[PATCH v9 0/7] Add character devices for indices, platform-dump

[Sathvika Vasireddy]

On 3/15/25 2:57 PM, Haren Myneni wrote:
> Several APIs such as rtas_get_indices(), rtas_get_dynamic_sensor(),
> rtas_set_dynamic_indicator(), rtas_platform_dump() and
> rtas_physical_attestation()  provided by librtas library are
> implemented in user space using rtas syscall in combination with
> writable mappings of /dev/mem. But this implementation is not
> compatible with system lockdown which prohibits /dev/mem access.
> The current kernel already provides char based driver interfaces
> for several RTAS calls such as VPD and system parameters to
> support lockdown feature.
>
> This patch series adds new char based drivers, /dev/papr-indices
> for ibm,get-indices, ibm,get-dynamic-sensor-state and
> ibm,set-dynamic-indicator RTAS Calls. /dev/papr-platform-dump
> for ibm,platform-dump and /dev/papr-physical-attestation
> fir ibm,physical-attestation. Providing the similar
> open/ioctl/read interfaces to the user space as in the case of
> VPD and system parameters.
>
> I have made changes to librtas library to use the new kernel
> interfaces if the corresponding device entry is available.
>
> This patch series has the following patches:
> powerpc/pseries: Define common functions for RTAS sequence calls
> - For some of sequence based RTAS calls, the OS should not start
>    another sequence with different input until the previous sequence
>    is completed. So the sequence should be completed during ioctl()
>    and expose the entire buffer during read(). ibm,get-indices is
>    sequence based RTAS function similar to ibm,get-vpd and we already
>    have the corresponding implementation for VPD driver. So update
>    papr_rtas_sequence struct for RTAS call specific functions and move
>    the top level sequence functions in to a separate file.
>
> powerpc/pseries: Define papr_indices_io_block for papr-indices ioctls
> - /dev/papr-indices driver supports ibm,get-indices,
>    ibm,get-dynamic-sensor-state and ibm,set-dynamic-indicator RTAS Calls.
>    papr-indices.h introduces 3 different ioctls for these RTAS calls and
>    the corresponding ioctl input buffer.
>
> powerpc/pseries: Add papr-indices char driver for ibm,get-indices
> - Introduce /dev/papr-indices char based driver and add support for
>    get-indices RTAS function
>
> powerpc/pseries: Add ibm,set-dynamic-indicator RTAS call support
> - Update /dev/papr-indices for set-dynamic-indicator RTAS function
>
> powerpc/pseries: Add ibm,get-dynamic-sensor-state RTAS call support
> -  Update /dev/papr-indices for  get-dynamic-sensor-state RTAS function
>
> powerpc/pseries: Add papr-platform-dump character driver for dump
>     retrieval
> - Introduce /dev/papr-platform-dump char driver and adds support for
>    ibm,platform-dump. Received suggestions from the previous post as a
>    separate patch - Updated the patch with invalidating the dump using
>    a separate ioctl.
>
> powerpc/pseries: Add a char driver for papr-physical-attestation RTAS
> - Introduce /dev/papr-physical-attestation char driver to provide
>    kernel interface for ibm,physical-attestation RTAS function.
>
> Thanks to Sathvika Vasireddy for testing these kernel APIs with various
> tools.
>   
> Changelog:
> v9:
> - Fixed syntax issue in papr-rtas-common.c as reported by
>    Mukesh Kumar Chaurasiya
>
> v8:
> - Fixed build warnings for the proper function parameter descriptions
>    (vpd_sequence_begin(), few papr_rtas_*() functions, and etc) as
>    reported by kernel test robot<lkp at intel.com>
>
> v7:
> - Pass the proper next value to the subsequent RTAS calls for the
>    get-indices sequence RTAS.
>    (Vasireddy Sathvika found this bug).
>
> v6:
> - Define the proper command ID for PAPR_PHY_ATTEST_IOC_HANDLE ioctl
> - Update ioctls description in ioctl-number.rst.
>
> v5:
> - Return with -EINPROGRESS in papr_platform_dump_invalidate_ioctl()
>    if the complete dump is not read (Suggested by Michal Suchánek).
>
> v4:
> - Include patch "Add char driver for papr-physical-attestation RTAS"
>    in this series. ibm,physical-attestation is sequence based RTAS
>    call and the implementation is also similar to ibm,get-vpd and
>    ibm,get-indices.
>
> v3:
> - put_unused_fd() only after get_unused_fd() successful for the failure
>    case later ("Add papr-platform-dump character driver for dump
>    retrieval" patch).
>
> v2:
> - Added unlock rtas_ibm_set_dynamic_indicator_lock and
>    rtas_ibm_get_dynamic_sensor_state_lock mutex for failure cases
>    as reported by Dan Carpenter
> - Fixed build warnings for the proper function parameter descriptions
>    as reported by kernel test robot<lkp at intel.com>
>
> Haren Myneni (7):
>    powerpc/pseries: Define common functions for RTAS sequence calls
>    powerpc/pseries: Define papr_indices_io_block for papr-indices ioctls
>    powerpc/pseries: Add papr-indices char driver for ibm,get-indices
>    powerpc/pseries: Add ibm,set-dynamic-indicator RTAS call support
>    powerpc/pseries: Add ibm,get-dynamic-sensor-state RTAS call support
>    powerpc/pseries: Add papr-platform-dump character driver for dump
>      retrieval
>    powerpc/pseries: Add a char driver for physical-attestation RTAS
>
>   .../userspace-api/ioctl/ioctl-number.rst      |   6 +
>   arch/powerpc/include/asm/rtas.h               |   4 +
>   arch/powerpc/include/uapi/asm/papr-indices.h  |  41 ++
>   .../uapi/asm/papr-physical-attestation.h      |  31 ++
>   .../include/uapi/asm/papr-platform-dump.h     |  15 +
>   arch/powerpc/kernel/rtas.c                    |   8 +-
>   arch/powerpc/platforms/pseries/Makefile       |   3 +-
>   arch/powerpc/platforms/pseries/papr-indices.c | 488 ++++++++++++++++++
>   .../platforms/pseries/papr-phy-attest.c       | 288 +++++++++++
>   .../platforms/pseries/papr-platform-dump.c    | 411 +++++++++++++++
>   .../platforms/pseries/papr-rtas-common.c      | 311 +++++++++++
>   .../platforms/pseries/papr-rtas-common.h      |  61 +++
>   arch/powerpc/platforms/pseries/papr-vpd.c     | 351 ++-----------
>   13 files changed, 1706 insertions(+), 312 deletions(-)
>   create mode 100644 arch/powerpc/include/uapi/asm/papr-indices.h
>   create mode 100644 arch/powerpc/include/uapi/asm/papr-physical-attestation.h
>   create mode 100644 arch/powerpc/include/uapi/asm/papr-platform-dump.h
>   create mode 100644 arch/powerpc/platforms/pseries/papr-indices.c
>   create mode 100644 arch/powerpc/platforms/pseries/papr-phy-attest.c
>   create mode 100644 arch/powerpc/platforms/pseries/papr-platform-dump.c
>   create mode 100644 arch/powerpc/platforms/pseries/papr-rtas-common.c
>   create mode 100644 arch/powerpc/platforms/pseries/papr-rtas-common.h
Userspace tools that use these interfaces are displaying consistent 
results across old/new librtas and kernel combinations.

For this series:
Tested-by: Sathvika Vasireddy <sv at linux.ibm.com>

Thanks,
Sathvika
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