Re: [PATCH v12 20/32] MdePkg: Define ConfidentialComputingGuestAttr

["Ni, Ray" <ray.ni@intel.com>]

I don't prefer to use a dynamic PCD for passing data.

Because developers don't know when this PCD value is finalized (PCD always has a default value).

If the value is determined in PEI and consumed in DXE, HOB is a better choice.
If the value is determined in PEI and consumed in PEI, PPI is a better choice. (you can use PPI depex)
If the value is determined in DXE and consumed in DXE, Protocol is a better choice. (You can use Protocol depex)

-----Original Message-----
From: Brijesh Singh <brijesh.singh@amd.com> 
Sent: Thursday, November 11, 2021 6:15 AM
To: devel@edk2.groups.io
Cc: James Bottomley <jejb@linux.ibm.com>; Xu, Min M <min.m.xu@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>; Tom Lendacky <thomas.lendacky@amd.com>; Justen, Jordan L <jordan.l.justen@intel.com>; Ard Biesheuvel <ardb+tianocore@kernel.org>; Erdem Aktas <erdemaktas@google.com>; Michael Roth <Michael.Roth@amd.com>; Gerd Hoffmann <kraxel@redhat.com>; Kinney, Michael D <michael.d.kinney@intel.com>; Liming Gao <gaoliming@byosoft.com.cn>; Liu, Zhiguang <zhiguang.liu@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar, Rahul1 <rahul1.kumar@intel.com>; Dong, Eric <eric.dong@intel.com>; Brijesh Singh <brijesh.singh@amd.com>; Michael Roth <michael.roth@amd.com>
Subject: [PATCH v12 20/32] MdePkg: Define ConfidentialComputingGuestAttr

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275

While initializing APs, the MpInitLib may need to know whether the guest is running with active AMD SEV or Intel TDX memory encryption.

Add a new ConfidentialComputingGuestAttr PCD that can be used to query the memory encryption attribute.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Suggested-by: Jiewen Yao <jiewen.yao@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 MdePkg/MdePkg.dec                             |  4 +++
 .../Include/ConfidentialComputingGuestAttr.h  | 25 +++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 MdePkg/Include/ConfidentialComputingGuestAttr.h

diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec index 8b18415b107a..cd903c35d2ff 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -2396,5 +2396,9 @@ [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
   # @Prompt FSB Clock.
   gEfiMdePkgTokenSpaceGuid.PcdFSBClock|200000000|UINT32|0x0000000c
 
+  ## This dynamic PCD indicates the memory encryption attribute of the guest.
+  # @Prompt Memory encryption attribute  
+ gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0|UINT64|0x
+ 0000002e
+
 [UserExtensions.TianoCore."ExtraFiles"]
   MdePkgExtra.uni
diff --git a/MdePkg/Include/ConfidentialComputingGuestAttr.h b/MdePkg/Include/ConfidentialComputingGuestAttr.h
new file mode 100644
index 000000000000..495b0df0ac33
--- /dev/null
+++ b/MdePkg/Include/ConfidentialComputingGuestAttr.h
@@ -0,0 +1,25 @@
+/** @file
+Definitions for Confidential Computing Attribute
+
+Copyright (c) 2021 AMD Inc. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef CONFIDENTIAL_COMPUTING_GUEST_ATTR_H_
+#define CONFIDENTIAL_COMPUTING_GUEST_ATTR_H_
+
+typedef enum {
+  /* The guest is running with memory encryption disabled. */
+  CCAttrNotEncrypted = 0,
+
+  /* The guest is running with AMD SEV memory encryption enabled. */
+  CCAttrAmdSev      = 0x100,
+  CCAttrAmdSevEs    = 0x101,
+  CCAttrAmdSevSnp   = 0x102,
+
+  /* The guest is running with Intel TDX memory encryption enabled. */
+  CCAttrIntelTdx    = 0x200,
+} CONFIDENTIAL_COMPUTING_GUEST_ATTR;
+
+#endif
--
2.25.1