Intel has submitted a patch to Tianocore to add STM support!
[edk2] [patch 0/4] Add STM (Smi Tranfer Monitor) support
This patch series is used to add STM support to UefiCpuPkg. More details about STM are described in:
http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-manual-325462.pdf
https://firmware.intel.com/sites/default/files/STM_User_Guide-001.pdf
https://firmware.intel.com/sites/default/files/A_Tour_Beyond_BIOS_Launching_STM_to_Monitor_SMM_in_EFI_Developer_Kit_II.pdf
28 files changed, 6036 insertions(+), 65 deletions(-)
More info:
https://lists.01.org/mailman/listinfo/edk2-devel
https://firmwaresecurity.com/tag/stm/