[PATCH 05/23] MdePkg: Add TdxProbeLib to probe Intel Tdx

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

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

Guest software can be designed to run either as a TD, as a legacy virtual
machine, or directly on the CPU, based on enumeration of its run-time
environment. CPUID leaf 0x21 emulation is done by the Intel TDX module.
Sub-leaf 0 returns the values of "IntelTDX    " in EBX/EDX/ECX.

TdxProbeLib provides *TdxIsEnabled* to determine Td or Non-Td.

On IA32 it always return FALSE because Intel TDX only works on X64.

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>
---
 MdePkg/Include/Library/TdxProbeLib.h          | 25 +++++
 MdePkg/Library/TdxProbeLib/InternalTdxProbe.h | 25 +++++
 MdePkg/Library/TdxProbeLib/TdProbeNull.c      | 25 +++++
 MdePkg/Library/TdxProbeLib/TdxProbeLib.c      | 35 +++++++
 MdePkg/Library/TdxProbeLib/TdxProbeLib.inf    | 34 +++++++
 MdePkg/Library/TdxProbeLib/X64/TdProbe.nasm   | 97 +++++++++++++++++++
 MdePkg/MdePkg.dec                             |  3 +
 MdePkg/MdePkg.dsc                             |  1 +
 8 files changed, 245 insertions(+)
 create mode 100644 MdePkg/Include/Library/TdxProbeLib.h
 create mode 100644 MdePkg/Library/TdxProbeLib/InternalTdxProbe.h
 create mode 100644 MdePkg/Library/TdxProbeLib/TdProbeNull.c
 create mode 100644 MdePkg/Library/TdxProbeLib/TdxProbeLib.c
 create mode 100644 MdePkg/Library/TdxProbeLib/TdxProbeLib.inf
 create mode 100644 MdePkg/Library/TdxProbeLib/X64/TdProbe.nasm

