Files
system76-edk2/OvmfPkg/Library/BaseMemEncryptSevLib/DxeMemEncryptSevLib.inf
Tom Lendacky 85b8eac59b OvfmPkg/VmgExitLib: Validate #VC MMIO is to un-encrypted memory
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108

When SEV-ES is active, and MMIO operation will trigger a #VC and the
VmgExitLib exception handler will process this MMIO operation.

A malicious hypervisor could try to extract information from encrypted
memory by setting a reserved bit in the guests nested page tables for
a non-MMIO area. This can result in the encrypted data being copied into
the GHCB shared buffer area and accessed by the hypervisor.

Prevent this by ensuring that the MMIO source/destination is un-encrypted
memory. For the APIC register space, access is allowed in general.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <0cf28470ad5e694af45f7f0b35296628f819567d.1610045305.git.thomas.lendacky@amd.com>
2021-01-07 19:34:39 +00:00

58 lines
1.3 KiB
INI

## @file
# Library provides the helper functions for SEV guest
#
# Copyright (c) 2017 - 2020, Advanced Micro Devices. All rights reserved.<BR>
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
#
##
[Defines]
INF_VERSION = 1.25
BASE_NAME = DxeMemEncryptSevLib
FILE_GUID = c1594631-3888-4be4-949f-9c630dbc842b
MODULE_TYPE = BASE
VERSION_STRING = 1.0
LIBRARY_CLASS = MemEncryptSevLib|DXE_CORE DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SMM_DRIVER UEFI_DRIVER
#
# The following information is for reference only and not required by the build
# tools.
#
# VALID_ARCHITECTURES = IA32 X64
#
[Packages]
MdeModulePkg/MdeModulePkg.dec
MdePkg/MdePkg.dec
OvmfPkg/OvmfPkg.dec
UefiCpuPkg/UefiCpuPkg.dec
[Sources]
DxeMemEncryptSevLibInternal.c
PeiDxeMemEncryptSevLibInternal.c
[Sources.X64]
X64/MemEncryptSevLib.c
X64/PeiDxeVirtualMemory.c
X64/VirtualMemory.c
X64/VirtualMemory.h
[Sources.IA32]
Ia32/MemEncryptSevLib.c
[LibraryClasses]
BaseLib
CacheMaintenanceLib
CpuLib
DebugLib
MemoryAllocationLib
PcdLib
[FeaturePcd]
gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire
[Pcd]
gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask