Re: [PATCH v2 15/16] UefiCpuPkg: CpuIo2Smm: Support of CpuIo driver under StandaloneMm

["Leif Lindholm" <leif@nuviainc.com>]

On Wed, Jan 06, 2021 at 16:46:57 +0100, Laszlo Ersek wrote:
> On 01/05/21 19:59, Kun Qin wrote:
> > This change added support of CpuIo driver under StandaloneMm. The core
> > services switched to gMmst based instead of gMmst. It also abstracts
> 
> (1) typo: "gMmst based instead of gMmst" -- that's the same thing
> 
> (2) renames like this should not be mixed with logic changes /
> refactorings, so this would be two patches minimally
> 
> (3) in fact I disagree with renaming gSmst to gMmst (and the resultant
> fallout). I see very little value in this, it only complicates the git
> history, takes up reviewer resources, and risks regressions. Unless
> absolutely necessary for getting the driver build in the new context, I
> would strongly advise against the rename. If the rename is unavoidable,
> then see (2) please -- do it in a separate patch.
> 
> (4) If I understand correctly, this is the first time when UefiCpuPkg
> content is consumed in AARCH64 platforms. I wonder if that means that
> the CpuIo2Smm should no longer exist under UefiCpuPkg at all. UefiCpuPkg
> has been traditionally IA32/X64 only, and while the *name* of the
> package certainly does not require or imply that, over time those two
> things *have* become synonymous. For example, the SMM Core lives under
> MdeModulePkg; I wonder if the same should happen to CpuIo2Smm as well.
> Adding Ard, Leif and Mike.

I don't really have an opinion of CpuIo2Smm (but I guess it makes
sense to move it if the SMM core lives in MdeModulePkg).

I do think most of ArmPkg ultimately belongs under UefiCpuPkg, with
the rest under MdeModulePkg.

Best Regards,

Leif

> Thanks
> Laszlo
> 
> > standalone and traditional MM driver entrypoints into separate files to
> > allow maximal common implementations.
> > 
> > Cc: Eric Dong <eric.dong@intel.com>
> > Cc: Ray Ni <ray.ni@intel.com>
> > Cc: Laszlo Ersek <lersek@redhat.com>
> > Cc: Rahul Kumar <rahul1.kumar@intel.com>
> > 
> > Signed-off-by: Kun Qin <kun.q@outlook.com>
> > ---
> > 
> > Notes:
> >     v2:
> >     - Removed "EFIAPI" for internal functions.
> > 
> >  UefiCpuPkg/CpuIo2Smm/{CpuIo2Smm.c => CpuIo2Common.c}           |  15 +-
> >  UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c                               | 384 +-------------------
> >  UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.c                      |  31 ++
> >  UefiCpuPkg/CpuIo2Smm/{CpuIo2Smm.h => CpuIo2Common.h}           |  17 +-
> >  UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf                             |   7 +-
> >  UefiCpuPkg/CpuIo2Smm/{CpuIo2Smm.inf => CpuIo2StandaloneMm.inf} |  23 +-
> >  UefiCpuPkg/UefiCpuPkg.dsc                                      |   6 +
> >  7 files changed, 75 insertions(+), 408 deletions(-)
> > 
> > diff --git a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c b/UefiCpuPkg/CpuIo2Smm/CpuIo2Common.c
> > similarity index 94%
> > copy from UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c
> > copy to UefiCpuPkg/CpuIo2Smm/CpuIo2Common.c
> > index b840d3e10cae..fef434795908 100644
> > --- a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c
> > +++ b/UefiCpuPkg/CpuIo2Smm/CpuIo2Common.c
> > @@ -6,7 +6,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> >  
> >  **/
> >  
> > -#include "CpuIo2Smm.h"
> > +#include "CpuIo2Common.h"
> >  
> >  //
> >  // Handle for the SMM CPU I/O Protocol
> > @@ -371,18 +371,13 @@ CpuIoServiceWrite (
> >  /**
> >    The module Entry Point SmmCpuIoProtocol driver
> >  
> > -  @param[in] ImageHandle  The firmware allocated handle for the EFI image.
