1 files changed, 53 insertions, 0 deletions
diff --git a/UefiCpuPkg/Include/Guid/MmCpuSyncConfig.h b/UefiCpuPkg/Include/Guid/MmCpuSyncConfig.h
new file mode 100644
index 0000000000..16d96a8290
--- /dev/null
+++ b/UefiCpuPkg/Include/Guid/MmCpuSyncConfig.h
@@ -0,0 +1,53 @@
+/** @file
+  This file defines MM_CPU_SYNC_CONFIG which controls how BSP synchronizes with APs
+  in x86 SMM environment.
+
+  Copyright (c) 2024, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MM_CPU_SYNC_CONFIG_H_
+#define MM_CPU_SYNC_CONFIG_H_
+
+///
+/// The GUID of the MmCpuSyncConfig GUIDed HOB.
+///
+#define MM_CPU_SYNC_CONFIG_HOB_GUID \
+  { \
+    0x8b90bd26, 0xe4f9, 0x45c2, {0x92, 0xa2, 0x9e, 0xac, 0xe6, 0x0e, 0x9d, 0xcc}  \
+  }
+
+typedef enum {
+  MmCpuSyncModeTradition,
+  MmCpuSyncModeRelaxedAp,
+  MmCpuSyncModeMax
+} MM_CPU_SYNC_MODE;
+
+///
+/// The structure defines the data layout of the MmCpuSyncConfig GUIDed HOB.
+///
+typedef struct {
+  ///
+  /// 0: Traditional CPU synchronization method is used when processing an SMI.
+  /// 1: Relaxed CPU synchronization method is used when processing an SMI.
+  ///
+  MM_CPU_SYNC_MODE    RelaxedApMode;
+
+  ///
+  /// The 1st BSP/AP synchronization timeout value in SMM.
+  /// The value shall match with the PcdCpuSmmApSyncTimeout.
+  ///
+  UINT64              Timeout;
+
+  ///
+  /// The 2nd BSP/AP synchronization timeout value in SMM.
+  /// The value shall match with the PcdCpuSmmApSyncTimeout2.
+  ///
+  UINT64              Timeout2;
+} MM_CPU_SYNC_CONFIG;
+
+extern EFI_GUID  gMmCpuSyncConfigHobGuid;
+
+#endif