[GIT PULL] x86 fixes

Ingo Molnar
2026-03-29T05:35:39Z

Linus,

Please pull the latest x86/urgent Git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-2026-03-29

for you to fetch changes up to a3e93cac25316aad03bf561e3c205f4ca0b8f452:

Miscellaneous x86 fixes:

- Fix an early boot crash in AMD SEV-SNP guests, caused by incorrect
FSGSBASE init ordering. (Nikunj A Dadhania)

- Remove X86_CR4_FRED from the CR4 pinned bits mask, to fix a race
window during the bootup of SEV-{ES,SNP} or TDX guests, which
can crash them if they trigger exceptions in that window.
(Borislav Petkov)

- Fix early boot failures on SEV-ES/SNP guests, due to incorrect
early GHCB access. (Nikunj A Dadhania)

- Add clarifying comment to the CRn pinning logic, to avoid
future confusion & bugs. (Peter Zijlstra)

Thanks,

Ingo

------------------>
Borislav Petkov (AMD) (1):
x86/cpu: Remove X86_CR4_FRED from the CR4 pinned bits mask

Nikunj A Dadhania (2):
x86/cpu: Enable FSGSBASE early in cpu_init_exception_handling()
x86/fred: Fix early boot failures on SEV-ES/SNP guests

Peter Zijlstra (1):
x86/cpu: Add comment clarifying CRn pinning

arch/x86/coco/sev/noinstr.c | 6 ++++++
arch/x86/entry/entry_fred.c | 14 ++++++++++++++
arch/x86/kernel/cpu/common.c | 33 ++++++++++++++++++++++++++-------
3 files changed, 46 insertions(+), 7 deletions(-)