> > -  @param[in] SystemTable  A pointer to the EFI System Table.
> > -
> >    @retval EFI_SUCCESS  The entry point is executed successfully.
> >    @retval Other        Some error occurs when executing this entry point.
> >  
> >  **/
> >  EFI_STATUS
> > -EFIAPI
> > -SmmCpuIo2Initialize (
> > -  IN EFI_HANDLE        ImageHandle,
> > -  IN EFI_SYSTEM_TABLE  *SystemTable
> > +CommonCpuIo2Initialize (
> > +  VOID
> >    )
> >  {
> >    EFI_STATUS  Status;
> > @@ -390,12 +385,12 @@ SmmCpuIo2Initialize (
> >    //
> >    // Copy the SMM CPU I/O Protocol instance into the System Management System Table
> >    //
> > -  CopyMem (&gSmst->SmmIo, &mSmmCpuIo2, sizeof (mSmmCpuIo2));
> > +  CopyMem (&gMmst->MmIo, &mSmmCpuIo2, sizeof (mSmmCpuIo2));
> >  
> >    //
> >    // Install the SMM CPU I/O Protocol into the SMM protocol database
> >    //
> > -  Status = gSmst->SmmInstallProtocolInterface (
> > +  Status = gMmst->MmInstallProtocolInterface (
> >                      &mHandle,
> >                      &gEfiSmmCpuIo2ProtocolGuid,
> >                      EFI_NATIVE_INTERFACE,
> > diff --git a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c b/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c
> > index b840d3e10cae..062d1a47a09f 100644
> > --- a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c
> > +++ b/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.c
> > @@ -6,367 +6,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> >  
> >  **/
> >  
> > -#include "CpuIo2Smm.h"
> > +#include <PiSmm.h>
> >  
> > -//
> > -// Handle for the SMM CPU I/O Protocol
> > -//
> > -EFI_HANDLE  mHandle = NULL;
> > -
> > -//
> > -// SMM CPU I/O Protocol instance
> > -//
> > -EFI_SMM_CPU_IO2_PROTOCOL mSmmCpuIo2 = {
> > -  {
> > -    CpuMemoryServiceRead,
> > -    CpuMemoryServiceWrite
> > -  },
> > -  {
> > -    CpuIoServiceRead,
> > -    CpuIoServiceWrite
> > -  }
> > -};
> > -
> > -//
> > -// Lookup table for increment values based on transfer widths
> > -//
> > -UINT8 mStride[] = {
> > -  1, // SMM_IO_UINT8
> > -  2, // SMM_IO_UINT16
> > -  4, // SMM_IO_UINT32
> > -  8  // SMM_IO_UINT64
> > -};
> > -
> > -/**
> > -  Check parameters to a SMM CPU I/O Protocol service request.
> > -
> > -  @param[in]  MmioOperation  TRUE for an MMIO operation, FALSE for I/O Port operation.
> > -  @param[in]  Width          Signifies the width of the I/O operations.
> > -  @param[in]  Address        The base address of the I/O operations.  The caller is
> > -                             responsible for aligning the Address if required.
> > -  @param[in]  Count          The number of I/O operations to perform.
> > -  @param[in]  Buffer         For read operations, the destination buffer to store
> > -                             the results.  For write operations, the source buffer
> > -                             from which to write data.
> > -
> > -  @retval EFI_SUCCESS            The data was read from or written to the device.
> > -  @retval EFI_UNSUPPORTED        The Address is not valid for this system.
> > -  @retval EFI_INVALID_PARAMETER  Width or Count, or both, were invalid.
