| Message ID | 20200420070711.223545-1-vaibhav@linux.ibm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | powerpc/papr_scm: Add support for reporting nvdimm health | expand |
Vaibhav Jain <vaibhav@linux.ibm.com> writes: > The PAPR standard[1][3] provides mechanisms to query the health and > performance stats of an NVDIMM via various hcalls as described in > Ref[2]. Until now these stats were never available nor exposed to the > user-space tools like 'ndctl'. This is partly due to PAPR platform not > having support for ACPI and NFIT. Hence 'ndctl' is unable to query and > report the dimm health status and a user had no way to determine the > current health status of a NDVIMM. > > To overcome this limitation, this patch-set updates papr_scm kernel > module to query and fetch nvdimm health stats using hcalls described > in Ref[2]. This health and performance stats are then exposed to > userspace via syfs and PAPR-nvDimm-Specific-Methods(PDSM) issued by > libndctl. > > These changes coupled with proposed ndtcl changes located at Ref[4] > should provide a way for the user to retrieve NVDIMM health status > using ndtcl. > > Below is a sample output using proposed kernel + ndctl for PAPR NVDIMM > in a emulation environment: > > # ndctl list -DH > [ > { > "dev":"nmem0", > "health":{ > "health_state":"fatal", > "shutdown_state":"dirty" > } > } > ] > > Dimm health report output on a pseries guest lpar with vPMEM or HMS > based nvdimms that are in perfectly healthy conditions: > > # ndctl list -d nmem0 -H > [ > { > "dev":"nmem0", > "health":{ > "health_state":"ok", > "shutdown_state":"clean" > } > } > ] > > PAPR nvDimm-Specific-Methods(PDSM) > ================================== > > PDSM requests are issued by vendor specific code in libndctl to > execute certain operations or fetch information from NVDIMMS. PDSMs > requests can be sent to papr_scm module via libndctl(userspace) and > libnvdimm (kernel) using the ND_CMD_CALL ioctl command which can be > handled in the dimm control function papr_scm_ndctl(). Current > patchset proposes a single PDSM to retrieve NVDIMM health, defined in > the newly introduced uapi header named 'papr_scm_pdsm.h'. Support for > more PDSMs will be added in future. > > Structure of the patch-set > ========================== > > The patchset starts with implementing support for fetching nvdimm health > information from PHYP and partially exposing it to user-space via a nvdimm > sysfs flag. > > Second & Third patches deal with implementing support for servicing PDSM > commands in papr_scm module. > > Finally the Fourth patch implements support for servicing PDSM > 'PAPR_SCM_PDSM_HEALTH' that returns the nvdimm health information to > libndctl. You can add to the series. Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> -aneesh
The PAPR standard[1][3] provides mechanisms to query the health and performance stats of an NVDIMM via various hcalls as described in Ref[2]. Until now these stats were never available nor exposed to the user-space tools like 'ndctl'. This is partly due to PAPR platform not having support for ACPI and NFIT. Hence 'ndctl' is unable to query and report the dimm health status and a user had no way to determine the current health status of a NDVIMM. To overcome this limitation, this patch-set updates papr_scm kernel module to query and fetch nvdimm health stats using hcalls described in Ref[2]. This health and performance stats are then exposed to userspace via syfs and PAPR-nvDimm-Specific-Methods(PDSM) issued by libndctl. These changes coupled with proposed ndtcl changes located at Ref[4] should provide a way for the user to retrieve NVDIMM health status using ndtcl. Below is a sample output using proposed kernel + ndctl for PAPR NVDIMM in a emulation environment: # ndctl list -DH [ { "dev":"nmem0", "health":{ "health_state":"fatal", "shutdown_state":"dirty" } } ] Dimm health report output on a pseries guest lpar with vPMEM or HMS based nvdimms that are in perfectly healthy conditions: # ndctl list -d nmem0 -H [ { "dev":"nmem0", "health":{ "health_state":"ok", "shutdown_state":"clean" } } ] PAPR nvDimm-Specific-Methods(PDSM) ================================== PDSM requests are issued by vendor specific code in libndctl to execute certain operations or fetch information from NVDIMMS. PDSMs requests can be sent to papr_scm module via libndctl(userspace) and libnvdimm (kernel) using the ND_CMD_CALL ioctl command which can be handled in the dimm control function papr_scm_ndctl(). Current patchset proposes a single PDSM to retrieve NVDIMM health, defined in the newly introduced uapi header named 'papr_scm_pdsm.h'. Support for more PDSMs will be added in future. Structure of the patch-set ========================== The patchset starts with implementing support for fetching nvdimm health information from PHYP and partially exposing it to user-space via a nvdimm sysfs flag. Second & Third patches deal with implementing support for servicing PDSM commands in papr_scm module. Finally the Fourth patch implements support for servicing PDSM 'PAPR_SCM_PDSM_HEALTH' that returns the nvdimm health information to libndctl. Changelog: ========== v5..v6: * Incorporate review comments from Mpe and Dan Williams. * Changed the usage of term DSM to PDSM as former conflicted with usage in ACPI context. * UAPI updates to remove usage of bool and marking the structs defined as 'packed'. * Simplified the health-bitmap handling in papr_scm to use u64 instead of __be64 integers. * Caching of the health information so reading the dimm-flag file doesn't result in costly hcalls everytime. * Changed dimm-flag 'save_fail' to 'flush_fail' * Moved the dimm flag file from 'papr_flags' to 'papr/flags'. * Added a patch to document H_SCM_HEALTH hcall return values. * Added sysfs ABI documentation for newly introduce dimm-flag sysfs file 'papr/flags' v4..v5: * Fixed a bug in new implementation of papr_scm_ndctl() that was triggering a false error condition. v3..v4: * Restructured papr_scm_ndctl() to dispatch ND_CMD_CALL commands to a new function named papr_scm_service_dsm() to serivice DSM requests. [Aneesh] v2..v3: * Updated the papr_scm_dsm.h header to be more confimant general kernel guidelines for UAPI headers. [Aneesh] * Changed the definition of macro PAPR_SCM_DIMM_UNARMED_MASK to not include case when the nvdimm is unarmed because its a vPMEM nvdimm. [Aneesh] v1..v2: * Restructured the patch-set based on review comments on V1 patch-set to simplify the patch review. Multiple small patches have been combined into single patches to reduce cross referencing that was needed in earlier patch-set. Hence most of the patches in this patch-set as now new. [Aneesh] * Removed the initial work done for fetch nvdimm performance statistics. These changes will be re-proposed in a separate patch-set. [Aneesh] * Simplified handling of versioning of 'struct nd_papr_scm_dimm_health_stat_v1' as only one version of the structure is currently in existence. References: [1] "Power Architecture Platform Reference" https://en.wikipedia.org/wiki/Power_Architecture_Platform_Reference [2] commit 58b278f568f0 ("powerpc: Provide initial documentation for PAPR hcalls") [3] "Linux on Power Architecture Platform Reference" https://members.openpowerfoundation.org/document/dl/469 [4] https://patchwork.kernel.org/project/linux-nvdimm/list/?series=244625 Vaibhav Jain (4): powerpc: Document details on H_SCM_HEALTH hcall powerpc/papr_scm: Fetch nvdimm health information from PHYP ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods powerpc/papr_scm: Implement support for PAPR_SCM_PDSM_HEALTH Documentation/ABI/testing/sysfs-bus-papr-scm | 27 ++ Documentation/powerpc/papr_hcalls.rst | 43 ++- arch/powerpc/include/asm/papr_scm.h | 49 +++ arch/powerpc/include/uapi/asm/papr_scm_pdsm.h | 192 +++++++++++ arch/powerpc/platforms/pseries/papr_scm.c | 317 +++++++++++++++++- include/uapi/linux/ndctl.h | 1 + 6 files changed, 617 insertions(+), 12 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-papr-scm create mode 100644 arch/powerpc/include/asm/papr_scm.h create mode 100644 arch/powerpc/include/uapi/asm/papr_scm_pdsm.h