REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3168
This interface provides an abstration layer to allow MM modules to access
requested areas that are outside of MMRAM. On MM model that blocks all
non-MMRAM accesses, areas requested through this API will be mapped or
unblocked for accessibility inside MM environment.
For MM modules that need to access regions outside of MMRAMs, the agents
that set up these regions are responsible for invoking this API in order
for these memory areas to be accessible from inside MM.
Example usages:
1. To enable runtime cache feature for variable service, Variable MM
module will need to access the allocated runtime buffer. Thus the agent
sets up these buffers, VariableSmmRuntimeDxe, will need to invoke this
API to make these regions accessible by Variable MM.
2. For TPM ACPI table to communicate to physical presence handler, the
corresponding NVS region has to be accessible from inside MM. Once the
NVS region are assigned, it needs to be unblocked thourgh this API.
Cc: Michael D Kinney <michael.d.kin...@intel.com>
Cc: Liming Gao <gaolim...@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang....@intel.com>
Cc: Hao A Wu <hao.a...@intel.com>
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Signed-off-by: Kun Qin <ku...@outlook.com>
---
Notes:
v4:
- Added more commit message [Laszlo]
- Added UNI file [Hao]
v3:
- Move interface to MdePkg [Hao, Liming, Jiewen]
- Remove Dxe prefix [Jiewen]
v2:
- Resend with practical usage. No change [Hao]
MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.c | 44
++++++++++++++++++++
MdePkg/Include/Library/MmUnblockMemoryLib.h | 44
++++++++++++++++++++
MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.inf | 34
+++++++++++++++
MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.uni | 21 ++++++++++
MdePkg/MdePkg.dec | 5 +++
MdePkg/MdePkg.dsc | 1 +
6 files changed, 149 insertions(+)
diff --git a/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.c
b/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.c
new file mode 100644
index 000000000000..abdce41f10d1
--- /dev/null
+++ b/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.c
@@ -0,0 +1,44 @@
+/** @file
+ Null instance of MM Unblock Page Library.
+
+ This library provides an interface to request non-MMRAM pages to be
mapped/unblocked
+ from inside MM environment.
+
+ For MM modules that need to access regions outside of MMRAMs, the agents
that set up
+ these regions are responsible for invoking this API in order for these
memory areas
+ to be accessed from inside MM.
+
+ Copyright (c) Microsoft Corporation.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+/**
+ This API provides a way to unblock certain data pages to be accessible
inside MM environment.
+
+ @param UnblockAddress The address of buffer caller requests to
unblock, the address
+ has to be page aligned.
+ @param NumberOfPages The number of pages requested to be
unblocked from MM
+ environment.
+
+ @return EFI_SUCCESS The request goes through successfully.
+ @return EFI_NOT_AVAILABLE_YET The requested functionality is not produced
yet.
+ @return EFI_UNSUPPORTED The requested functionality is not supported
on current platform.
+ @return EFI_SECURITY_VIOLATION The requested address failed to pass
security check for
+ unblocking.
+ @return EFI_INVALID_PARAMETER Input address either NULL pointer or not
page aligned.
+ @return EFI_ACCESS_DENIED The request is rejected due to system has
passed certain boot
+ phase.
+
+**/
+EFI_STATUS
+EFIAPI
+MmUnblockMemoryRequest (
+ IN EFI_PHYSICAL_ADDRESS UnblockAddress,
+ IN UINT64 NumberOfPages
+ )
+{
+ return RETURN_UNSUPPORTED;
+}
diff --git a/MdePkg/Include/Library/MmUnblockMemoryLib.h
b/MdePkg/Include/Library/MmUnblockMemoryLib.h
new file mode 100644
index 000000000000..980afe9a5fd3
--- /dev/null
+++ b/MdePkg/Include/Library/MmUnblockMemoryLib.h
@@ -0,0 +1,44 @@
+/** @file
+ MM Unblock Memory Library Interface.
+
+ This library provides an interface to request non-MMRAM pages to be
mapped/unblocked
+ from inside MM environment.
+
+ For MM modules that need to access regions outside of MMRAMs, the agents
that set up
+ these regions are responsible for invoking this API in order for these
memory areas
+ to be accessed from inside MM.
+
+ Copyright (c) Microsoft Corporation.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MM_UNBLOCK_MEMORY_LIB_H_
+#define MM_UNBLOCK_MEMORY_LIB_H_
+
+/**
+ This API provides a way to unblock certain data pages to be accessible
inside MM environment.
