/** @file | |
Secure Encrypted Virtualization (SEV) library helper function | |
Copyright (c) 2017 - 2020, AMD Incorporated. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include <Library/BaseLib.h> | |
#include <Library/DebugLib.h> | |
#include <Library/MemEncryptSevLib.h> | |
#include <Library/PcdLib.h> | |
#include <Register/Amd/SmramSaveStateMap.h> | |
#include <Register/SmramSaveStateMap.h> | |
#include <Uefi/UefiBaseType.h> | |
/** | |
Locate the page range that covers the initial (pre-SMBASE-relocation) SMRAM | |
Save State Map. | |
@param[out] BaseAddress The base address of the lowest-address page that | |
covers the initial SMRAM Save State Map. | |
@param[out] NumberOfPages The number of pages in the page range that covers | |
the initial SMRAM Save State Map. | |
@retval RETURN_SUCCESS BaseAddress and NumberOfPages have been set on | |
output. | |
@retval RETURN_UNSUPPORTED SMM is unavailable. | |
**/ | |
RETURN_STATUS | |
EFIAPI | |
MemEncryptSevLocateInitialSmramSaveStateMapPages ( | |
OUT UINTN *BaseAddress, | |
OUT UINTN *NumberOfPages | |
) | |
{ | |
UINTN MapStart; | |
UINTN MapEnd; | |
UINTN MapPagesStart; // MapStart rounded down to page boundary | |
UINTN MapPagesEnd; // MapEnd rounded up to page boundary | |
UINTN MapPagesSize; // difference between MapPagesStart and MapPagesEnd | |
if (!FeaturePcdGet (PcdSmmSmramRequire)) { | |
return RETURN_UNSUPPORTED; | |
} | |
MapStart = SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET; | |
MapEnd = MapStart + sizeof (AMD_SMRAM_SAVE_STATE_MAP); | |
MapPagesStart = MapStart & ~(UINTN)EFI_PAGE_MASK; | |
MapPagesEnd = ALIGN_VALUE (MapEnd, EFI_PAGE_SIZE); | |
MapPagesSize = MapPagesEnd - MapPagesStart; | |
ASSERT ((MapPagesSize & EFI_PAGE_MASK) == 0); | |
*BaseAddress = MapPagesStart; | |
*NumberOfPages = MapPagesSize >> EFI_PAGE_SHIFT; | |
return RETURN_SUCCESS; | |
} |