diff --git a/OvmfPkg/Library/DxePciLibI440FxQ35/DxePciLibI440FxQ35.inf b/OvmfPkg/Library/DxePciLibI440FxQ35/DxePciLibI440FxQ35.inf
new file mode 100644
index 0000000000..2bd10cc232
--- /dev/null
+++ b/OvmfPkg/Library/DxePciLibI440FxQ35/DxePciLibI440FxQ35.inf
@@ -0,0 +1,47 @@
+## @file
+#  An instance of the PCI Library that is based on both the PCI CF8 Library and
+#  the PCI Express Library.
+#
+#  This PciLib instance caches the OVMF platform type (I440FX vs. Q35) in
+#  its entry point function, then delegates function calls to one of the
+#  PciCf8Lib or PciExpressLib "backends" as appropriate.
+#
+#  Copyright (C) 2016, Red Hat, Inc.
+#
+#  Copyright (c) 2007 - 2014, Intel Corporation. All rights reserved.<BR>
+#
+#  This program and the accompanying materials are licensed and made available
+#  under the terms and conditions of the BSD License which accompanies this
+#  distribution. The full text of the license may be found at
+#  http://opensource.org/licenses/bsd-license.php.
+#
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR
+#  IMPLIED.
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = DxePciLibI440FxQ35
+  FILE_GUID                      = 5360bff6-3911-4495-ae3c-b02ff004b585
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = PciLib|DXE_DRIVER DXE_RUNTIME_DRIVER SMM_CORE DXE_SMM_DRIVER UEFI_DRIVER UEFI_APPLICATION
+  CONSTRUCTOR                    = InitializeConfigAccessMethod
+
+#  VALID_ARCHITECTURES           = IA32 X64
+
+[Sources]
+  PciLib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  PcdLib
+  PciCf8Lib
+  PciExpressLib
+
+[Pcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId
diff --git a/OvmfPkg/Library/DxePciLibI440FxQ35/PciLib.c b/OvmfPkg/Library/DxePciLibI440FxQ35/PciLib.c
new file mode 100644
index 0000000000..6c1a272973
--- /dev/null
+++ b/OvmfPkg/Library/DxePciLibI440FxQ35/PciLib.c
@@ -0,0 +1,1229 @@
+/** @file
+  PCI Library functions that use
+  (a) I/O ports 0xCF8 and 0xCFC to perform PCI Configuration cycles, layering
+      on top of one PCI CF8 Library instance; or
+  (b) PCI Library functions that use the 256 MB PCI Express MMIO window to
+      perform PCI Configuration cycles, layering on PCI Express Library.
+
+  The decision is made in the entry point function, based on the OVMF platform
+  type, and then adhered to during the lifetime of the client module.
+
+  Copyright (C) 2016, Red Hat, Inc.
+
+  Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+
+#include <Base.h>
+
+#include <IndustryStandard/Q35MchIch9.h>
+
+#include <Library/PciLib.h>
+#include <Library/PciCf8Lib.h>
+#include <Library/PciExpressLib.h>
+#include <Library/PcdLib.h>
+
+STATIC BOOLEAN mRunningOnQ35;
+
+RETURN_STATUS
+EFIAPI
+InitializeConfigAccessMethod (
+  VOID
+  )
+{
+  mRunningOnQ35 = (PcdGet16 (PcdOvmfHostBridgePciDevId) ==
+                   INTEL_Q35_MCH_DEVICE_ID);
+  return RETURN_SUCCESS;
+}
+
+/**
+  Registers a PCI device so PCI configuration registers may be accessed after 
+  SetVirtualAddressMap().
+  
+  Registers the PCI device specified by Address so all the PCI configuration registers 
+  associated with that PCI device may be accessed after SetVirtualAddressMap() is called.
+  
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address The 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
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressRegisterForRuntimeAccess (Address) :
+         PciCf8RegisterForRuntimeAccess (Address);
+}
+
+/**
+  Reads an 8-bit PCI configuration register.
+
+  Reads and returns the 8-bit PCI configuration register specified by Address.
