diff --git a/MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsicSev.inf b/MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsicSev.inf
index 34f9d1d106..336d79736d 100644
--- a/MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsicSev.inf
+++ b/MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsicSev.inf
@@ -51,3 +51,5 @@
BaseLib
RegisterFilterLib
+[LibraryClasses.X64]
+ TdxLib
diff --git a/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdx.c b/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdx.c
new file mode 100644
index 0000000000..1e539dbfbb
--- /dev/null
+++ b/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdx.c
@@ -0,0 +1,674 @@
+/** @file
+ TDX I/O Library routines.
+
+ Copyright (c) 2020-2021, Intel Corporation. All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+#include "BaseIoLibIntrinsicInternal.h"
+#include
+#include
+#include
+#include
+#include "IoLibTdx.h"
+
+// Size of TDVMCALL Access, including IO and MMIO
+#define TDVMCALL_ACCESS_SIZE_1 1
+#define TDVMCALL_ACCESS_SIZE_2 2
+#define TDVMCALL_ACCESS_SIZE_4 4
+#define TDVMCALL_ACCESS_SIZE_8 8
+
+// Direction of TDVMCALL Access, including IO and MMIO
+#define TDVMCALL_ACCESS_READ 0
+#define TDVMCALL_ACCESS_WRITE 1
+
+BOOLEAN mTdxEnabled = FALSE;
+BOOLEAN mTdxProbed = FALSE;
+
+/**
+ Check if it is Tdx guest.
+
+ @return TRUE It is Tdx guest
+ @return FALSE It is not Tdx guest
+
+**/
+BOOLEAN
+EFIAPI
+IsTdxGuest (
+ VOID
+ )
+{
+ if (mTdxProbed) {
+ return mTdxEnabled;
+ }
+
+ mTdxEnabled = TdIsEnabled ();
+ mTdxProbed = TRUE;
+
+ return mTdxEnabled;
+}
+
+/**
+ Reads an 8-bit I/O port.
+
+ TDVMCALL_IO is invoked to read I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT8
+EFIAPI
+TdIoRead8 (
+ IN UINTN Port
+ )
+{
+ UINT64 Status;
+ UINT64 Val;
+
+ Status = TdVmCall (TDVMCALL_IO, TDVMCALL_ACCESS_SIZE_1, TDVMCALL_ACCESS_READ, Port, 0, &Val);
+ if (Status != 0) {
+ TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+ }
+
+ return (UINT8)Val;
+}
+
+/**
+ Reads a 16-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT16
+EFIAPI
+TdIoRead16 (
+ IN UINTN Port
+ )
+{
+ UINT64 Status;
+ UINT64 Val;
+
+ ASSERT ((Port & 1) == 0);
+
+ Status = TdVmCall (TDVMCALL_IO, TDVMCALL_ACCESS_SIZE_2, TDVMCALL_ACCESS_READ, Port, 0, &Val);
+ if (Status != 0) {
+ TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+ }
+
+ return (UINT16)Val;
+}
+
+/**
+ Reads a 32-bit I/O port.
+
+ TDVMCALL_IO is invoked to read I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT32
+EFIAPI
+TdIoRead32 (
+ IN UINTN Port
+ )
+{
+ UINT64 Status;
+ UINT64 Val;
+
+ ASSERT ((Port & 3) == 0);
+
+ Status = TdVmCall (TDVMCALL_IO, TDVMCALL_ACCESS_SIZE_4, TDVMCALL_ACCESS_READ, Port, 0, &Val);
+ if (Status != 0) {
+ TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+ }
+
+ return (UINT32)Val;
+}
+
+/**
+ Writes an 8-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT8
+EFIAPI
+TdIoWrite8 (
+ IN UINTN Port,
+ IN UINT8 Value
+ )
+{
+ UINT64 Status;
+ UINT64 Val;
+
+ Val = Value;
+ Status = TdVmCall (TDVMCALL_IO, TDVMCALL_ACCESS_SIZE_1, TDVMCALL_ACCESS_WRITE, Port, Val, 0);
+ if (Status != 0) {
+ TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+ }
+
+ return Value;
+}
+
+/**
+ Writes a 16-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT16
+EFIAPI
+TdIoWrite16 (
+ IN UINTN Port,
+ IN UINT16 Value
+ )
+{
+ UINT64 Status;
+ UINT64 Val;
+
+ ASSERT ((Port & 1) == 0);
+ Val = Value;
+ Status = TdVmCall (TDVMCALL_IO, TDVMCALL_ACCESS_SIZE_2, TDVMCALL_ACCESS_WRITE, Port, Val, 0);
+ if (Status != 0) {
+ TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+ }
+
+ return Value;
+}
+
+/**
+ Writes a 32-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT32
+EFIAPI
+TdIoWrite32 (
+ IN UINTN Port,
+ IN UINT32 Value
+ )
+{
+ UINT64 Status;
+ UINT64 Val;
+
+ ASSERT ((Port & 3) == 0);
+ Val = Value;
+ Status = TdVmCall (TDVMCALL_IO, TDVMCALL_ACCESS_SIZE_4, TDVMCALL_ACCESS_WRITE, Port, Val, 0);
+ if (Status != 0) {
+ TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+ }
+
+ return Value;
+}
+
+/**
+ Reads an 8-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT8
+EFIAPI
+TdMmioRead8 (
+ IN UINTN Address
+ )
+{
+ UINT64 Value;
+ UINT64 Status;
+
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_1, TDVMCALL_ACCESS_READ, Address | TdSharedPageMask (), 0, &Value);
+ if (Status != 0) {
+ Value = *(volatile UINT64 *)Address;
+ }
+
+ return (UINT8)Value;
+}
+
+/**
+ Writes an 8-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read write registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT8
+EFIAPI
+TdMmioWrite8 (
+ IN UINTN Address,
+ IN UINT8 Value
+ )
+{
+ UINT64 Val;
+ UINT64 Status;
+
+ Val = Value;
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_1, TDVMCALL_ACCESS_WRITE, Address | TdSharedPageMask (), Val, 0);
+ if (Status != 0) {
+ *(volatile UINT8 *)Address = Value;
+ }
+
+ return Value;
+}
+
+/**
+ Reads a 16-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT16
+EFIAPI
+TdMmioRead16 (
+ IN UINTN Address
+ )
+{
+ UINT64 Value;
+ UINT64 Status;
+
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_2, TDVMCALL_ACCESS_READ, Address | TdSharedPageMask (), 0, &Value);
+ if (Status != 0) {
+ Value = *(volatile UINT64 *)Address;
+ }
+
+ return (UINT16)Value;
+}
+
+/**
+ Writes a 16-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT16
+EFIAPI
+TdMmioWrite16 (
+ IN UINTN Address,
+ IN UINT16 Value
+ )
+{
+ UINT64 Val;
+ UINT64 Status;
+
+ ASSERT ((Address & 1) == 0);
+
+ Val = Value;
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_2, TDVMCALL_ACCESS_WRITE, Address | TdSharedPageMask (), Val, 0);
+ if (Status != 0) {
+ *(volatile UINT16 *)Address = Value;
+ }
+
+ return Value;
+}
+
+/**
+ Reads a 32-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT32
+EFIAPI
+TdMmioRead32 (
+ IN UINTN Address
+ )
+{
+ UINT64 Value;
+ UINT64 Status;
+
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_4, TDVMCALL_ACCESS_READ, Address | TdSharedPageMask (), 0, &Value);
+ if (Status != 0) {
+ Value = *(volatile UINT64 *)Address;
+ }
+
+ return (UINT32)Value;
+}
+
+/**
+ Writes a 32-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT32
+EFIAPI
+TdMmioWrite32 (
+ IN UINTN Address,
+ IN UINT32 Value
+ )
+{
+ UINT64 Val;
+ UINT64 Status;
+
+ ASSERT ((Address & 3) == 0);
+
+ Val = Value;
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_4, TDVMCALL_ACCESS_WRITE, Address | TdSharedPageMask (), Val, 0);
+ if (Status != 0) {
+ *(volatile UINT32 *)Address = Value;
+ }
+
+ return Value;
+}
+
+/**
+ Reads a 64-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT64
+EFIAPI
+TdMmioRead64 (
+ IN UINTN Address
+ )
+{
+ UINT64 Value;
+ UINT64 Status;
+
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_8, TDVMCALL_ACCESS_READ, Address | TdSharedPageMask (), 0, &Value);
+ if (Status != 0) {
+ Value = *(volatile UINT64 *)Address;
+ }
+
+ return Value;
+}
+
+/**
+ Writes a 64-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+**/
+UINT64
+EFIAPI
+TdMmioWrite64 (
+ IN UINTN Address,
+ IN UINT64 Value
+ )
+{
+ UINT64 Status;
+ UINT64 Val;
+
+ ASSERT ((Address & 7) == 0);
+
+ Val = Value;
+ Status = TdVmCall (TDVMCALL_MMIO, TDVMCALL_ACCESS_SIZE_8, TDVMCALL_ACCESS_WRITE, Address | TdSharedPageMask (), Val, 0);
+ if (Status != 0) {
+ *(volatile UINT64 *)Address = Value;
+ }
+
+ return Value;
+}
+
+/**
+ Reads an 8-bit I/O port fifo into a block of memory.
