Re: [edk2-devel] [PATCH V2 0/3] Introduce TdProtocol into EDK2

["Sami Mujawar" <sami.mujawar@arm.com>]

Hi Min,

Thank you for this patch.

I think it would greatly help if the EFI_TD_PROTOCOL is changed to something more architecture neutral. As I understand, this patch series is removing the dependency on TPM for measurement and is instead providing a lightweight interface for extending measurements for Confidential Compute Architecture (CCA) guests.

Considering this, it would be good to generalise EFI_TD_PROTOCOL as a Confidential Compute Architecture Measurement (CCAM) protocol.
In fact, your v2 series demonstrates this need with the introduction of MEASURE_BOOT_PROTOCOLS in "[PATCH V2 2/3] SecurityPkg: Support TdProtocol in DxeTpm2MeasureBootLib [https://edk2.groups.io/g/devel/message/81651]".

As it stands, I feel most of the code can be reused/common.  Some interfaces may need to use an architecture specific library, and some configuration options would need to be defined using PCDs.

Kindly let me know your thoughts.

Regards,

Sami Mujawar

On 08/10/2021, 06:24, "devel@edk2.groups.io on behalf of Min Xu via groups.io" <devel@edk2.groups.io on behalf of min.m.xu=intel.com@groups.io> wrote:

    BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3625

    If TD-Guest firmware supports measurement and an event is created,
    TD-Guest firmware is designed to report the event log with the same data
    structure in TCG-Platform-Firmware-Profile specification with
    EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 format.

    The TD-Guest firmware supports measurement, the TD Guest Firmware is
    designed to produce EFI_TD_PROTOCOL with new GUID EFI_TD_PROTOCOL_GUID
    to report event log and provides hash capability.

    https://software.intel.com/content/dam/develop/external/us/en/documents/
    intel-tdx-guest-hypervisor-communication-interface-1.0-344426-002.pdf
    Section 4.3.2 includes the EFI_TD_PROTOCOL.

    Patch #1:
    Introduce the TD Protocol definition into MdePkg

    Patch #2:
    Update DxeTpm2MeasureBootLib to support TD based measure boot.

    Patch #3:
    Update DxeTpmMeasurementLib to support TD based measurement.

    Code is at https://github.com/mxu9/edk2/tree/td_protocol.v2

    v2 changes:
     - TD based measure boot is implemented in DxeTpm2MeasureBootLib.
       This minimize the code changes.
     - TD based measurement is added. It is implemented in
       DxeTpmMeasurementLib.
     - Fix the typo in comments.

    Cc: Michael D Kinney <michael.d.kinney@intel.com>
    Cc: Liming Gao <gaoliming@byosoft.com.cn>
    Cc: Zhiguang Liu <zhiguang.liu@intel.com>
    Cc: Jiewen Yao <jiewen.yao@intel.com>
    Cc: Jian J Wang <jian.j.wang@intel.com>
    Cc: Ken Lu <ken.lu@intel.com>
    Signed-off-by: Min Xu <min.m.xu@intel.com>

    Min Xu (3):
      MdePkg: Introduce TdProtocol for TD-Guest firmware
      SecurityPkg: Support TdProtocol in DxeTpm2MeasureBootLib
      SecurityPkg: Support TdProtocol in DxeTpmMeasurementLib

     MdePkg/Include/Protocol/TdProtocol.h          | 305 +++++++++++++++
     MdePkg/MdePkg.dec                             |   3 +
     .../DxeTpm2MeasureBootLib.c                   | 346 ++++++++++++++----
     .../DxeTpm2MeasureBootLib.inf                 |   1 +
     .../DxeTpmMeasurementLib.c                    |  87 ++++-
     .../DxeTpmMeasurementLib.inf                  |   1 +
     6 files changed, 672 insertions(+), 71 deletions(-)
     create mode 100644 MdePkg/Include/Protocol/TdProtocol.h

    -- 
    2.29.2.windows.2