+  This function must guarantee that all PCI read and write operations are
+  serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+
+  @return The read value from the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciRead8 (
+  IN      UINTN                     Address
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressRead8 (Address) :
+         PciCf8Read8 (Address);
+}
+
+/**
+  Writes an 8-bit PCI configuration register.
+
+  Writes the 8-bit PCI configuration register specified by Address with the
+  value specified by Value. Value is returned. This function must guarantee
+  that all PCI read and write operations are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  Value   The value to write.
+
+  @return The value written to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciWrite8 (
+  IN      UINTN                     Address,
+  IN      UINT8                     Value
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressWrite8 (Address, Value) :
+         PciCf8Write8 (Address, Value);
+}
+
+/**
+  Performs a bitwise OR of an 8-bit PCI configuration register with
+  an 8-bit value.
+
+  Reads the 8-bit PCI configuration register specified by Address, performs a
+  bitwise OR between the read result and the value specified by
+  OrData, and writes the result to the 8-bit PCI configuration register
+  specified by Address. The value written to the PCI configuration register is
+  returned. This function must guarantee that all PCI read and write operations
+  are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  OrData  The value to OR with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciOr8 (
+  IN      UINTN                     Address,
+  IN      UINT8                     OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressOr8 (Address, OrData) :
+         PciCf8Or8 (Address, OrData);
+}
+
+/**
+  Performs a bitwise AND of an 8-bit PCI configuration register with an 8-bit
+  value.
+
+  Reads the 8-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData, and
+  writes the result to the 8-bit PCI configuration register specified by
+  Address. The value written to the PCI configuration register is returned.
+  This function must guarantee that all PCI read and write operations are
+  serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  AndData The value to AND with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciAnd8 (
+  IN      UINTN                     Address,
+  IN      UINT8                     AndData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressAnd8 (Address, AndData) :
+         PciCf8And8 (Address, AndData);
+}
+
+/**
+  Performs a bitwise AND of an 8-bit PCI configuration register with an 8-bit
+  value, followed a  bitwise OR with another 8-bit value.
+
+  Reads the 8-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData,
+  performs a bitwise OR between the result of the AND operation and
+  the value specified by OrData, and writes the result to the 8-bit PCI
+  configuration register specified by Address. The value written to the PCI
+  configuration register is returned. This function must guarantee that all PCI
+  read and write operations are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  AndData The value to AND with the PCI configuration register.
+  @param  OrData  The value to OR with the result of the AND operation.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciAndThenOr8 (
+  IN      UINTN                     Address,
+  IN      UINT8                     AndData,
+  IN      UINT8                     OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressAndThenOr8 (Address, AndData, OrData) :
+         PciCf8AndThenOr8 (Address, AndData, OrData);
+}
+
+/**
+  Reads a bit field of a PCI configuration register.
+
+  Reads the bit field in an 8-bit PCI configuration register. The bit field is
+  specified by the StartBit and the EndBit. The value of the bit field is
+  returned.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If StartBit is greater than 7, then ASSERT().
+  If EndBit is greater than 7, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to read.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..7.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..7.
+
+  @return The value of the bit field read from the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciBitFieldRead8 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldRead8 (Address, StartBit, EndBit) :
+         PciCf8BitFieldRead8 (Address, StartBit, EndBit);
+}
+
+/**
+  Writes a bit field to a PCI configuration register.
+
+  Writes Value to the bit field of the PCI configuration register. The bit
+  field is specified by the StartBit and the EndBit. All other bits in the
+  destination PCI configuration register are preserved. The new value of the
+  8-bit register is returned.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If StartBit is greater than 7, then ASSERT().
+  If EndBit is greater than 7, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..7.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..7.
+  @param  Value     The new value of the bit field.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciBitFieldWrite8 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT8                     Value
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldWrite8 (Address, StartBit, EndBit, Value) :
+         PciCf8BitFieldWrite8 (Address, StartBit, EndBit, Value);
+}
+
+/**
+  Reads a bit field in an 8-bit PCI configuration, performs a bitwise OR, and
+  writes the result back to the bit field in the 8-bit port.
