Re: [PATCH v1 08/18] StandaloneMmPkg/MemLib: AARCH64 Specific instance of memory check library.

["Yao, Jiewen" <jiewen.yao@intel.com>]

You are right.

I propose to add Arm and X86 specific folder - just include PA calculation.
We can leave the generic function in common folder.

The final layout can be:
StandaloneMmPkg/Library/MmMemLib/MmMemLib.c
StandaloneMmPkg/Library/MmMemLib/MmMemLib.inf
StandaloneMmPkg/Library/MmMemLib/Arm/ArchSpecific.c
StandaloneMmPkg/Library/MmMemLib/AArch64/ArchSpecific.c StandaloneMmPkg/Library/MmMemLib/Ia32/ArchSpecific.c
StandaloneMmPkg/Library/MmMemLib/X64/ArchSpecific.c

Thank you
Yao Jiewen

> -----Original Message-----
> From: Achin Gupta [mailto:achin.gupta@arm.com]
> Sent: Wednesday, April 25, 2018 3:36 AM
> To: Yao, Jiewen <jiewen.yao@intel.com>
> Cc: Supreeth Venkatesh <supreeth.venkatesh@arm.com>;
> ard.biesheuvel@linaro.org; edk2-devel@lists.01.org; leif.lindholm@linaro.org;
> Gao, Liming <liming.gao@intel.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>; nd@arm.com
> Subject: Re: [edk2] [PATCH v1 08/18] StandaloneMmPkg/MemLib: AARCH64
> Specific instance of memory check library.
> 
> Hi Jiewen,
> 
> On Mon, Apr 16, 2018 at 10:30:55PM +0000, Yao, Jiewen wrote:
> > Hi
> > I don't think this lib is generic, because it hardcode the physical address bits.
> >
> > PhysicalAddressBits = 36;
> >
> > For X86 CPU, we get it from CPUID. :-)
> >
> > As enhancement, we may put most common C-code logic (such as CopyMem,
> or memmap calculation) to StandaloneMmPkg/MemLib, and only include the
> PhysicalAddresBit calculation under StandaloneMmPkg/MemLib/Arm folder.
> >
> > As such, we know clearly on which one is ARM specific.
> 
> My point was that the hardocoded PA bits were not introduced to make this code
> work on Arm. This has been present in the StandaloneMmPkg from the outset. I
> guess for x86 you have moved on to getting this information from the
> CPUID. Afaics, this function is not be used on Arm platforms but Supreeth will
> double check. If that is the case then only the generic library will be required
> minus this function.
> 
> cheers,
> Achin
> 
> >
> > Thank you
> > Yao Jiewen
> >
> > > -----Original Message-----
> > > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> Achin
> > > Gupta
> > > Sent: Monday, April 16, 2018 11:13 PM
> > > To: Supreeth Venkatesh <supreeth.venkatesh@arm.com>
> > > Cc: ard.biesheuvel@linaro.org; edk2-devel@lists.01.org;
> > > leif.lindholm@linaro.org; Yao, Jiewen <jiewen.yao@intel.com>; Gao, Liming
> > > <liming.gao@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>;
> > > nd@arm.com
> > > Subject: Re: [edk2] [PATCH v1 08/18] StandaloneMmPkg/MemLib: AARCH64
> > > Specific instance of memory check library.
> > >
> > > Hi Supreeth,
> > >
> > > On Fri, Apr 06, 2018 at 03:42:13PM +0100, Supreeth Venkatesh wrote:
> > > > MM memory check library library implementation. This library consumes
> > > > MM_ACCESS_PROTOCOL to get MMRAM information. In order to use this
> > > > library instance, the platform should produce all MMRAM range via
> > > > MM_ACCESS_PROTOCOL, including the range for firmware (like MM Core
> > > > and MM driver) and/or specific dedicated hardware.
> > > >
> > > > This patch provides services for MM Memory Operation.
