Re: [PATCH v4 2/5] ArmPkg/Drivers: Add EFI_MM_COMMUNICATION_PROTOCOL DXE driver.

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Hi Sughosh,

On Tue, 27 Nov 2018 at 07:19, Sughosh Ganu <sughosh.ganu@arm.com> wrote:
>
> From: Achin Gupta <achin.gupta@arm.com>
>
> PI v1.5 Specification Volume 4 defines Management Mode Core Interface
> and defines EFI_MM_COMMUNICATION_PROTOCOL. This protocol provides a
> means of communicating between drivers outside of MM and MMI
> handlers inside of MM.
>
> This patch implements the EFI_MM_COMMUNICATION_PROTOCOL DXE runtime
> driver for AARCH64 platforms. It uses SMCs allocated from the standard
> SMC range defined in DEN0060A_ARM_MM_Interface_Specification.pdf
> to communicate with the standalone MM environment in the secure world.
>
> This patch also adds the MM Communication driver (.inf) file to
> define entry point for this driver and other compile
> related information the driver needs.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Sughosh Ganu <sughosh.ganu@arm.com>
> ---
>  ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf |  56 +++
>  ArmPkg/Drivers/MmCommunicationDxe/MmCommunicate.h     |  28 ++
>  ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c   | 378 ++++++++++++++++++++
>  3 files changed, 462 insertions(+)
>
> diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> new file mode 100644
> index 000000000000..88beafa39c05
> --- /dev/null
> +++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> @@ -0,0 +1,56 @@
> +#/** @file
> +#
> +#  DXE MM Communicate driver
> +#
> +#  Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.
> +#
> +#  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                      = ArmMmCommunication
> +  FILE_GUID                      = 09EE81D3-F15E-43F4-85B4-CB9873DA5D6B
> +  MODULE_TYPE                    = DXE_RUNTIME_DRIVER
> +  VERSION_STRING                 = 1.0
> +  ENTRY_POINT                    = MmCommunicationInitialize
> +
> +#
> +# The following is for reference only and not required by
> +# build tools
> +#
> +# VALID_ARCHITECTURES            = AARCH64
> +#
> +
> +[Sources.AARCH64]
> +  MmCommunication.c
> +
> +[Packages]
> +  ArmPkg/ArmPkg.dec
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  ArmLib
> +  ArmSmcLib
> +  BaseMemoryLib
> +  DebugLib
> +  DxeServicesTableLib
> +  HobLib
> +  UefiDriverEntryPoint
> +
> +[Protocols]
> +  gEfiMmCommunicationProtocolGuid              ## PRODUCES
> +
> +[Pcd.common]
> +  gArmTokenSpaceGuid.PcdMmBufferBase
> +  gArmTokenSpaceGuid.PcdMmBufferSize
> +
> +[Depex]
> +  gEfiCpuArchProtocolGuid
> diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunicate.h b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunicate.h
> new file mode 100644
> index 000000000000..0bf1c8d4ca0e
> --- /dev/null
> +++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunicate.h
> @@ -0,0 +1,28 @@
> +/** @file
> +
> +  Copyright (c) 2016-2018, ARM Limited. All rights reserved.
> +
> +  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.
> +
> +**/
> +
> +#if !defined _MM_COMMUNICATE_H_
> +#define _MM_COMMUNICATE_H_
> +
> +#define MM_MAJOR_VER_MASK        0xEFFF0000
> +#define MM_MINOR_VER_MASK        0x0000FFFF
> +#define MM_MAJOR_VER_SHIFT       16
> +
> +#define MM_MAJOR_VER(x) (((x) & MM_MAJOR_VER_MASK) >> MM_MAJOR_VER_SHIFT)
> +#define MM_MINOR_VER(x) ((x) & MM_MINOR_VER_MASK)
> +
> +#define MM_CALLER_MAJOR_VER      0x1UL
> +#define MM_CALLER_MINOR_VER      0x0
> +
> +#endif /* _MM_COMMUNICATE_H_ */
> diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
> new file mode 100644
> index 000000000000..4e1218671d9a
> --- /dev/null
> +++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
> @@ -0,0 +1,378 @@
> +/** @file
> +
> +  Copyright (c) 2016-2018, ARM Limited. All rights reserved.
> +
> +  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 <Library/ArmLib.h>
> +#include <Library/ArmSmcLib.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/DxeServicesTableLib.h>
> +#include <Library/HobLib.h>
> +#include <Library/PcdLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/UefiRuntimeServicesTableLib.h>
> +
> +#include <Protocol/MmCommunication.h>
> +
> +#include <IndustryStandard/ArmStdSmc.h>
> +
> +#include "MmCommunicate.h"
> +
> +//
> +// Address, Length of the pre-allocated buffer for communication with the secure
> +// world.
