Re: [PATCH v15 00/28] x86: Secure Launch support for Intel TXT

[ross.philipson@oracle.com]

On 12/15/25 7:46 PM, Jarkko Sakkinen wrote:
> On Mon, Dec 15, 2025 at 03:32:48PM -0800, Ross Philipson wrote:
>> Secure Launch is a vendor-neutral approach to implementing TGC Dynamic
>> Root of Trust (DRTM) support in the kernel. This is complementary to
>> better known Static Root of Trust (SRTM) schemes such as UEFI SecureBoot.
>>
>> This series provides the common infrastructure along with Intel TXT
>> support, without needing the tboot exokernel. Support for AMD SKINIT is
>> pending the common infrastructure getting nailed down, and ARM are
>> looking to build on it too.
>>
>> Originally, tboot were approached to see if they'd take support for
>> other vendors, but they elected not to. Hence this approach instead.
>>
>> Work is being coordinated by the Trenchboot project, https://trenchboot.org/,
>> organising Secure Launch support for upstream open source projects including
>> Grub, iPXE and Xen. The goal of the Trenchboot project is to make DTRM easy
>> to use.  e.g. for Grub, it's simply adding "slaunch" as a command in the boot
>> stanza.  See https://trenchboot.org/user-docs/QUICKSTART/#linux-quick-start-guide
>> for more details
>>
>> Patch set based on commit:
>> torvalds/master/fd57572253bc356330dbe5b233c2e1d8426c66fd
>>
>> Depends on v3 of the following TPM patch set (note this patch
>> set is being actively worked on separately):
>> [PATCH v3 00/10]  tpm: Decouple Trenchboot dependencies
>> Message ID: 20250929194832.2913286-1-jarkko@kernel.org
>>
>> Finally we would like to thank everyone for their input and
>> assistance. It has all been very helpful in improving the quality of
>> our solution and in reviewing/strengthening our security posture.
>>
>> Thanks
>> Ross Philipson and Daniel P. Smith
>>
>> Changes in v15:
>>
>>   - Rewriting and reformatting of the cover letter, commit message and
>>     code comments per requests from maintainers.
>>   - Introduction of a early TPM driver in the x86 setup kernel to allow
>>     TPM extend command very early in the boot.
>>   - Remove previous TPM extending architecture that attempted to update
>>     the TPM PCRs later in the boot process.
>>   - Split slaunch.h into 2 files, with a new txt.h. The former contains
>>     platform agnostic definitions for the SL feature. The new txt.h file
>>     contains Intel TXT definitions from the public specs.
>>   - Split TPM headers up following the specifications where the
>>     technologies are defined.
>>   - Include set of split up TPM header files to allow TPM driver reuse
>>     in other environments (e.g. early kernel, x86).
>>   - Fix code formatting and type-os.
>>
>>
>> Alec Brown (1):
>>    tpm: Remove main TPM header from TPM event log header
>>
>> Daniel P. Smith (6):
>>    tpm/tpm_tis: Close all localities
>>    tpm/tpm_tis: Address positive localities in tpm_tis_request_locality()
>>    Documentation/x86: Secure Launch kernel documentation
>>    x86: Add early SHA-1 support for Secure Launch early measurements
>>    x86: Add early SHA-256 support for Secure Launch early measurements
>>    x86: Secure Launch late initcall platform module
>>
>> Ross Philipson (21):
>>    tpm: Initial step to reorganize TPM public headers
>>    tpm: Move TPM1 specific definitions and functions to new headers
>>    tpm: Move TPM2 specific definitions and functions to new headers
>>    tpm: Move TPM common base definitions to new public common header
>>    tpm: Move platform specific definitions to the new PTP header
>>    tpm: Add TPM buffer support header for standalone reuse
>>    tpm/tpm_tis: Allow locality to be set to a different value
>>    tpm/sysfs: Show locality used by kernel
>>    x86: Secure Launch Kconfig
>>    x86: Secure Launch Resource Table header file
>>    x86: Secure Launch main header file
>>    x86/txt: Intel Trusted eXecution Technology (TXT) definitions
>>    x86/tpm: Early TPM PCR extending driver
>>    x86/msr: Add variable MTRR base/mask and x2apic ID registers
>>    x86/boot: Place TXT MLE header in the kernel_info section
>>    x86: Secure Launch kernel early boot stub
>>    x86: Secure Launch kernel late boot stub
>>    x86: Secure Launch SMP bringup support
>>    kexec: Secure Launch kexec SEXIT support
>>    x86/reboot: Secure Launch SEXIT support on reboot paths
>>    x86/efi: EFI stub DRTM launch support for Secure Launch
>>
>>   Documentation/arch/x86/boot.rst               |  21 +
>>   Documentation/security/index.rst              |   1 +
>>   .../security/launch-integrity/index.rst       |  11 +
>>   .../security/launch-integrity/principles.rst  | 308 +++++++
>>   .../secure_launch_details.rst                 | 587 +++++++++++++
>>   .../secure_launch_overview.rst                | 240 ++++++
