[PATCH 0/4] x86/CPU: Fix CR4 pinning and FRED in CoCo guests
From: Borislav Petkov
Date: Fri Mar 20 2026 - 07:54:30 EST
From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>
Hi,
the respective patches have very detailed explanations about what this is
addressing but basically, there's a window in time during boot when FRED is
not setup properly yet and if a CoCo guest generates an exception, it would
explode.
So this shuffles things a bit so that that doesn't happen.
Thx.
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(-)
--
2.51.0