> > -
> > -**/
> > -EFI_STATUS
> > -CpuIoCheckParameter (
> > -  IN BOOLEAN           MmioOperation,
> > -  IN EFI_SMM_IO_WIDTH  Width,
> > -  IN UINT64            Address,
> > -  IN UINTN             Count,
> > -  IN VOID              *Buffer
> > -  )
> > -{
> > -  UINT64  MaxCount;
> > -  UINT64  Limit;
> > -
> > -  //
> > -  // Check to see if Buffer is NULL
> > -  //
> > -  if (Buffer == NULL) {
> > -    return EFI_INVALID_PARAMETER;
> > -  }
> > -
> > -  //
> > -  // Check to see if Width is in the valid range
> > -  //
> > -  if ((UINT32)Width > SMM_IO_UINT64) {
> > -    return EFI_INVALID_PARAMETER;
> > -  }
> > -
> > -  //
> > -  // Check to see if Width is in the valid range for I/O Port operations
> > -  //
> > -  if (!MmioOperation && (Width == SMM_IO_UINT64)) {
> > -    return EFI_INVALID_PARAMETER;
> > -  }
> > -
> > -  //
> > -  // Check to see if any address associated with this transfer exceeds the maximum
> > -  // allowed address.  The maximum address implied by the parameters passed in is
> > -  // Address + Size * Count.  If the following condition is met, then the transfer
> > -  // is not supported.
> > -  //
> > -  //    Address + Size * Count > (MmioOperation ? MAX_ADDRESS : MAX_IO_PORT_ADDRESS) + 1
> > -  //
> > -  // Since MAX_ADDRESS can be the maximum integer value supported by the CPU and Count
> > -  // can also be the maximum integer value supported by the CPU, this range
> > -  // check must be adjusted to avoid all overflow conditions.
> > -  //
> > -  // The following form of the range check is equivalent but assumes that
> > -  // MAX_ADDRESS and MAX_IO_PORT_ADDRESS are of the form (2^n - 1).
> > -  //
> > -  Limit = (MmioOperation ? MAX_ADDRESS : MAX_IO_PORT_ADDRESS);
> > -  if (Count == 0) {
> > -    if (Address > Limit) {
> > -      return EFI_UNSUPPORTED;
> > -    }
> > -  } else {
> > -    MaxCount = RShiftU64 (Limit, Width);
> > -    if (MaxCount < (Count - 1)) {
> > -      return EFI_UNSUPPORTED;
> > -    }
> > -    if (Address > LShiftU64 (MaxCount - Count + 1, Width)) {
> > -      return EFI_UNSUPPORTED;
> > -    }
> > -  }
> > -
> > -  //
> > -  // Check to see if Address is aligned
> > -  //
> > -  if ((Address & ((UINT64)mStride[Width] - 1)) != 0) {
> > -    return EFI_UNSUPPORTED;
> > -  }
> > -
> > -  return EFI_SUCCESS;
> > -}
> > -
> > -/**
> > -  Reads memory-mapped registers.
> > -
> > -  The I/O operations are carried out exactly as requested.  The caller is
> > -  responsible for any alignment and I/O width issues that the bus, device,
> > -  platform, or type of I/O might require.
> > -
> > -  @param[in]  This     The EFI_SMM_CPU_IO2_PROTOCOL instance.
> > -  @param[in]  Width    Signifies the width of the I/O operations.
> > -  @param[in]  Address  The base address of the I/O operations.  The caller is
> > -                       responsible for aligning the Address if required.
> > -  @param[in]  Count    The number of I/O operations to perform.
> > -  @param[out] Buffer   For read operations, the destination buffer to store
> > -                       the results.  For write operations, the source buffer
> > -                       from which to write data.
> > -
> > -  @retval EFI_SUCCESS            The data was read from or written to the device.
> > -  @retval EFI_UNSUPPORTED        The Address is not valid for this system.
> > -  @retval EFI_INVALID_PARAMETER  Width or Count, or both, were invalid.
