OvmfPkg: Introduce lazy accept in PlatformInitLib and PlatformPei

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3937

There are below major changes in PlatformInitLib/PlatformPei
1. ProcessHobList
  The unaccepted memory is accepted if it is under 4G address.
  Please be noted: in current stage, we only accept the memory under 4G.
  We will re-visit here in the future when on-demand accept memory is
  required.

2. TransferTdxHobList
  Transfer the unaccepted memory hob to EFI_RESOURCE_SYSTEM_MEMORY hob
  if it is accepted.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

OvmfPkg/Library/PlatformInitLib/IntelTdx.c

@@ -7,6 +7,7 @@
 
 **/
 
+#include <Base.h>
 #include <PiPei.h>
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
@@ -25,6 +26,7 @@
 #include <ConfidentialComputingGuestAttr.h>
 
 #define ALIGNED_2MB_MASK  0x1fffff
+#define MEGABYTE_SHIFT    20
 
 /**
   This function will be called to accept pages. Only BSP accepts pages.
@@ -375,11 +377,15 @@ ProcessHobList (
   EFI_STATUS            Status;
   EFI_PEI_HOB_POINTERS  Hob;
   EFI_PHYSICAL_ADDRESS  PhysicalEnd;
+  UINT64                ResourceLength;
+  UINT64                AccumulateAcceptedMemory;
 
   Status = EFI_SUCCESS;
   ASSERT (VmmHobList != NULL);
   Hob.Raw = (UINT8 *)VmmHobList;
 
+  AccumulateAcceptedMemory = 0;
+
   //
   // Parse the HOB list until end of list or matching type is found.
   //
@@ -394,6 +400,14 @@ ProcessHobList (
         DEBUG ((DEBUG_INFO, "Owner: %g\n\n", &Hob.ResourceDescriptor->Owner));
 
         PhysicalEnd    = Hob.ResourceDescriptor->PhysicalStart + Hob.ResourceDescriptor->ResourceLength;
+        ResourceLength = Hob.ResourceDescriptor->ResourceLength;
+
+        if (Hob.ResourceDescriptor->PhysicalStart >= BASE_4GB) {
+          //
+          // In current stage, we only accept the memory under 4G
+          //
+          break;
+        }
 
         Status = BspAcceptMemoryResourceRange (
                    Hob.ResourceDescriptor->PhysicalStart,
@@ -402,6 +416,8 @@ ProcessHobList (
         if (EFI_ERROR (Status)) {
           break;
         }
+
+        AccumulateAcceptedMemory += ResourceLength;
       }
     }
 
@@ -460,6 +476,60 @@ ProcessTdxHobList (
   return Status;
 }
 
+/**
+ * Build ResourceDescriptorHob for the unaccepted memory region.
+ * This memory region may be splitted into 2 parts because of lazy accept.
+ *
+ * @param Hob     Point to the EFI_HOB_RESOURCE_DESCRIPTOR
+ * @return VOID
+ */
+VOID
+BuildResourceDescriptorHobForUnacceptedMemory (
+  IN EFI_HOB_RESOURCE_DESCRIPTOR  *Hob
+  )
+{
+  EFI_PHYSICAL_ADDRESS         PhysicalStart;
+  EFI_PHYSICAL_ADDRESS         PhysicalEnd;
+  UINT64                       ResourceLength;
+  EFI_RESOURCE_TYPE            ResourceType;
+  EFI_RESOURCE_ATTRIBUTE_TYPE  ResourceAttribute;
+  UINT64                       MaxAcceptedMemoryAddress;
+
+  ASSERT (Hob->ResourceType == BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED);
+
+  ResourceType      = BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED;
+  ResourceAttribute = Hob->ResourceAttribute;
+  PhysicalStart     = Hob->PhysicalStart;
+  ResourceLength    = Hob->ResourceLength;
+  PhysicalEnd       = PhysicalStart + ResourceLength;
+
+  //
+  // In the first stage of lazy-accept, all the memory under 4G will be accepted.
+  // The memory above 4G will not be accepted.
+  //
+  MaxAcceptedMemoryAddress = BASE_4GB;
+
+  if (PhysicalEnd <= MaxAcceptedMemoryAddress) {
+    //
+    // This memory region has been accepted.
+    //
+    ResourceType       = EFI_RESOURCE_SYSTEM_MEMORY;
+    ResourceAttribute |= (EFI_RESOURCE_ATTRIBUTE_PRESENT | EFI_RESOURCE_ATTRIBUTE_INITIALIZED | EFI_RESOURCE_ATTRIBUTE_TESTED);
+  } else if (PhysicalStart >= MaxAcceptedMemoryAddress) {
+    //
+    // This memory region hasn't been accepted.
+    // So keep the ResourceType and ResourceAttribute unchange.
+    //
+  }
+
+  BuildResourceDescriptorHob (
+    ResourceType,
+    ResourceAttribute,
+    PhysicalStart,
+    ResourceLength
+    );
+}
+
 /**
   Transfer the incoming HobList for the TD to the final HobList for Dxe.
   The Hobs transferred in this function are ResourceDescriptor hob and
@@ -489,16 +559,16 @@ TransferTdxHobList (
         ResourceAttribute = Hob.ResourceDescriptor->ResourceAttribute;
 
         if (ResourceType == BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED) {
-          ResourceType       = EFI_RESOURCE_SYSTEM_MEMORY;
+          BuildResourceDescriptorHobForUnacceptedMemory (Hob.ResourceDescriptor);
-          ResourceAttribute |= (EFI_RESOURCE_ATTRIBUTE_PRESENT | EFI_RESOURCE_ATTRIBUTE_INITIALIZED | EFI_RESOURCE_ATTRIBUTE_TESTED);
+        } else {
-        }
-
           BuildResourceDescriptorHob (
             ResourceType,
             ResourceAttribute,
             Hob.ResourceDescriptor->PhysicalStart,
             Hob.ResourceDescriptor->ResourceLength
             );
+        }
+
         break;
       case EFI_HOB_TYPE_MEMORY_ALLOCATION:
         BuildMemoryAllocationHob (

OvmfPkg/Library/PlatformInitLib/MemDetect.c

@@ -42,6 +42,8 @@ Module Name:
 
 #include <Library/PlatformInitLib.h>
 
+#define MEGABYTE_SHIFT  20
+
 VOID
 EFIAPI
 PlatformQemuUc32BaseInitialization (