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

Ross Philipson
2025-12-15T23:40:38Z

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