diff options
| -rw-r--r-- | OvmfPkg/PlatformPei/Platform.c | 2 | ||||
| -rw-r--r-- | OvmfPkg/PlatformPei/PlatformId.c | 124 | ||||
| -rw-r--r-- | OvmfPkg/PlatformPei/PlatformId.h | 26 | ||||
| -rw-r--r-- | OvmfPkg/PlatformPei/PlatformPei.inf | 4 |
4 files changed, 155 insertions, 1 deletions
diff --git a/OvmfPkg/PlatformPei/Platform.c b/OvmfPkg/PlatformPei/Platform.c index df35726..0114529 100644 --- a/OvmfPkg/PlatformPei/Platform.c +++ b/OvmfPkg/PlatformPei/Platform.c @@ -40,6 +40,7 @@ #include <OvmfPlatforms.h>
#include "Platform.h"
+#include "PlatformId.h"
EFI_PEI_PPI_DESCRIPTOR mPpiBootMode[] = {
{
@@ -363,6 +364,7 @@ InitializePlatform ( MiscInitializationForMicrovm (PlatformInfoHob);
} else {
MiscInitialization (PlatformInfoHob);
+ PlatformIdInitialization (PeiServices);
}
IntelTdxInitialize ();
diff --git a/OvmfPkg/PlatformPei/PlatformId.c b/OvmfPkg/PlatformPei/PlatformId.c new file mode 100644 index 0000000..afa2f81 --- /dev/null +++ b/OvmfPkg/PlatformPei/PlatformId.c @@ -0,0 +1,124 @@ +/**@file
+ PlatformId Event HOB creation
+
+ Copyright (c) 2024, Google LLC. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Guid/TcgEventHob.h>
+#include <IndustryStandard/UefiTcgPlatform.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/PeiServicesLib.h>
+#include <Library/PrintLib.h>
+#include <Library/QemuFwCfgLib.h>
+
+#define DPREFIX "sp800155evts: "
+
+/**
+ * Creates an EFI_HOB_TYPE_GUID_EXTENSION HOB for a given SP800155 event.
+ * Associates the string data with gTcg800155PlatformIdEventHobGuid. Any
+ * unused bytes or out-of-bounds event sizes are considered corrupted and
+ * are discarded.
+**/
+STATIC
+VOID
+PlatformIdRegisterSp800155 (
+ IN CONST EFI_PEI_SERVICES **PeiServices,
+ IN UINT8 *Evt,
+ IN UINTN EvtSize
+ )
+{
+ EFI_STATUS Status;
+ VOID *Hob;
+ EFI_HOB_GUID_TYPE *GuidHob;
+ UINT8 *EvtDest;
+
+ Status = (*PeiServices)->CreateHob (
+ PeiServices,
+ EFI_HOB_TYPE_GUID_EXTENSION,
+ sizeof (EFI_HOB_GUID_TYPE) + (UINT16)EvtSize,
+ &Hob
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, DPREFIX "GUID HOB creation failed, skipping\n"));
+ return;
+ }
+
+ GuidHob = (EFI_HOB_GUID_TYPE *)Hob;
+ CopyGuid (&GuidHob->Name, &gTcg800155PlatformIdEventHobGuid);
+ EvtDest = (UINT8 *)GET_GUID_HOB_DATA (Hob);
+ CopyMem (EvtDest, Evt, EvtSize);
+ // Fill the remaining HOB padding bytes with 0s.
+ SetMem (EvtDest + EvtSize, GET_GUID_HOB_DATA_SIZE (Hob) - EvtSize, 0);
+}
+
+/**
+ * Reads the given path from the fw_cfg file and registers it as an
+ * EFI_HOB_GUID_EXTENSION HOB with gTcg800155PlatformIdEventHobGuid.
+ * Returns FALSE iff the file does not exist.
