Files
system76-edk2/OvmfPkg/ResetVector/ResetVector.inf
Tom Lendacky 8a2732186a OvmfPkg/ResetVector: Add support for a 32-bit SEV check
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

During BSP startup, the reset vector code will issue a CPUID instruction
while in 32-bit mode. When running as an SEV-ES guest, this will trigger
a #VC exception.

Add exception handling support to the early reset vector code to catch
these exceptions.  Also, since the guest is in 32-bit mode at this point,
writes to the GHCB will be encrypted and thus not able to be read by the
hypervisor, so use the GHCB CPUID request/response protocol to obtain the
requested CPUID function values and provide these to the guest.

The exception handling support is active during the SEV check and uses the
OVMF temporary RAM space for a stack. After the SEV check is complete, the
exception handling support is removed and the stack pointer cleared.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-17 02:46:39 +00:00

46 lines
1.3 KiB
INI

## @file
# Reset Vector
#
# Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
##
[Defines]
INF_VERSION = 0x00010005
BASE_NAME = ResetVector
FILE_GUID = 1BA0062E-C779-4582-8566-336AE8F78F09
MODULE_TYPE = SEC
VERSION_STRING = 1.1
#
# The following information is for reference only and not required by the build tools.
#
# VALID_ARCHITECTURES = IA32 X64
#
[Sources]
ResetVector.nasmb
[Packages]
OvmfPkg/OvmfPkg.dec
MdePkg/MdePkg.dec
MdeModulePkg/MdeModulePkg.dec
UefiCpuPkg/UefiCpuPkg.dec
[BuildOptions]
*_*_IA32_NASMB_FLAGS = -I$(WORKSPACE)/UefiCpuPkg/ResetVector/Vtf0/
*_*_X64_NASMB_FLAGS = -I$(WORKSPACE)/UefiCpuPkg/ResetVector/Vtf0/
[Pcd]
gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbSize
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableSize
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPageTablesBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPageTablesSize
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize