[RFC PATCH 09/14] UefiCpuPkg/MpInitLib: Allocate MP buffer as runtime memory

["Tobin Feldman-Fitzthum" <tobin@linux.ibm.com>]

Another temporary change to support the persistence of the MH.
The Mp buffer needs to be allocated as runtime memory or it
may be overwritten by the OS.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@linux.ibm.com>
---
 UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf | 2 ++
 UefiCpuPkg/Library/MpInitLib/MpLib.c          | 7 ++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
index 34abf25d43..0b26cf6aaf 100644
--- a/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
+++ b/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
@@ -39,6 +39,7 @@
   MdePkg/MdePkg.dec
   UefiCpuPkg/UefiCpuPkg.dec
   MdeModulePkg/MdeModulePkg.dec
+  OvmfPkg/OvmfPkg.dec
 
 [LibraryClasses]
   BaseLib
@@ -65,6 +66,7 @@
   gUefiCpuPkgTokenSpaceGuid.PcdSevEsIsEnabled                      ## CONSUMES
   gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase                   ## SOMETIMES_CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbBase                       ## CONSUMES
+  gUefiOvmfPkgTokenSpaceGuid.PcdStartConfidentialMigrationHandler
 
 [Ppis]
   gEdkiiPeiShadowMicrocodePpiGuid        ## SOMETIMES_CONSUMES
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 2568986d8c..0ca2858ca3 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -1974,7 +1974,12 @@ MpInitLibInitialize (
   BufferSize += VolatileRegisters.Idtr.Limit + 1;
   BufferSize += sizeof (CPU_MP_DATA);
   BufferSize += (sizeof (CPU_AP_DATA) + sizeof (CPU_INFO_IN_HOB))* MaxLogicalProcessorNumber;
-  MpBuffer    = AllocatePages (EFI_SIZE_TO_PAGES (BufferSize));
+  if (PcdGetBool (PcdStartConfidentialMigrationHandler)) {
+    MpBuffer    = AllocateRuntimePages (EFI_SIZE_TO_PAGES (BufferSize));
+  }
+  else {
+    MpBuffer    = AllocatePages (EFI_SIZE_TO_PAGES (BufferSize));
+  }
   ASSERT (MpBuffer != NULL);
   ZeroMem (MpBuffer, BufferSize);
   Buffer = (UINTN) MpBuffer;
-- 
2.20.1