> > -  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
> > -                                 lack of resources
> > -
> > -**/
> > -EFI_STATUS
> > -EFIAPI
> > -CpuMemoryServiceRead (
> > -  IN  CONST EFI_SMM_CPU_IO2_PROTOCOL  *This,
> > -  IN  EFI_SMM_IO_WIDTH                Width,
> > -  IN  UINT64                          Address,
> > -  IN  UINTN                           Count,
> > -  OUT VOID                            *Buffer
> > -  )
> > -{
> > -  EFI_STATUS  Status;
> > -  UINT8       Stride;
> > -  UINT8       *Uint8Buffer;
> > -
> > -  Status = CpuIoCheckParameter (TRUE, Width, Address, Count, Buffer);
> > -  if (EFI_ERROR (Status)) {
> > -    return Status;
> > -  }
> > -
> > -  //
> > -  // Select loop based on the width of the transfer
> > -  //
> > -  Stride = mStride[Width];
> > -  for (Uint8Buffer = Buffer; Count > 0; Address += Stride, Uint8Buffer += Stride, Count--) {
> > -    if (Width == SMM_IO_UINT8) {
> > -      *Uint8Buffer = MmioRead8 ((UINTN)Address);
> > -    } else if (Width == SMM_IO_UINT16) {
> > -      *((UINT16 *)Uint8Buffer) = MmioRead16 ((UINTN)Address);
> > -    } else if (Width == SMM_IO_UINT32) {
> > -      *((UINT32 *)Uint8Buffer) = MmioRead32 ((UINTN)Address);
> > -    } else if (Width == SMM_IO_UINT64) {
> > -      *((UINT64 *)Uint8Buffer) = MmioRead64 ((UINTN)Address);
> > -    }
> > -  }
> > -  return EFI_SUCCESS;
> > -}
> > -
> > -/**
> > -  Writes memory-mapped registers.
> > -
> > -  The I/O operations are carried out exactly as requested.  The caller is
> > -  responsible for any alignment and I/O width issues that the bus, device,
> > -  platform, or type of I/O might require.
> > -
> > -  @param[in]  This     The EFI_SMM_CPU_IO2_PROTOCOL instance.
> > -  @param[in]  Width    Signifies the width of the I/O operations.
> > -  @param[in]  Address  The base address of the I/O operations.  The caller is
> > -                       responsible for aligning the Address if required.
> > -  @param[in]  Count    The number of I/O operations to perform.
> > -  @param[in]  Buffer   For read operations, the destination buffer to store
> > -                       the results.  For write operations, the source buffer
> > -                       from which to write data.
> > -
> > -  @retval EFI_SUCCESS            The data was read from or written to the device.
> > -  @retval EFI_UNSUPPORTED        The Address is not valid for this system.
> > -  @retval EFI_INVALID_PARAMETER  Width or Count, or both, were invalid.
> > -  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
> > -                                 lack of resources
> > -
> > -**/
> > -EFI_STATUS
> > -EFIAPI
> > -CpuMemoryServiceWrite (
> > -  IN CONST EFI_SMM_CPU_IO2_PROTOCOL  *This,
> > -  IN EFI_SMM_IO_WIDTH                Width,
> > -  IN UINT64                          Address,
> > -  IN UINTN                           Count,
> > -  IN VOID                            *Buffer
> > -  )
> > -{
> > -  EFI_STATUS  Status;
> > -  UINT8       Stride;
> > -  UINT8       *Uint8Buffer;
> > -
> > -  Status = CpuIoCheckParameter (TRUE, Width, Address, Count, Buffer);
> > -  if (EFI_ERROR (Status)) {
> > -    return Status;
> > -  }
> > -
> > -  //
> > -  // Select loop based on the width of the transfer
> > -  //
> > -  Stride = mStride[Width];
> > -  for (Uint8Buffer = Buffer; Count > 0; Address += Stride, Uint8Buffer += Stride, Count--) {
> > -    if (Width == SMM_IO_UINT8) {
> > -      MmioWrite8 ((UINTN)Address, *Uint8Buffer);
> > -    } else if (Width == SMM_IO_UINT16) {
> > -      MmioWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
> > -    } else if (Width == SMM_IO_UINT32) {
> > -      MmioWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
> > -    } else if (Width == SMM_IO_UINT64) {
> > -      MmioWrite64 ((UINTN)Address, *((UINT64 *)Uint8Buffer));
> > -    }
> > -  }
> > -  return EFI_SUCCESS;
> > -}
> > -
> > -/**
> > -  Reads I/O registers.
