Re: [edk2-devel] [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

["Kun Qin" <kun.q@outlook.com>]

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Hi Liming/Mike/Jiewen,

Do you have any opinions/objections on putting this interface definition in MdePkg as suggested by Hao? The reason it might be suitable for MdePkg is because of its similarity with SmmMemLib. But I understand that this is not an industrial standard interface (at least not yet). Could you please shed some light on your thoughts here? Any input is appreciated.

Regards,
Kun

From: Kun Qin<mailto:kun.q@outlook.com>
Sent: Tuesday, February 23, 2021 17:48
To: devel@edk2.groups.io<mailto:devel@edk2.groups.io>; jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>; Wu, Hao A<mailto:hao.a.wu@intel.com>; gaoliming<mailto:gaoliming@byosoft.com.cn>; Kinney, Michael D<mailto:michael.d.kinney@intel.com>; Liu, Zhiguang<mailto:zhiguang.liu@intel.com>
Cc: Wang, Jian J<mailto:jian.j.wang@intel.com>; Dong, Eric<mailto:eric.dong@intel.com>; Ni, Ray<mailto:ray.ni@intel.com>; Yao, Jiewen<mailto:jiewen.yao@intel.com>
Subject: Re: [edk2-devel] [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

Hi Jiewen,

I agree with your  assessment that it could have a PEI and potentially MM instance. Will remove the prefix and change them to `MmUnblockMemoryLib` in v3 patches. Thanks for the input.

Regards,
Kun

From: Yao, Jiewen<mailto:jiewen.yao@intel.com>
Sent: Tuesday, February 23, 2021 17:33
To: Wu, Hao A<mailto:hao.a.wu@intel.com>; Kun Qin<mailto:kun.q@outlook.com>; devel@edk2.groups.io<mailto:devel@edk2.groups.io>; gaoliming<mailto:gaoliming@byosoft.com.cn>; Kinney, Michael D<mailto:michael.d.kinney@intel.com>; Liu, Zhiguang<mailto:zhiguang.liu@intel.com>
Cc: Wang, Jian J<mailto:jian.j.wang@intel.com>; Dong, Eric<mailto:eric.dong@intel.com>; Ni, Ray<mailto:ray.ni@intel.com>; Yao, Jiewen<mailto:jiewen.yao@intel.com>
Subject: Re: [edk2-devel] [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

I feel the name is confusing.

The class name is DxeMmUnblockMemoryLib. But actually, this is not related to DXE phase.

I believe, it is also applicable to PEI phase, if we have a PEI instance. Please correct me if I am wrong.
Also, we can have SMM instance, right?

If that is true, then I prefer to remove Dxe prefix.

From: Wu, Hao A <hao.a.wu@intel.com>
Sent: Wednesday, February 24, 2021 9:27 AM
To: Kun Qin <kun.q@outlook.com>; devel@edk2.groups.io; Yao, Jiewen <jiewen.yao@intel.com>; gaoliming <gaoliming@byosoft.com.cn>; Kinney, Michael D <michael.d.kinney@intel.com>; Liu, Zhiguang <zhiguang.liu@intel.com>
Cc: Wang, Jian J <jian.j.wang@intel.com>; Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>
Subject: RE: [edk2-devel] [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

Thanks Kun,

For putting the new library in MdePkg, I am not sure whether this is a similar case to SmmMemLib.
I looped Jiewen, Liming and Mike to check if they have comments on this.

Best Regards,
Hao Wu

From: Kun Qin <kun.q@outlook.com<mailto:kun.q@outlook.com>>
Sent: Wednesday, February 24, 2021 3:30 AM
To: devel@edk2.groups.io<mailto:devel@edk2.groups.io>; Wu, Hao A <hao.a.wu@intel.com<mailto:hao.a.wu@intel.com>>; Yao, Jiewen <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>; gaoliming <gaoliming@byosoft.com.cn<mailto:gaoliming@byosoft.com.cn>>; Kinney, Michael D <michael.d.kinney@intel.com<mailto:michael.d.kinney@intel.com>>; Liu, Zhiguang <zhiguang.liu@intel.com<mailto:zhiguang.liu@intel.com>>
Cc: Wang, Jian J <jian.j.wang@intel.com<mailto:jian.j.wang@intel.com>>; Dong, Eric <eric.dong@intel.com<mailto:eric.dong@intel.com>>; Ni, Ray <ray.ni@intel.com<mailto:ray.ni@intel.com>>
Subject: RE: [edk2-devel] [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

Hi Hao,

Thanks for the suggestion. I can move the library to MdePkg similar to SmmMemLib and add the change for OVMF.

