diff --git a/MdePkg/Include/Library/PciCf8Lib.h b/MdePkg/Include/Library/PciCf8Lib.h
index e1f7e888eb..e2415ff936 100644
--- a/MdePkg/Include/Library/PciCf8Lib.h
+++ b/MdePkg/Include/Library/PciCf8Lib.h
@@ -39,6 +39,30 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define PCI_CF8_LIB_ADDRESS(Bus,Device,Function,Offset) \
   (((Offset) & 0xfff) | (((Function) & 0x07) << 12) | (((Device) & 0x1f) << 15) | (((Bus) & 0xff) << 20))
 
+/**
+  Register a PCI device so PCI configuration registers may be accessed after 
+  SetVirtualAddressMap().
+  
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address Address that encodes the PCI Bus, Device, Function and
+                  Register.
+  
+  @retval RETURN_SUCCESS           The PCI device was registered for runtime access.
+  @retval RETURN_UNSUPPORTED       An attempt was made to call this function 
+                                   after ExitBootServices().
+  @retval RETURN_UNSUPPORTED       The resources required to access the PCI device
+                                   at runtime could not be mapped.
+  @retval RETURN_OUT_OF_RESOURCES  There are not enough resources available to
+                                   complete the registration.
+
+**/
+RETURN_STATUS
+EFIAPI
+PciCf8RegisterForRuntimeAccess (
+  IN UINTN  Address
+  );
+
 /**
   Reads an 8-bit PCI configuration register.
 
diff --git a/MdePkg/Include/Library/PciExpressLib.h b/MdePkg/Include/Library/PciExpressLib.h
index 68d17901f6..098f815510 100644
--- a/MdePkg/Include/Library/PciExpressLib.h
+++ b/MdePkg/Include/Library/PciExpressLib.h
@@ -38,6 +38,30 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define PCI_EXPRESS_LIB_ADDRESS(Bus,Device,Function,Offset) \
   (((Offset) & 0xfff) | (((Function) & 0x07) << 12) | (((Device) & 0x1f) << 15) | (((Bus) & 0xff) << 20))
 
+/**
+  Register a PCI device so PCI configuration registers may be accessed after 
+  SetVirtualAddressMap().
+  
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address Address that encodes the PCI Bus, Device, Function and
+                  Register.
+  
+  @retval RETURN_SUCCESS           The PCI device was registered for runtime access.
+  @retval RETURN_UNSUPPORTED       An attempt was made to call this function 
+                                   after ExitBootServices().
+  @retval RETURN_UNSUPPORTED       The resources required to access the PCI device
+                                   at runtime could not be mapped.
+  @retval RETURN_OUT_OF_RESOURCES  There are not enough resources available to
+                                   complete the registration.
+
+**/
+RETURN_STATUS
+EFIAPI
+PciExpressRegisterForRuntimeAccess (
+  IN UINTN  Address
+  );
+
 /**
   Reads an 8-bit PCI configuration register.
 
diff --git a/MdePkg/Include/Library/PciLib.h b/MdePkg/Include/Library/PciLib.h
index 4e413aa9f1..184b9f6d7d 100644
--- a/MdePkg/Include/Library/PciLib.h
+++ b/MdePkg/Include/Library/PciLib.h
@@ -40,6 +40,30 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define PCI_LIB_ADDRESS(Bus,Device,Function,Offset)   \
   (((Offset) & 0xfff) | (((Function) & 0x07) << 12) | (((Device) & 0x1f) << 15) | (((Bus) & 0xff) << 20))
 
+/**
+  Register a PCI device so PCI configuration registers may be accessed after 
+  SetVirtualAddressMap().
+  
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address Address that encodes the PCI Bus, Device, Function and
+                  Register.
+  
+  @retval RETURN_SUCCESS           The PCI device was registered for runtime access.
+  @retval RETURN_UNSUPPORTED       An attempt was made to call this function 
+                                   after ExitBootServices().
+  @retval RETURN_UNSUPPORTED       The resources required to access the PCI device
+                                   at runtime could not be mapped.
+  @retval RETURN_OUT_OF_RESOURCES  There are not enough resources available to
+                                   complete the registration.
+
+**/
+RETURN_STATUS
+EFIAPI
+PciRegisterForRuntimeAccess (
+  IN UINTN  Address
+  );
+
 /**
   Reads an 8-bit PCI configuration register.
 
diff --git a/MdePkg/Include/Library/PciSegmentLib.h b/MdePkg/Include/Library/PciSegmentLib.h
index 2801053710..e65e9a3590 100644
--- a/MdePkg/Include/Library/PciSegmentLib.h
+++ b/MdePkg/Include/Library/PciSegmentLib.h
@@ -63,6 +63,30 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     (LShiftU64((Segment) & 0xffff, 32)) \
   )
 
+/**
+  Register a PCI device so PCI configuration registers may be accessed after 
+  SetVirtualAddressMap().
+  
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address Address that encodes the PCI Bus, Device, Function and
+                  Register.
+  
+  @retval RETURN_SUCCESS           The PCI device was registered for runtime access.
+  @retval RETURN_UNSUPPORTED       An attempt was made to call this function 
+                                   after ExitBootServices().
+  @retval RETURN_UNSUPPORTED       The resources required to access the PCI device
+                                   at runtime could not be mapped.
+  @retval RETURN_OUT_OF_RESOURCES  There are not enough resources available to
+                                   complete the registration.
+
+**/
+RETURN_STATUS
+EFIAPI
+PciSegmentRegisterForRuntimeAccess (
+  IN UINTN  Address
+  );
+
 /**
   Reads an 8-bit PCI configuration register.