>>   arch/x86/Kconfig                              |  14 +
>>   arch/x86/boot/compressed/Makefile             |   8 +
>>   arch/x86/boot/compressed/early_tpm_extend.c   | 601 ++++++++++++++
>>   arch/x86/boot/compressed/head_64.S            |  29 +
>>   arch/x86/boot/compressed/kernel_info.S        |  50 +-
>>   arch/x86/boot/compressed/sha1.c               |   7 +
>>   arch/x86/boot/compressed/sha256.c             |   6 +
>>   arch/x86/boot/compressed/sl_main.c            | 638 +++++++++++++++
>>   arch/x86/boot/compressed/sl_stub.S            | 770 ++++++++++++++++++
>>   arch/x86/boot/compressed/tpm.h                |  42 +
>>   arch/x86/boot/compressed/vmlinux.lds.S        |   7 +
>>   arch/x86/include/asm/msr-index.h              |   5 +
>>   arch/x86/include/asm/realmode.h               |   3 +
>>   arch/x86/include/asm/txt.h                    | 330 ++++++++
>>   arch/x86/include/uapi/asm/bootparam.h         |   1 +
>>   arch/x86/kernel/Makefile                      |   2 +
>>   arch/x86/kernel/asm-offsets.c                 |  20 +
>>   arch/x86/kernel/reboot.c                      |  14 +
>>   arch/x86/kernel/setup.c                       |   3 +
>>   arch/x86/kernel/slaunch.c                     | 615 ++++++++++++++
>>   arch/x86/kernel/slmodule.c                    | 348 ++++++++
>>   arch/x86/kernel/smpboot.c                     |  47 +-
>>   arch/x86/realmode/init.c                      |   8 +
>>   arch/x86/realmode/rm/header.S                 |   3 +
>>   arch/x86/realmode/rm/trampoline_64.S          |  32 +
>>   drivers/char/tpm/tpm-buf.c                    |  10 +-
>>   drivers/char/tpm/tpm-chip.c                   |  34 +-
>>   drivers/char/tpm/tpm-sysfs.c                  |  10 +
>>   drivers/char/tpm/tpm.h                        | 180 +---
>>   drivers/char/tpm/tpm1-cmd.c                   |  18 +-
>>   drivers/char/tpm/tpm1_structs.h               |  97 +++
>>   drivers/char/tpm/tpm2-cmd.c                   |  32 +-
>>   drivers/char/tpm/tpm2-space.c                 |  13 -
>>   drivers/char/tpm/tpm2_structs.h               |  58 ++
>>   drivers/char/tpm/tpm_tis_core.c               |  21 +-
>>   drivers/char/tpm/tpm_tis_core.h               |  64 +-
>>   drivers/firmware/efi/libstub/efistub.h        |   8 +
>>   drivers/firmware/efi/libstub/x86-stub.c       | 100 +++
>>   drivers/iommu/intel/dmar.c                    |   4 +
>>   include/keys/trusted_tpm.h                    |   1 -
>>   include/linux/slaunch.h                       | 251 ++++++
>>   include/linux/slr_table.h                     | 308 +++++++
>>   include/linux/tpm.h                           | 240 +-----
>>   include/linux/tpm1.h                          |  87 ++
>>   include/linux/tpm2.h                          | 247 ++++++
>>   include/linux/tpm_buf.h                       |  57 ++
>>   include/linux/tpm_command.h                   |  30 -
>>   include/linux/tpm_common.h                    |  99 +++
>>   include/linux/tpm_eventlog.h                  |   4 +-
>>   include/linux/tpm_ptp.h                       | 139 ++++
>>   kernel/kexec_core.c                           |   8 +
>>   security/keys/trusted-keys/trusted_tpm1.c     |   1 -
>>   security/keys/trusted-keys/trusted_tpm2.c     |   1 -
>>   59 files changed, 6319 insertions(+), 574 deletions(-)
>>   create mode 100644 Documentation/security/launch-integrity/index.rst
>>   create mode 100644 Documentation/security/launch-integrity/principles.rst
>>   create mode 100644 Documentation/security/launch-integrity/secure_launch_details.rst
>>   create mode 100644 Documentation/security/launch-integrity/secure_launch_overview.rst
>>   create mode 100644 arch/x86/boot/compressed/early_tpm_extend.c
>>   create mode 100644 arch/x86/boot/compressed/sha1.c
>>   create mode 100644 arch/x86/boot/compressed/sha256.c
>>   create mode 100644 arch/x86/boot/compressed/sl_main.c
>>   create mode 100644 arch/x86/boot/compressed/sl_stub.S
>>   create mode 100644 arch/x86/boot/compressed/tpm.h
>>   create mode 100644 arch/x86/include/asm/txt.h
>>   create mode 100644 arch/x86/kernel/slaunch.c
>>   create mode 100644 arch/x86/kernel/slmodule.c
>>   create mode 100644 drivers/char/tpm/tpm1_structs.h
>>   create mode 100644 drivers/char/tpm/tpm2_structs.h
>>   create mode 100644 include/linux/slaunch.h
>>   create mode 100644 include/linux/slr_table.h
>>   create mode 100644 include/linux/tpm1.h
>>   create mode 100644 include/linux/tpm2.h
>>   create mode 100644 include/linux/tpm_buf.h
>>   delete mode 100644 include/linux/tpm_command.h
>>   create mode 100644 include/linux/tpm_common.h
>>   create mode 100644 include/linux/tpm_ptp.h
>>
>> -- 
>> 2.43.7
>>
> 
> Most likely I'll review this after the holidays (for heads up).
> 
> BR, Jarkko

Thank you Jarkko.