diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
index 7253997a6f..a2cd134bea 100644
--- a/MdePkg/Include/Library/BaseLib.h
+++ b/MdePkg/Include/Library/BaseLib.h
@@ -4813,6 +4813,56 @@ SpeculationBarrier (
   VOID
   );
 
+#if defined (MDE_CPU_X64)
+//
+// The page size for the PVALIDATE instruction
+//
+typedef enum {
+  PvalidatePageSize4K = 0,
+  PvalidatePageSize2MB,
+} PVALIDATE_PAGE_SIZE;
+
+//
+// PVALIDATE Return Code.
+//
+#define PVALIDATE_RET_SUCCESS         0
+#define PVALIDATE_RET_FAIL_INPUT      1
+#define PVALIDATE_RET_SIZE_MISMATCH   6
+
+//
+// The PVALIDATE instruction did not make any changes to the RMP entry.
+//
+#define PVALIDATE_RET_NO_RMPUPDATE    255
+
+/**
+ Execute a PVALIDATE instruction to validate or to rescinds validation of a guest
+ page's RMP entry.
+
+ The instruction is available only when CPUID Fn8000_001F_EAX[SNP]=1.
+
+ The function is available on X64.
+
+ @param[in]    PageSize         The page size to use.
+ @param[in]    Validate         If TRUE, validate the guest virtual address
+                                otherwise invalidate the guest virtual address.
+ @param[in]    Address          The guest virtual address.
+
+ @retval PVALIDATE_RET_SUCCESS        The PVALIDATE instruction succeeded, and
+                                      updated the RMP entry.
+ @retval PVALIDATE_RET_NO_RMPUPDATE   The PVALIDATE instruction succeeded, but
+                                      did not update the RMP entry.
+ @return                              Failure code from the PVALIDATE
+                                      instruction.
+**/
+UINT32
+EFIAPI
+AsmPvalidate (
+  IN   PVALIDATE_PAGE_SIZE     PageSize,
+  IN   BOOLEAN                 Validate,
+  IN   PHYSICAL_ADDRESS        Address
+  );
+#endif
+
 
 #if defined (MDE_CPU_IA32) || defined (MDE_CPU_X64)
 ///
diff --git a/MdePkg/Include/X64/Nasm.inc b/MdePkg/Include/X64/Nasm.inc
index 527f71e9eb..528bb33856 100644
--- a/MdePkg/Include/X64/Nasm.inc
+++ b/MdePkg/Include/X64/Nasm.inc
@@ -33,6 +33,14 @@
     DB 0xF3, 0x48, 0x0F, 0xAE, 0xE8
 %endmacro
 
+;
+; Macro for the PVALIDATE instruction, defined in AMD APM volume 3.
+; NASM feature request URL: https://bugzilla.nasm.us/show_bug.cgi?id=3392753
+;
+%macro PVALIDATE       0
+    DB 0xF2, 0x0F, 0x01, 0xFF
+%endmacro
+
 ; NASM provides built-in macros STRUC and ENDSTRUC for structure definition.
 ; For example, to define a structure called mytype containing a longword,
 ; a word, a byte and a string of bytes, you might code
diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf
index b76f3af380..89a52f72c0 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -317,6 +317,7 @@
   X64/GccInlinePriv.c | GCC
   X64/EnableDisableInterrupts.nasm
   X64/DisablePaging64.nasm
+  X64/Pvalidate.nasm
   X64/RdRand.nasm
   X64/XGetBv.nasm
   X64/XSetBv.nasm
diff --git a/MdePkg/Library/BaseLib/X64/Pvalidate.nasm b/MdePkg/Library/BaseLib/X64/Pvalidate.nasm
new file mode 100644
index 0000000000..a7d1779134
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/Pvalidate.nasm
@@ -0,0 +1,42 @@
+;-----------------------------------------------------------------------------
+;
+; Copyright (c) 2021, AMD. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;-----------------------------------------------------------------------------
+
+%include "Nasm.inc"
+
+    SECTION .text
+
+;-----------------------------------------------------------------------------
+;  UINT32
+;  EFIAPI
+;  AsmPvalidate (
+;    IN   UINT32              PageSize
+;    IN   UINT32              Validate,
+;    IN   UINT64              Address
+;    )
+;-----------------------------------------------------------------------------
+global ASM_PFX(AsmPvalidate)
+ASM_PFX(AsmPvalidate):
+  mov     rax, r8
+
+  PVALIDATE
+
+  ; Save the carry flag.
+  setc    dl
+
+  ; The PVALIDATE instruction returns the status in rax register.
+  cmp     rax, 0
+  jne     PvalidateExit
+
+  ; Check the carry flag to determine if RMP entry was updated.
+  cmp     dl, 0
+  je      PvalidateExit
+
+  ; Return the PVALIDATE_RET_NO_RMPUPDATE.
+  mov     rax, 255
+
+PvalidateExit:
+  ret