/vas-api.c | 473 +++++++++++++ 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 | 27 +- arch/powerpc/platforms/powernv/vas-fault.c | 173 +---- arch/powerpc/platforms/powernv/vas-trace.h | 4 +- arch/powerpc/platforms/powernv/vas-window.c | 264 ++++---- arch/powerpc/platforms/powernv/vas.h | 48 +- arch/powerpc/platforms/pseries/Makefile | 1 + arch/powerpc/platforms/pseries/vas.c | 636 ++++++++++++++++++ arch/powerpc/platforms/pseries/vas.h | 125 ++++ drivers/crypto/nx/Kconfig | 1 + drivers/crypto/nx/Makefile | 2 +- drivers/crypto/nx/nx-common-powernv.c | 6 +- .../{nx-842-pseries.c => nx-common-pseries.c} | 138 ++++ 23 files changed, 1717 insertions(+), 616 deletions(-) create mode 100644 arch/powerpc/platforms/book3s/Kconfig create mode 100644 arch/powerpc/platforms/book3s/Makefile create mode 100644 arch/powerpc/platforms/book3s/vas-api.c delete mode 100644 arch/powerpc/platforms/powernv/vas-api.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%) -- 2.18.2