+
+  Reads the 8-bit PCI configuration register specified by Address, performs a
+  bitwise OR between the read result and the value specified by
+  OrData, and writes the result to the 8-bit PCI configuration register
+  specified by Address. The value written to the PCI configuration register is
+  returned. This function must guarantee that all PCI read and write operations
+  are serialized. Extra left bits in OrData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If StartBit is greater than 7, then ASSERT().
+  If EndBit is greater than 7, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..7.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..7.
+  @param  OrData    The value to OR with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciBitFieldOr8 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT8                     OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldOr8 (Address, StartBit, EndBit, OrData) :
+         PciCf8BitFieldOr8 (Address, StartBit, EndBit, OrData);
+}
+
+/**
+  Reads a bit field in an 8-bit PCI configuration register, performs a bitwise
+  AND, and writes the result back to the bit field in the 8-bit register.
+
+  Reads the 8-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData, and
+  writes the result to the 8-bit PCI configuration register specified by
+  Address. The value written to the PCI configuration register is returned.
+  This function must guarantee that all PCI read and write operations are
+  serialized. Extra left bits in AndData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If StartBit is greater than 7, then ASSERT().
+  If EndBit is greater than 7, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..7.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..7.
+  @param  AndData   The value to AND with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciBitFieldAnd8 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT8                     AndData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldAnd8 (Address, StartBit, EndBit, AndData) :
+         PciCf8BitFieldAnd8 (Address, StartBit, EndBit, AndData);
+}
+
+/**
+  Reads a bit field in an 8-bit port, performs a bitwise AND followed by a
+  bitwise OR, and writes the result back to the bit field in the
+  8-bit port.
+
+  Reads the 8-bit PCI configuration register specified by Address, performs a
+  bitwise AND followed by a bitwise OR between the read result and
+  the value specified by AndData, and writes the result to the 8-bit PCI
+  configuration register specified by Address. The value written to the PCI
+  configuration register is returned. This function must guarantee that all PCI
+  read and write operations are serialized. Extra left bits in both AndData and
+  OrData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If StartBit is greater than 7, then ASSERT().
+  If EndBit is greater than 7, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..7.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..7.
+  @param  AndData   The value to AND with the PCI configuration register.
+  @param  OrData    The value to OR with the result of the AND operation.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT8
+EFIAPI
+PciBitFieldAndThenOr8 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT8                     AndData,
+  IN      UINT8                     OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldAndThenOr8 (Address, StartBit, EndBit, AndData, OrData) :
+         PciCf8BitFieldAndThenOr8 (Address, StartBit, EndBit, AndData, OrData);
+}
+
+/**
+  Reads a 16-bit PCI configuration register.
+
+  Reads and returns the 16-bit PCI configuration register specified by Address.
+  This function must guarantee that all PCI read and write operations are
+  serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+
+  @return The read value from the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciRead16 (
+  IN      UINTN                     Address
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressRead16 (Address) :
+         PciCf8Read16 (Address);
+}
+
+/**
+  Writes a 16-bit PCI configuration register.
+
+  Writes the 16-bit PCI configuration register specified by Address with the
+  value specified by Value. Value is returned. This function must guarantee
+  that all PCI read and write operations are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  Value   The value to write.
+
+  @return The value written to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciWrite16 (
+  IN      UINTN                     Address,
+  IN      UINT16                    Value
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressWrite16 (Address, Value) :
+         PciCf8Write16 (Address, Value);
+}
+
+/**
+  Performs a bitwise OR of a 16-bit PCI configuration register with
+  a 16-bit value.
+
+  Reads the 16-bit PCI configuration register specified by Address, performs a
+  bitwise OR between the read result and the value specified by
+  OrData, and writes the result to the 16-bit PCI configuration register
+  specified by Address. The value written to the PCI configuration register is
+  returned. This function must guarantee that all PCI read and write operations
+  are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  OrData  The value to OR with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciOr16 (
+  IN      UINTN                     Address,
+  IN      UINT16                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressOr16 (Address, OrData) :
+         PciCf8Or16 (Address, OrData);
+}
+
+/**
+  Performs a bitwise AND of a 16-bit PCI configuration register with a 16-bit
+  value.