+
+ Reads the 8-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 8-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoRead8 is invoked to read the I/O port fifo.
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo8 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ )
+{
+ UINT8 *Buf8;
+ UINTN Index;
+
+ Buf8 = (UINT8 *)Buffer;
+ for (Index = 0; Index < Count; Index++) {
+ Buf8[Index] = TdIoRead8 (Port);
+ }
+}
+
+/**
+ Writes a block of memory into an 8-bit I/O port fifo.
+
+ Writes the 8-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 8-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoWrite8 is invoked to write data to the I/O port.
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo8 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ )
+{
+ UINT8 *Buf8;
+ UINTN Index;
+
+ Buf8 = (UINT8 *)Buffer;
+ for (Index = 0; Index < Count; Index++) {
+ TdIoWrite8 (Port, Buf8[Index]);
+ }
+}
+
+/**
+ Reads a 16-bit I/O port fifo into a block of memory.
+
+ Reads the 16-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 16-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoRead16 is invoked to read data from the I/O port.
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo16 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ )
+{
+ UINT16 *Buf16;
+ UINTN Index;
+
+ Buf16 = (UINT16 *)Buffer;
+ for (Index = 0; Index < Count; Index++) {
+ Buf16[Index] = TdIoRead16 (Port);
+ }
+}
+
+/**
+ Writes a block of memory into a 16-bit I/O port fifo.
+
+ Writes the 16-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 16-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoWrite16 is invoked to write data to the I/O port.
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo16 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ )
+{
+ UINT16 *Buf16;
+ UINTN Index;
+
+ Buf16 = (UINT16 *)Buffer;
+ for (Index = 0; Index < Count; Index++) {
+ TdIoWrite16 (Port, Buf16[Index]);
+ }
+}
+
+/**
+ Reads a 32-bit I/O port fifo into a block of memory.
+
+ Reads the 32-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 32-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoRead32 is invoked to read data from the I/O port.
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo32 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ )
+{
+ UINT32 *Buf32;
+ UINTN Index;
+
+ Buf32 = (UINT32 *)Buffer;
+ for (Index = 0; Index < Count; Index++) {
+ Buf32[Index] = TdIoRead32 (Port);
+ }
+}
+
+/**
+ Writes a block of memory into a 32-bit I/O port fifo.
+
+ Writes the 32-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 32-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoWrite32 is invoked to write data to the I/O port.
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo32 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ )
+{
+ UINT32 *Buf32;
+ UINTN Index;
+
+ Buf32 = (UINT32 *)Buffer;
+ for (Index = 0; Index < Count; Index++) {
+ TdIoWrite32 (Port, Buf32[Index]);
+ }
+}
diff --git a/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdxNull.c b/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdxNull.c
new file mode 100644
index 0000000000..7262704d6b
--- /dev/null
+++ b/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdxNull.c
@@ -0,0 +1,497 @@
+/** @file
+ Copyright (c) 2021, Intel Corporation. All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include
+#include "BaseIoLibIntrinsicInternal.h"
+#include "IoLibTdx.h"
+
+/**
+ Check if it is Tdx guest.
+
+ @return TRUE It is Tdx guest
+ @return FALSE It is not Tdx guest
+
+**/
+BOOLEAN
+EFIAPI
+IsTdxGuest (
+ VOID
+ )
+{
+ return FALSE;
+}
+
+/**
+ Reads an 8-bit I/O port.
+
+ TDVMCALL_IO is invoked to read I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT8
+EFIAPI
+TdIoRead8 (
+ IN UINTN Port
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Reads a 16-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT16
+EFIAPI
+TdIoRead16 (
+ IN UINTN Port
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Reads a 32-bit I/O port.
