diff --git a/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.c b/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.c
index 30f69b999a..2d106bb50b 100644
--- a/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.c
+++ b/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.c
@@ -74,8 +74,8 @@ EFI_FW_VOL_BLOCK_DEVICE mEmuVarsFvb = {
     }
   },
   NULL, // BufferPtr
-  FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize), // BlockSize
-  2 * FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize), // Size
+  EMU_FVB_BLOCK_SIZE, // BlockSize
+  EMU_FVB_SIZE, // Size
   {     // FwVolBlockInstance
     FvbProtocolGetAttributes,
     FvbProtocolSetAttributes,
@@ -185,14 +185,14 @@ FvbProtocolGetBlockSize (
 {
   EFI_FW_VOL_BLOCK_DEVICE *FvbDevice;
 
-  if (Lba > 1) {
+  if (Lba >= EMU_FVB_NUM_TOTAL_BLOCKS) {
     return EFI_INVALID_PARAMETER;
   }
 
   FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
   *BlockSize = FvbDevice->BlockSize;
-  *NumberOfBlocks = (UINTN) (2 - (UINTN) Lba);
+  *NumberOfBlocks = (UINTN)(EMU_FVB_NUM_TOTAL_BLOCKS - Lba);
 
   return EFI_SUCCESS;
 }
@@ -322,68 +322,58 @@ FvbProtocolEraseBlocks (
   )
 {
   EFI_FW_VOL_BLOCK_DEVICE *FvbDevice;
-  VA_LIST                 args;
+  VA_LIST                 Args;
   EFI_LBA                 StartingLba;
   UINTN                   NumOfLba;
-  UINT8                   Erase;
-  VOID                    *ErasePtr;
+  UINT8                   *ErasePtr;
   UINTN                   EraseSize;
 
   FvbDevice = FVB_DEVICE_FROM_THIS (This);
-  Erase = 0;
-
-  VA_START (args, This);
 
+  //
+  // Check input parameters
+  //
+  VA_START (Args, This);
   do {
-    StartingLba = VA_ARG (args, EFI_LBA);
+    StartingLba = VA_ARG (Args, EFI_LBA);
     if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
       break;
     }
+    NumOfLba = VA_ARG (Args, UINTN);
 
-    NumOfLba = VA_ARG (args, UINTN);
-
-    //
-    // Check input parameters
-    //
-    if ((NumOfLba == 0) || (StartingLba > 1) || ((StartingLba + NumOfLba) > 2)) {
-      VA_END (args);
+    if (StartingLba > EMU_FVB_NUM_TOTAL_BLOCKS ||
+        NumOfLba > EMU_FVB_NUM_TOTAL_BLOCKS - StartingLba) {
+      VA_END (Args);
       return EFI_INVALID_PARAMETER;
     }
-
-    if (StartingLba == 0) {
-      Erase = (UINT8) (Erase | BIT0);
-    }
-    if ((StartingLba + NumOfLba) == 2) {
-      Erase = (UINT8) (Erase | BIT1);
-    }
-
   } while (1);
+  VA_END (Args);
 
-  VA_END (args);
+  //
+  // Erase blocks
+  //
+  VA_START (Args, This);
+  do {
+    StartingLba = VA_ARG (Args, EFI_LBA);
+    if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
+      break;
+    }
+    NumOfLba = VA_ARG (Args, UINTN);
 
-  ErasePtr = (UINT8*) FvbDevice->BufferPtr;
-  EraseSize = 0;
+    ErasePtr = FvbDevice->BufferPtr;
+    ErasePtr += (UINTN)StartingLba * FvbDevice->BlockSize;
+    EraseSize = NumOfLba * FvbDevice->BlockSize;
 