> > -
> > -  The I/O operations are carried out exactly as requested.  The caller is
> > -  responsible for any alignment and I/O width issues that the bus, device,
> > -  platform, or type of I/O might require.
> > -
> > -  @param[in]  This     The EFI_SMM_CPU_IO2_PROTOCOL instance.
> > -  @param[in]  Width    Signifies the width of the I/O operations.
> > -  @param[in]  Address  The base address of the I/O operations.  The caller is
> > -                       responsible for aligning the Address if required.
> > -  @param[in]  Count    The number of I/O operations to perform.
> > -  @param[out] Buffer   For read operations, the destination buffer to store
> > -                       the results.  For write operations, the source buffer
> > -                       from which to write data.
> > -
> > -  @retval EFI_SUCCESS            The data was read from or written to the device.
> > -  @retval EFI_UNSUPPORTED        The Address is not valid for this system.
> > -  @retval EFI_INVALID_PARAMETER  Width or Count, or both, were invalid.
> > -  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
> > -                                 lack of resources
> > -
> > -**/
> > -EFI_STATUS
> > -EFIAPI
> > -CpuIoServiceRead (
> > -  IN  CONST EFI_SMM_CPU_IO2_PROTOCOL  *This,
> > -  IN  EFI_SMM_IO_WIDTH                Width,
> > -  IN  UINT64                          Address,
> > -  IN  UINTN                           Count,
> > -  OUT VOID                            *Buffer
> > -  )
> > -{
> > -  EFI_STATUS  Status;
> > -  UINT8       Stride;
> > -  UINT8       *Uint8Buffer;
> > -
> > -  Status = CpuIoCheckParameter (FALSE, Width, Address, Count, Buffer);
> > -  if (EFI_ERROR (Status)) {
> > -    return Status;
> > -  }
> > -
> > -  //
> > -  // Select loop based on the width of the transfer
> > -  //
> > -  Stride = mStride[Width];
> > -  for (Uint8Buffer = Buffer; Count > 0; Address += Stride, Uint8Buffer += Stride, Count--) {
> > -    if (Width == SMM_IO_UINT8) {
> > -      *Uint8Buffer = IoRead8 ((UINTN)Address);
> > -    } else if (Width == SMM_IO_UINT16) {
> > -      *((UINT16 *)Uint8Buffer) = IoRead16 ((UINTN)Address);
> > -    } else if (Width == SMM_IO_UINT32) {
> > -      *((UINT32 *)Uint8Buffer) = IoRead32 ((UINTN)Address);
> > -    }
> > -  }
> > -
> > -  return EFI_SUCCESS;
> > -}
> > -
> > -/**
> > -  Write I/O registers.
> > -
> > -  The I/O operations are carried out exactly as requested.  The caller is
> > -  responsible for any alignment and I/O width issues that the bus, device,
> > -  platform, or type of I/O might require.
> > -
> > -  @param[in]  This     The EFI_SMM_CPU_IO2_PROTOCOL instance.
> > -  @param[in]  Width    Signifies the width of the I/O operations.
> > -  @param[in]  Address  The base address of the I/O operations.  The caller is
> > -                       responsible for aligning the Address if required.
> > -  @param[in]  Count    The number of I/O operations to perform.
> > -  @param[in]  Buffer   For read operations, the destination buffer to store
> > -                       the results.  For write operations, the source buffer
> > -                       from which to write data.
> > -
> > -  @retval EFI_SUCCESS            The data was read from or written to the device.
> > -  @retval EFI_UNSUPPORTED        The Address is not valid for this system.
> > -  @retval EFI_INVALID_PARAMETER  Width or Count, or both, were invalid.
