MdePkg: Add TdxLib to wrap Tdx operations

[mirror_edk2.git] / MdePkg / Library / TdxLib / AcceptPages.c

/** @file\r
\r
  Unaccepted memory is a special type of private memory. In Td guest\r
  TDCALL [TDG.MEM.PAGE.ACCEPT] is invoked to accept the unaccepted\r
  memory before use it.\r
\r
  Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <IndustryStandard/Tdx.h>\r
#include <Uefi/UefiBaseType.h>\r
#include <Library/TdxLib.h>\r
#include <Library/BaseMemoryLib.h>\r
\r
UINT64  mNumberOfDuplicatedAcceptedPages;\r
\r
#define TDX_ACCEPTPAGE_MAX_RETRIED  3\r
\r
// PageSize is mapped to PageLevel like below:\r
// 4KB - 0, 2MB - 1\r
UINT32  mTdxAcceptPageLevelMap[2] = {\r
  SIZE_4KB,\r
  SIZE_2MB\r
};\r
\r
#define INVALID_ACCEPT_PAGELEVEL  ARRAY_SIZE(mTdxAcceptPageLevelMap)\r
\r
/**\r
  This function gets the PageLevel according to the input page size.\r
\r
  @param[in]  PageSize    Page size\r
\r
  @return UINT32          The mapped page level\r
**/\r
UINT32\r
GetGpaPageLevel (\r
  UINT32  PageSize\r
  )\r
{\r
  UINT32  Index;\r
\r
  for (Index = 0; Index < ARRAY_SIZE (mTdxAcceptPageLevelMap); Index++) {\r
    if (mTdxAcceptPageLevelMap[Index] == PageSize) {\r
      break;\r
    }\r
  }\r
\r
  return Index;\r
}\r
\r
/**\r
  This function accept a pending private page, and initialize the page to\r
  all-0 using the TD ephemeral private key.\r
\r
  Sometimes TDCALL [TDG.MEM.PAGE.ACCEPT] may return\r
  TDX_EXIT_REASON_PAGE_SIZE_MISMATCH. It indicates the input PageLevel is\r
  not workable. In this case we need to try to fallback to a smaller\r
  PageLevel if possible.\r
\r
  @param[in]  StartAddress      Guest physical address of the private\r
                                page to accept. [63:52] and [11:0] must be 0.\r
  @param[in]  NumberOfPages     Number of the pages to be accepted.\r
  @param[in]  PageSize          GPA page size. Only accept 2M/4K size.\r
\r
  @return EFI_SUCCESS           Accept successfully\r
  @return others                Indicate other errors\r
**/\r
EFI_STATUS\r
EFIAPI\r
TdAcceptPages (\r
  IN UINT64  StartAddress,\r
  IN UINT64  NumberOfPages,\r
  IN UINT32  PageSize\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINT64      Address;\r
  UINT64      TdxStatus;\r
  UINT64      Index;\r
  UINT32      GpaPageLevel;\r
  UINT32      PageSize2;\r
  UINTN       Retried;\r
\r
  Retried = 0;\r
\r
  if ((StartAddress & ~0xFFFFFFFFFF000ULL) != 0) {\r
    ASSERT (FALSE);\r
    DEBUG ((DEBUG_ERROR, "Accept page address(0x%llx) is not valid. [63:52] and [11:0] must be 0\n", StartAddress));\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Address = StartAddress;\r
\r
  GpaPageLevel = GetGpaPageLevel (PageSize);\r
  if (GpaPageLevel == INVALID_ACCEPT_PAGELEVEL) {\r
    ASSERT (FALSE);\r
    DEBUG ((DEBUG_ERROR, "Accept page size must be 4K/2M. Invalid page size - 0x%llx\n", PageSize));\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Status = EFI_SUCCESS;\r
  for (Index = 0; Index < NumberOfPages; Index++) {\r
    Retried = 0;\r
\r
DoAcceptPage:\r
    TdxStatus = TdCall (TDCALL_TDACCEPTPAGE, Address | GpaPageLevel, 0, 0, 0);\r
    if (TdxStatus != TDX_EXIT_REASON_SUCCESS) {\r
      if ((TdxStatus & ~0xFFFFULL) == TDX_EXIT_REASON_PAGE_ALREADY_ACCEPTED) {\r
        //\r
        // Already accepted\r
        //\r
        mNumberOfDuplicatedAcceptedPages++;\r
        DEBUG ((DEBUG_WARN, "Page at Address (0x%llx) has already been accepted. - %d\n", Address, mNumberOfDuplicatedAcceptedPages));\r
      } else if ((TdxStatus & ~0xFFFFULL) == TDX_EXIT_REASON_PAGE_SIZE_MISMATCH) {\r
        //\r
        // GpaPageLevel is mismatch, fall back to a smaller GpaPageLevel if possible\r
        //\r
        DEBUG ((DEBUG_VERBOSE, "Address %llx cannot be accepted in PageLevel of %d\n", Address, GpaPageLevel));\r
\r
        if (GpaPageLevel == 0) {\r
          //\r
          // Cannot fall back to smaller page level\r
          //\r
          DEBUG ((DEBUG_ERROR, "AcceptPage cannot fallback from PageLevel %d\n", GpaPageLevel));\r
          Status = EFI_INVALID_PARAMETER;\r
          break;\r
        } else {\r
          //\r
          // Fall back to a smaller page size\r
          //\r
          PageSize2 = mTdxAcceptPageLevelMap[GpaPageLevel - 1];\r
          Status    = TdAcceptPages (Address, 512, PageSize2);\r
          if (EFI_ERROR (Status)) {\r
            break;\r
          }\r
        }\r
      } else if ((TdxStatus & ~0xFFFFULL) == TDX_EXIT_REASON_OPERAND_BUSY) {\r
        //\r
        // Concurrent TDG.MEM.PAGE.ACCEPT is using the same Secure EPT entry\r
        // So try it again. There is a max retried count. If Retried exceeds the max count,\r
        // report the error and quit.\r
        //\r
        Retried += 1;\r
        if (Retried > TDX_ACCEPTPAGE_MAX_RETRIED) {\r
          DEBUG ((\r
            DEBUG_ERROR,\r
            "Address %llx (%d) failed to be accepted because of OPERAND_BUSY. Retried %d time.\n",\r
            Address,\r
            Index,\r
            Retried\r
            ));\r
          Status = EFI_INVALID_PARAMETER;\r
          break;\r
        } else {\r
          goto DoAcceptPage;\r
        }\r
      } else {\r
        //\r
        // Other errors\r
        //\r
        DEBUG ((\r
          DEBUG_ERROR,\r
          "Address %llx (%d) failed to be accepted. Error = 0x%llx\n",\r
          Address,\r
          Index,\r
          TdxStatus\r
          ));\r
        Status = EFI_INVALID_PARAMETER;\r
        break;\r
      }\r
    }\r
\r
    Address += PageSize;\r
  }\r
\r
  return Status;\r
}\r