diff options
Diffstat (limited to 'MdePkg/Library/TdxLib/AcceptPages.c')
| -rw-r--r-- | MdePkg/Library/TdxLib/AcceptPages.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/MdePkg/Library/TdxLib/AcceptPages.c b/MdePkg/Library/TdxLib/AcceptPages.c new file mode 100644 index 0000000..3a2182e --- /dev/null +++ b/MdePkg/Library/TdxLib/AcceptPages.c @@ -0,0 +1,181 @@ +/** @file
+
+ Unaccepted memory is a special type of private memory. In Td guest
+ TDCALL [TDG.MEM.PAGE.ACCEPT] is invoked to accept the unaccepted
+ memory before use it.
+
+ Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <IndustryStandard/Tdx.h>
+#include <Uefi/UefiBaseType.h>
+#include <Library/TdxLib.h>
+#include <Library/BaseMemoryLib.h>
+
+UINT64 mNumberOfDuplicatedAcceptedPages;
+
+#define TDX_ACCEPTPAGE_MAX_RETRIED 3
+
+// PageSize is mapped to PageLevel like below:
+// 4KB - 0, 2MB - 1
+UINT32 mTdxAcceptPageLevelMap[2] = {
+ SIZE_4KB,
+ SIZE_2MB
+};
+
+#define INVALID_ACCEPT_PAGELEVEL ARRAY_SIZE(mTdxAcceptPageLevelMap)
+
+/**
+ This function gets the PageLevel according to the input page size.
+
+ @param[in] PageSize Page size
+
+ @return UINT32 The mapped page level
+**/
+UINT32
+GetGpaPageLevel (
+ UINT32 PageSize
+ )
+{
+ UINT32 Index;
+
+ for (Index = 0; Index < ARRAY_SIZE (mTdxAcceptPageLevelMap); Index++) {
+ if (mTdxAcceptPageLevelMap[Index] == PageSize) {
+ break;
+ }
+ }
+
+ return Index;
+}
+
+/**
+ This function accept a pending private page, and initialize the page to
+ all-0 using the TD ephemeral private key.
+
+ Sometimes TDCALL [TDG.MEM.PAGE.ACCEPT] may return
+ TDX_EXIT_REASON_PAGE_SIZE_MISMATCH. It indicates the input PageLevel is
+ not workable. In this case we need to try to fallback to a smaller
+ PageLevel if possible.
+
+ @param[in] StartAddress Guest physical address of the private
+ page to accept. [63:52] and [11:0] must be 0.
+ @param[in] NumberOfPages Number of the pages to be accepted.
+ @param[in] PageSize GPA page size. Only accept 2M/4K size.
+
+ @return EFI_SUCCESS Accept successfully
+ @return others Indicate other errors
+**/
+EFI_STATUS
+EFIAPI
+TdAcceptPages (
+ IN UINT64 StartAddress,
+ IN UINT64 NumberOfPages,
+ IN UINT32 PageSize
+ )
+{
+ EFI_STATUS Status;
+ UINT64 Address;
+ UINT64 TdxStatus;
+ UINT64 Index;
+ UINT32 GpaPageLevel;
+ UINT32 PageSize2;
+ UINTN Retried;
+
+ Retried = 0;
+
+ if ((StartAddress & ~0xFFFFFFFFFF000ULL) != 0) {
+ ASSERT (FALSE);
+ DEBUG ((DEBUG_ERROR, "Accept page address(0x%llx) is not valid. [63:52] and [11:0] must be 0\n", StartAddress));
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Address = StartAddress;
+
+ GpaPageLevel = GetGpaPageLevel (PageSize);
+ if (GpaPageLevel == INVALID_ACCEPT_PAGELEVEL) {
+ ASSERT (FALSE);
+ DEBUG ((DEBUG_ERROR, "Accept page size must be 4K/2M. Invalid page size - 0x%llx\n", PageSize));
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Status = EFI_SUCCESS;
+ for (Index = 0; Index < NumberOfPages; Index++) {
+ Retried = 0;
+
+DoAcceptPage:
+ TdxStatus = TdCall (TDCALL_TDACCEPTPAGE, Address | GpaPageLevel, 0, 0, 0);
+ if (TdxStatus != TDX_EXIT_REASON_SUCCESS) {
+ if ((TdxStatus & ~0xFFFFULL) == TDX_EXIT_REASON_PAGE_ALREADY_ACCEPTED) {
+ //
+ // Already accepted
+ //
+ mNumberOfDuplicatedAcceptedPages++;
+ DEBUG ((DEBUG_WARN, "Page at Address (0x%llx) has already been accepted. - %d\n", Address, mNumberOfDuplicatedAcceptedPages));
+ } else if ((TdxStatus & ~0xFFFFULL) == TDX_EXIT_REASON_PAGE_SIZE_MISMATCH) {
+ //
+ // GpaPageLevel is mismatch, fall back to a smaller GpaPageLevel if possible
+ //
+ DEBUG ((DEBUG_VERBOSE, "Address %llx cannot be accepted in PageLevel of %d\n", Address, GpaPageLevel));
+
+ if (GpaPageLevel == 0) {
+ //
+ // Cannot fall back to smaller page level
+ //
+ DEBUG ((DEBUG_ERROR, "AcceptPage cannot fallback from PageLevel %d\n", GpaPageLevel));
+ Status = EFI_INVALID_PARAMETER;
+ break;
+ } else {
+ //
+ // Fall back to a smaller page size
+ //
+ PageSize2 = mTdxAcceptPageLevelMap[GpaPageLevel - 1];
+ Status = TdAcceptPages (Address, 512, PageSize2);
+ if (EFI_ERROR (Status)) {
+ break;
+ }
+ }
+ } else if ((TdxStatus & ~0xFFFFULL) == TDX_EXIT_REASON_OPERAND_BUSY) {
+ //
+ // Concurrent TDG.MEM.PAGE.ACCEPT is using the same Secure EPT entry
+ // So try it again. There is a max retried count. If Retried exceeds the max count,
+ // report the error and quit.
+ //
+ Retried += 1;
+ if (Retried > TDX_ACCEPTPAGE_MAX_RETRIED) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "Address %llx (%d) failed to be accepted because of OPERAND_BUSY. Retried %d time.\n",
+ Address,
+ Index,
+ Retried
+ ));
+ Status = EFI_INVALID_PARAMETER;
+ break;
+ } else {
+ goto DoAcceptPage;
+ }
+ } else {
+ //
+ // Other errors
+ //
+ DEBUG ((
+ DEBUG_ERROR,
+ "Address %llx (%d) failed to be accepted. Error = 0x%llx\n",
+ Address,
+ Index,
+ TdxStatus
+ ));
+ Status = EFI_INVALID_PARAMETER;
+ break;
+ }
+ }
+
+ Address += PageSize;
+ }
+
+ return Status;
+}
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