> > > > The management mode Mem Library provides function for checking if
> buffer
> > > > is outside MMRAM and valid. It also provides functions for copy data
> > > > from MMRAM to non-MMRAM, from non-MMRAM to MMRAM,
> > > > from non-MMRAM to non-MMRAM, or set data in non-MMRAM.
> > > >
> > > > Contributed-under: TianoCore Contribution Agreement 1.1
> > > > Signed-off-by: Achin Gupta <achin.gupta@arm.com>
> > > > Signed-off-by: Supreeth Venkatesh <supreeth.venkatesh@arm.com>
> > > > ---
> > > >  StandaloneMmPkg/Include/Library/MemLib.h    | 140
> ++++++++++++++
> > > >  StandaloneMmPkg/Library/MemLib/Arm/MemLib.c | 276
> > > ++++++++++++++++++++++++++++
> > >
> > > Why is this Library Arm specific. Apart from cosmetics tweaks, it has not
> > > changed since it was originally contributed?
> > >
> > > cheers,
> > > Achin
> > >
> > > >  StandaloneMmPkg/Library/MemLib/MemLib.inf   |  47 +++++
> > > >  3 files changed, 463 insertions(+)
> > > >  create mode 100644 StandaloneMmPkg/Include/Library/MemLib.h
> > > >  create mode 100644 StandaloneMmPkg/Library/MemLib/Arm/MemLib.c
> > > >  create mode 100644 StandaloneMmPkg/Library/MemLib/MemLib.inf
> > > >
> > > > diff --git a/StandaloneMmPkg/Include/Library/MemLib.h
> > > b/StandaloneMmPkg/Include/Library/MemLib.h
> > > > new file mode 100644
> > > > index 0000000000..3264f10010
> > > > --- /dev/null
> > > > +++ b/StandaloneMmPkg/Include/Library/MemLib.h
> > > > @@ -0,0 +1,140 @@
> > > > +/** @file
> > > > +  Provides services for MM Memory Operation.
> > > > +
> > > > +  The MM Mem Library provides function for checking if buffer is outside
> > > MMRAM and valid.
> > > > +  It also provides functions for copy data from MMRAM to non-MMRAM,
> > > from non-MMRAM to MMRAM,
> > > > +  from non-MMRAM to non-MMRAM, or set data in non-MMRAM.
> > > > +
> > > > +  Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
> > > > +  Copyright (c) 2016 - 2017, ARM Limited. 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.
> > > > +
> > > > +**/
> > > > +
> > > > +#ifndef _MM_MEM_LIB_H_
> > > > +#define _MM_MEM_LIB_H_
> > > > +
> > > > +/**
> > > > +  This function check if the buffer is valid per processor architecture and
> not
> > > overlap with MMRAM.
> > > > +
> > > > +  @param Buffer  The buffer start address to be checked.
> > > > +  @param Length  The buffer length to be checked.
> > > > +
> > > > +  @retval TRUE  This buffer is valid per processor architecture and not
> > > overlap with MMRAM.
> > > > +  @retval FALSE This buffer is not valid per processor architecture or
> overlap
> > > with MMRAM.
> > > > +**/
> > > > +BOOLEAN
> > > > +EFIAPI
> > > > +MmIsBufferOutsideMmValid (
> > > > +  IN EFI_PHYSICAL_ADDRESS  Buffer,
> > > > +  IN UINT64                Length
> > > > +  );
> > > > +
> > > > +/**
> > > > +  Copies a source buffer (non-MMRAM) to a destination buffer
> (MMRAM).
> > > > +
> > > > +  This function copies a source buffer (non-MMRAM) to a destination
> buffer
> > > (MMRAM).
> > > > +  It checks if source buffer is valid per processor architecture and not
> overlap
> > > with MMRAM.
> > > > +  If the check passes, it copies memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it return EFI_SECURITY_VIOLATION.
> > > > +  The implementation must be reentrant.