diff --git a/MdePkg/Include/Library/TdxProbeLib.h b/MdePkg/Include/Library/TdxProbeLib.h
new file mode 100644
index 000000000000..d4fa4ba4cdf8
--- /dev/null
+++ b/MdePkg/Include/Library/TdxProbeLib.h
@@ -0,0 +1,25 @@
+/** @file
+  TdxProbeLib definitions
+
+  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef TDX_PROBE_LIB_H_
+#define TDX_PROBE_LIB_H_
+
+#include <Library/BaseLib.h>
+
+/**
+  Whether Intel TDX is enabled.
+
+  @return TRUE    TDX enabled
+  @return FALSE   TDX not enabled
+**/
+BOOLEAN
+EFIAPI
+TdxIsEnabled (
+  VOID);
+
+#endif
diff --git a/MdePkg/Library/TdxProbeLib/InternalTdxProbe.h b/MdePkg/Library/TdxProbeLib/InternalTdxProbe.h
new file mode 100644
index 000000000000..53cbbeda8cd8
--- /dev/null
+++ b/MdePkg/Library/TdxProbeLib/InternalTdxProbe.h
@@ -0,0 +1,25 @@
+/** @file
+  Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef INTERNAL_TDX_PROBE_H_
+#define INTERNAL_TDX_PROBE_H_
+
+#define PROBE_IS_TD_GUEST     0
+#define PROBE_NOT_TD_GUEST    1
+
+/**
+  The internal Td Probe implementation.
+
+  @return 0       TD guest
+  @return others  Non-TD guest
+**/
+UINTN
+EFIAPI
+TdProbe (
+  VOID
+  );
+
+#endif
diff --git a/MdePkg/Library/TdxProbeLib/TdProbeNull.c b/MdePkg/Library/TdxProbeLib/TdProbeNull.c
new file mode 100644
index 000000000000..12e9e1f8a7d4
--- /dev/null
+++ b/MdePkg/Library/TdxProbeLib/TdProbeNull.c
@@ -0,0 +1,25 @@
+/** @file
+
+  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <Library/BaseLib.h>
+#include "InternalTdxProbe.h"
+
+/**
+  TDX only works in X64. So allways return -1 to indicate Non-Td.
+
+  @return 0       TD guest
+  @return others  Non-TD guest
+**/
+UINTN
+EFIAPI
+TdProbe (
+  VOID
+  )
+{
+  return PROBE_NOT_TD_GUEST;
+}
diff --git a/MdePkg/Library/TdxProbeLib/TdxProbeLib.c b/MdePkg/Library/TdxProbeLib/TdxProbeLib.c
new file mode 100644
index 000000000000..3f4524dc16a6
--- /dev/null
+++ b/MdePkg/Library/TdxProbeLib/TdxProbeLib.c
@@ -0,0 +1,35 @@
+/** @file
+  instance of TdxProbeLib
+
+  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <Library/BaseLib.h>
+#include <Library/TdxProbeLib.h>
+#include "InternalTdxProbe.h"
+
+BOOLEAN mTdxEnabled = FALSE;
+BOOLEAN mTdxProbed = FALSE;
+
+/**
+  Whether Intel TDX is enabled.
+
+  @return TRUE    TDX enabled
+  @return FALSE   TDX not enabled
+**/
+BOOLEAN
+EFIAPI
+TdxIsEnabled (
+  VOID)
+{
+  if (mTdxProbed) {
+    return mTdxEnabled;
+  }
+
+  mTdxEnabled = TdProbe () == PROBE_IS_TD_GUEST;
+  mTdxProbed = TRUE;
+  return mTdxEnabled;
+}
diff --git a/MdePkg/Library/TdxProbeLib/TdxProbeLib.inf b/MdePkg/Library/TdxProbeLib/TdxProbeLib.inf
new file mode 100644
index 000000000000..59fc12c41569
--- /dev/null
+++ b/MdePkg/Library/TdxProbeLib/TdxProbeLib.inf
@@ -0,0 +1,34 @@
+## @file
+#  Tdx Probe library instance
+#
+#  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = TdxProbeLib
+  FILE_GUID                      = 26BF0B58-6E9D-4375-A363-52FD83FB82CE
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = TdxProbeLib
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  TdxProbeLib.c
+  InternalTdxProbe.h
+
+[Sources.X64]
+  X64/TdProbe.nasm
+
+[Sources.IA32]
+  TdProbeNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
diff --git a/MdePkg/Library/TdxProbeLib/X64/TdProbe.nasm b/MdePkg/Library/TdxProbeLib/X64/TdProbe.nasm
new file mode 100644
index 000000000000..ed941830f0ca
--- /dev/null
+++ b/MdePkg/Library/TdxProbeLib/X64/TdProbe.nasm
@@ -0,0 +1,97 @@
+;------------------------------------------------------------------------------
+;*
+;* CPUID leaf 0x21 emulation is done by the Intel TDX module. Sub-leaf 0
+;* returns the values of "IntelTDX    " in EBX/EDX/ECX.
+;*
+;* Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+;* SPDX-License-Identifier: BSD-2-Clause-Patent
+;*
+;*
+;------------------------------------------------------------------------------
+
+DEFAULT REL
+SECTION .text
+
+%define TD_PROBE_TD_GUEST             0
+%define TD_PROBE_NOT_TD_GUEST         1
+
+%macro td_push_regs 0
+    push rbp
+    mov  rbp, rsp
+    push r15
+    push r14
+    push r13
+    push r12
+    push rbx
+    push rsi
+    push rdi
+%endmacro
+
+%macro td_pop_regs 0
+    pop rdi
+    pop rsi
+    pop rbx
+    pop r12
+    pop r13
+    pop r14
+    pop r15
+    pop rbp
+%endmacro
+
+
+global ASM_PFX(TdProbe)
+ASM_PFX(TdProbe):
+
+    td_push_regs
+
+    ;
+    ; CPUID (0)
+    ;
+    mov     eax, 0
+    cpuid
+    cmp     ebx, 0x756e6547  ; "Genu"
+    jne     .not_td
+    cmp     edx, 0x49656e69  ; "ineI"
+    jne     .not_td
+    cmp     ecx, 0x6c65746e  ; "ntel"
+    jne     .not_td
+
+    ;
+    ; CPUID (1)
+    ;
+    mov     eax, 1
+    cpuid
+    test    ecx, 0x80000000
+    jz      .not_td
+
+    ;
+    ; CPUID[0].EAX >= 0x21?
+    ;
+    mov     eax, 0
+    cpuid
+    cmp     eax, 0x21
+    jl      .not_td
+
+    ;
+    ; CPUID (0x21,0)
+    ;
+    mov     eax, 0x21
+    mov     ecx, 0
+    cpuid
+
+    cmp     ebx, 0x65746E49   ; "Inte"
+    jne     .not_td
+    cmp     edx, 0x5844546C   ; "lTDX"
+    jne     .not_td
+    cmp     ecx, 0x20202020   ; "    "
+    jne     .not_td
+
+    mov     rax, TD_PROBE_TD_GUEST
+    jmp     .exit
+
+.not_td:
+    mov     rax, TD_PROBE_NOT_TD_GUEST
+
+.exit:
+    td_pop_regs
+    ret
diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index a28a2daaffa8..5702b0596499 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -296,6 +296,9 @@
   ##  @libraryclass  Provides services to log the SMI handler registration.
   SmiHandlerProfileLib|Include/Library/SmiHandlerProfileLib.h
 
+  ##  @libraryclass  Provides function to support TDX probe processing.
+  TdxProbeLib|Include/Library/TdxProbeLib.h
+
 [Guids]
   #
   # GUID defined in UEFI2.1/UEFI2.0/EFI1.1
diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
index a94959169b2f..a62a9504bc12 100644
--- a/MdePkg/MdePkg.dsc
+++ b/MdePkg/MdePkg.dsc
@@ -130,6 +130,7 @@
   MdePkg/Library/StandaloneMmServicesTableLib/StandaloneMmServicesTableLib.inf
 
   MdePkg/Library/RegisterFilterLibNull/RegisterFilterLibNull.inf
+  MdePkg/Library/TdxProbeLib/TdxProbeLib.inf
 
 [Components.IA32, Components.X64, Components.ARM, Components.AARCH64]
   #
-- 
2.29.2.windows.2