Works

MdeModulePkg/Include/Guid/CacheAttributesChangeEvent.h

@@ -0,0 +1,18 @@
+/** @file
+  Event group triggered when caching attributes are updated in the system.
+
+  Copyright (c) Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  MU_CHANGE: WHOLE FILE
+**/
+
+#ifndef CACHE_ATTRIBUTES_CHANGE_EVENT_H_
+#define CACHE_ATTRIBUTES_CHANGE_EVENT_H_
+
+#define CACHE_ATTRIBUTES_CHANGE_EVENT_GUID \
+   { 0XB8E477C7, 0X26A9, 0X4B9A, { 0XA7, 0XC9, 0X5F, 0X8F, 0X1F, 0X3D, 0X9C, 0X7B } }
+
+extern EFI_GUID  gCacheAttributesChangeEventGuid;
+
+#endif

MdeModulePkg/MdeModulePkg.dec

@@ -579,6 +579,10 @@
   gEdk2JedecSfdpSpiDxeDriverGuid  = { 0xBE71701E, 0xB63C, 0x4574, { 0x9C, 0x5C, 0x36, 0x29, 0xE8, 0xEA, 0xC4, 0x14 }}
   gEdk2JedecSfdpSpiSmmDriverGuid  = { 0x95A1E915, 0x195C, 0x477C, { 0x92, 0x6F, 0x7E, 0x24, 0x67, 0xC1, 0xB3, 0x1F }}
 
+  # MU_CHANGE START
+  gCacheAttributesChangeEventGuid = { 0XB8E477C7, 0X26A9, 0X4B9A, { 0XA7, 0XC9, 0X5F, 0X8F, 0X1F, 0X3D, 0X9C, 0X7B } }
+  # MU_CHANGE END
+
 [Ppis]
   ## Include/Ppi/FirmwareVolumeShadowPpi.h
   gEdkiiPeiFirmwareVolumeShadowPpiGuid = { 0x7dfe756c, 0xed8d, 0x4d77, {0x9e, 0xc4, 0x39, 0x9a, 0x8a, 0x81, 0x51, 0x16 } }

UefiCpuPkg/MpDxe/LoongArch64/MpDxe.c

@@ -4,6 +4,8 @@
   Copyright (c) 2024, Loongson Technology Corporation Limited. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  MU_CHANGE: WHOLE FILE
 **/
 
 #include "MpDxe.h"
@@ -543,7 +545,6 @@ InitializeMpSupport (
   ASSERT_EFI_ERROR (Status);
 }
 
-
 EFI_STATUS
 EFIAPI
 InitializeMp (

UefiCpuPkg/MpDxe/MpDxe.c

@@ -4,12 +4,16 @@
   Copyright (c) 2008 - 2022, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
+  MU_CHANGE: WHOLE FILE
 **/
 
 #include "MpDxe.h"
+#include <Guid/CacheAttributesChangeEvent.h>
+#include <Library/MtrrLib.h>
 
-EFI_HANDLE  mMpServiceHandle    = NULL;
-UINTN       mNumberOfProcessors = 1;
+EFI_HANDLE  mMpServiceHandle            = NULL;
+UINTN       mNumberOfProcessors         = 1;
+EFI_EVENT   mCacheAttributesChangeEvent = NULL;
 
 EFI_MP_SERVICES_PROTOCOL  mMpServicesTemplate = {
   GetNumberOfProcessors,
@@ -21,6 +25,49 @@ EFI_MP_SERVICES_PROTOCOL  mMpServicesTemplate = {
   WhoAmI
 };
 
+/**
+  A minimal wrapper function that allows MtrrSetAllMtrrs() to be passed to
+  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() as Procedure.
+
+  @param[in] Buffer  Pointer to an MTRR_SETTINGS object, to be passed to
+                     MtrrSetAllMtrrs().
+**/
+VOID
+EFIAPI
+SetMtrrsFromBuffer (
+  IN VOID  *Buffer
+  )
+{
+  MtrrSetAllMtrrs (Buffer);
+}
+
+// MU_CHANGE START: Cache Attribute Change Event
+VOID
+EFIAPI
+CacheAttributesChangeCallback (
+  IN EFI_EVENT  Event,
+  IN VOID       *Context
+  )
+{
+  MTRR_SETTINGS  MtrrSettings;
+
+  DEBUG ((DEBUG_INFO, "MpDxe updating MTRRs with APs\n"));
+
+  MtrrGetAllMtrrs (&MtrrSettings);
+
+  MpInitLibStartupAllAPs (
+    SetMtrrsFromBuffer,
+    FALSE,
+    NULL,
+    0,
+    &MtrrSettings,
+    NULL
+    );
+  // we purposefully don't close the event here, because we want to be called for every update
+}
+
+// MU_CHANGE END: Cache Attribute Change Event
+
 /**
   This service retrieves the number of logical processor in the platform
   and the number of those logical processors that are enabled on this boot.
@@ -752,14 +799,18 @@ InitializeMpExceptionHandlers (
   VOID
   )
 {
-  // //
-  // // Enable non-stop mode for #PF triggered by Heap Guard or NULL Pointer
-  // // Detection.
-  // //
+  // MU_CHANGE START - These modes are only for testing - Commenting to untangle
+  // the dependency on DebugExceptionHandler/PageFaultExceptionHandler
+  //
+  // Enable non-stop mode for #PF triggered by Heap Guard or NULL Pointer
+  // Detection.
+  //
   // if (HEAP_GUARD_NONSTOP_MODE || NULL_DETECTION_NONSTOP_MODE) {
   //   RegisterCpuInterruptHandler (EXCEPT_IA32_DEBUG, DebugExceptionHandler);
-  //   RegisterCpuInterruptHandler (EXCEPT_IA32_PAGE_FAULT, PageFaultExceptionHandler);
+  //   RegisterCpuInterruptHandler (EXCEPT_IA32_PAGE_FAULT,
+  //   PageFaultExceptionHandler);
   // }
+  // MU_CHANGE END
 