+
+  Reads the 16-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData, and
+  writes the result to the 16-bit PCI configuration register specified by
+  Address. The value written to the PCI configuration register is returned.
+  This function must guarantee that all PCI read and write operations are
+  serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  AndData The value to AND with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciAnd16 (
+  IN      UINTN                     Address,
+  IN      UINT16                    AndData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressAnd16 (Address, AndData) :
+         PciCf8And16 (Address, AndData);
+}
+
+/**
+  Performs a bitwise AND of a 16-bit PCI configuration register with a 16-bit
+  value, followed a  bitwise OR with another 16-bit value.
+
+  Reads the 16-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData,
+  performs a bitwise OR between the result of the AND operation and
+  the value specified by OrData, and writes the result to the 16-bit PCI
+  configuration register specified by Address. The value written to the PCI
+  configuration register is returned. This function must guarantee that all PCI
+  read and write operations are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  AndData The value to AND with the PCI configuration register.
+  @param  OrData  The value to OR with the result of the AND operation.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciAndThenOr16 (
+  IN      UINTN                     Address,
+  IN      UINT16                    AndData,
+  IN      UINT16                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressAndThenOr16 (Address, AndData, OrData) :
+         PciCf8AndThenOr16 (Address, AndData, OrData);
+}
+
+/**
+  Reads a bit field of a PCI configuration register.
+
+  Reads the bit field in a 16-bit PCI configuration register. The bit field is
+  specified by the StartBit and the EndBit. The value of the bit field is
+  returned.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+  If StartBit is greater than 15, then ASSERT().
+  If EndBit is greater than 15, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to read.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..15.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..15.
+
+  @return The value of the bit field read from the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciBitFieldRead16 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldRead16 (Address, StartBit, EndBit) :
+         PciCf8BitFieldRead16 (Address, StartBit, EndBit);
+}
+
+/**
+  Writes a bit field to a PCI configuration register.
+
+  Writes Value to the bit field of the PCI configuration register. The bit
+  field is specified by the StartBit and the EndBit. All other bits in the
+  destination PCI configuration register are preserved. The new value of the
+  16-bit register is returned.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+  If StartBit is greater than 15, then ASSERT().
+  If EndBit is greater than 15, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..15.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..15.
+  @param  Value     The new value of the bit field.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciBitFieldWrite16 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT16                    Value
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldWrite16 (Address, StartBit, EndBit, Value) :
+         PciCf8BitFieldWrite16 (Address, StartBit, EndBit, Value);
+}
+
+/**
+  Reads a bit field in a 16-bit PCI configuration, performs a bitwise OR, and
+  writes the result back to the bit field in the 16-bit port.
+
+  Reads the 16-bit PCI configuration register specified by Address, performs a
+  bitwise OR between the read result and the value specified by
+  OrData, and writes the result to the 16-bit PCI configuration register
+  specified by Address. The value written to the PCI configuration register is
+  returned. This function must guarantee that all PCI read and write operations
+  are serialized. Extra left bits in OrData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+  If StartBit is greater than 15, then ASSERT().
+  If EndBit is greater than 15, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..15.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..15.
+  @param  OrData    The value to OR with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciBitFieldOr16 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT16                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldOr16 (Address, StartBit, EndBit, OrData) :
+         PciCf8BitFieldOr16 (Address, StartBit, EndBit, OrData);
+}
+
+/**
+  Reads a bit field in a 16-bit PCI configuration register, performs a bitwise
+  AND, and writes the result back to the bit field in the 16-bit register.
+
+  Reads the 16-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData, and
+  writes the result to the 16-bit PCI configuration register specified by
+  Address. The value written to the PCI configuration register is returned.
