[PATCH V12 02/47] MdePkg: Update Cpuid.h for 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. [TDX-Module] Chap 10.2 defines the flow and the new CPUID
leaf 0x21.

[TDX-Module] Architecture Specification: Intel(R) Trust Domain Extensions
Module, Chap 10.2, 344425-003US, August 2021
https://www.intel.com/content/dam/develop/external/us/en/documents/
tdx-module-1.0-public-spec-v0.931.pdf

Cc: Ray Ni <ray.ni@intel.com>
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>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 MdePkg/Include/Register/Intel/Cpuid.h | 35 +++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/MdePkg/Include/Register/Intel/Cpuid.h b/MdePkg/Include/Register/Intel/Cpuid.h
index bd6349d7940d..350bf60252e1 100644
--- a/MdePkg/Include/Register/Intel/Cpuid.h
+++ b/MdePkg/Include/Register/Intel/Cpuid.h
@@ -12,6 +12,8 @@
   @par Specification Reference:
   Intel(R) 64 and IA-32 Architectures Software Developer's Manual, Volume 2A,
   November 2018, CPUID instruction.
+  Architecture Specification: Intel(R) Trust Domain Extensions Module, Chap 10.2
+  344425-003US, August 2021
 
 **/
 
@@ -321,9 +323,9 @@ typedef union {
     ///
     UINT32    RDRAND              : 1;
     ///
-    /// [Bit 31] Always returns 0.
+    /// [Bit 31] A value of 1 indicates that processor is in Para-Virtualized.
     ///
-    UINT32    NotUsed             : 1;
+    UINT32    ParaVirtualized     : 1;
   } Bits;
   ///
   /// All bit fields as a 32-bit value
@@ -3689,6 +3691,35 @@ typedef union {
 /// @}
 ///
 
+/**
+  CPUID Guest TD Run Time Environment Enumeration Leaf
+
+  @note
+  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 21H emulation is done by the Intel TDX module. Sub-leaf 0 returns the values
+  shown below. Other sub-leaves return 0 in EAX/EBX/ECX/EDX.
+    EAX: 0x00000000
+    EBX: 0x65746E49 "Inte"
+    ECX: 0x20202020 "    "
+    EDX: 0x5844546C "lTDX"
+
+  @param   EAX  CPUID_GUESTTD_RUNTIME_ENVIRONMENT                        (0x21)
+  @param   ECX  Level number
+
+**/
+#define CPUID_GUESTTD_RUNTIME_ENVIRONMENT  0x21
+
+///
+/// @{ CPUID Guest TD signature values returned by Intel processors
+///
+#define CPUID_GUESTTD_SIGNATURE_GENUINE_INTEL_EBX  SIGNATURE_32 ('I', 'n', 't', 'e')
+#define CPUID_GUESTTD_SIGNATURE_GENUINE_INTEL_ECX  SIGNATURE_32 (' ', ' ', ' ', ' ')
+#define CPUID_GUESTTD_SIGNATURE_GENUINE_INTEL_EDX  SIGNATURE_32 ('l', 'T', 'D', 'X')
+///
+/// @}
+///
+
 /**
   CPUID Extended Function
 
-- 
2.29.2.windows.2