[SRU][Q:gcp][PATCH 0/2] Fix attestation failure due to vTPM device error

[Tim Whisonant]

BugLink: https://bugs.launchpad.net/bugs/2116545

SRU Justification:

[Impact]

UBUNTU: SAUCE: Revert "x86/mtrr: Rename mtrr_overwrite_state() to guest_force_mtrr_state()"

This reverts commit 6a5abeea9c72e1d2c538622b4cf66c80cc816fd3.

Google requests that this commit be removed from 6.14 kernels.
As such, questing:linux-gcp is also affected. This commit
along with 8e690b817e38769dc2fa0e7473e5a5dc1fc25795
("x86/kvm: Override default caching mode for SEV-SNP and TDX")
are responsible for a TPM failure encountered on their TDX-enabled
deployments. When present, error message "TPM fail - No TPM chip
found" is observed during boot and the TPM is not available.

UBUNTU: SAUCE: Revert "x86/kvm: Override default caching mode for SEV-SNP and TDX"

This reverts commit 8e690b817e38769dc2fa0e7473e5a5dc1fc25795.

Google requests that this commit be removed from 6.14 kernels.
As such, questing:linux-gcp is also affected. This commit
along with 6a5abeea9c72e1d2c538622b4cf66c80cc816fd3
("x86/mtrr: Rename mtrr_overwrite_state() to guest_force_mtrr_state()")
are responsible for a TPM failure encountered on their TDX-enabled
deployments. When present, error message "TPM fail - No TPM chip
found" is observed during boot and the TPM is not available.

[Fix]

Questing:gcp    revert upstream commits
Plucky:gcp      fixed separately
Noble:gcp-6.14  fixed separately

[Test Plan]

Compile and boot tested.

[Where problems could occur]

This change is considered low risk as the commits were cleanly
reverted.

Tim Whisonant (2):
  UBUNTU: SAUCE: Revert "x86/mtrr: Rename mtrr_overwrite_state() to
    guest_force_mtrr_state()"
  UBUNTU: SAUCE: Revert "x86/kvm: Override default caching mode for
    SEV-SNP and TDX"

 arch/x86/hyperv/ivm.c              |  2 +-
 arch/x86/include/asm/mtrr.h        | 10 +++++-----
 arch/x86/kernel/cpu/mtrr/generic.c |  6 +++---
 arch/x86/kernel/cpu/mtrr/mtrr.c    |  2 +-
 arch/x86/kernel/kvm.c              |  4 ----
 arch/x86/xen/enlighten_pv.c        |  4 ++--
 6 files changed, 12 insertions(+), 16 deletions(-)

-- 
2.43.0