[RFC PATCH v1 2/5] OvmfPkg/MemcryptSevLib: Add SEV helper library

[Brijesh Singh <brijesh.ksingh@gmail.com>]

The library contain common helper routines for SEV feature.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 OvmfPkg/Include/Library/MemcryptSevLib.h          |   42 +++++++++++++
 OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.c   |   66 +++++++++++++++++++++
 OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.inf |   44 ++++++++++++++
 OvmfPkg/OvmfPkgIa32X64.dsc                        |    4 +
 OvmfPkg/OvmfPkgX64.dsc                            |    4 +
 5 files changed, 160 insertions(+)
 create mode 100644 OvmfPkg/Include/Library/MemcryptSevLib.h
 create mode 100644 OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.c
 create mode 100644 OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.inf

diff --git a/OvmfPkg/Include/Library/MemcryptSevLib.h b/OvmfPkg/Include/Library/MemcryptSevLib.h
new file mode 100644
index 0000000..89f9c86
--- /dev/null
+++ b/OvmfPkg/Include/Library/MemcryptSevLib.h
@@ -0,0 +1,42 @@
+/** @file
+  Copyright (C) 2017 Advanced Micro Devices.
+
+  This program and the accompanying materials are licensed and made available
+  under the terms and conditions of the BSD License which accompanies this
+  distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+**/
+
+#ifndef __MEMCRYPT_SEV_LIB_H__
+#define __MEMCRYPT_SEV_LIB_H__
+
+#include <Uefi/UefiBaseType.h>
+#include <Base.h>
+
+/**
+ 
+ Initialize SEV memory encryption
+
+**/
+
+RETURN_STATUS
+EFIAPI
+MemcryptSevInitialize (
+  VOID
+  );
+
+/**
+ 
+ Return TRUE when SEV is active otherwise FALSE
+
+ **/
+BOOLEAN
+EFIAPI
+SevActive (
+  VOID
+  );
+
+#endif
diff --git a/OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.c b/OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.c
new file mode 100644
index 0000000..2d60b75
--- /dev/null
+++ b/OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.c
@@ -0,0 +1,66 @@
+/** @file
+
+  Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "Uefi.h"
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Library/MemcryptSevLib.h>
+
+#define KVM_FEATURE_MEMORY_ENCRYPTION 0x100
+
+RETURN_STATUS
+EFIAPI
+MemcryptSevInitialize (
+  VOID
+  )
+{
+  UINT32 EBX;
+  UINT64 MeMask = 0;
+
+  if (SevActive ()) {
+     // CPUID Fn8000_001f[EBX] - Bit 5:0 (memory encryption bit position)
+     AsmCpuid(0x8000001f, NULL, &EBX, NULL, NULL);
+     MeMask = (1ULL << (EBX & 0x3f));
+     DEBUG ((DEBUG_INFO, "KVM Secure Encrypted Virtualization (SEV) is enabled\n"));
+     DEBUG ((DEBUG_INFO, "MemEncryptionMask 0x%lx\n", MeMask));
+  }
+
+  PcdSet64S (PcdPteMemoryEncryptionAddressOrMask, MeMask);
+
+  return RETURN_SUCCESS;
+}
+
+BOOLEAN
+EFIAPI
+SevActive (
+  VOID
+  )
+{
+  UINT32 KVMFeatures, EAX;
+
+  // Check if KVM memory encyption feature is set
+  AsmCpuid(0x40000001, &KVMFeatures, NULL, NULL, NULL);
+  if (KVMFeatures & KVM_FEATURE_MEMORY_ENCRYPTION) {
+
+     // Check whether SEV is enabled
+     // CPUID Fn8000_001f[EAX] - Bit 0  (SEV is enabled)
+     AsmCpuid(0x8000001f, &EAX, NULL, NULL, NULL);
+
+     return TRUE;
+  }
+
+  return FALSE;
+}
+
diff --git a/OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.inf b/OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.inf
new file mode 100644
index 0000000..8e8d7e0
--- /dev/null
+++ b/OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.inf
@@ -0,0 +1,44 @@
+## @file
+#
+# Copyright (c) 2017 Advanced Micro Devices. All rights reserved.<BR>
+#
+#  This program and the accompanying materials
+#  are licensed and made available under the terms and conditions of the BSD License
+#  which accompanies this distribution. The full text of the license may be found at
+#  http://opensource.org/licenses/bsd-license.php
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = MemcryptSevLib
+  FILE_GUID                      = c1594631-3888-4be4-949f-9c630dbc842b
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = MemcryptSevLib
+  
+#
+# The following information is for reference only and not required by the build tools.
+#
+# VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  OvmfPkg/OvmfPkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec
+
+[Sources]
+  MemcryptSevLib.c
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  PcdLib
+
+[Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 56f7ff9..a35e1d2 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -129,6 +129,7 @@
   QemuFwCfgLib|OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf
   VirtioLib|OvmfPkg/Library/VirtioLib/VirtioLib.inf
   LoadLinuxLib|OvmfPkg/Library/LoadLinuxLib/LoadLinuxLib.inf
+  MemcryptSevLib|OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.inf
 !if $(SMM_REQUIRE) == FALSE
   LockBoxLib|OvmfPkg/Library/LockBoxLib/LockBoxBaseLib.inf
 !endif
@@ -509,6 +510,9 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber|64
   gUefiCpuPkgTokenSpaceGuid.PcdCpuApInitTimeOutInMicroSeconds|50000
 
+  # Set memory encryption mask
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask|0x0
+
 !if $(SMM_REQUIRE) == TRUE
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmSyncMode|0x01
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmApSyncTimeout|100000
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index d0b0b0e..5d853d6 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -129,6 +129,7 @@
   QemuFwCfgLib|OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf
   VirtioLib|OvmfPkg/Library/VirtioLib/VirtioLib.inf
   LoadLinuxLib|OvmfPkg/Library/LoadLinuxLib/LoadLinuxLib.inf
+  MemcryptSevLib|OvmfPkg/Library/MemcryptSevLib/MemcryptSevLib.inf
 !if $(SMM_REQUIRE) == FALSE
   LockBoxLib|OvmfPkg/Library/LockBoxLib/LockBoxBaseLib.inf
 !endif
@@ -508,6 +509,9 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber|64
   gUefiCpuPkgTokenSpaceGuid.PcdCpuApInitTimeOutInMicroSeconds|50000
 
+  # Set memory encryption mask
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask|0x0
+
 !if $(SMM_REQUIRE) == TRUE
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmSyncMode|0x01
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmApSyncTimeout|100000