On 3/12/25 4:20 AM, 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.
Changelog:
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 <l...@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 <l...@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 | 310 +++++++++++
.../platforms/pseries/papr-rtas-common.h | 61 +++
arch/powerpc/platforms/pseries/papr-vpd.c | 351 ++-----------
13 files changed, 1705 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 <s...@linux.ibm.com>
Thanks,
Sathvika