> > -  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
> > -                                 lack of resources
> > -
> > -**/
> > -EFI_STATUS
> > -EFIAPI
> > -CpuIoServiceWrite (
> > -  IN CONST EFI_SMM_CPU_IO2_PROTOCOL  *This,
> > -  IN EFI_SMM_IO_WIDTH                Width,
> > -  IN UINT64                          Address,
> > -  IN UINTN                           Count,
> > -  IN VOID                            *Buffer
> > -  )
> > -{
> > -  EFI_STATUS  Status;
> > -  UINT8       Stride;
> > -  UINT8       *Uint8Buffer;
> > -
> > -  //
> > -  // Make sure the parameters are valid
> > -  //
> > -  Status = CpuIoCheckParameter (FALSE, Width, Address, Count, Buffer);
> > -  if (EFI_ERROR (Status)) {
> > -    return Status;
> > -  }
> > -
> > -  //
> > -  // Select loop based on the width of the transfer
> > -  //
> > -  Stride = mStride[Width];
> > -  for (Uint8Buffer = (UINT8 *)Buffer; Count > 0; Address += Stride, Uint8Buffer += Stride, Count--) {
> > -    if (Width == SMM_IO_UINT8) {
> > -      IoWrite8 ((UINTN)Address, *Uint8Buffer);
> > -    } else if (Width == SMM_IO_UINT16) {
> > -      IoWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
> > -    } else if (Width == SMM_IO_UINT32) {
> > -      IoWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
> > -    }
> > -  }
> > -
> > -  return EFI_SUCCESS;
> > -}
> > +#include "CpuIo2Common.h"
> >  
> >  /**
> >    The module Entry Point SmmCpuIoProtocol driver
> > @@ -380,28 +22,10 @@ CpuIoServiceWrite (
> >  **/
> >  EFI_STATUS
> >  EFIAPI
> > -SmmCpuIo2Initialize (
> > +TraditionalMmCpuIo2Initialize (
> >    IN EFI_HANDLE        ImageHandle,
> >    IN EFI_SYSTEM_TABLE  *SystemTable
> >    )
> >  {
> > -  EFI_STATUS  Status;
> > -
> > -  //
> > -  // Copy the SMM CPU I/O Protocol instance into the System Management System Table
> > -  //
> > -  CopyMem (&gSmst->SmmIo, &mSmmCpuIo2, sizeof (mSmmCpuIo2));
> > -
> > -  //
> > -  // Install the SMM CPU I/O Protocol into the SMM protocol database
> > -  //
> > -  Status = gSmst->SmmInstallProtocolInterface (
> > -                    &mHandle,
> > -                    &gEfiSmmCpuIo2ProtocolGuid,
> > -                    EFI_NATIVE_INTERFACE,
> > -                    &mSmmCpuIo2
> > -                    );
> > -  ASSERT_EFI_ERROR (Status);
> > -
> > -  return Status;
> > +  return CommonCpuIo2Initialize ();
> >  }
> > diff --git a/UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.c b/UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.c
> > new file mode 100644
> > index 000000000000..2978f82eb815
> > --- /dev/null
> > +++ b/UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.c
> > @@ -0,0 +1,31 @@
> > +/** @file
> > +  Produces the SMM CPU I/O Protocol.
> > +
> > +Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
> > +SPDX-License-Identifier: BSD-2-Clause-Patent
> > +
> > +**/
> > +
> > +#include <PiMm.h>
> > +
> > +#include "CpuIo2Common.h"
> > +
> > +/**
> > +  The module Entry Point SmmCpuIoProtocol driver
> > +
> > +  @param[in] ImageHandle  The firmware allocated handle for the EFI image.
> > +  @param[in] SystemTable  A pointer to the EFI System Table.
> > +
> > +  @retval EFI_SUCCESS  The entry point is executed successfully.
> > +  @retval Other        Some error occurs when executing this entry point.