+  This function must guarantee that all PCI read and write operations are
+  serialized. Extra left bits in AndData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+  If StartBit is greater than 15, then ASSERT().
+  If EndBit is greater than 15, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..15.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..15.
+  @param  AndData   The value to AND with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciBitFieldAnd16 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT16                    AndData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldAnd16 (Address, StartBit, EndBit, AndData) :
+         PciCf8BitFieldAnd16 (Address, StartBit, EndBit, AndData);
+}
+
+/**
+  Reads a bit field in a 16-bit port, performs a bitwise AND followed by a
+  bitwise OR, and writes the result back to the bit field in the
+  16-bit port.
+
+  Reads the 16-bit PCI configuration register specified by Address, performs a
+  bitwise AND followed by a bitwise OR between the read result and
+  the value specified by AndData, and writes the result to the 16-bit PCI
+  configuration register specified by Address. The value written to the PCI
+  configuration register is returned. This function must guarantee that all PCI
+  read and write operations are serialized. Extra left bits in both AndData and
+  OrData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 16-bit boundary, then ASSERT().
+  If StartBit is greater than 15, then ASSERT().
+  If EndBit is greater than 15, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..15.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..15.
+  @param  AndData   The value to AND with the PCI configuration register.
+  @param  OrData    The value to OR with the result of the AND operation.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT16
+EFIAPI
+PciBitFieldAndThenOr16 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT16                    AndData,
+  IN      UINT16                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldAndThenOr16 (Address, StartBit, EndBit, AndData, OrData) :
+         PciCf8BitFieldAndThenOr16 (Address, StartBit, EndBit, AndData, OrData);
+}
+
+/**
+  Reads a 32-bit PCI configuration register.
+
+  Reads and returns the 32-bit PCI configuration register specified by Address.
+  This function must guarantee that all PCI read and write operations are
+  serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+
+  @return The read value from the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciRead32 (
+  IN      UINTN                     Address
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressRead32 (Address) :
+         PciCf8Read32 (Address);
+}
+
+/**
+  Writes a 32-bit PCI configuration register.
+
+  Writes the 32-bit PCI configuration register specified by Address with the
+  value specified by Value. Value is returned. This function must guarantee
+  that all PCI read and write operations are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  Value   The value to write.
+
+  @return The value written to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciWrite32 (
+  IN      UINTN                     Address,
+  IN      UINT32                    Value
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressWrite32 (Address, Value) :
+         PciCf8Write32 (Address, Value);
+}
+
+/**
+  Performs a bitwise OR of a 32-bit PCI configuration register with
+  a 32-bit value.
+
+  Reads the 32-bit PCI configuration register specified by Address, performs a
+  bitwise OR between the read result and the value specified by
+  OrData, and writes the result to the 32-bit PCI configuration register
+  specified by Address. The value written to the PCI configuration register is
+  returned. This function must guarantee that all PCI read and write operations
+  are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  OrData  The value to OR with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciOr32 (
+  IN      UINTN                     Address,
+  IN      UINT32                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressOr32 (Address, OrData) :
+         PciCf8Or32 (Address, OrData);
+}
+
+/**
+  Performs a bitwise AND of a 32-bit PCI configuration register with a 32-bit
+  value.
+
+  Reads the 32-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData, and
+  writes the result to the 32-bit PCI configuration register specified by
+  Address. The value written to the PCI configuration register is returned.
+  This function must guarantee that all PCI read and write operations are
+  serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  AndData The value to AND with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciAnd32 (
+  IN      UINTN                     Address,
+  IN      UINT32                    AndData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressAnd32 (Address, AndData) :
+         PciCf8And32 (Address, AndData);
+}
+
+/**
+  Performs a bitwise AND of a 32-bit PCI configuration register with a 32-bit
+  value, followed a  bitwise OR with another 32-bit value.
+
+  Reads the 32-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData,
+  performs a bitwise OR between the result of the AND operation and
+  the value specified by OrData, and writes the result to the 32-bit PCI
+  configuration register specified by Address. The value written to the PCI
+  configuration register is returned. This function must guarantee that all PCI
+  read and write operations are serialized.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+
+  @param  Address The address that encodes the PCI Bus, Device, Function and
+                  Register.
