diff --git a/ArmVirtPkg/Library/FdtPciHostBridgeLib/FdtPciHostBridgeLib.c b/ArmVirtPkg/Library/FdtPciHostBridgeLib/FdtPciHostBridgeLib.c
index 0aff149e8029..74fda4d23fa3 100644
--- a/ArmVirtPkg/Library/FdtPciHostBridgeLib/FdtPciHostBridgeLib.c
+++ b/ArmVirtPkg/Library/FdtPciHostBridgeLib/FdtPciHostBridgeLib.c
@@ -87,9 +87,10 @@ ProcessPciHost (
   OUT  UINT64    *IoBase,
   OUT  UINT64    *IoSize,
   OUT  UINT64    *IoTranslation,
-  OUT  UINT64    *MmioBase,
-  OUT  UINT64    *MmioSize,
-  OUT  UINT64    *MmioTranslation,
+  OUT  UINT64    *Mmio32Base,
+  OUT  UINT64    *Mmio32Size,
+  OUT  UINT64    *Mmio64Base,
+  OUT  UINT64    *Mmio64Size,
   OUT  UINT32    *BusMin,
   OUT  UINT32    *BusMax
   )
@@ -101,6 +102,7 @@ ProcessPciHost (
   UINT32                      Len;
   UINT32                      RecordIdx;
   EFI_STATUS                  Status;
+  UINT64                      MmioTranslation;
 
   //
   // The following output arguments are initialized only in
@@ -109,8 +111,8 @@ ProcessPciHost (
   //
   *IoBase = 0;
   *IoTranslation = 0;
-  *MmioBase = 0;
-  *MmioTranslation = 0;
+  *Mmio32Base = 0;
+  *Mmio64Base = MAX_UINT64;
   *BusMin = 0;
   *BusMax = 0;
 
@@ -120,7 +122,8 @@ ProcessPciHost (
   // above, they are initialized early.
   //
   *IoSize = 0;
-  *MmioSize = 0;
+  *Mmio32Size = 0;
+  *Mmio64Size = 0;
 
   Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
                   (VOID **)&FdtClient);
@@ -207,26 +210,39 @@ ProcessPciHost (
       break;
 
     case DTB_PCI_HOST_RANGE_MMIO32:
-      *MmioBase = SwapBytes64 (Record->ChildBase);
-      *MmioSize = SwapBytes64 (Record->Size);
-      *MmioTranslation = SwapBytes64 (Record->CpuBase) - *MmioBase;
+      *Mmio32Base = SwapBytes64 (Record->ChildBase);
+      *Mmio32Size = SwapBytes64 (Record->Size);
+      MmioTranslation = SwapBytes64 (Record->CpuBase) - *Mmio32Base;
 
-      if (*MmioBase > MAX_UINT32 || *MmioSize > MAX_UINT32 ||
-          *MmioBase + *MmioSize > SIZE_4GB) {
+      if (*Mmio32Base > MAX_UINT32 || *Mmio32Size > MAX_UINT32 ||
+          *Mmio32Base + *Mmio32Size > SIZE_4GB) {
         DEBUG ((EFI_D_ERROR, "%a: MMIO32 space invalid\n", __FUNCTION__));
         return EFI_PROTOCOL_ERROR;
       }
 
-      if (*MmioTranslation != 0) {
+      if (MmioTranslation != 0) {
         DEBUG ((EFI_D_ERROR, "%a: unsupported nonzero MMIO32 translation "
-          "0x%Lx\n", __FUNCTION__, *MmioTranslation));
+          "0x%Lx\n", __FUNCTION__, MmioTranslation));
+        return EFI_UNSUPPORTED;
+      }
+
+      break;
+
+    case DTB_PCI_HOST_RANGE_MMIO64:
+      *Mmio64Base = SwapBytes64 (Record->ChildBase);
+      *Mmio64Size = SwapBytes64 (Record->Size);
+      MmioTranslation = SwapBytes64 (Record->CpuBase) - *Mmio64Base;
+
+      if (MmioTranslation != 0) {
+        DEBUG ((EFI_D_ERROR, "%a: unsupported nonzero MMIO64 translation "
+          "0x%Lx\n", __FUNCTION__, MmioTranslation));
         return EFI_UNSUPPORTED;
       }
 
       break;
     }
   }
-  if (*IoSize == 0 || *MmioSize == 0) {
+  if (*IoSize == 0 || *Mmio32Size == 0) {
     DEBUG ((EFI_D_ERROR, "%a: %a space empty\n", __FUNCTION__,
       (*IoSize == 0) ? "IO" : "MMIO32"));
     return EFI_PROTOCOL_ERROR;
@@ -239,9 +255,9 @@ ProcessPciHost (
   ASSERT (PcdGet64 (PcdPciExpressBaseAddress) == ConfigBase);
 
   DEBUG ((EFI_D_INFO, "%a: Config[0x%Lx+0x%Lx) Bus[0x%x..0x%x] "
-    "Io[0x%Lx+0x%Lx)@0x%Lx Mem[0x%Lx+0x%Lx)@0x%Lx\n", __FUNCTION__, ConfigBase,
-    ConfigSize, *BusMin, *BusMax, *IoBase, *IoSize, *IoTranslation, *MmioBase,
-    *MmioSize, *MmioTranslation));
+    "Io[0x%Lx+0x%Lx)@0x%Lx Mem32[0x%Lx+0x%Lx) Mem64[0x%Lx+0x%Lx)\n",
+    __FUNCTION__, ConfigBase, ConfigSize, *BusMin, *BusMax, *IoBase, *IoSize,
+    *IoTranslation, *Mmio32Base, *Mmio32Size, *Mmio64Base, *Mmio64Size));
   return EFI_SUCCESS;
 }
 
@@ -263,7 +279,8 @@ PciHostBridgeGetRootBridges (
 {
   PCI_ROOT_BRIDGE     *RootBridge;
   UINT64              IoBase, IoSize, IoTranslation;
-  UINT64              Mmio32Base, Mmio32Size, Mmio32Translation;
+  UINT64              Mmio32Base, Mmio32Size;
+  UINT64              Mmio64Base, Mmio64Size;
   UINT32              BusMin, BusMax;
   EFI_STATUS          Status;
 
@@ -275,7 +292,7 @@ PciHostBridgeGetRootBridges (
   }
 
   Status = ProcessPciHost (&IoBase, &IoSize, &IoTranslation, &Mmio32Base,
-             &Mmio32Size, &Mmio32Translation, &BusMin, &BusMax);
+             &Mmio32Size, &Mmio64Base, &Mmio64Size, &BusMin, &BusMax);
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_INFO,
       "%a: failed to discover PCI host bridge: %s not present\n",
@@ -304,8 +321,8 @@ PciHostBridgeGetRootBridges (
   RootBridge->Io.Limit              = IoBase + IoSize - 1;
   RootBridge->Mem.Base              = Mmio32Base;
   RootBridge->Mem.Limit             = Mmio32Base + Mmio32Size - 1;
-  RootBridge->MemAbove4G.Base       = MAX_UINT64;
-  RootBridge->MemAbove4G.Limit      = 0;
+  RootBridge->MemAbove4G.Base       = Mmio64Base;
+  RootBridge->MemAbove4G.Limit      = Mmio64Base + Mmio64Size - 1;
 
   //
   // No separate ranges for prefetchable and non-prefetchable BARs