-  if ((Erase & BIT0) != 0) {
-    EraseSize = EraseSize + FvbDevice->BlockSize;
-  } else {
-    ErasePtr = (VOID*) ((UINT8*)ErasePtr + FvbDevice->BlockSize);
-  }
+    SetMem (ErasePtr, EraseSize, ERASED_UINT8);
+  } while (1);
+  VA_END (Args);
 
-  if ((Erase & BIT1) != 0) {
-    EraseSize = EraseSize + FvbDevice->BlockSize;
-  }
-
-  if (EraseSize != 0) {
-    SetMem (
-      (VOID*) ErasePtr,
-      EraseSize,
-      ERASED_UINT8
-      );
-    VA_START (args, This);
-    PlatformFvbBlocksErased (This, args);
-    VA_END (args);
-  }
+  //
+  // Call platform hook
+  //
+  VA_START (Args, This);
+  PlatformFvbBlocksErased (This, Args);
+  VA_END (Args);
 
   return EFI_SUCCESS;
 }
@@ -458,31 +448,30 @@ FvbProtocolWrite (
   IN        UINT8                               *Buffer
   )
 {
-
   EFI_FW_VOL_BLOCK_DEVICE *FvbDevice;
   UINT8                   *FvbDataPtr;
+  EFI_STATUS              Status;
 
   FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
-  if ((Lba > 1) || (Offset > FvbDevice->BlockSize)) {
+  if (Lba >= EMU_FVB_NUM_TOTAL_BLOCKS ||
+      Offset > FvbDevice->BlockSize) {
     return EFI_INVALID_PARAMETER;
   }
 
-  if ((Offset + *NumBytes) > FvbDevice->BlockSize) {
+  Status = EFI_SUCCESS;
+  if (*NumBytes > FvbDevice->BlockSize - Offset) {
     *NumBytes = FvbDevice->BlockSize - Offset;
+    Status = EFI_BAD_BUFFER_SIZE;
   }
 
-  FvbDataPtr =
-    (UINT8*) FvbDevice->BufferPtr +
-    MultU64x32 (Lba, (UINT32) FvbDevice->BlockSize) +
-    Offset;
+  FvbDataPtr = FvbDevice->BufferPtr;
+  FvbDataPtr += (UINTN)Lba * FvbDevice->BlockSize;
+  FvbDataPtr += Offset;
 
-  if (*NumBytes > 0) {
-    CopyMem (FvbDataPtr, Buffer, *NumBytes);
-    PlatformFvbDataWritten (This, Lba, Offset, *NumBytes, Buffer);
-  }
-
-  return EFI_SUCCESS;
+  CopyMem (FvbDataPtr, Buffer, *NumBytes);
+  PlatformFvbDataWritten (This, Lba, Offset, *NumBytes, Buffer);
+  return Status;
 }
 
 
@@ -545,28 +534,28 @@ FvbProtocolRead (
 {
   EFI_FW_VOL_BLOCK_DEVICE *FvbDevice;
   UINT8                   *FvbDataPtr;
+  EFI_STATUS              Status;
 
   FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
-  if ((Lba > 1) || (Offset > FvbDevice->BlockSize)) {
+  if (Lba >= EMU_FVB_NUM_TOTAL_BLOCKS ||
+      Offset > FvbDevice->BlockSize) {
     return EFI_INVALID_PARAMETER;
   }
 
-  if ((Offset + *NumBytes) > FvbDevice->BlockSize) {
+  Status = EFI_SUCCESS;
+  if (*NumBytes > FvbDevice->BlockSize - Offset) {
     *NumBytes = FvbDevice->BlockSize - Offset;
+    Status = EFI_BAD_BUFFER_SIZE;
   }
 
-  FvbDataPtr =
-    (UINT8*) FvbDevice->BufferPtr +
-    MultU64x32 (Lba, (UINT32) FvbDevice->BlockSize) +
-    Offset;
+  FvbDataPtr = FvbDevice->BufferPtr;
+  FvbDataPtr += (UINTN)Lba * FvbDevice->BlockSize;
+  FvbDataPtr += Offset;
 