+  @param  AndData The value to AND with the PCI configuration register.
+  @param  OrData  The value to OR with the result of the AND operation.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciAndThenOr32 (
+  IN      UINTN                     Address,
+  IN      UINT32                    AndData,
+  IN      UINT32                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressAndThenOr32 (Address, AndData, OrData) :
+         PciCf8AndThenOr32 (Address, AndData, OrData);
+}
+
+/**
+  Reads a bit field of a PCI configuration register.
+
+  Reads the bit field in a 32-bit PCI configuration register. The bit field is
+  specified by the StartBit and the EndBit. The value of the bit field is
+  returned.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+  If StartBit is greater than 31, then ASSERT().
+  If EndBit is greater than 31, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to read.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..31.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..31.
+
+  @return The value of the bit field read from the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciBitFieldRead32 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldRead32 (Address, StartBit, EndBit) :
+         PciCf8BitFieldRead32 (Address, StartBit, EndBit);
+}
+
+/**
+  Writes a bit field to a PCI configuration register.
+
+  Writes Value to the bit field of the PCI configuration register. The bit
+  field is specified by the StartBit and the EndBit. All other bits in the
+  destination PCI configuration register are preserved. The new value of the
+  32-bit register is returned.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+  If StartBit is greater than 31, then ASSERT().
+  If EndBit is greater than 31, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..31.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..31.
+  @param  Value     The new value of the bit field.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciBitFieldWrite32 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT32                    Value
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldWrite32 (Address, StartBit, EndBit, Value) :
+         PciCf8BitFieldWrite32 (Address, StartBit, EndBit, Value);
+}
+
+/**
+  Reads a bit field in a 32-bit PCI configuration, performs a bitwise OR, and
+  writes the result back to the bit field in the 32-bit port.
+
+  Reads the 32-bit PCI configuration register specified by Address, performs a
+  bitwise OR between the read result and the value specified by
+  OrData, and writes the result to the 32-bit PCI configuration register
+  specified by Address. The value written to the PCI configuration register is
+  returned. This function must guarantee that all PCI read and write operations
+  are serialized. Extra left bits in OrData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+  If StartBit is greater than 31, then ASSERT().
+  If EndBit is greater than 31, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..31.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..31.
+  @param  OrData    The value to OR with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciBitFieldOr32 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT32                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldOr32 (Address, StartBit, EndBit, OrData) :
+         PciCf8BitFieldOr32 (Address, StartBit, EndBit, OrData);
+}
+
+/**
+  Reads a bit field in a 32-bit PCI configuration register, performs a bitwise
+  AND, and writes the result back to the bit field in the 32-bit register.
+
+  Reads the 32-bit PCI configuration register specified by Address, performs a
+  bitwise AND between the read result and the value specified by AndData, and
+  writes the result to the 32-bit PCI configuration register specified by
+  Address. The value written to the PCI configuration register is returned.
+  This function must guarantee that all PCI read and write operations are
+  serialized. Extra left bits in AndData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+  If StartBit is greater than 31, then ASSERT().
+  If EndBit is greater than 31, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..31.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..31.
+  @param  AndData   The value to AND with the PCI configuration register.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciBitFieldAnd32 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT32                    AndData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldAnd32 (Address, StartBit, EndBit, AndData) :
+         PciCf8BitFieldAnd32 (Address, StartBit, EndBit, AndData);
+}
+
+/**
+  Reads a bit field in a 32-bit port, performs a bitwise AND followed by a
+  bitwise OR, and writes the result back to the bit field in the
+  32-bit port.
+
+  Reads the 32-bit PCI configuration register specified by Address, performs a
+  bitwise AND followed by a bitwise OR between the read result and
+  the value specified by AndData, and writes the result to the 32-bit PCI
+  configuration register specified by Address. The value written to the PCI
+  configuration register is returned. This function must guarantee that all PCI
+  read and write operations are serialized. Extra left bits in both AndData and
+  OrData are stripped.