> > > > +
> > > > +  @param  DestinationBuffer   The pointer to the destination buffer of
> the
> > > memory copy.
> > > > +  @param  SourceBuffer        The pointer to the source buffer of
> the
> > > memory copy.
> > > > +  @param  Length              The number of bytes to copy from
> > > SourceBuffer to DestinationBuffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is copied.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmCopyMemToSmram (
> > > > +  OUT VOID       *DestinationBuffer,
> > > > +  IN CONST VOID  *SourceBuffer,
> > > > +  IN UINTN       Length
> > > > +  );
> > > > +
> > > > +/**
> > > > +  Copies a source buffer (MMRAM) to a destination buffer
> (NON-MMRAM).
> > > > +
> > > > +  This function copies a source buffer (non-MMRAM) to a destination
> buffer
> > > (MMRAM).
> > > > +  It checks if destination buffer is valid per processor architecture and not
> > > overlap with MMRAM.
> > > > +  If the check passes, it copies memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it returns EFI_SECURITY_VIOLATION.
> > > > +  The implementation must be reentrant.
> > > > +
> > > > +  @param  DestinationBuffer   The pointer to the destination buffer of
> the
> > > memory copy.
> > > > +  @param  SourceBuffer        The pointer to the source buffer of
> the
> > > memory copy.
> > > > +  @param  Length              The number of bytes to copy from
> > > SourceBuffer to DestinationBuffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is copied.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmCopyMemFromSmram (
> > > > +  OUT VOID       *DestinationBuffer,
> > > > +  IN CONST VOID  *SourceBuffer,
> > > > +  IN UINTN       Length
> > > > +  );
> > > > +
> > > > +/**
> > > > +  Copies a source buffer (NON-MMRAM) to a destination buffer
> > > (NON-MMRAM).
> > > > +
> > > > +  This function copies a source buffer (non-MMRAM) to a destination
> buffer
> > > (MMRAM).
> > > > +  It checks if source buffer and destination buffer are valid per processor
> > > architecture and not overlap with MMRAM.
> > > > +  If the check passes, it copies memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it returns EFI_SECURITY_VIOLATION.
> > > > +  The implementation must be reentrant, and it must handle the case
> where
> > > source buffer overlaps destination buffer.
> > > > +
> > > > +  @param  DestinationBuffer   The pointer to the destination buffer of
> the
> > > memory copy.
> > > > +  @param  SourceBuffer        The pointer to the source buffer of
> the
> > > memory copy.
> > > > +  @param  Length              The number of bytes to copy from
> > > SourceBuffer to DestinationBuffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is copied.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmCopyMem (
> > > > +  OUT VOID       *DestinationBuffer,
> > > > +  IN CONST VOID  *SourceBuffer,
> > > > +  IN UINTN       Length
> > > > +  );
> > > > +
> > > > +/**
> > > > +  Fills a target buffer (NON-MMRAM) with a byte value.
> > > > +
> > > > +  This function fills a target buffer (non-MMRAM) with a byte value.
> > > > +  It checks if target buffer is valid per processor architecture and not
> overlap
> > > with MMRAM.
> > > > +  If the check passes, it fills memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it returns EFI_SECURITY_VIOLATION.
> > > > +
> > > > +  @param  Buffer    The memory to set.
> > > > +  @param  Length    The number of bytes to set.
> > > > +  @param  Value     The value with which to fill Length bytes of
> Buffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The Buffer is invalid per processor
> > > architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is set.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmSetMem (
> > > > +  OUT VOID  *Buffer,
> > > > +  IN UINTN  Length,
> > > > +  IN UINT8  Value
> > > > +  );
> > > > +
> > > > +#endif
> > > > diff --git a/StandaloneMmPkg/Library/MemLib/Arm/MemLib.c
> > > b/StandaloneMmPkg/Library/MemLib/Arm/MemLib.c
> > > > new file mode 100644
> > > > index 0000000000..432a45698b
> > > > --- /dev/null
> > > > +++ b/StandaloneMmPkg/Library/MemLib/Arm/MemLib.c
> > > > @@ -0,0 +1,276 @@
> > > > +/** @file
> > > > +  Instance of MM memory check library.