   //
   // Setup stack switch for Stack Guard feature.
@@ -816,6 +867,35 @@ InitializeMpSupport (
                     );
     ASSERT_EFI_ERROR (Status);
   }
+
+  // MU_CHANGE START: CacheAttributesChange Event
+  // Register for the CacheAttributesChangeEvent
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  CacheAttributesChangeCallback,
+                  NULL,
+                  &gCacheAttributesChangeEventGuid,
+                  &mCacheAttributesChangeEvent
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "Failed to create CacheAttributesChangeEvent\n"));
+    ASSERT_EFI_ERROR (Status);
+  }
+
+  // MU_CHANGE END: CacheAttributesChange Event
 }
 
 // MU_CHANGE End - CodeQL Change - unguardednullreturndereference
+
+EFI_STATUS
+EFIAPI
+InitializeMp (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  InitializeMpSupport ();
+
+  return EFI_SUCCESS;
+}

UefiCpuPkg/MpDxe/MpDxe.h

@@ -4,10 +4,11 @@
   Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
+  MU_CHANGE: WHOLE FILE
 **/
 
-#ifndef _MP_DXE_H_
-#define _MP_DXE_H_
+#ifndef MP_DXE_H_
+#define MP_DXE_H_
 
 #include <PiDxe.h>
 
@@ -489,4 +490,4 @@ WhoAmI (
   OUT UINTN                    *ProcessorNumber
   );
 
-#endif // _MP_DXE_H_
+#endif // MP_DXE_H_

UefiCpuPkg/MpDxe/MpDxe.inf

@@ -7,6 +7,7 @@
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
+#  MU_CHANGE: WHOLE FILE
 ##
 
 [Defines]
@@ -61,35 +62,14 @@
 
 [Protocols]
   gEfiMpServiceProtocolGuid                     ## PRODUCES
-  # gEfiCpuArchProtocolGuid                       ## CONSUMES
-  # gEfiMemoryAttributeProtocolGuid               ## TCBZ3519 MU_CHANGE PRODUCES
-  # gEfiSmmBase2ProtocolGuid                      ## SOMETIMES_CONSUMES
-  # gMemoryProtectionNonstopModeProtocolGuid      ## MU_CHANGE: PRODUCES
-  # gEdkiiGcdSyncCompleteProtocolGuid             ## MU_CHANGE: PRODUCES
-# gEfiCpuArchProtocolGuid                       ## PRODUCES
 
-# [Guids]
-#   gIdleLoopEventGuid                            ## CONSUMES           ## Event
-#   gEfiVectorHandoffTableGuid                    ## SOMETIMES_CONSUMES ## SystemTable
+[Guids]
+  gCacheAttributesChangeEventGuid               ## CONSUMES
 
 [Ppis]
   gEfiSecPlatformInformation2PpiGuid            ## UNDEFINED # HOB
   gEfiSecPlatformInformationPpiGuid             ## UNDEFINED # HOB
 
-# [Pcd]
-#   gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask    ## CONSUMES
-#   # MU_CHANGE START Remove memory protection PCD references
-#   # gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard                       ## CONSUMES
-#   # gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask               ## CONSUMES
-#   # gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask    ## CONSUMES
-#   # MU_CHANGE END
-#   gEfiMdeModulePkgTokenSpaceGuid.PcdTdxSharedBitMask                    ## CONSUMES
-#   gUefiCpuPkgTokenSpaceGuid.PcdCpuStackSwitchExceptionList              ## CONSUMES
-#   gUefiCpuPkgTokenSpaceGuid.PcdCpuKnownGoodStackSize                    ## CONSUMES
-
-# [Pcd.LoongArch64]
-#   gUefiCpuPkgTokenSpaceGuid.PcdLoongArchExceptionVectorBaseAddress      ## CONSUMES
-
 [Depex]
   gEfiCpuArchProtocolGuid
 

UefiCpuPkg/MpDxe/MpDxe.uni

@@ -7,6 +7,7 @@
 //
 // SPDX-License-Identifier: BSD-2-Clause-Patent
 //
+//  MU_CHANGE: WHOLE FILE
 // **/
 
 

UefiCpuPkg/MpDxe/MpDxeExtra.uni

@@ -5,6 +5,7 @@
 //
 // SPDX-License-Identifier: BSD-2-Clause-Patent
 //
+// MU_CHANGE: WHOLE FILE
 // **/
 
 #string STR_PROPERTIES_MODULE_NAME