/** @file Secure Encrypted Virtualization (SEV) library helper function Copyright (c) 2017 - 2020, AMD Incorporated. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent **/ #include #include #include #include #include #include #include /** 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; }