linux/arch/x86/coco
Nikunj A Dadhania 3645eb7e39 x86/fred: Fix early boot failures on SEV-ES/SNP guests
FRED-enabled SEV-(ES,SNP) guests fail to boot due to the following issues
in the early boot sequence:

* FRED does not have a #VC exception handler in the dispatch logic

* Early FRED #VC exceptions attempt to use uninitialized per-CPU GHCBs
  instead of boot_ghcb

Add X86_TRAP_VC case to fred_hwexc() with a new exc_vmm_communication()
function that provides the unified entry point FRED requires, dispatching
to existing user/kernel handlers based on privilege level. The function is
already declared via DECLARE_IDTENTRY_VC().

Fix early GHCB access by falling back to boot_ghcb in
__sev_{get,put}_ghcb() when per-CPU GHCBs are not yet initialized.

Fixes: 14619d912b ("x86/fred: FRED entry/exit and dispatch code")
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@kernel.org>  # 6.12+
Link: https://patch.msgid.link/20260318075654.1792916-4-nikunj@amd.com
2026-03-23 14:18:18 +01:00
..
sev x86/fred: Fix early boot failures on SEV-ES/SNP guests 2026-03-23 14:18:18 +01:00
tdx x86/tdx: tdx_mcall_get_report0: Return -EBUSY on TDCALL_OPERAND_BUSY error 2025-05-08 19:17:43 -07:00
Makefile x86/sev: Move SEV compilation units 2024-07-11 11:55:58 +02:00
core.c x86/apic: Add new driver for Secure AVIC 2025-08-28 17:57:19 +02:00