> > > > +
> > > > +  MM memory check library library implementation. This library
> consumes
> > > MM_ACCESS_PROTOCOL
> > > > +  to get MMRAM information. In order to use this library instance, the
> > > platform should produce
> > > > +  all MMRAM range via MM_ACCESS_PROTOCOL, including the range for
> > > firmware (like MM Core
> > > > +  and MM driver) and/or specific dedicated hardware.
> > > > +
> > > > +  Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
> > > > +  Copyright (c) 2016 - 2017, ARM Limited. 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 <PiMm.h>
> > > > +
> > > > +#include <Library/BaseLib.h>
> > > > +#include <Library/BaseMemoryLib.h>
> > > > +#include <Library/DebugLib.h>
> > > > +
> > > > +EFI_MMRAM_DESCRIPTOR *mMmMemLibInternalMmramRanges;
> > > > +UINTN                mMmMemLibInternalMmramCount;
> > > > +
> > > > +//
> > > > +// Maximum support address used to check input buffer
> > > > +//
> > > > +EFI_PHYSICAL_ADDRESS
> mMmMemLibInternalMaximumSupportAddress =
> > > 0;
> > > > +
> > > > +/**
> > > > +  Calculate and save the maximum support address.
> > > > +
> > > > +**/
> > > > +VOID
> > > > +MmMemLibInternalCalculateMaximumSupportAddress (
> > > > +  VOID
> > > > +  )
> > > > +{
> > > > +  UINT8        PhysicalAddressBits;
> > > > +
> > > > +  PhysicalAddressBits = 36;
> > > > +
> > > > +  //
> > > > +  // Save the maximum support address in one global variable
> > > > +  //
> > > > +  mMmMemLibInternalMaximumSupportAddress =
> > > (EFI_PHYSICAL_ADDRESS)(UINTN)(LShiftU64 (1, PhysicalAddressBits) - 1);
> > > > +  DEBUG ((DEBUG_INFO,
> "mMmMemLibInternalMaximumSupportAddress =
> > > 0x%lx\n", mMmMemLibInternalMaximumSupportAddress));
> > > > +}
> > > > +
> > > > +/**
> > > > +  This function check if the buffer is valid per processor architecture and
> not
> > > overlap with MMRAM.
> > > > +
> > > > +  @param Buffer  The buffer start address to be checked.
> > > > +  @param Length  The buffer length to be checked.
> > > > +
> > > > +  @retval TRUE  This buffer is valid per processor architecture and not
> > > overlap with MMRAM.
> > > > +  @retval FALSE This buffer is not valid per processor architecture or
> overlap
> > > with MMRAM.
> > > > +**/
> > > > +BOOLEAN
> > > > +EFIAPI
> > > > +MmIsBufferOutsideMmValid (
> > > > +  IN EFI_PHYSICAL_ADDRESS  Buffer,
> > > > +  IN UINT64                Length
> > > > +  )
> > > > +{
> > > > +  UINTN  Index;
> > > > +
> > > > +  //
> > > > +  // Check override.
> > > > +  // NOTE: (B:0->L:4G) is invalid for IA32, but (B:1->L:4G-1)/(B:4G-1->L:1)
> is
> > > valid.
