Agreed with Isaac that having the compression capability be more general use 
would be nice. However, I think it would better match the EDK II design style 
if we had a second implementation of LargeVariable*Lib that added the 
compression capability on top of the original LargeVariable*Lib.

I also think having a PCD to explicitly control whether to apply compression to 
the FSP NVS buffer is important. Because there are some FSP implementations 
like ICX and SPR that already include the CompressLib inside the FSP binary 
itself. On those FSP implementations, the data in the 
FSP_NON_VOLATILE_STORAGE_HOB is already compressed. Said PCD would simply 
control which instance of the LibraryClass gets linked with SaveMemoryConfigDxe.

Also agreed with Isaac to please be careful to make sure that any new 
LibraryClasses are in the Include/*.dsc files somewhere so existing boards 
don't need modifications to their BoardPkg.dsc file.

Thanks,
Nate

-----Original Message-----
From: Oram, Isaac W <isaac.w.o...@intel.com> 
Sent: Tuesday, August 23, 2022 11:34 AM
To: devel@edk2.groups.io; mikub...@linux.microsoft.com
Cc: Chiu, Chasel <chasel.c...@intel.com>; Desimone, Nathaniel L 
<nathaniel.l.desim...@intel.com>; Gao, Liming <gaolim...@byosoft.com.cn>; Dong, 
Eric <eric.d...@intel.com>
Subject: RE: [edk2-devel] [edk2-platforms][PATCH v2 1/1] MinPlatformPkg: Add 
FspNvsBuffer compression option

Implementing this way will break the build for most of the open MinPlatform 
ports.  At minimum, please add the CompressLib to CoreCommonLib.dsc next to the 
UefiDecompressLib instantiation so that it is included automatically for most 
boards.

Regarding the design, I agree this is a good capability.  And it makes sense to 
me to be board controlled rather than FSP controlled.

I wonder if it might be better to modify the LargeVariableRead/Write such that 
it compresses/decompresses large variables automatically.  Could be controlled 
via library class instance or maybe via PatchablePerModule PCD.  Boards would 
still have a lot of control if they wanted.

Regards,
Isaac

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Michael Kubacki
Sent: Monday, August 22, 2022 8:23 PM
To: devel@edk2.groups.io
Cc: Chiu, Chasel <chasel.c...@intel.com>; Desimone, Nathaniel L 
<nathaniel.l.desim...@intel.com>; Oram, Isaac W <isaac.w.o...@intel.com>; Gao, 
Liming <gaolim...@byosoft.com.cn>; Dong, Eric <eric.d...@intel.com>
Subject: [edk2-devel] [edk2-platforms][PATCH v2 1/1] MinPlatformPkg: Add 
FspNvsBuffer compression option

From: Michael Kubacki <michael.kuba...@microsoft.com>

Adds a PCD called "PcdEnableCompressedFspNvsBuffer" that allows the 
"FspNvsBuffer" UEFI variable data to be saved as compressed data.

Especially due to the nature of the data saved in this variable, it compresses 
well. For example, it has been found to reduce ~63KB of data to ~13KB. Boot 
time impact has been found to be negligible.

The default value is FALSE to keep default behavior consistent.

Decompression can be performed on the variable data using the standard 
UefiDecompressLib.

Cc: Chasel Chiu <chasel.c...@intel.com>
Cc: Nate DeSimone <nathaniel.l.desim...@intel.com>
Cc: Isaac Oram <isaac.w.o...@intel.com>
Cc: Liming Gao <gaolim...@byosoft.com.cn>
Cc: Eric Dong <eric.d...@intel.com>
Signed-off-by: Michael Kubacki <michael.kuba...@microsoft.com>
---

Notes:
    v2: Rebase onto 9769bf28d1fc

 Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c   
| 62 ++++++++++++++++----
 Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf 
|  4 ++
 Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec                               
|  6 ++
 Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc                               
|  1 +
 4 files changed, 60 insertions(+), 13 deletions(-)

diff --git 
a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c 
b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c
index 0215e8eeddfb..95b8cef8b32b 100644
--- 
a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c
+++ b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemo
+++ ryConfig.c
@@ -3,6 +3,7 @@
   exists, and saves the data to nvRAM.
 
 Copyright (c) 2017 - 2022, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -10,6 +11,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent  #include 
<Base.h>  #include <Uefi.h>  #include <Library/BaseLib.h>
+#include <Library/CompressLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiRuntimeServicesTableLib.h>
 #include <Library/HobLib.h>
@@ -19,6 +21,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent  #include 
<Library/BaseMemoryLib.h>  #include <Library/LargeVariableReadLib.h>  #include 
<Library/LargeVariableWriteLib.h>
+#include <Library/PcdLib.h>
 #include <Library/VariableWriteLib.h>
 #include <Guid/FspNonVolatileStorageHob2.h>
 
@@ -38,20 +41,26 @@ SaveMemoryConfigEntryPoint (
   IN EFI_SYSTEM_TABLE   *SystemTable
   )
 {
-  EFI_STATUS        Status;
-  EFI_HOB_GUID_TYPE *GuidHob;
-  VOID              *HobData;
-  VOID              *VariableData;
-  UINTN             DataSize;
-  UINTN             BufferSize;
-  BOOLEAN           DataIsIdentical;
+  EFI_STATUS         Status;
+  EFI_HOB_GUID_TYPE  *GuidHob;
+  VOID               *HobData;
+  VOID               *VariableData;
+  UINTN              DataSize;
+  UINTN              BufferSize;
+  BOOLEAN            DataIsIdentical;
+  VOID               *CompressedData;
+  UINT64             CompressedSize;
+  UINTN              CompressedAllocationPages;
 