+
+ @param UnblockAddress The address of buffer caller requests to
unblock, the address
+ has to be page aligned.
+ @param NumberOfPages The number of pages requested to be
unblocked from MM
+ environment.
+
+ @return EFI_SUCCESS The request goes through successfully.
+ @return EFI_NOT_AVAILABLE_YET The requested functionality is not produced
yet.
+ @return EFI_UNSUPPORTED The requested functionality is not supported
on current platform.
+ @return EFI_SECURITY_VIOLATION The requested address failed to pass
security check for
+ unblocking.
+ @return EFI_INVALID_PARAMETER Input address either NULL pointer or not
page aligned.
+ @return EFI_ACCESS_DENIED The request is rejected due to system has
passed certain boot
+ phase.
+
+**/
+EFI_STATUS
+EFIAPI
+MmUnblockMemoryRequest (
+ IN EFI_PHYSICAL_ADDRESS UnblockAddress,
+ IN UINT64 NumberOfPages
+);
+
+#endif // MM_UNBLOCK_MEMORY_LIB_H_
diff --git a/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.inf
b/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.inf
new file mode 100644
index 000000000000..8ecb767ff7bd
--- /dev/null
+++ b/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.inf
@@ -0,0 +1,34 @@
+## @file
+# Null instance of MM Unblock Page Library.
+#
+# This library provides an interface to request non-MMRAM pages to be
mapped/unblocked
+# from inside MM environment.
+#
+# For MM modules that need to access regions outside of MMRAMs, the agents
that set up
+# these regions are responsible for invoking this API in order for these
memory areas
+# to be accessed from inside MM.
+#
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+ INF_VERSION = 0x0001001B
+ BASE_NAME = MmUnblockMemoryLibNull
+ MODULE_UNI_FILE = MmUnblockMemoryLibNull.uni
+ FILE_GUID = 9E890F68-5C95-4C31-95DD-59E6286F85EA
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = MmUnblockMemoryLib
+
+#
+# VALID_ARCHITECTURES = IA32 X64
+#
+
+[Sources]
+ MmUnblockMemoryLibNull.c
+
+[Packages]
+ MdePkg/MdePkg.dec
diff --git a/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.uni
b/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.uni
new file mode 100644
index 000000000000..d7f2709a3dce
--- /dev/null
+++ b/MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.uni
@@ -0,0 +1,21 @@
+// /** @file
+// Null instance of MM Unblock Page Library.
+//
+// This library provides an interface to request non-MMRAM pages to be
mapped/unblocked
+// from inside MM environment.
+//
+// For MM modules that need to access regions outside of MMRAMs, the agents
that set up
+// these regions are responsible for invoking this API in order for these
memory areas
+// to be accessed from inside MM.
+//
+// Copyright (c) Microsoft Corporation.
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT #language en-US "Null instance of MM
Unblock Page Library."
+
+#string STR_MODULE_DESCRIPTION #language en-US "This library provides
an interface to request non-MMRAM pages to be mapped/unblocked from inside MM
environment.\n"
+ "For MM modules that
need to access regions outside of MMRAMs, the agents that set up these regions
are responsible for invoking this API in order for these memory areas to be
accessed from inside MM."
+
diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index 3928db65d188..32a9e009c813 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -257,6 +257,11 @@ [LibraryClasses]
#
UnitTestHostBaseLib|Test/UnitTest/Include/Library/UnitTestHostBaseLib.h
+ ## @libraryclass This library provides an interface for DXE drivers to
request MM environment
+ # to map/unblock a memory region for accessibility inside MM.
+ #
+ MmUnblockMemoryLib|Include/Library/MmUnblockMemoryLib.h
+
[LibraryClasses.IA32, LibraryClasses.X64]
## @libraryclass Abstracts both S/W SMI generation and detection.
##
diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
index ce009086815f..79629e3f93ba 100644
--- a/MdePkg/MdePkg.dsc
+++ b/MdePkg/MdePkg.dsc
@@ -168,6 +168,7 @@ [Components.IA32, Components.X64]
MdePkg/Library/SmmPciExpressLib/SmmPciExpressLib.inf
MdePkg/Library/SmiHandlerProfileLibNull/SmiHandlerProfileLibNull.inf
MdePkg/Library/MmServicesTableLib/MmServicesTableLib.inf
+ MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.inf
[Components.EBC]
MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsic.inf
--
2.30.0.windows.1
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