sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

OvmfPkg: Obtain SEV encryption mask with the new MemEncryptSevLib API

Browse Source 
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108

The early assembler code performs validation for some of the SEV-related
information, specifically the encryption bit position. The new
MemEncryptSevGetEncryptionMask() interface provides access to this
validated value.

To ensure that we always use a validated encryption mask for an SEV-ES
guest, update all locations that use CPUID to calculate the encryption
mask to use the new interface.

Also, clean up some call areas where extra masking was being performed
and where a function call was being used instead of the local variable
that was just set using the function.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Rebecca Cran <rebecca@bsdio.com>
Cc: Peter Grehan <grehan@freebsd.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien@xen.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <9de678c0d66443c6cc33e004a4cac0a0223c2ebc.1610045305.git.thomas.lendacky@amd.com>
This commit is contained in:
Tom Lendacky
2021-01-07 12:48:17 -06:00
committed by mergify[bot]
parent b97dc4b92b
commit 45388d046c
4 changed files with 11 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.c
View File

@@ -3,7 +3,7 @@
Virtual Memory Management Services to set or clear the memory encryption bit
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
Copyright (c) 2017 - 2020, AMD Incorporated. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -12,6 +12,7 @@
**/
#include <Library/CpuLib.h>
#include <Library/MemEncryptSevLib.h>
#include <Register/Amd/Cpuid.h>
#include <Register/Cpuid.h>
@@ -39,17 +40,12 @@ GetMemEncryptionAddressMask (
)
{
UINT64 EncryptionMask;
CPUID_MEMORY_ENCRYPTION_INFO_EBX Ebx;
if (mAddressEncMaskChecked) {
return mAddressEncMask;
}
//
// CPUID Fn8000_001F[EBX] Bit 0:5 (memory encryption bit position)
//
AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, NULL, &Ebx.Uint32, NULL, NULL);
EncryptionMask = LShiftU64 (1, Ebx.Bits.PtePosBits);
EncryptionMask = MemEncryptSevGetEncryptionMask ();
mAddressEncMask = EncryptionMask & PAGING_1G_ADDRESS_MASK_64;
mAddressEncMaskChecked = TRUE;
@@ -289,8 +285,7 @@ SetPageTablePoolReadOnly (
LevelSize[3] = SIZE_1GB;
LevelSize[4] = SIZE_512GB;
AddressEncMask = GetMemEncryptionAddressMask() &
PAGING_1G_ADDRESS_MASK_64;
AddressEncMask = GetMemEncryptionAddressMask();
PageTable = (UINT64 *)(UINTN)PageTableBase;
PoolUnitSize = PAGE_TABLE_POOL_UNIT_SIZE;
@@ -437,7 +432,7 @@ Split1GPageTo2M (
AddressEncMask = GetMemEncryptionAddressMask ();
ASSERT (PageDirectoryEntry != NULL);
ASSERT (*PageEntry1G & GetMemEncryptionAddressMask ());
ASSERT (*PageEntry1G & AddressEncMask);
//
// Fill in 1G page entry.
//