[PATCH V3 06/29] MdePkg: Add helper functions for Tdx guest in BaseIoLibIntrinsic

["Min Xu" <min.m.xu@intel.com>]

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

Intel TDX architecture does not prescribe a specific software convention
to perform I/O from the guest TD. Guest TD providers have many choices to
provide I/O to the guest. The common I/O models are emulated devices,
para-virtualized devices, SRIOV devices and Direct Device assignments.

TDVF chooses para-virtualized I/O (Choice-A) which use the TDG.VP.VMCALL
function to invoke the funtions provided by the host VMM to perform I/O.
Another choice (Choice-B) is the emulation performed by the #VE handler.

There are 2 benefits of para-virtualized I/O:
1. Performance.
   VMEXIT/VMENTRY is skipped so that the performance is better than #VE
   handler.
2. De-couple with #VE handler.
   Choice-B depends on the #VE handler which means I/O is not available
   until #VE handler is installed. For example, in PEI phase #VE handler
   is installed in CpuMpPei, while communication with Qemu (via I/O port)
   happen earlier than it.

IoLibInternalTdx.c provides the helper functions for Tdx guest.
IoLibInternalTdxNull.c provides the null version of the helper functions.
It is included in the Non-X64 IoLib so that the build will not be broken.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 .../BaseIoLibIntrinsic/IoLibInternalTdx.c     | 704 ++++++++++++++++++
 .../BaseIoLibIntrinsic/IoLibInternalTdxNull.c | 499 +++++++++++++
 MdePkg/Library/BaseIoLibIntrinsic/IoLibTdx.h  | 411 ++++++++++
 3 files changed, 1614 insertions(+)
 create mode 100644 MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdx.c
 create mode 100644 MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdxNull.c
 create mode 100644 MdePkg/Library/BaseIoLibIntrinsic/IoLibTdx.h

diff --git a/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdx.c b/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdx.c
new file mode 100644
index 000000000000..d93f59f9c952
--- /dev/null
+++ b/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdx.c
@@ -0,0 +1,704 @@
+/** @file
+  TDX I/O Library routines.
+
+  Copyright (c) 2020-2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+#include "BaseIoLibIntrinsicInternal.h"
+#include <Include/IndustryStandard/Tdx.h>
+#include <Library/TdxLib.h>
+#include <Library/BaseLib.h>
+#include <Register/Intel/Cpuid.h>
+#include <Base.h>
+#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
+  )
+{
+  UINT32    Eax;
+  UINT32    Ebx;
+  UINT32    Ecx;
+  UINT32    Edx;
+  UINT32    LargestEax;
+
+  if (mTdxProbed) {
+    return mTdxEnabled;
+  }
+
+  mTdxEnabled = FALSE;
+
+  do {
+    AsmCpuid (CPUID_SIGNATURE, &LargestEax, &Ebx, &Ecx, &Edx);
+
+    if (Ebx != CPUID_SIGNATURE_GENUINE_INTEL_EBX
+      || Edx != CPUID_SIGNATURE_GENUINE_INTEL_EDX
+      || Ecx != CPUID_SIGNATURE_GENUINE_INTEL_ECX) {
+      break;
+    }
+
+    AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, &Ecx, NULL);
+    if ((Ecx & BIT31) == 0) {
+      break;
+    }
+
+    if (LargestEax < 0x21) {
+      break;
+    }
+
+    AsmCpuidEx (0x21, 0, &Eax, &Ebx, &Ecx, &Edx);
+    if (Ebx != SIGNATURE_32 ('I', 'n', 't', 'e')
+      || Edx != SIGNATURE_32 ('l', 'T', 'D', 'X')
+      || Ecx != SIGNATURE_32 (' ', ' ', ' ', ' ')) {
+      break;
+    }
+
+    mTdxEnabled = TRUE;
+  }while (FALSE);
+
+  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 000000000000..f518d8ffd825
--- /dev/null
+++ b/MdePkg/Library/BaseIoLibIntrinsic/IoLibInternalTdxNull.c
@@ -0,0 +1,499 @@
+/** @file
+  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <Library/BaseLib.h>
+#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 000000000000..3aad197d3b39
--- /dev/null
+++ b/MdePkg/Library/BaseIoLibIntrinsic/IoLibTdx.h
@@ -0,0 +1,411 @@
+/** @file
+  Header file for Tdx IO library.
+
+  Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>
+   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
-- 
2.29.2.windows.2