+
+ TDVMCALL_IO is invoked to read I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT32
+EFIAPI
+TdIoRead32 (
+ IN UINTN Port
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Writes an 8-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT8
+EFIAPI
+TdIoWrite8 (
+ IN UINTN Port,
+ IN UINT8 Value
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Writes a 16-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT16
+EFIAPI
+TdIoWrite16 (
+ IN UINTN Port,
+ IN UINT16 Value
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Writes a 32-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT32
+EFIAPI
+TdIoWrite32 (
+ IN UINTN Port,
+ IN UINT32 Value
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Reads an 8-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT8
+EFIAPI
+TdMmioRead8 (
+ IN UINTN Address
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Writes an 8-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read write registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT8
+EFIAPI
+TdMmioWrite8 (
+ IN UINTN Address,
+ IN UINT8 Val
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Reads a 16-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT16
+EFIAPI
+TdMmioRead16 (
+ IN UINTN Address
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Writes a 16-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT16
+EFIAPI
+TdMmioWrite16 (
+ IN UINTN Address,
+ IN UINT16 Val
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Reads a 32-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT32
+EFIAPI
+TdMmioRead32 (
+ IN UINTN Address
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Writes a 32-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT32
+EFIAPI
+TdMmioWrite32 (
+ IN UINTN Address,
+ IN UINT32 Val
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Reads a 64-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT64
+EFIAPI
+TdMmioRead64 (
+ IN UINTN Address
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Writes a 64-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+**/
+UINT64
+EFIAPI
+TdMmioWrite64 (
+ IN UINTN Address,
+ IN UINT64 Value
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/**
+ Reads an 8-bit I/O port fifo into a block of memory.
+
+ Reads the 8-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 8-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoRead8 is invoked to read the I/O port fifo.
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo8 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ )
+{
+ ASSERT (FALSE);
+}
+
+/**
+ Writes a block of memory into an 8-bit I/O port fifo.
+
+ Writes the 8-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 8-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoWrite8 is invoked to write data to the I/O port.
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo8 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ )
+{
+ ASSERT (FALSE);
+}
+
+/**
+ Reads a 16-bit I/O port fifo into a block of memory.
+
+ Reads the 16-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 16-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoRead16 is invoked to read data from the I/O port.
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo16 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ )
+{
+ ASSERT (FALSE);
+}
+
+/**
+ Writes a block of memory into a 16-bit I/O port fifo.
+
+ Writes the 16-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 16-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoWrite16 is invoked to write data to the I/O port.
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo16 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ )
+{
+ ASSERT (FALSE);
+}
+
+/**
+ Reads a 32-bit I/O port fifo into a block of memory.
+
+ Reads the 32-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 32-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoRead32 is invoked to read data from the I/O port.
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo32 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ )
+{
+ ASSERT (FALSE);
+}
+
+/**
+ Writes a block of memory into a 32-bit I/O port fifo.
+
+ Writes the 32-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 32-bit I/O port operations are not supported, then ASSERT().
+
+ In TDX a serial of TdIoWrite32 is invoked to write data to the I/O port.
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo32 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ )
+{
+ ASSERT (FALSE);
+}
diff --git a/MdePkg/Library/BaseIoLibIntrinsic/IoLibTdx.h b/MdePkg/Library/BaseIoLibIntrinsic/IoLibTdx.h
new file mode 100644
index 0000000000..ab2fa771f6
--- /dev/null
+++ b/MdePkg/Library/BaseIoLibIntrinsic/IoLibTdx.h
@@ -0,0 +1,410 @@
+/** @file
+ Header file for Tdx IO library.
+
+ Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef IOLIB_TDX_H_
+#define IOLIB_TDX_H_
+
+/**
+ Check if it is Tdx guest.
+
+ @return TRUE It is Tdx guest
+ @return FALSE It is not Tdx guest
+
+**/
+BOOLEAN
+EFIAPI
+IsTdxGuest (
+ VOID
+ );
+
+/**
+ Reads an 8-bit I/O port.
+
+ TDVMCALL_IO is invoked to read I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT8
+EFIAPI
+TdIoRead8 (
+ IN UINTN Port
+ );
+
+/**
+ Reads a 16-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT16
+EFIAPI
+TdIoRead16 (
+ IN UINTN Port
+ );
+
+/**
+ Reads a 32-bit I/O port.
+
+ TDVMCALL_IO is invoked to read I/O port.
+
+ @param Port The I/O port to read.
+
+ @return The value read.
+
+**/
+UINT32
+EFIAPI
+TdIoRead32 (
+ IN UINTN Port
+ );
+
+/**
+ Writes an 8-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT8
+EFIAPI
+TdIoWrite8 (
+ IN UINTN Port,
+ IN UINT8 Value
+ );
+
+/**
+ Writes a 16-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT16
+EFIAPI
+TdIoWrite16 (
+ IN UINTN Port,
+ IN UINT16 Value
+ );
+
+/**
+ Writes a 32-bit I/O port.