+
+  If Address > 0x0FFFFFFF, then ASSERT().
+  If Address is not aligned on a 32-bit boundary, then ASSERT().
+  If StartBit is greater than 31, then ASSERT().
+  If EndBit is greater than 31, then ASSERT().
+  If EndBit is less than StartBit, then ASSERT().
+  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
+
+  @param  Address   The PCI configuration register to write.
+  @param  StartBit  The ordinal of the least significant bit in the bit field.
+                    Range 0..31.
+  @param  EndBit    The ordinal of the most significant bit in the bit field.
+                    Range 0..31.
+  @param  AndData   The value to AND with the PCI configuration register.
+  @param  OrData    The value to OR with the result of the AND operation.
+
+  @return The value written back to the PCI configuration register.
+
+**/
+UINT32
+EFIAPI
+PciBitFieldAndThenOr32 (
+  IN      UINTN                     Address,
+  IN      UINTN                     StartBit,
+  IN      UINTN                     EndBit,
+  IN      UINT32                    AndData,
+  IN      UINT32                    OrData
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressBitFieldAndThenOr32 (Address, StartBit, EndBit, AndData, OrData) :
+         PciCf8BitFieldAndThenOr32 (Address, StartBit, EndBit, AndData, OrData);
+}
+
+/**
+  Reads a range of PCI configuration registers into a caller supplied buffer.
+
+  Reads the range of PCI configuration registers specified by StartAddress and
+  Size into the buffer specified by Buffer. This function only allows the PCI
+  configuration registers from a single PCI function to be read. Size is
+  returned. When possible 32-bit PCI configuration read cycles are used to read
+  from StartAdress to StartAddress + Size. Due to alignment restrictions, 8-bit
+  and 16-bit PCI configuration read cycles may be used at the beginning and the
+  end of the range.
+
+  If StartAddress > 0x0FFFFFFF, then ASSERT().
+  If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
+  If Size > 0 and Buffer is NULL, then ASSERT().
+
+  @param  StartAddress  The starting address that encodes the PCI Bus, Device,
+                        Function and Register.
+  @param  Size          The size in bytes of the transfer.
+  @param  Buffer        The pointer to a buffer receiving the data read.
+
+  @return Size
+
+**/
+UINTN
+EFIAPI
+PciReadBuffer (
+  IN      UINTN                     StartAddress,
+  IN      UINTN                     Size,
+  OUT     VOID                      *Buffer
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressReadBuffer (StartAddress, Size, Buffer) :
+         PciCf8ReadBuffer (StartAddress, Size, Buffer);
+}
+
+/**
+  Copies the data in a caller supplied buffer to a specified range of PCI
+  configuration space.
+
+  Writes the range of PCI configuration registers specified by StartAddress and
+  Size from the buffer specified by Buffer. This function only allows the PCI
+  configuration registers from a single PCI function to be written. Size is
+  returned. When possible 32-bit PCI configuration write cycles are used to
+  write from StartAdress to StartAddress + Size. Due to alignment restrictions,
+  8-bit and 16-bit PCI configuration write cycles may be used at the beginning
+  and the end of the range.
+
+  If StartAddress > 0x0FFFFFFF, then ASSERT().
+  If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
+  If Size > 0 and Buffer is NULL, then ASSERT().
+
+  @param  StartAddress  The starting address that encodes the PCI Bus, Device,
+                        Function and Register.
+  @param  Size          The size in bytes of the transfer.
+  @param  Buffer        The pointer to a buffer containing the data to write.
+
+  @return Size written to StartAddress.
+
+**/
+UINTN
+EFIAPI
+PciWriteBuffer (
+  IN      UINTN                     StartAddress,
+  IN      UINTN                     Size,
+  IN      VOID                      *Buffer
+  )
+{
+  return mRunningOnQ35 ?
+         PciExpressWriteBuffer (StartAddress, Size, Buffer) :
+         PciCf8WriteBuffer (StartAddress, Size, Buffer);
+}