4 files changed, 95 insertions, 2 deletions
diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
index 1171a0ffb5..7253997a6f 100644
--- a/MdePkg/Include/Library/BaseLib.h
+++ b/MdePkg/Include/Library/BaseLib.h
@@ -2,7 +2,7 @@
   Provides string functions, linked list functions, math functions, synchronization
   functions, file path functions, and CPU architecture-specific functions.
 
-Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>
 Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
 Copyright (c) Microsoft Corporation.<BR>
 Portions Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
@@ -7438,6 +7438,29 @@ AsmXGetBv (
   IN UINT32  Index
   );
 
+/**
+  Executes a XSETBV instruction to write a 64-bit value to a Extended Control
+  Register(XCR), and returns the value.
+
+  Writes the 64-bit value specified by Value to the XCR specified by Index. The
+  64-bit value written to the XCR is returned. No parameter checking is
+  performed on Index or Value, and some of these may cause CPU exceptions. The
+  caller must either guarantee that Index and Value are valid, or the caller
+  must establish proper exception handlers. This function is only available on
+  IA-32 and x64.
+
+  @param  Index The 32-bit XCR index to write.
+  @param  Value The 64-bit value to write to the XCR.
+
+  @return Value
+
+**/
+UINT64
+EFIAPI
+AsmXSetBv (
+  IN UINT32  Index,
+  IN UINT64  Value
+  );
 
 /**
   Executes a VMGEXIT instruction (VMMCALL with a REP prefix)
diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf
index 3b85c56c3c..fe8f68bbcf 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -1,7 +1,7 @@
 ## @file
 #  Base Library implementation.
 #
-#  Copyright (c) 2007 - 2020, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2007 - 2021, Intel Corporation. All rights reserved.<BR>
 #  Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
 #  Portions copyright (c) 2011 - 2013, ARM Ltd. All rights reserved.<BR>
 #  Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
@@ -184,6 +184,7 @@
   Ia32/DisableCache.nasm| GCC
   Ia32/RdRand.nasm
   Ia32/XGetBv.nasm
+  Ia32/XSetBv.nasm
   Ia32/VmgExit.nasm
 
   Ia32/DivS64x64Remainder.c
@@ -318,6 +319,7 @@
   X64/DisablePaging64.nasm
   X64/RdRand.nasm
   X64/XGetBv.nasm
+  X64/XSetBv.nasm
   X64/VmgExit.nasm
   ChkStkGcc.c  | GCC
 
diff --git a/MdePkg/Library/BaseLib/Ia32/XSetBv.nasm b/MdePkg/Library/BaseLib/Ia32/XSetBv.nasm
new file mode 100644
index 0000000000..cf638d9a4d
--- /dev/null
+++ b/MdePkg/Library/BaseLib/Ia32/XSetBv.nasm
@@ -0,0 +1,34 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+;   XSetBv.nasm
+;
+; Abstract:
+;
+;   AsmXSetBv function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; UINT64
+; EFIAPI
+; AsmXSetBv (
+;   IN UINT32  Index,
+;   IN UINT64  Value
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmXSetBv)
+ASM_PFX(AsmXSetBv):
+    mov     edx, [esp + 12]
+    mov     eax, [esp + 8]
+    mov     ecx, [esp + 4]
+    xsetbv
+    ret
diff --git a/MdePkg/Library/BaseLib/X64/XSetBv.nasm b/MdePkg/Library/BaseLib/X64/XSetBv.nasm
new file mode 100644
index 0000000000..c07e9b4c88
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/XSetBv.nasm
@@ -0,0 +1,34 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+;   XSetBv.nasm
+;
+; Abstract:
+;
+;   AsmXSetBv function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+    DEFAULT REL
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; UINT64
+; EFIAPI
+; AsmXSetBv (
+;   IN UINT32  Index,
+;   IN UINT64  Value
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmXSetBv)
+ASM_PFX(AsmXSetBv):
+    mov     rax, rdx                    ; meanwhile, rax <- return value
+    shr     rdx, 0x20                    ; edx:eax contains the value to write
+    xsetbv
+    ret