> +//
> +STATIC ARM_MEMORY_REGION_DESCRIPTOR  mNsCommBuffMemRegion;
> +
> +// Notification event when virtual address map is set.
> +STATIC EFI_EVENT  mSetVirtualAddressMapEvent;
> +
> +//
> +// Handle to install the MM Communication Protocol
> +//
> +STATIC EFI_HANDLE  mMmCommunicateHandle;
> +
> +/**
> +  Communicates with a registered handler.
> +
> +  This function provides an interface to send and receive messages to the
> +  Standalone MM environment on behalf of UEFI services.  This function is part
> +  of the MM Communication Protocol that may be called in physical mode prior to
> +  SetVirtualAddressMap() and in virtual mode after SetVirtualAddressMap().
> +
> +  @param[in]      This                The EFI_MM_COMMUNICATION_PROTOCOL
> +                                      instance.
> +  @param[in, out] CommBuffer          A pointer to the buffer to convey
> +                                      into MMRAM.
> +  @param[in, out] CommSize            The size of the data buffer being
> +                                      passed in. This is optional.
> +
> +  @retval EFI_SUCCESS                 The message was successfully posted.
> +  @retval EFI_INVALID_PARAMETER       The CommBuffer was NULL.
> +  @retval EFI_BAD_BUFFER_SIZE         The buffer size is incorrect for the MM
> +                                      implementation. If this error is
> +                                      returned, the MessageLength field in
> +                                      the CommBuffer header or the integer
> +                                      pointed by CommSize are updated to reflect
> +                                      the maximum payload size the
> +                                      implementation can accommodate.
> +  @retval EFI_ACCESS_DENIED           The CommunicateBuffer parameter
> +                                      or CommSize parameter, if not omitted,
> +                                      are in address range that cannot be
> +                                      accessed by the MM environment
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +MmCommunicationCommunicate (
> +  IN CONST EFI_MM_COMMUNICATION_PROTOCOL  *This,
> +  IN OUT VOID                             *CommBuffer,
> +  IN OUT UINTN                            *CommSize OPTIONAL
> +  )
> +{
> +  EFI_MM_COMMUNICATE_HEADER   *CommunicateHeader;
> +  ARM_SMC_ARGS                CommunicateSmcArgs;
> +  EFI_STATUS                  Status;
> +  UINTN                       BufferSize;
> +
> +  Status = EFI_ACCESS_DENIED;
> +  BufferSize = 0;
> +
> +  ZeroMem (&CommunicateSmcArgs, sizeof (ARM_SMC_ARGS));
> +
> +  //
> +  // Check parameters
> +  //
> +  if (CommBuffer == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  CommunicateHeader = CommBuffer;
> +  // CommBuffer is a mandatory parameter. Hence, Rely on
> +  // MessageLength + Header to ascertain the
> +  // total size of the communication payload rather than
> +  // rely on optional CommSize parameter
> +  BufferSize = CommunicateHeader->MessageLength +
> +               sizeof (CommunicateHeader->HeaderGuid) +
> +               sizeof (CommunicateHeader->MessageLength);
> +
> +  // If the length of the CommBuffer is 0 then return the expected length.
> +  if (CommSize) {
> +    // This case can be used by the consumer of this driver to find out the
> +    // max size that can be used for allocating CommBuffer.
> +    if ((*CommSize == 0) ||
> +        (*CommSize > mNsCommBuffMemRegion.Length)) {
> +      *CommSize = mNsCommBuffMemRegion.Length;
> +      return EFI_BAD_BUFFER_SIZE;
> +    }
> +    //
> +    // CommSize must match MessageLength + sizeof (EFI_MM_COMMUNICATE_HEADER);
> +    //
> +    if (*CommSize != BufferSize) {
> +        return EFI_INVALID_PARAMETER;
> +    }
> +  }
> +
> +  //
> +  // If the buffer size is 0 or greater than what can be tolerated by the MM
> +  // environment then return the expected size.
> +  //
> +  if ((BufferSize == 0) ||
> +      (BufferSize > mNsCommBuffMemRegion.Length)) {
> +    CommunicateHeader->MessageLength = mNsCommBuffMemRegion.Length -
> +                                       sizeof (CommunicateHeader->HeaderGuid) -
> +                                       sizeof (CommunicateHeader->MessageLength);
> +    return EFI_BAD_BUFFER_SIZE;
> +  }
> +
> +  // SMC Function ID
> +  CommunicateSmcArgs.Arg0 = ARM_SMC_ID_MM_COMMUNICATE_AARCH64;
> +
> +  // Cookie
> +  CommunicateSmcArgs.Arg1 = 0;
> +
> +  // Copy Communication Payload
> +  CopyMem ((VOID *)mNsCommBuffMemRegion.VirtualBase, CommBuffer, BufferSize);
> +
> +  // comm_buffer_address (64-bit physical address)
> +  CommunicateSmcArgs.Arg2 = (UINTN)mNsCommBuffMemRegion.PhysicalBase;
> +
> +  // comm_size_address (not used, indicated by setting to zero)
> +  CommunicateSmcArgs.Arg3 = 0;
> +
> +  // Call the Standalone MM environment.