+
+ TDVMCALL_IO is invoked to write I/O port.
+
+ @param Port The I/O port to write.
+ @param Value The value to write to the I/O port.
+
+ @return The value written the I/O port.
+
+**/
+UINT32
+EFIAPI
+TdIoWrite32 (
+ IN UINTN Port,
+ IN UINT32 Value
+ );
+
+/**
+ Reads an 8-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT8
+EFIAPI
+TdMmioRead8 (
+ IN UINTN Address
+ );
+
+/**
+ Writes an 8-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read write registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT8
+EFIAPI
+TdMmioWrite8 (
+ IN UINTN Address,
+ IN UINT8 Val
+ );
+
+/**
+ Reads a 16-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT16
+EFIAPI
+TdMmioRead16 (
+ IN UINTN Address
+ );
+
+/**
+ Writes a 16-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT16
+EFIAPI
+TdMmioWrite16 (
+ IN UINTN Address,
+ IN UINT16 Val
+ );
+
+/**
+ Reads a 32-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT32
+EFIAPI
+TdMmioRead32 (
+ IN UINTN Address
+ );
+
+/**
+ Writes a 32-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+ @return Value.
+
+**/
+UINT32
+EFIAPI
+TdMmioWrite32 (
+ IN UINTN Address,
+ IN UINT32 Val
+ );
+
+/**
+ Reads a 64-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to read MMIO registers.
+
+ @param Address The MMIO register to read.
+
+ @return The value read.
+
+**/
+UINT64
+EFIAPI
+TdMmioRead64 (
+ IN UINTN Address
+ );
+
+/**
+ Writes a 64-bit MMIO register.
+
+ TDVMCALL_MMIO is invoked to write MMIO registers.
+
+ @param Address The MMIO register to write.
+ @param Value The value to write to the MMIO register.
+
+**/
+UINT64
+EFIAPI
+TdMmioWrite64 (
+ IN UINTN Address,
+ IN UINT64 Value
+ );
+
+/**
+ Reads an 8-bit I/O port fifo into a block of memory in Tdx.
+
+ Reads the 8-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 8-bit I/O port operations are not supported, then ASSERT().
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo8 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ );
+
+/**
+ Writes a block of memory into an 8-bit I/O port fifo in Tdx.
+
+ Writes the 8-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 8-bit I/O port operations are not supported, then ASSERT().
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo8 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ );
+
+/**
+ Reads a 16-bit I/O port fifo into a block of memory in Tdx.
+
+ Reads the 16-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 16-bit I/O port operations are not supported, then ASSERT().
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo16 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ );
+
+/**
+ Writes a block of memory into a 16-bit I/O port fifo in Tdx.
+
+ Writes the 16-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 16-bit I/O port operations are not supported, then ASSERT().
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo16 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ );
+
+/**
+ Reads a 32-bit I/O port fifo into a block of memory in Tdx.
+
+ Reads the 32-bit I/O fifo port specified by Port.
+ The port is read Count times, and the read data is
+ stored in the provided Buffer.
+
+ This function must guarantee that all I/O read and write operations are
+ serialized.
+
+ If 32-bit I/O port operations are not supported, then ASSERT().
+
+ @param Port The I/O port to read.
+ @param Count The number of times to read I/O port.
+ @param Buffer The buffer to store the read data into.
+
+**/
+VOID
+EFIAPI
+TdIoReadFifo32 (
+ IN UINTN Port,
+ IN UINTN Count,
+ OUT VOID *Buffer
+ );
+
+/**
+ Writes a block of memory into a 32-bit I/O port fifo in Tdx.
+
+ Writes the 32-bit I/O fifo port specified by Port.
+ The port is written Count times, and the write data is
+ retrieved from the provided Buffer.
+
+ This function must guarantee that all I/O write and write operations are
+ serialized.
+
+ If 32-bit I/O port operations are not supported, then ASSERT().
+
+ @param Port The I/O port to write.
+ @param Count The number of times to write I/O port.
+ @param Buffer The buffer to retrieve the write data from.
+
+**/
+VOID
+EFIAPI
+TdIoWriteFifo32 (
+ IN UINTN Port,
+ IN UINTN Count,
+ IN VOID *Buffer
+ );
+
+#endif