Re: [PATCH v6 0/7] tsm-mr: Unified Measurement Register ABI for TVMs

[Mikko Ylinen <mikko.ylinen@linux.intel.com>]

Hi,

On Tue, May 06, 2025 at 05:57:06PM -0500, Cedric Xing wrote:
> NOTE: This patch series introduces the Measurement Register (MR) ABI, and
> is a continuation of the RFC series on the same topic [1].
> 
> Introduce the CONFIG_TSM_MEASUREMENTS helper library (tsm-mr) as a
> cross-vendor transport schema to allow TVM (TEE VM) guest drivers to export
> CC (Confidential Compute) architecture-specific MRs (Measurement Registers)
> as sysfs attributes/files. Enable applications to read, write/extend MRs
> like regular files, supporting various usages such as configuration
> verification (e.g., verify a TVM's configuration against digests stored in
> static/immutable MRs like MRCONFIGID on TDX or HOSTDATA on SEV) and runtime
> measurements (e.g., extend the measurement of a container image to an RTMR
> before running it).
> 
> Patches included in this series:
> 
> - Patch 1 adds the tsm-mr library to help TVM guest drivers exposing MRs as
>   sysfs attributes.
> - Patch 2 provides a sample module demonstrating the usage of the new
>   tsm-mr library.
> - The remaining patches update the TDX guest driver to expose TDX MRs with
>   the help of the tsm-mr library.
> 
> [1]: https://lore.kernel.org/linux-coco/20241210-tsm-rtmr-v3-0-5997d4dbda73@intel.com/

I ran some TDX RTMR extend tests with this series and everything works
as expected, so:

Tested-by: Mikko Ylinen <mikko.ylinen@linux.intel.com>

> 
> ---
> Changes in v6:
> - tsm-mr: Rename MR root directory name to "measurements" for improved
>   clarity.
> - tsm-mr: Drop @mr from the parameter list of tsm_measurements.refresh().
> - tsm-mr-sample: Remove redundant debug messages following the introduction
>   of tracepoints.
> - tdx-guest: Split and refactor changes into 3 separate commits for easier
>   review.
> - Add collected "Acked-by" tags to respective commits.
> - Link to v5: https://lore.kernel.org/r/20250424-tdx-rtmr-v5-0-4fe28ddf85d4@intel.com
> 
> Changes in v5:
> - tsm-mr: Fix typo in MAINTAINERS.
> - tsm-mr-sample: Fix Kconfig dependencies by adding `select VIRT_DRIVERS`.
> - Link to v4: https://lore.kernel.org/r/20250414-tdx-rtmr-v4-0-7edfa8d98716@intel.com
> 
> Changes in v4:
> - tsm-mr: Add details to ABI doc.
> - tsm-mr: Add driver-api doc.
> - tsm-mr: Add tracepoints.
> - tsm-mr: Use the constant string "mr" as the group/directory name for MR
>   sysfs attributes.
> - x86/tdx: Revise error codes returned by tdx_mcall_* functions.
> - tdx-guest: Merge all TDREPORT code paths into a common function.
> - Link to v3: https://lore.kernel.org/r/20250407-tdx-rtmr-v3-0-54f17bc65228@intel.com
> 
> Changes in v3:
> - tsm-mr: Separate measurement support (tsm-mr) from the original tsm
>   source code. Modules depending on tsm-mr should `select TSM_MEASUREMENTS`
>   in Kconfig. (Dan Williams)
> - tsm-mr: Revise tsm-mr APIs to allow callers to decide where to host the
>   MR attributes in sysfs.
> - tsm-mr: Drop TSM_MR_F_EXTENSIBLE and route all "write" requests to the CC
>   guest driver, which decides how to handle writes (e.g., by extending the
>   buffer on input to the specified MR).
> - tsm-mr: Update the naming pattern for MR attributes from
>   MRNAME/HASH/digest to MRNAME:HASH.
> - tsm-mr: Drop TSM_MR_MAXBANKS kernel config.
> - x86/tdx: Return -EBUSY from tdx_mcall_get_report0 on TDCALL_OPERAND_BUSY
>   error.
> - tdx-guest: Move MR attributes from /sys/kernel/tsm/tdx/ to
>   /sys/class/misc/tdx_guest/ because MR names are architecture-specific, so
>   their attributes should reside in an architecture-specific location.
> - tdx-guest: Remove hash from `mrconfigid`, `mrowner`, `mrownerconfig`.
> - tdx-guest: Remove `servtd_hash`, `report0`, and `reportdata`.
> - Link to v2: https://lore.kernel.org/r/20250223-tdx-rtmr-v2-0-f2d85b0a5f94@intel.com
> 
> Changes in v2:
> - Added TSM_MR_MAXBANKS Kconfig option
> - Updated Kconfig dependency for TSM_REPORTS
> - Updated comments in include/linux/tsm.h
> - Updated drivers/virt/coco/tdx-guest/tdx-guest.c to use `IS_BUILTIN()` for
>   determining if static buffer addresses can be converted to GPAs by
>   `virt_to_phys()`
> - Renamed function `tdx_mcall_rtmr_extend()` -> `tdx_mcall_extend_rtmr()`
> - Link to v1: https://lore.kernel.org/r/20250212-tdx-rtmr-v1-0-9795dc49e132@intel.com
> 
> ---
> Cedric Xing (7):
>       tsm-mr: Add TVM Measurement Register support
>       tsm-mr: Add tsm-mr sample code
>       x86/tdx: Add tdx_mcall_extend_rtmr() interface
>       x86/tdx: tdx_mcall_get_report0: Return -EBUSY on TDCALL_OPERAND_BUSY error
>       virt: tdx-guest: Expose TDX MRs as sysfs attributes
>       virt: tdx-guest: Refactor and streamline TDREPORT generation
>       virt: tdx-guest: Transition to scoped_cond_guard for mutex operations
> 
>  .../testing/sysfs-devices-virtual-misc-tdx_guest   |  63 ++++++
>  Documentation/driver-api/coco/index.rst            |  12 +
>  .../driver-api/coco/measurement-registers.rst      |  12 +
>  Documentation/driver-api/index.rst                 |   1 +
>  MAINTAINERS                                        |   7 +-
>  arch/x86/coco/tdx/tdx.c                            |  50 +++-
>  arch/x86/include/asm/shared/tdx.h                  |   1 +
>  arch/x86/include/asm/tdx.h                         |   2 +
>  drivers/virt/coco/Kconfig                          |   5 +
>  drivers/virt/coco/Makefile                         |   1 +
>  drivers/virt/coco/tdx-guest/Kconfig                |   1 +
>  drivers/virt/coco/tdx-guest/tdx-guest.c            | 251 ++++++++++++++-------
>  drivers/virt/coco/tsm-mr.c                         | 248 ++++++++++++++++++++
>  include/linux/tsm-mr.h                             |  89 ++++++++
>  include/trace/events/tsm_mr.h                      |  80 +++++++
>  samples/Kconfig                                    |  11 +
>  samples/Makefile                                   |   1 +
>  samples/tsm-mr/Makefile                            |   2 +
>  samples/tsm-mr/tsm_mr_sample.c                     | 131 +++++++++++
>  19 files changed, 881 insertions(+), 87 deletions(-)
> ---
> base-commit: 92a09c47464d040866cf2b4cd052bc60555185fb
> change-id: 20250209-tdx-rtmr-255479667146
> 
> Best regards,
> -- 
> Cedric Xing <cedric.xing@intel.com>
>

-- Regards, Mikko