> > +
> > +**/
> > +EFI_STATUS
> > +EFIAPI
> > +StandaloneMmCpuIo2Initialize (
> > +  IN EFI_HANDLE           ImageHandle,
> > +  IN EFI_MM_SYSTEM_TABLE  *SystemTable
> > +  )
> > +{
> > +  return CommonCpuIo2Initialize ();
> > +}
> > diff --git a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.h b/UefiCpuPkg/CpuIo2Smm/CpuIo2Common.h
> > similarity index 92%
> > rename from UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.h
> > rename to UefiCpuPkg/CpuIo2Smm/CpuIo2Common.h
> > index 4c133b58c9f4..6759cc1c8777 100644
> > --- a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.h
> > +++ b/UefiCpuPkg/CpuIo2Smm/CpuIo2Common.h
> > @@ -9,14 +9,14 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> >  #ifndef _CPU_IO2_SMM_H_
> >  #define _CPU_IO2_SMM_H_
> >  
> > -#include <PiSmm.h>
> > +#include <PiMm.h>
> >  
> >  #include <Protocol/SmmCpuIo2.h>
> >  
> >  #include <Library/BaseLib.h>
> >  #include <Library/DebugLib.h>
> >  #include <Library/IoLib.h>
> > -#include <Library/SmmServicesTableLib.h>
> > +#include <Library/MmServicesTableLib.h>
> >  #include <Library/BaseMemoryLib.h>
> >  
> >  #define MAX_IO_PORT_ADDRESS   0xFFFF
> > @@ -153,4 +153,17 @@ CpuIoServiceWrite (
> >    IN VOID                            *Buffer
> >    );
> >  
> > +
> > +/**
> > +  The module Entry Point SmmCpuIoProtocol driver
> > +
> > +  @retval EFI_SUCCESS  The entry point is executed successfully.
> > +  @retval Other        Some error occurs when executing this entry point.
> > +
> > +**/
> > +EFI_STATUS
> > +CommonCpuIo2Initialize (
> > +  VOID
> > +  );
> > +
> >  #endif
> > diff --git a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf b/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf
> > index bc78fa4e42d2..031db1d100b9 100644
> > --- a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf
> > +++ b/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf
> > @@ -14,7 +14,7 @@ [Defines]
> >    MODULE_TYPE                    = DXE_SMM_DRIVER
> >    VERSION_STRING                 = 1.0
> >    PI_SPECIFICATION_VERSION       = 0x0001000A
> > -  ENTRY_POINT                    = SmmCpuIo2Initialize
> > +  ENTRY_POINT                    = TraditionalMmCpuIo2Initialize
> >  
> >  #
> >  # The following information is for reference only and not required by the build tools.
> > @@ -24,7 +24,8 @@ [Defines]
> >  
> >  [Sources]
> >    CpuIo2Smm.c
> > -  CpuIo2Smm.h
> > +  CpuIo2Common.c
> > +  CpuIo2Common.h
> >  
> >  [Packages]
> >    MdePkg/MdePkg.dec
> > @@ -34,7 +35,7 @@ [LibraryClasses]
> >    BaseLib
> >    DebugLib
> >    IoLib
> > -  SmmServicesTableLib
> > +  MmServicesTableLib
> >    BaseMemoryLib
> >  
> >  [Protocols]
> > diff --git a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf b/UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.inf
> > similarity index 56%
> > copy from UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf
> > copy to UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.inf
> > index bc78fa4e42d2..cce7742bee7a 100644
> > --- a/UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf
> > +++ b/UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.inf
> > @@ -8,13 +8,12 @@
> >  
> >  [Defines]
> >    INF_VERSION                    = 0x00010005
> > -  BASE_NAME                      = CpuIo2Smm
> > -  MODULE_UNI_FILE                = CpuIo2Smm.uni
> > -  FILE_GUID                      = A47EE2D8-F60E-42fd-8E58-7BD65EE4C29B
> > -  MODULE_TYPE                    = DXE_SMM_DRIVER
> > +  BASE_NAME                      = CpuIo2StandaloneMm
> > +  FILE_GUID                      = E3121A26-BB1C-4A18-8E23-2EA3F0412248
> > +  MODULE_TYPE                    = MM_STANDALONE
> >    VERSION_STRING                 = 1.0
> > -  PI_SPECIFICATION_VERSION       = 0x0001000A
> > -  ENTRY_POINT                    = SmmCpuIo2Initialize
> > +  PI_SPECIFICATION_VERSION       = 0x00010032
> > +  ENTRY_POINT                    = StandaloneMmCpuIo2Initialize
> >  
> >  #
> >  # The following information is for reference only and not required by the build tools.
