Tom Lendacky a21a3438f7 OvmfPkg: Make an Ia32/X64 hybrid build work with SEV
The BaseMemEncryptSevLib functionality was updated to rely on the use of
the OVMF/SEV workarea to check for SEV guests. However, this area is only
updated when running the X64 OVMF build, not the hybrid Ia32/X64 build.
Base SEV support is allowed under the Ia32/X64 build, but it now fails
to boot as a result of the change.

Update the ResetVector code to check for SEV features when built for
32-bit mode, not just 64-bit mode (requiring updates to both the Ia32
and Ia32X64 fdf files).

Fixes: f1d1c337e7c0575da7fd248b2dd9cffc755940df
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Min Xu <min.m.xu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-20 06:29:34 +00:00

128 lines
2.9 KiB
NASM

;------------------------------------------------------------------------------
; @file
; Main routine of the pre-SEC code up through the jump into SEC
;
; Copyright (c) 2008 - 2009, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
;------------------------------------------------------------------------------
BITS 16
;
; Modified: EBX, ECX, EDX, EBP
;
; @param[in,out] RAX/EAX Initial value of the EAX register
; (BIST: Built-in Self Test)
; @param[in,out] DI 'BP': boot-strap processor, or
; 'AP': application processor
; @param[out] RBP/EBP Address of Boot Firmware Volume (BFV)
; @param[out] DS Selector allowing flat access to all addresses
; @param[out] ES Selector allowing flat access to all addresses
; @param[out] FS Selector allowing flat access to all addresses
; @param[out] GS Selector allowing flat access to all addresses
; @param[out] SS Selector allowing flat access to all addresses
;
; @return None This routine jumps to SEC and does not return
;
Main16:
OneTimeCall EarlyInit16
;
; Transition the processor from 16-bit real mode to 32-bit flat mode
;
OneTimeCall TransitionFromReal16To32BitFlat
BITS 32
; Clear the WorkArea header. The SEV probe routines will populate the
; work area when detected.
mov byte[WORK_AREA_GUEST_TYPE], 0
%ifdef ARCH_X64
jmp SearchBfv
;
; Entry point of Main32
;
Main32:
OneTimeCall InitTdx
SearchBfv:
%endif
;
; Search for the Boot Firmware Volume (BFV)
;
OneTimeCall Flat32SearchForBfvBase
;
; EBP - Start of BFV
;
;
; Search for the SEC entry point
;
OneTimeCall Flat32SearchForSecEntryPoint
;
; ESI - SEC Core entry point
; EBP - Start of BFV
;
%ifdef ARCH_IA32
;
; SEV support can be built and run using the Ia32/X64 split environment.
; Set the OVMF/SEV work area as appropriate.
;
OneTimeCall CheckSevFeatures
;
; Restore initial EAX value into the EAX register
;
mov eax, esp
;
; Jump to the 32-bit SEC entry point
;
jmp esi
%else
;
; Transition the processor from 32-bit flat mode to 64-bit flat mode
;
OneTimeCall Transition32FlatTo64Flat
BITS 64
;
; Some values were calculated in 32-bit mode. Make sure the upper
; 32-bits of 64-bit registers are zero for these values.
;
mov rax, 0x00000000ffffffff
and rsi, rax
and rbp, rax
and rsp, rax
;
; RSI - SEC Core entry point
; RBP - Start of BFV
;
;
; Restore initial EAX value into the RAX register
;
mov rax, rsp
;
; Jump to the 64-bit SEC entry point
;
jmp rsi
%endif