> > > > +  //
> > > > +  if ((Length > mMmMemLibInternalMaximumSupportAddress) ||
> > > > +      (Buffer > mMmMemLibInternalMaximumSupportAddress) ||
> > > > +      ((Length != 0) && (Buffer >
> > > (mMmMemLibInternalMaximumSupportAddress - (Length - 1)))) ) {
> > > > +    //
> > > > +    // Overflow happen
> > > > +    //
> > > > +    DEBUG ((
> > > > +      DEBUG_ERROR,
> > > > +      "MmIsBufferOutsideMmValid: Overflow: Buffer (0x%lx) - Length
> > > (0x%lx), MaximumSupportAddress (0x%lx)\n",
> > > > +      Buffer,
> > > > +      Length,
> > > > +      mMmMemLibInternalMaximumSupportAddress
> > > > +      ));
> > > > +    return FALSE;
> > > > +  }
> > > > +
> > > > +  for (Index = 0; Index < mMmMemLibInternalMmramCount; Index ++) {
> > > > +    if (((Buffer >= mMmMemLibInternalMmramRanges[Index].CpuStart)
> &&
> > > (Buffer < mMmMemLibInternalMmramRanges[Index].CpuStart +
> > > mMmMemLibInternalMmramRanges[Index].PhysicalSize)) ||
> > > > +        ((mMmMemLibInternalMmramRanges[Index].CpuStart >=
> Buffer)
> > > && (mMmMemLibInternalMmramRanges[Index].CpuStart < Buffer +
> Length))) {
> > > > +      DEBUG ((
> > > > +        DEBUG_ERROR,
> > > > +        "MmIsBufferOutsideMmValid: Overlap: Buffer (0x%lx) - Length
> > > (0x%lx), ",
> > > > +        Buffer,
> > > > +        Length
> > > > +        ));
> > > > +      DEBUG ((
> > > > +        DEBUG_ERROR,
> > > > +        "CpuStart (0x%lx) - PhysicalSize (0x%lx)\n",
> > > > +        mMmMemLibInternalMmramRanges[Index].CpuStart,
> > > > +        mMmMemLibInternalMmramRanges[Index].PhysicalSize
> > > > +        ));
> > > > +      return FALSE;
> > > > +    }
> > > > +  }
> > > > +
> > > > +  return TRUE;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Copies a source buffer (non-MMRAM) to a destination buffer
> (MMRAM).
> > > > +
> > > > +  This function copies a source buffer (non-MMRAM) to a destination
> buffer
> > > (MMRAM).
> > > > +  It checks if source buffer is valid per processor architecture and not
> overlap
> > > with MMRAM.
> > > > +  If the check passes, it copies memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it return EFI_SECURITY_VIOLATION.
> > > > +  The implementation must be reentrant.
> > > > +
> > > > +  @param  DestinationBuffer   The pointer to the destination buffer of
> the
> > > memory copy.
> > > > +  @param  SourceBuffer        The pointer to the source buffer of
> the
> > > memory copy.
> > > > +  @param  Length              The number of bytes to copy from
> > > SourceBuffer to DestinationBuffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is copied.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmCopyMemToMmram (
> > > > +  OUT VOID       *DestinationBuffer,
> > > > +  IN CONST VOID  *SourceBuffer,
> > > > +  IN UINTN       Length
> > > > +  )
> > > > +{
> > > > +  if (!MmIsBufferOutsideMmValid
> > > ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
> > > > +    DEBUG ((DEBUG_ERROR, "MmCopyMemToMmram: Security
> Violation:
> > > Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
> > > > +    return EFI_SECURITY_VIOLATION;
> > > > +  }
> > > > +  CopyMem (DestinationBuffer, SourceBuffer, Length);
> > > > +  return EFI_SUCCESS;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Copies a source buffer (MMRAM) to a destination buffer
> (NON-MMRAM).
> > > > +
> > > > +  This function copies a source buffer (non-MMRAM) to a destination
> buffer
> > > (MMRAM).
> > > > +  It checks if destination buffer is valid per processor architecture and not
> > > overlap with MMRAM.
> > > > +  If the check passes, it copies memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it returns EFI_SECURITY_VIOLATION.
> > > > +  The implementation must be reentrant.
> > > > +
> > > > +  @param  DestinationBuffer   The pointer to the destination buffer of
> the
> > > memory copy.
