[PATCH v10 0/2] Enable Secure TSC for SEV-SNP

[Nikunj A Dadhania <nikunj@amd.com>]

Patches are based on kvm/next with [1] applied

Testing Secure TSC
------------------

Secure TSC guest patches are available as part of v6.14.

QEMU changes:
https://github.com/AMDESE/qemu/tree/snp-securetsc-latest

QEMU command line SEV-SNP with Secure TSC:

  qemu-system-x86_64 -cpu EPYC-Milan-v2 -smp 4 \
    -object memory-backend-memfd,id=ram1,size=1G,share=true,prealloc=false,reserve=false \
    -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,secure-tsc=on,stsc-freq=2000000000 \
    -machine q35,confidential-guest-support=sev0,memory-backend=ram1 \
    ...

Changelog:
----------
v10:
* Rebased on kvm/next
* Collect RB from Kai Huang

v9: https://lore.kernel.org/kvm/20250716060836.2231613-1-nikunj@amd.com/
* Set guest_tsc_protected during guest vCPU creation (Kai Huang)
* Improve error handling (Kai Huang)
* Disable MSR_AMD64_GUEST_TSC_FREQ write interception (Sean)


1. https://lore.kernel.org/kvm/20250804090945.267199-1-nikunj@amd.com/

Nikunj A Dadhania (2):
  x86/cpufeatures: Add SNP Secure TSC
  KVM: SVM: Enable Secure TSC for SNP guests

 arch/x86/include/asm/cpufeatures.h |  1 +
 arch/x86/include/asm/svm.h         |  1 +
 arch/x86/kvm/svm/sev.c             | 27 +++++++++++++++++++++++++++
 arch/x86/kvm/svm/svm.c             |  2 ++
 arch/x86/kvm/svm/svm.h             |  2 ++
 5 files changed, 33 insertions(+)


base-commit: 196d9e72c4b0bd68b74a4ec7f52d248f37d0f030
prerequisite-patch-id: 97788f545096df9ccc70cc99571d545fe4503f01
prerequisite-patch-id: 7a0edf8fa18231f19c781b4d412df4bafcb3d1ae
-- 
2.43.0