> +  ArmCallSmc (&CommunicateSmcArgs);
> +
> +  switch (CommunicateSmcArgs.Arg0) {
> +  case ARM_SMC_MM_RET_SUCCESS:
> +    ZeroMem (CommBuffer, BufferSize);
> +    // On successful return, the size of data being returned is inferred from
> +    // MessageLength + Header.
> +    CommunicateHeader = (EFI_MM_COMMUNICATE_HEADER *)mNsCommBuffMemRegion.VirtualBase;
> +    BufferSize = CommunicateHeader->MessageLength +
> +                 sizeof (CommunicateHeader->HeaderGuid) +
> +                 sizeof (CommunicateHeader->MessageLength);
> +
> +    CopyMem (
> +      CommBuffer,
> +      (VOID *)mNsCommBuffMemRegion.VirtualBase,
> +      BufferSize
> +      );
> +    Status = EFI_SUCCESS;
> +    break;
> +
> +  case ARM_SMC_MM_RET_INVALID_PARAMS:
> +    Status = EFI_INVALID_PARAMETER;
> +    break;
> +
> +  case ARM_SMC_MM_RET_DENIED:
> +    Status = EFI_ACCESS_DENIED;
> +    break;
> +
> +  case ARM_SMC_MM_RET_NO_MEMORY:
> +    // Unexpected error since the CommSize was checked for zero length
> +    // prior to issuing the SMC
> +    Status = EFI_OUT_OF_RESOURCES;
> +    ASSERT (0);
> +    break;
> +
> +  default:
> +    Status = EFI_ACCESS_DENIED;
> +    ASSERT (0);
> +  }
> +
> +  return Status;
> +}
> +
> +//
> +// MM Communication Protocol instance
> +//
> +EFI_MM_COMMUNICATION_PROTOCOL  mMmCommunication = {
> +  MmCommunicationCommunicate
> +};
> +
> +/**
> +  Notification callback on SetVirtualAddressMap event.
> +
> +  This function notifies the MM communication protocol interface on
> +  SetVirtualAddressMap event and converts pointers used in this driver
> +  from physical to virtual address.
> +
> +  @param  Event          SetVirtualAddressMap event.
> +  @param  Context        A context when the SetVirtualAddressMap triggered.
> +
> +  @retval EFI_SUCCESS    The function executed successfully.
> +  @retval Other          Some error occurred when executing this function.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +NotifySetVirtualAddressMap (
> +  IN EFI_EVENT  Event,
> +  IN VOID      *Context
> +  )
> +{
> +  EFI_STATUS  Status;
> +
> +  Status = gRT->ConvertPointer (
> +                  EFI_OPTIONAL_PTR,
> +                  (VOID **)&mNsCommBuffMemRegion.VirtualBase
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    DEBUG ((DEBUG_ERROR, "NotifySetVirtualAddressMap():"
> +            " Unable to convert MM runtime pointer. Status:0x%r\n", Status));
> +  }
> +
> +}
> +
> +STATIC
> +EFI_STATUS
> +GetMmCompatibility ()
> +{
> +  EFI_STATUS   Status;
> +  UINT32       MmVersion;
> +  ARM_SMC_ARGS MmVersionArgs;
> +
> +  // MM_VERSION uses SMC32 calling conventions
> +  MmVersionArgs.Arg0 = ARM_SMC_ID_MM_VERSION_AARCH32;
> +
> +  ArmCallSmc (&MmVersionArgs);
> +
> +  MmVersion = MmVersionArgs.Arg0;
> +
> +  if ((MM_MAJOR_VER(MmVersion) == MM_CALLER_MAJOR_VER) &&
> +      (MM_MINOR_VER(MmVersion) >= MM_CALLER_MINOR_VER)) {
> +    DEBUG ((DEBUG_INFO, "MM Version: Major=0x%x, Minor=0x%x\n",
> +            MM_MAJOR_VER(MmVersion), MM_MINOR_VER(MmVersion)));
> +    Status = EFI_SUCCESS;
> +  } else {
> +    DEBUG ((DEBUG_ERROR, "Incompatible MM Versions.\n Current Version: Major=0x%x, Minor=0x%x.\n Expected: Major=0x%x, Minor>=0x%x.\n",
> +            MM_MAJOR_VER(MmVersion), MM_MINOR_VER(MmVersion), MM_CALLER_MAJOR_VER, MM_CALLER_MINOR_VER));
> +    Status = EFI_UNSUPPORTED;
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  The Entry Point for MM Communication
> +
> +  This function installs the MM communication protocol interface and finds out
> +  what type of buffer management will be required prior to invoking the
> +  communication SMC.
> +
> +  @param  ImageHandle    The firmware allocated handle for the EFI image.
> +  @param  SystemTable    A pointer to the EFI System Table.
> +
> +  @retval EFI_SUCCESS    The entry point is executed successfully.
> +  @retval Other          Some error occurred when executing this entry point.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +MmCommunicationInitialize (
> +  IN EFI_HANDLE         ImageHandle,
> +  IN EFI_SYSTEM_TABLE  *SystemTable
> +  )
> +{
> +  EFI_STATUS                 Status;
> +
> +  // Check if we can make the MM call
> +  Status = GetMmCompatibility ();
> +  if (EFI_ERROR(Status)) {
> +    goto ReturnErrorStatus;
> +  }
> +
> +  mNsCommBuffMemRegion.PhysicalBase = PcdGet64 (PcdMmBufferBase);
> +  // During boot , Virtual and Physical are same
> +  mNsCommBuffMemRegion.VirtualBase = mNsCommBuffMemRegion.PhysicalBase;
> +  mNsCommBuffMemRegion.Length = PcdGet64 (PcdMmBufferSize);
> +
> +  ASSERT (mNsCommBuffMemRegion.PhysicalBase != 0);
> +
> +  ASSERT (mNsCommBuffMemRegion.Length != 0);
> +
> +  Status = gDS->AddMemorySpace (
> +                  EfiGcdMemoryTypeReserved,
> +                  mNsCommBuffMemRegion.PhysicalBase,
> +                  mNsCommBuffMemRegion.Length,
> +                  EFI_MEMORY_WB |
> +                  EFI_MEMORY_XP |
> +                  EFI_MEMORY_RUNTIME
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    DEBUG ((DEBUG_ERROR, "MmCommunicateInitialize: "
> +            "Failed to add MM-NS Buffer Memory Space\n"));
> +    goto ReturnErrorStatus;
> +  }
> +
> +  Status = gDS->SetMemorySpaceAttributes (
> +                  mNsCommBuffMemRegion.PhysicalBase,
> +                  mNsCommBuffMemRegion.Length,
> +                  EFI_MEMORY_WB | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    DEBUG ((DEBUG_ERROR, "MmCommunicateInitialize: "
> +            "Failed to set MM-NS Buffer Memory attributes\n"));
> +    goto CleanAddedMemorySpace;
> +  }
> +
> +  // Install the communication protocol
> +  Status = gBS->InstallProtocolInterface (
> +                  &mMmCommunicateHandle,
> +                  &gEfiMmCommunicationProtocolGuid,
> +                  EFI_NATIVE_INTERFACE,
> +                  &mMmCommunication
> +                  );
> +  if (EFI_ERROR(Status)) {
> +    DEBUG ((DEBUG_ERROR, "MmCommunicationInitialize: "
> +            "Failed to install MM communication protocol\n"));
> +    goto CleanAllocatedPages;
> +  }
> +
> +  // Register notification callback when virtual address is associated
> +  // with the physical address.
> +  // Create a Set Virtual Address Map event.
> +  Status = gBS->CreateEvent (
> +                  EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE,
> +                  TPL_NOTIFY,
> +                  NotifySetVirtualAddressMap,
> +                  NULL,
> +                  &mSetVirtualAddressMapEvent
> +                  );
> +  if (Status == EFI_SUCCESS) {
> +    return Status;
> +  }
> +
> +  gBS->UninstallProtocolInterface (
> +         mMmCommunicateHandle,
> +         &gEfiMmCommunicationProtocolGuid,
> +         &mMmCommunication
> +         );
> +
> +CleanAllocatedPages:
> +  gBS->FreePages (
> +         mNsCommBuffMemRegion.PhysicalBase,
> +         EFI_SIZE_TO_PAGES (mNsCommBuffMemRegion.Length)
> +         );
> +

Do we still need this?


> +CleanAddedMemorySpace:
> +  gDS->RemoveMemorySpace (
> +         mNsCommBuffMemRegion.PhysicalBase,
> +         mNsCommBuffMemRegion.Length
> +         );
> +
> +ReturnErrorStatus:
> +  return EFI_INVALID_PARAMETER;
> +}
> --
> 2.7.4
>