+**/
+BOOLEAN
+PlatformIdRegisterEvent (
+ IN CONST EFI_PEI_SERVICES **PeiServices,
+ IN CONST CHAR8 *Path
+ )
+{
+ EFI_STATUS Status;
+ UINTN NumPages;
+ EFI_PHYSICAL_ADDRESS Pages;
+ FIRMWARE_CONFIG_ITEM FdtItem;
+ UINTN FdtSize;
+ UINT8 *Evt;
+
+ Status = QemuFwCfgFindFile (Path, &FdtItem, &FdtSize);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ if (FdtSize > MAX_UINT16 - sizeof (EFI_HOB_GUID_TYPE)) {
+ DEBUG ((DEBUG_ERROR, DPREFIX "Eventdata too large for HOB, skipping\n"));
+ return TRUE;
+ }
+
+ NumPages = EFI_SIZE_TO_PAGES (FdtSize);
+ Status = (*PeiServices)->AllocatePages (
+ PeiServices,
+ EfiBootServicesData,
+ NumPages,
+ &Pages
+ );
+ if (EFI_ERROR (Status)) {
+ return TRUE;
+ }
+
+ Evt = (UINT8 *)(UINTN)Pages;
+ QemuFwCfgSelectItem (FdtItem);
+ QemuFwCfgReadBytes (FdtSize, Evt);
+ PlatformIdRegisterSp800155 (PeiServices, Evt, FdtSize);
+
+ Status = (*PeiServices)->FreePages (PeiServices, Pages, NumPages);
+ ASSERT_EFI_ERROR (Status);
+ return TRUE;
+}
+
+VOID
+PlatformIdInitialization (
+ IN CONST EFI_PEI_SERVICES **PeiServices
+ )
+{
+ UINTN Index;
+ CHAR8 Path[64];
+
+ for (Index = 0; ; Index++) {
+ AsciiSPrint (Path, sizeof (Path), "opt/org.tianocode/sp800155evt/%d", Index);
+ if (!PlatformIdRegisterEvent (PeiServices, Path)) {
+ break;
+ }
+ }
+}
diff --git a/OvmfPkg/PlatformPei/PlatformId.h b/OvmfPkg/PlatformPei/PlatformId.h new file mode 100644 index 0000000..c8b5528 --- /dev/null +++ b/OvmfPkg/PlatformPei/PlatformId.h @@ -0,0 +1,26 @@ +/** @file
+ PlatformId internal header for PlatformPei
+
+ Copyright (c) 2024, Google LLC. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef __PLATFORM_PEI_PLATFORMID_H__
+#define __PLATFORM_PEI_PLATFORMID_H__
+
+/**
+ * Reads opt/org.tianocode/sp800155evt/%d from 0 to the first positive integer
+ * where the file does not exist and registers each file's contents in an
+ * EFI_HOB_GUID_TYPE with name gTcg800155PlatformIdEventHobGuid. These HOBs
+ * are used by a later driver to write to the event log as unmeasured events.
+ * These events inform the event log analyzer of firmware provenance and
+ * reference integrity manifests.
+**/
+VOID
+PlatformIdInitialization (
+ IN CONST EFI_PEI_SERVICES **PeiServices
+ );
+
+#endif // __PLATFORM_PEI_PLATFORMID_H__
diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf b/OvmfPkg/PlatformPei/PlatformPei.inf index e036018..0bb1a46 100644 --- a/OvmfPkg/PlatformPei/PlatformPei.inf +++ b/OvmfPkg/PlatformPei/PlatformPei.inf @@ -31,6 +31,8 @@ MemTypeInfo.c
Platform.c
Platform.h
+ PlatformId.c
+ PlatformId.h
IntelTdx.c
SmmRelocation.c
@@ -47,6 +49,7 @@ gFdtHobGuid
gUefiOvmfPkgPlatformInfoGuid
gGhcbApicIdsGuid
+ gTcg800155PlatformIdEventHobGuid ## SOMETIMES_PRODUCES
[LibraryClasses]
BaseLib
@@ -148,4 +151,3 @@ [Depex]
TRUE
-
|