-  DataSize        = 0;
-  BufferSize      = 0;
-  VariableData    = NULL;
-  GuidHob         = NULL;
-  HobData         = NULL;
-  DataIsIdentical = FALSE;
+  DataSize                  = 0;
+  BufferSize                = 0;
+  VariableData              = NULL;
+  GuidHob                   = NULL;
+  HobData                   = NULL;
+  DataIsIdentical           = FALSE;
+  CompressedData            = NULL;
+  CompressedSize            = 0;
+  CompressedAllocationPages = 0;
 
   //
   // Search for the Memory Configuration GUID HOB.  If it is not present, then 
@@ -73,6 +82,29 @@ SaveMemoryConfigEntryPoint (
     }
   }
 
+  if (PcdGetBool (PcdEnableCompressedFspNvsBuffer)) {
+    if (DataSize > 0) {
+      CompressedAllocationPages = EFI_SIZE_TO_PAGES (DataSize);
+      CompressedData            = AllocatePages (CompressedAllocationPages);
+      if (CompressedData == NULL) {
+        DEBUG ((DEBUG_ERROR, "[%a] - Failed to allocate compressed data 
buffer.\n", __FUNCTION__));
+        ASSERT_EFI_ERROR (EFI_OUT_OF_RESOURCES);
+        return EFI_OUT_OF_RESOURCES;
+      }
+
+      CompressedSize = EFI_PAGES_TO_SIZE (CompressedAllocationPages);
+      Status         = Compress (HobData, DataSize, CompressedData, 
&CompressedSize);
+      if (EFI_ERROR (Status)) {
+        DEBUG ((DEBUG_ERROR, "[%a] - failed to compress data. Status = %r\n", 
__FUNCTION__, Status));
+        ASSERT_EFI_ERROR (Status);
+        return Status;
+      }
+    }
+
+    HobData  = CompressedData;
+    DataSize = (UINTN)CompressedSize;
+  }
+
   if (HobData != NULL) {
     DEBUG ((DEBUG_INFO, "FspNvsHob.NvsDataLength:%d\n", DataSize));
     DEBUG ((DEBUG_INFO, "FspNvsHob.NvsDataPtr   : 0x%x\n", HobData));
@@ -136,6 +168,10 @@ SaveMemoryConfigEntryPoint (
     DEBUG((DEBUG_ERROR, "Memory S3 Data HOB was not found\n"));
   }
 
+  if (CompressedData != NULL) {
+    FreePages (CompressedData, CompressedAllocationPages);  }
+
   //
   // This driver does not produce any protocol services, so always unload it.
   //
diff --git 
a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf
 
b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf
index 61e85a658693..0f12deb131ca 100644
--- 
a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf
+++ b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemo
+++ ryConfig.inf
@@ -26,6 +26,7 @@ [LibraryClasses]
   LargeVariableReadLib
   LargeVariableWriteLib
   BaseLib
+  CompressLib
 
 [Packages]
   MdePkg/MdePkg.dec
@@ -45,6 +46,9 @@ [Guids]
   gFspNonVolatileStorageHob2Guid                ## CONSUMES
   gFspNvsBufferVariableGuid                     ## PRODUCES
 
+[Pcd]
+  gMinPlatformPkgTokenSpaceGuid.PcdEnableCompressedFspNvsBuffer
+
 [Depex]
   gEfiVariableArchProtocolGuid        AND
   gEfiVariableWriteArchProtocolGuid
\ No newline at end of file
diff --git a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec 
b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec
index 8e603b7bf94b..94353cb76824 100644
--- a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec
+++ b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec
@@ -306,6 +306,12 @@ [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, 
PcdsDynamicEx]
 
   gMinPlatformPkgTokenSpaceGuid.PcdPlatformMemoryCheckLevel|0|UINT32|0x30000009
 
+  ## Controls whether the FSP NVS buffer is saved as compressed data.
+  # Data compression can significantly reduce variable storage usage for FSP 
NVS buffer data.
+  # Platforms that choose to compress the data will need to decompress 
+ the variable data upon  # extraction.
+  
+ gMinPlatformPkgTokenSpaceGuid.PcdEnableCompressedFspNvsBuffer|FALSE|BO
+ OLEAN|0x30000010
+
   ## This PCD is to control which device is the potential trusted console 
input device.<BR><BR>
   # For example:<BR>
   # USB Short Form: UsbHID(0xFFFF,0xFFFF,0x1,0x1)<BR> diff --git 
a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc 
b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc
index 09aa6fe4d51c..ae170f87d548 100644
--- a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc
+++ b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc
@@ -106,6 +106,7 @@ [LibraryClasses.common.DXE_DRIVER]
   
FspWrapperPlatformLib|MinPlatformPkg/FspWrapper/Library/DxeFspWrapperPlatformLib/DxeFspWrapperPlatformLib.inf
   
TestPointCheckLib|MinPlatformPkg/Test/Library/TestPointCheckLib/DxeTestPointCheckLib.inf
   TestPointLib|MinPlatformPkg/Test/Library/TestPointLib/DxeTestPointLib.inf
+  CompressLib|MinPlatformPkg/Library/CompressLib/CompressLib.inf
 
 [LibraryClasses.common.DXE_SMM_DRIVER]
   
TestPointCheckLib|MinPlatformPkg/Test/Library/TestPointCheckLib/SmmTestPointCheckLib.inf
--
2.28.0.windows.1



-=-=-=-=-=-=
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#92644): https://edk2.groups.io/g/devel/message/92644
Mute This Topic: https://groups.io/mt/93197638/1492418
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [isaac.w.o...@intel.com] 
-=-=-=-=-=-=




-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#92727): https://edk2.groups.io/g/devel/message/92727
Mute This Topic: https://groups.io/mt/93197638/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-


Reply via email to