Liming/Zhiguang,

I am happy to prepare patches to cover the dependency change in ed2-platform in a separate patch series. But please let me know if you would like to proceed otherwise.

Thanks,
Kun

From: Wu, Hao A<mailto:hao.a.wu@intel.com>
Sent: Monday, February 22, 2021 17:42
To: Kun Qin<mailto:kun.q@outlook.com>; devel@edk2.groups.io<mailto:devel@edk2.groups.io>; Yao, Jiewen<mailto:jiewen.yao@intel.com>; gaoliming<mailto:gaoliming@byosoft.com.cn>; Kinney, Michael D<mailto:michael.d.kinney@intel.com>; Liu, Zhiguang<mailto:zhiguang.liu@intel.com>
Cc: Wang, Jian J<mailto:jian.j.wang@intel.com>; Dong, Eric<mailto:eric.dong@intel.com>; Ni, Ray<mailto:ray.ni@intel.com>
Subject: Re: [edk2-devel] [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

Hello Kun,

Sorry for the delayed response.

Except for missing the UNI file for the newly added library, I do not have other comment for the implementation at this moment.
But I am wondering if this library can be added into the MdePkg as the case for MdePkg\Library\SmmMemLib\
I have looped in Jiewen, Liming and Mike for comments.

Also, since:
* New library dependency for VariableSmmRuntimeDxe.inf
* INF file separation and new library dependency in Tcg2Smm
I think the series needs to prepare the changes for platforms under edk2 (OVMF) and edk2-platforms repositories that consume the above 2 modules.
I am not exactly sure on how this should be handled within edk2-platforms, so I added Liming and Zhiguang here for comments.

Best Regards,
Hao Wu

From: Kun Qin <kun.q@outlook.com<mailto:kun.q@outlook.com>>
Sent: Tuesday, February 23, 2021 6:15 AM
To: devel@edk2.groups.io<mailto:devel@edk2.groups.io>; Wu, Hao A <hao.a.wu@intel.com<mailto:hao.a.wu@intel.com>>
Cc: Wang, Jian J <jian.j.wang@intel.com<mailto:jian.j.wang@intel.com>>; Dong, Eric <eric.dong@intel.com<mailto:eric.dong@intel.com>>; Ni, Ray <ray.ni@intel.com<mailto:ray.ni@intel.com>>; Yao, Jiewen <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>
Subject: RE: [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

Hi Hao,

The patch series was resent with intended usage in VariableRuntime and Tcg2 drivers. Could you please provide feedback on them? Any input is appreciated.

Regards,
Kun

From: Kun Qin<mailto:kun.q@outlook.com>
Sent: Tuesday, February 9, 2021 17:25
To: devel@edk2.groups.io<mailto:devel@edk2.groups.io>
Cc: Jian J Wang<mailto:jian.j.wang@intel.com>; Hao A Wu<mailto:hao.a.wu@intel.com>; Eric Dong<mailto:eric.dong@intel.com>; Ray Ni<mailto:ray.ni@intel.com>; Jiewen Yao<mailto:jiewen.yao@intel.com>
Subject: [PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3168

This interface definition provides an abstraction layer for DXE drivers
to request certain memory blocks to be mapped/unblocked for accessibility
inside MM environment.

Cc: Jian J Wang <jian.j.wang@intel.com<mailto:jian.j.wang@intel.com>>
Cc: Hao A Wu <hao.a.wu@intel.com<mailto:hao.a.wu@intel.com>>
Cc: Eric Dong <eric.dong@intel.com<mailto:eric.dong@intel.com>>
Cc: Ray Ni <ray.ni@intel.com<mailto:ray.ni@intel.com>>
Cc: Jiewen Yao <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>

Signed-off-by: Kun Qin <kun.q@outlook.com<mailto:kun.q@outlook.com>>
---

Notes:
    v2:
    - Resend with practical usage. No change [Hao]

 MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c   | 40 ++++++++++++++++++++
 MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h                     | 40 ++++++++++++++++++++
 MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf | 29 ++++++++++++++
 MdeModulePkg/MdeModulePkg.dec                                            |  5 +++
 MdeModulePkg/MdeModulePkg.dsc                                            |  2 +
 5 files changed, 116 insertions(+)

diff --git a/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c
new file mode 100644
index 000000000000..774a7e41cfb0
--- /dev/null
+++ b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c
@@ -0,0 +1,40 @@
+/** @file
+  Null instance of MM Unblock Page Library.
+
+  This library provides an abstraction layer of requesting certain page access to be unblocked
+  by MM environment if applicable.
+
+  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
+DxeMmUnblockMemoryRequest (
+  IN EFI_PHYSICAL_ADDRESS   UnblockAddress,
+  IN UINT64                 NumberOfPages
+  )
+{
+  return EFI_UNSUPPORTED;
+}
diff --git a/MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h b/MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h
new file mode 100644
index 000000000000..8b63eb74a078
--- /dev/null
+++ b/MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h
@@ -0,0 +1,40 @@
+/** @file
+  MM Unblock Memory Library Interface.
+
+  This library provides an abstraction layer of requesting certain page access to be unblocked
+  by MM environment if applicable.
+
+  Copyright (c), Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _DXE_MM_UNBLOCK_MEMORY_LIB_H_
+#define _DXE_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
+DxeMmUnblockMemoryRequest (
+  IN EFI_PHYSICAL_ADDRESS   UnblockAddress,
+  IN UINT64                 NumberOfPages
+);
+
+#endif // _DXE_MM_UNBLOCK_MEMORY_LIB_H_
diff --git a/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf
new file mode 100644
index 000000000000..e40462e5ab81
--- /dev/null
+++ b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf
@@ -0,0 +1,29 @@
+## @file
+#  Null instance of MM Unblock Page Library.
+#
+#  This library provides an abstraction layer of requesting certain page access to be unblocked
+#  by MM environment if applicable.
+#
+#  Copyright (c), Microsoft Corporation.
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x0001001B
+  BASE_NAME                      = DxeMmUnblockMemoryLibNull
+  FILE_GUID                      = 9E890F68-5C95-4C31-95DD-59E6286F85EA
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = DxeMmUnblockMemoryLib
+
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  DxeMmUnblockMemoryLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 148395511034..1bb5017da2c5 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -154,6 +154,11 @@ [LibraryClasses]
   #
   VariablePolicyHelperLib|Include/Library/VariablePolicyHelperLib.h

+  ##  @libraryclass  This library provides an interface for DXE drivers to request MM environment
+  #   to map/unblock a memory region for accessibility inside MM.
+  #
+  DxeMmUnblockMemoryLib|Include/Library/DxeMmUnblockMemoryLib.h
+
 [Guids]
   ## MdeModule package token space guid
   # Include/Guid/MdeModulePkgTokenSpace.h
diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
index 7ca4a1bb3080..2bc6b8730b8b 100644
--- a/MdeModulePkg/MdeModulePkg.dsc
+++ b/MdeModulePkg/MdeModulePkg.dsc
@@ -100,6 +100,7 @@ [LibraryClasses]
   SafeIntLib|MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf
   DisplayUpdateProgressLib|MdeModulePkg/Library/DisplayUpdateProgressLibGraphics/DisplayUpdateProgressLibGraphics.inf
   VariablePolicyHelperLib|MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf
+  DxeMmUnblockMemoryLib|MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf

 [LibraryClasses.EBC.PEIM]
   IoLib|MdePkg/Library/PeiIoLibCpuIo/PeiIoLibCpuIo.inf
@@ -332,6 +333,7 @@ [Components]
   MdeModulePkg/Library/BaseBmpSupportLib/BaseBmpSupportLib.inf
   MdeModulePkg/Library/DisplayUpdateProgressLibGraphics/DisplayUpdateProgressLibGraphics.inf
   MdeModulePkg/Library/DisplayUpdateProgressLibText/DisplayUpdateProgressLibText.inf
+  MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf

   MdeModulePkg/Universal/BdsDxe/BdsDxe.inf
   MdeModulePkg/Application/BootManagerMenuApp/BootManagerMenuApp.inf
--
2.30.0.windows.1






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