> > > > +  @param  SourceBuffer        The pointer to the source buffer of
> the
> > > memory copy.
> > > > +  @param  Length              The number of bytes to copy from
> > > SourceBuffer to DestinationBuffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is copied.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmCopyMemFromMmram (
> > > > +  OUT VOID       *DestinationBuffer,
> > > > +  IN CONST VOID  *SourceBuffer,
> > > > +  IN UINTN       Length
> > > > +  )
> > > > +{
> > > > +  if (!MmIsBufferOutsideMmValid
> > > ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
> > > > +    DEBUG ((DEBUG_ERROR, "MmCopyMemFromMmram: Security
> > > Violation: Destination (0x%x), Length (0x%x)\n", DestinationBuffer, Length));
> > > > +    return EFI_SECURITY_VIOLATION;
> > > > +  }
> > > > +  CopyMem (DestinationBuffer, SourceBuffer, Length);
> > > > +  return EFI_SUCCESS;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Copies a source buffer (NON-MMRAM) to a destination buffer
> > > (NON-MMRAM).
> > > > +
> > > > +  This function copies a source buffer (non-MMRAM) to a destination
> buffer
> > > (MMRAM).
> > > > +  It checks if source buffer and destination buffer are valid per processor
> > > architecture and not overlap with MMRAM.
> > > > +  If the check passes, it copies memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it returns EFI_SECURITY_VIOLATION.
> > > > +  The implementation must be reentrant, and it must handle the case
> where
> > > source buffer overlaps destination buffer.
> > > > +
> > > > +  @param  DestinationBuffer   The pointer to the destination buffer of
> the
> > > memory copy.
> > > > +  @param  SourceBuffer        The pointer to the source buffer of
> the
> > > memory copy.
> > > > +  @param  Length              The number of bytes to copy from
> > > SourceBuffer to DestinationBuffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per
> > > processor architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is copied.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmCopyMem (
> > > > +  OUT VOID       *DestinationBuffer,
> > > > +  IN CONST VOID  *SourceBuffer,
> > > > +  IN UINTN       Length
> > > > +  )
> > > > +{
> > > > +  if (!MmIsBufferOutsideMmValid
> > > ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
> > > > +    DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation:
> Destination
> > > (0x%x), Length (0x%x)\n", DestinationBuffer, Length));
> > > > +    return EFI_SECURITY_VIOLATION;
> > > > +  }
> > > > +  if (!MmIsBufferOutsideMmValid
> > > ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
> > > > +    DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation: Source
> > > (0x%x), Length (0x%x)\n", SourceBuffer, Length));
> > > > +    return EFI_SECURITY_VIOLATION;
> > > > +  }
> > > > +  CopyMem (DestinationBuffer, SourceBuffer, Length);
> > > > +  return EFI_SUCCESS;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Fills a target buffer (NON-MMRAM) with a byte value.
> > > > +
> > > > +  This function fills a target buffer (non-MMRAM) with a byte value.
> > > > +  It checks if target buffer is valid per processor architecture and not
> overlap
> > > with MMRAM.
> > > > +  If the check passes, it fills memory and returns EFI_SUCCESS.
> > > > +  If the check fails, it returns EFI_SECURITY_VIOLATION.
> > > > +
> > > > +  @param  Buffer    The memory to set.
> > > > +  @param  Length    The number of bytes to set.
> > > > +  @param  Value     The value with which to fill Length bytes of
> Buffer.
> > > > +
> > > > +  @retval EFI_SECURITY_VIOLATION The Buffer is invalid per processor
> > > architecture or overlap with MMRAM.
