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| author | Min M Xu <min.m.xu@intel.com> | 2022-07-07 10:51:20 +0800 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2022-09-06 06:03:45 +0000 |
| commit | 1b1c58ab32c30d32ba7d037c0ea1da198c1b372b (patch) | |
| tree | cd61b7b8df12f2f9837f8334457e9236b36339bf /OvmfPkg/Library | |
| parent | c4bc1a9498f4e176cefaeba3211287b444a53882 (diff) | |
| download | edk2-1b1c58ab32c30d32ba7d037c0ea1da198c1b372b.tar.gz edk2-1b1c58ab32c30d32ba7d037c0ea1da198c1b372b.tar.bz2 edk2-1b1c58ab32c30d32ba7d037c0ea1da198c1b372b.zip | |
OvmfPkg: Update CcProbeLib to DxeCcProbeLib
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3974
CcProbeLib once was designed to probe the Confidential Computing guest
type by checking the PcdOvmfWorkArea. But this memory is allocated with
either EfiACPIMemoryNVS or EfiBootServicesData. It cannot be accessed
after ExitBootService. Please see the detailed analysis in BZ#3974.
To fix this issue, CcProbeLib is redesigned as 2 implementation:
- SecPeiCcProbeLib
- DxeCcProbeLib
In SecPeiCcProbeLib we check the CC guest type by reading the
PcdOvmfWorkArea. Because it is used in SEC / PEI and we don't worry about
the issues in BZ#3974.
In DxeCcProbeLib we cache the GuestType in Ovmf work area in a variable.
After that the Guest type is returned with the cached value. So that we
don't need to worry about the access to Ovmf work area after
ExitBootService.
The reason why we probe CC guest type in 2 different ways is the global
varialbe. Global variable cannot be used in SEC/PEI and CcProbe is called
very frequently.
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Diffstat (limited to 'OvmfPkg/Library')
| -rw-r--r-- | OvmfPkg/Library/CcProbeLib/CcProbeLib.c | 31 | ||||
| -rw-r--r-- | OvmfPkg/Library/CcProbeLib/DxeCcProbeLib.c | 68 | ||||
| -rw-r--r-- | OvmfPkg/Library/CcProbeLib/DxeCcProbeLib.inf (renamed from OvmfPkg/Library/CcProbeLib/CcProbeLib.inf) | 7 |
3 files changed, 72 insertions, 34 deletions
diff --git a/OvmfPkg/Library/CcProbeLib/CcProbeLib.c b/OvmfPkg/Library/CcProbeLib/CcProbeLib.c deleted file mode 100644 index d698e5c8d7..0000000000 --- a/OvmfPkg/Library/CcProbeLib/CcProbeLib.c +++ /dev/null @@ -1,31 +0,0 @@ -/** @file
-
- CcProbeLib is used to probe the Confidential computing guest type.
-
- Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
- SPDX-License-Identifier: BSD-2-Clause-Patent
-
-**/
-
-#include <Library/CcProbeLib.h>
-#include <WorkArea.h>
-
-/**
- Probe the ConfidentialComputing Guest type. See defition of
- CC_GUEST_TYPE in <ConfidentialComputingGuestAttr.h>.
-
- @return The guest type
-
-**/
-UINT8
-EFIAPI
-CcProbe (
- VOID
- )
-{
- OVMF_WORK_AREA *WorkArea;
-
- WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
-
- return WorkArea != NULL ? WorkArea->Header.GuestType : CcGuestTypeNonEncrypted;
-}
diff --git a/OvmfPkg/Library/CcProbeLib/DxeCcProbeLib.c b/OvmfPkg/Library/CcProbeLib/DxeCcProbeLib.c new file mode 100644 index 0000000000..868e32bf7f --- /dev/null +++ b/OvmfPkg/Library/CcProbeLib/DxeCcProbeLib.c @@ -0,0 +1,68 @@ +/** @file
+
+ CcProbeLib is used to probe the Confidential computing guest type.
+
+ Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi/UefiBaseType.h>
+#include <Library/CcProbeLib.h>
+#include <WorkArea.h>
+
+STATIC UINT8 mCcProbeGuestType = 0;
+STATIC BOOLEAN mCcProbed = FALSE;
+
+/**
+ * Read the the ConfidentialComputing Guest type from Ovmf work-area.
+ *
+ * @return The ConfidentialComputing Guest type
+ */
+STATIC
+UINT8
+ReadCcGuestType (
+ VOID
+ )
+{
+ OVMF_WORK_AREA *WorkArea;
+
+ if (!mCcProbed) {
+ WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
+ mCcProbeGuestType = WorkArea != NULL ? WorkArea->Header.GuestType : CcGuestTypeNonEncrypted;
+ mCcProbed = TRUE;
+ }
+
+ return mCcProbeGuestType;
+}
+
+/**
+ Probe the ConfidentialComputing Guest type. See defition of
+ CC_GUEST_TYPE in <ConfidentialComputingGuestAttr.h>.
+
+ @return The guest type
+
+**/
+UINT8
+EFIAPI
+CcProbe (
+ VOID
+ )
+{
+ return ReadCcGuestType ();
+}
+
+/**
+ * Constructor of DxeCcProbeLib
+ *
+ * @return EFI_SUCCESS Successfully called of constructor
+ */
+EFI_STATUS
+EFIAPI
+DxeCcProbeLibConstructor (
+ VOID
+ )
+{
+ ReadCcGuestType ();
+ return EFI_SUCCESS;
+}
diff --git a/OvmfPkg/Library/CcProbeLib/CcProbeLib.inf b/OvmfPkg/Library/CcProbeLib/DxeCcProbeLib.inf index 5300c9ba26..2fd0b4d46d 100644 --- a/OvmfPkg/Library/CcProbeLib/CcProbeLib.inf +++ b/OvmfPkg/Library/CcProbeLib/DxeCcProbeLib.inf @@ -8,14 +8,15 @@ [Defines]
INF_VERSION = 0x00010005
- BASE_NAME = CcProbeLib
+ BASE_NAME = DxeCcProbeLib
FILE_GUID = 05184ec9-abb0-4491-8584-e388639a7c48
MODULE_TYPE = BASE
VERSION_STRING = 1.0
- LIBRARY_CLASS = CcProbeLib
+ LIBRARY_CLASS = CcProbeLib|DXE_CORE DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SMM_DRIVER UEFI_DRIVER UEFI_APPLICATION
+ CONSTRUCTOR = DxeCcProbeLibConstructor
[Sources]
- CcProbeLib.c
+ DxeCcProbeLib.c
[Packages]
MdePkg/MdePkg.dec
|