> > @@ -23,18 +22,19 @@ [Defines]
> >  #
> >  
> >  [Sources]
> > -  CpuIo2Smm.c
> > -  CpuIo2Smm.h
> > +  CpuIo2StandaloneMm.c
> > +  CpuIo2Common.c
> > +  CpuIo2Common.h
> >  
> >  [Packages]
> >    MdePkg/MdePkg.dec
> >  
> >  [LibraryClasses]
> > -  UefiDriverEntryPoint
> > +  StandaloneMmDriverEntryPoint
> >    BaseLib
> >    DebugLib
> >    IoLib
> > -  SmmServicesTableLib
> > +  MmServicesTableLib
> >    BaseMemoryLib
> >  
> >  [Protocols]
> > @@ -42,6 +42,3 @@ [Protocols]
> >  
> >  [Depex]
> >    TRUE
> > -
> > -[UserExtensions.TianoCore."ExtraFiles"]
> > -  CpuIo2SmmExtra.uni
> > diff --git a/UefiCpuPkg/UefiCpuPkg.dsc b/UefiCpuPkg/UefiCpuPkg.dsc
> > index b2b6d78a71b0..4e46c600788f 100644
> > --- a/UefiCpuPkg/UefiCpuPkg.dsc
> > +++ b/UefiCpuPkg/UefiCpuPkg.dsc
> > @@ -38,6 +38,7 @@ [LibraryClasses]
> >    UefiRuntimeServicesTableLib|MdePkg/Library/UefiRuntimeServicesTableLib/UefiRuntimeServicesTableLib.inf
> >    UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.inf
> >    UefiDriverEntryPoint|MdePkg/Library/UefiDriverEntryPoint/UefiDriverEntryPoint.inf
> > +  StandaloneMmDriverEntryPoint|MdePkg/Library/StandaloneMmDriverEntryPoint/StandaloneMmDriverEntryPoint.inf
> >    DxeServicesTableLib|MdePkg/Library/DxeServicesTableLib/DxeServicesTableLib.inf
> >    PeimEntryPoint|MdePkg/Library/PeimEntryPoint/PeimEntryPoint.inf
> >    PeiServicesLib|MdePkg/Library/PeiServicesLib/PeiServicesLib.inf
> > @@ -89,10 +90,14 @@ [LibraryClasses.common.DXE_DRIVER]
> >  
> >  [LibraryClasses.common.DXE_SMM_DRIVER]
> >    SmmServicesTableLib|MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.inf
> > +  MmServicesTableLib|MdePkg/Library/MmServicesTableLib/MmServicesTableLib.inf
> >    MemoryAllocationLib|MdePkg/Library/SmmMemoryAllocationLib/SmmMemoryAllocationLib.inf
> >    HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
> >    CpuExceptionHandlerLib|UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
> >  
> > +[LibraryClasses.common.MM_STANDALONE]
> > +  MmServicesTableLib|MdePkg/Library/StandaloneMmServicesTableLib/StandaloneMmServicesTableLib.inf
> > +
> >  [LibraryClasses.common.UEFI_APPLICATION]
> >    UefiApplicationEntryPoint|MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf
> >    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
> > @@ -121,6 +126,7 @@ [Components.IA32, Components.X64]
> >        NULL|UefiCpuPkg/Library/CpuCommonFeaturesLib/CpuCommonFeaturesLib.inf
> >    }
> >    UefiCpuPkg/CpuIo2Smm/CpuIo2Smm.inf
> > +  UefiCpuPkg/CpuIo2Smm/CpuIo2StandaloneMm.inf
> >    UefiCpuPkg/CpuMpPei/CpuMpPei.inf
> >    UefiCpuPkg/CpuS3DataDxe/CpuS3DataDxe.inf
> >    UefiCpuPkg/Library/BaseUefiCpuLib/BaseUefiCpuLib.inf
> > 
>