> > > > +  @retval EFI_SUCCESS            Memory is set.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MmSetMem (
> > > > +  OUT VOID  *Buffer,
> > > > +  IN UINTN  Length,
> > > > +  IN UINT8  Value
> > > > +  )
> > > > +{
> > > > +  if (!MmIsBufferOutsideMmValid
> ((EFI_PHYSICAL_ADDRESS)(UINTN)Buffer,
> > > Length)) {
> > > > +    DEBUG ((DEBUG_ERROR, "MmSetMem: Security Violation: Source
> > > (0x%x), Length (0x%x)\n", Buffer, Length));
> > > > +    return EFI_SECURITY_VIOLATION;
> > > > +  }
> > > > +  SetMem (Buffer, Length, Value);
> > > > +  return EFI_SUCCESS;
> > > > +}
> > > > +
> > > > +/**
> > > > +  The constructor function initializes the Mm Mem library
> > > > +
> > > > +  @param  ImageHandle   The firmware allocated handle for the EFI
> > > image.
> > > > +  @param  SystemTable   A pointer to the EFI System Table.
> > > > +
> > > > +  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
> > > > +
> > > > +**/
> > > > +EFI_STATUS
> > > > +EFIAPI
> > > > +MemLibConstructor (
> > > > +  IN EFI_HANDLE             ImageHandle,
> > > > +  IN EFI_MM_SYSTEM_TABLE    *MmSystemTable
> > > > +  )
> > > > +{
> > > > +
> > > > +  //
> > > > +  // Calculate and save maximum support address
> > > > +  //
> > > > +  MmMemLibInternalCalculateMaximumSupportAddress ();
> > > > +
> > > > +  return EFI_SUCCESS;
> > > > +}
> > > > diff --git a/StandaloneMmPkg/Library/MemLib/MemLib.inf
> > > b/StandaloneMmPkg/Library/MemLib/MemLib.inf
> > > > new file mode 100644
> > > > index 0000000000..52b7c06397
> > > > --- /dev/null
> > > > +++ b/StandaloneMmPkg/Library/MemLib/MemLib.inf
> > > > @@ -0,0 +1,47 @@
> > > > +## @file
> > > > +#  Instance of MM memory check library.
> > > > +#
> > > > +#  MM memory check library library implementation. This library
> consumes
> > > MM_ACCESS_PROTOCOL
> > > > +#  to get MMRAM information. In order to use this library instance, the
> > > platform should produce
> > > > +#  all MMRAM range via MM_ACCESS_PROTOCOL, including the range
> for
> > > firmware (like MM Core
> > > > +#  and MM driver) and/or specific dedicated hardware.
> > > > +#
> > > > +#  Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
> > > > +#  Copyright (c) 2016 - 2017, ARM Limited. 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                    = 0x0001001A
> > > > +  BASE_NAME                      = MemLib
> > > > +  FILE_GUID                      =
> > > EA355F14-6409-4716-829F-37B3BC7C7F26
> > > > +  MODULE_TYPE                    = MM_STANDALONE
> > > > +  VERSION_STRING                 = 1.0
> > > > +  PI_SPECIFICATION_VERSION       = 0x00010032
> > > > +  LIBRARY_CLASS                  = MemLib|MM_STANDALONE
> > > MM_CORE_STANDALONE
> > > > +  CONSTRUCTOR                    = MemLibConstructor
> > > > +
> > > > +#
> > > > +# The following information is for reference only and not required by the
> > > build tools.
> > > > +#
> > > > +#  VALID_ARCHITECTURES           = AARCH64
> > > > +#
> > > > +
> > > > +[Sources.AARCH64]
> > > > +  Arm/MemLib.c
> > > > +
> > > > +[Packages]
> > > > +  MdePkg/MdePkg.dec
> > > > +  StandaloneMmPkg/StandaloneMmPkg.dec
> > > > +
> > > > +[LibraryClasses]
> > > > +  BaseMemoryLib
> > > > +  DebugLib
> > > > --
> > > > 2.16.2
> > > >
> > > _______________________________________________
> > > edk2-devel mailing list
> > > edk2-devel@lists.01.org
> > > https://lists.01.org/mailman/listinfo/edk2-devel