-  if (*NumBytes > 0) {
-    CopyMem (Buffer, FvbDataPtr, *NumBytes);
-    PlatformFvbDataRead (This, Lba, Offset, *NumBytes, Buffer);
-  }
-
-  return EFI_SUCCESS;
+  CopyMem (Buffer, FvbDataPtr, *NumBytes);
+  PlatformFvbDataRead (This, Lba, Offset, *NumBytes, Buffer);
+  return Status;
 }
 
 
@@ -663,7 +652,7 @@ InitializeFvAndVariableStoreHeaders (
       // EFI_FV_BLOCK_MAP_ENTRY    BlockMap[1];
       {
         {
-          2, // UINT32 NumBlocks;
+          EMU_FVB_NUM_TOTAL_BLOCKS, // UINT32 NumBlocks;
           EMU_FVB_BLOCK_SIZE  // UINT32 Length;
         }
       }
@@ -741,11 +730,13 @@ FvbInitialize (
   //
   // Verify that the PCD's are set correctly.
   //
+  ASSERT (FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize) %
+          EMU_FVB_BLOCK_SIZE == 0);
   if (
        (PcdGet32 (PcdVariableStoreSize) +
         PcdGet32 (PcdFlashNvStorageFtwWorkingSize)
        ) >
-       EMU_FVB_BLOCK_SIZE
+       EMU_FVB_NUM_SPARE_BLOCKS * EMU_FVB_BLOCK_SIZE
      ) {
     DEBUG ((EFI_D_ERROR, "EMU Variable invalid PCD sizes\n"));
     return EFI_INVALID_PARAMETER;
@@ -779,10 +770,7 @@ FvbInitialize (
       Initialize = FALSE;
     }
   } else {
-    Ptr = AllocateAlignedRuntimePages (
-            EFI_SIZE_TO_PAGES (EMU_FVB_SIZE),
-            SIZE_64KB
-            );
+    Ptr = AllocateRuntimePages (EFI_SIZE_TO_PAGES (EMU_FVB_SIZE));
   }
 
   mEmuVarsFvb.BufferPtr = Ptr;
@@ -808,7 +796,8 @@ FvbInitialize (
   //
   // Initialize the Fault Tolerant Write spare block
   //
-  SubPtr = (VOID*) ((UINT8*) Ptr + EMU_FVB_BLOCK_SIZE);
+  SubPtr = (VOID*) ((UINT8*) Ptr +
+                    EMU_FVB_NUM_SPARE_BLOCKS * EMU_FVB_BLOCK_SIZE);
   PcdStatus = PcdSet32S (PcdFlashNvStorageFtwSpareBase,
                 (UINT32)(UINTN) SubPtr);
   ASSERT_RETURN_ERROR (PcdStatus);
diff --git a/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.h b/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.h
index 4247d21d72..beb11e3f9a 100644
--- a/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.h
+++ b/OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.h
@@ -58,8 +58,14 @@ typedef struct {
 //
 // Constants
 //
-#define EMU_FVB_BLOCK_SIZE (FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize))
-#define EMU_FVB_SIZE (2 * FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize))
+#define EMU_FVB_BLOCK_SIZE \
+  EFI_PAGE_SIZE
+#define EMU_FVB_NUM_SPARE_BLOCKS \
+  EFI_SIZE_TO_PAGES ((UINTN)FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize))
+#define EMU_FVB_NUM_TOTAL_BLOCKS \
+  (2 * EMU_FVB_NUM_SPARE_BLOCKS)
+#define EMU_FVB_SIZE \
+  (EMU_FVB_NUM_TOTAL_BLOCKS * EMU_FVB_BLOCK_SIZE)
 #define FTW_WRITE_QUEUE_SIZE \
   (FixedPcdGet32 (PcdFlashNvStorageFtwWorkingSize) - \
    sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER))