Hi Kun,
Thank you for this patch.
Please find my response inline marked [SAMI].
Regards,
Sami Mujawar
From: Kun Qin <kuqin@microsoft.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4464
This change introduced the MM communicate support in PEI phase for ARM
based platforms. Similar to the DXE counterpart, `PcdMmBufferBase` is
used as communicate buffer and SMC will be invoked to communicate to
TrustZone when MMI is requested.
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Co-authored-by: Ronny Hansen <hansen.ronny@microsoft.com>
Co-authored-by: Shriram Masanamuthu Chinnathurai <shriramma@microsoft.com>
Co-authored-by: Preshit Harlikar <pharlikar@microsoft.com>
Signed-off-by: Kun Qin <kuqin@microsoft.com>
---
ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.c | 178 ++++++++++++++++++++
ArmPkg/ArmPkg.dsc | 2 +
ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.h | 76 +++++++++
ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.inf | 41 +++++
4 files changed, 297 insertions(+)
diff --git a/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.c b/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.c
new file mode 100644
index 000000000000..0f1f763a347d
--- /dev/null
+++ b/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.c
@@ -0,0 +1,178 @@
+/** @file -- MmCommunicationPei.c
+ Provides an interface to send MM request in PEI
+
+ Copyright (c) 2016-2021, Arm Limited. All rights reserved.<BR>
+ Copyright (c) Microsoft Corporation.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "MmCommunicationPei.h"
+
+//
+// Module globals
+//
+EFI_PEI_MM_COMMUNICATION_PPI mPeiMmCommunication = {
+ MmCommunicationPeim
+};
+
+EFI_PEI_PPI_DESCRIPTOR mPeiMmCommunicationPpi = {
+ (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
+ &gEfiPeiMmCommunicationPpiGuid,
+ &mPeiMmCommunication
+};
+
+/**
+ Entry point of PEI MM Communication driver
+
+ @param FileHandle Handle of the file being invoked.
+ Type EFI_PEI_FILE_HANDLE is defined in FfsFindNextFile().
+ @param PeiServices General purpose services available to every PEIM.
+
+ @retval EFI_SUCCESS If the interface could be successfully installed
+ @retval Others Returned from PeiServicesInstallPpi()
+**/
+EFI_STATUS
+EFIAPI
+MmCommunicationPeiInitialize (
+ IN EFI_PEI_FILE_HANDLE FileHandle,
+ IN CONST EFI_PEI_SERVICES **PeiServices
+ )
+{
+ return PeiServicesInstallPpi (&mPeiMmCommunicationPpi);
+}
+
+/**
+ MmCommunicationPeim
+ Communicates with a registered handler.
+ This function provides a service to send and receive messages from a registered UEFI service during PEI.
+
+ @param[in] This The EFI_PEI_MM_COMMUNICATION_PPI instance.
+ @param[in, out] CommBuffer Pointer to the data buffer
+ @param[in, out] CommSize The size of the data buffer being passed in. On exit, the
+ size of data being returned. Zero if the handler does not
+ wish to reply with any data.
+
+ @retval EFI_SUCCESS The message was successfully posted.
+ @retval EFI_INVALID_PARAMETER CommBuffer was NULL or *CommSize does not match
+ MessageLength + sizeof (EFI_MM_COMMUNICATE_HEADER).
+ @retval EFI_BAD_BUFFER_SIZE The buffer is too large 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.
+**/
+EFI_STATUS
+EFIAPI
+MmCommunicationPeim (
+ IN CONST EFI_PEI_MM_COMMUNICATION_PPI *This,
+ IN OUT VOID *CommBuffer,
+ IN OUT UINTN *CommSize
+ )
+{
+ EFI_MM_COMMUNICATE_HEADER *CommunicateHeader;
+ ARM_SMC_ARGS CommunicateSmcArgs;
+ EFI_STATUS Status;
+ UINTN BufferSize;
+
+ Status = EFI_ACCESS_DENIED;
+ BufferSize = 0;
[SAMI] Minor optimisation: The above initialisations are probably
not required.
+
+ ZeroMem (&CommunicateSmcArgs, sizeof (ARM_SMC_ARGS));
+
+ // Check that our static buffer is looking good.
+ // We are using PcdMmBufferBase to transfer variable data.
+ // We are not using the full size of the buffer since there is a cost
+ // of copying data between Normal and Secure World.
+ ASSERT (PcdGet64 (PcdMmBufferSize) > 0 && PcdGet64 (PcdMmBufferBase) != 0);
+
+ //
+ // Check parameters
+ //
+ if (CommBuffer == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
[SAMI] Should there be a check for CommSize as well? Otherwise the
code will crash a few lines below when doing CopyMem().
+
+ // If the length of the CommBuffer is 0 then return the expected length.
+ // 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 != NULL) && \
+ ((*CommSize == 0) || (*CommSize > (UINTN)PcdGet64 (PcdMmBufferSize))))
+ {
+ *CommSize = (UINTN)PcdGet64 (PcdMmBufferSize);
+ return EFI_BAD_BUFFER_SIZE;
+ }
+
+ CommunicateHeader = (EFI_MM_COMMUNICATE_HEADER *)(UINTN)(PcdGet64 (PcdMmBufferBase));
+
+ CopyMem ((VOID *)CommunicateHeader, CommBuffer, *CommSize);
[SAMI] If CommSize is NULL, the above the above line will result in
a crash, right?
+
+ // 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 CommSize is supplied it must match MessageLength + sizeof (EFI_MM_COMMUNICATE_HEADER);
+ //
+ if ((CommSize != NULL) && (*CommSize != BufferSize)) {
+ return EFI_INVALID_PARAMETER;
+ }
[SAMI] It may be better to do this check earlier in the code by
casting CommBuffer to EFI_MM_COMMUNICATE_HEADER * and calculating
the BufferSize. That way the CopyMem() above can be avoided if the
above test fails.
+
+ // SMC Function ID
+ CommunicateSmcArgs.Arg0 = ARM_SMC_ID_MM_COMMUNICATE_AARCH64;
+
+ // Cookie
+ CommunicateSmcArgs.Arg1 = 0;
+
+ // comm_buffer_address (64-bit physical address)
+ CommunicateSmcArgs.Arg2 = (UINTN)CommunicateHeader;
+
+ // 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:
+ // On successful return, the size of data being returned is inferred from
+ // MessageLength + Header.
+ BufferSize = CommunicateHeader->MessageLength +
+ sizeof (CommunicateHeader->HeaderGuid) +
+ sizeof (CommunicateHeader->MessageLength);
+ CopyMem (CommBuffer, (VOID *)CommunicateHeader, BufferSize);
[SAMI] Can there be a case where the returned MessageLength
results in the CommBuffer size being smaller, i.e. BufferSize
returned > *CommSize ?
I expect ARM_SMC_MM_RET_NO_MEMORY to have been returned in the
first place, but it may be worth adding a check to avoid potential
issues. What do you think?
+ if (CommSize != NULL) {
+ *CommSize = 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;
+}
diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
index 6b938ce8b671..4939b3d59b7f 100644
--- a/ArmPkg/ArmPkg.dsc
+++ b/ArmPkg/ArmPkg.dsc
@@ -162,6 +162,8 @@ [Components.common]
ArmPkg/Universal/Smbios/SmbiosMiscDxe/SmbiosMiscDxe.inf
ArmPkg/Universal/Smbios/OemMiscLibNull/OemMiscLibNull.inf
+ ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.inf
+
[Components.AARCH64]
ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
diff --git a/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.h b/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.h
new file mode 100644
index 000000000000..a99baa2496a9
--- /dev/null
+++ b/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.h
@@ -0,0 +1,76 @@
+/** @file -- MmCommunicationPei.h
+ Provides an interface to send MM request in PEI
+
+ Copyright (c) Microsoft Corporation.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef MM_COMMUNICATION_PEI_H_
+#define MM_COMMUNICATION_PEI_H_
+
+#include <PiPei.h>
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/ArmSmcLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Library/PeimEntryPoint.h>
+#include <Library/PeiServicesLib.h>
+#include <Library/HobLib.h>
+
+#include <Protocol/MmCommunication.h>
+
+#include <IndustryStandard/ArmStdSmc.h>
+
+#include <Ppi/MmCommunication.h>
+
+/**
+ Entry point of PEI MM Communication driver
+
+ @param FileHandle Handle of the file being invoked.
+ Type EFI_PEI_FILE_HANDLE is defined in FfsFindNextFile().
+ @param PeiServices General purpose services available to every PEIM.
+
+ @retval EFI_SUCCESS If the interface could be successfully installed
+ @retval Others Returned from PeiServicesInstallPpi()
+**/
+EFI_STATUS
+EFIAPI
+MmCommunicationPeiInitialize (
+ IN EFI_PEI_FILE_HANDLE FileHandle,
+ IN CONST EFI_PEI_SERVICES **PeiServices
+ );
+
+/**
+ MmCommunicationPeim
+ Communicates with a registered handler.
+ This function provides a service to send and receive messages from a registered UEFI service during PEI.
+
+ @param[in] This The EFI_PEI_MM_COMMUNICATION_PPI instance.
+ @param[in, out] CommBuffer Pointer to the data buffer
+ @param[in, out] CommSize The size of the data buffer being passed in. On exit, the
+ size of data being returned. Zero if the handler does not
+ wish to reply with any data.
+
+ @retval EFI_SUCCESS The message was successfully posted.
+ @retval EFI_INVALID_PARAMETER CommBuffer was NULL or *CommSize does not match
+ MessageLength + sizeof (EFI_MM_COMMUNICATE_HEADER).
+ @retval EFI_BAD_BUFFER_SIZE The buffer is too large 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.
+**/
+EFI_STATUS
+EFIAPI
+MmCommunicationPeim (
+ IN CONST EFI_PEI_MM_COMMUNICATION_PPI *This,
+ IN OUT VOID *CommBuffer,
+ IN OUT UINTN *CommSize
+ );
+
+#endif /* MM_COMMUNICATION_PEI_H_ */
diff --git a/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.inf b/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.inf
new file mode 100644
index 000000000000..f4e359dafd75
--- /dev/null
+++ b/ArmPkg/Drivers/MmCommunicationPei/MmCommunicationPei.inf
@@ -0,0 +1,41 @@
+## @file -- MmCommunicationPei.inf
+# PEI MM Communicate driver
+#
+# Copyright (c) 2016 - 2021, Arm Limited. All rights reserved.<BR>
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
[SAMI] The version should be 0x0001001B. See
https://github.com/tianocore-docs/edk2-InfSpecification/blob/master/3_edk_ii_inf_file_format/34_%5Bdefines%5D_section.md
+ BASE_NAME = MmCommunicationPei + FILE_GUID = 58FFB346-1B75-42C7-AD69-37C652423C1A + MODULE_TYPE = PEIM + VERSION_STRING = 1.0 + ENTRY_POINT = MmCommunicationPeiInitialize + +[Sources] + MmCommunicationPei.c + MmCommunicationPei.h + +[Packages] + MdePkg/MdePkg.dec + MdeModulePkg/MdeModulePkg.dec + ArmPkg/ArmPkg.dec + +[LibraryClasses] + DebugLib + ArmSmcLib + PeimEntryPoint + PeiServicesLib + HobLib + +[Pcd] + gArmTokenSpaceGuid.PcdMmBufferBase + gArmTokenSpaceGuid.PcdMmBufferSize + +[Ppis] + gEfiPeiMmCommunicationPpiGuid ## PRODUCES + +[Depex] + TRUE