From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by mx.groups.io with SMTP id smtpd.web12.2438.1571208381546184344 for ; Tue, 15 Oct 2019 23:46:21 -0700 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: intel.com, ip: 192.55.52.136, mailfrom: jian.j.wang@intel.com) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Oct 2019 23:46:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,302,1566889200"; d="scan'208";a="186062747" Received: from fmsmsx107.amr.corp.intel.com ([10.18.124.205]) by orsmga007.jf.intel.com with ESMTP; 15 Oct 2019 23:46:20 -0700 Received: from shsmsx108.ccr.corp.intel.com (10.239.4.97) by fmsmsx107.amr.corp.intel.com (10.18.124.205) with Microsoft SMTP Server (TLS) id 14.3.439.0; Tue, 15 Oct 2019 23:46:20 -0700 Received: from shsmsx107.ccr.corp.intel.com ([169.254.9.33]) by SHSMSX108.ccr.corp.intel.com ([169.254.8.225]) with mapi id 14.03.0439.000; Wed, 16 Oct 2019 14:46:16 +0800 From: "Wang, Jian J" To: "Kubacki, Michael A" , "devel@edk2.groups.io" CC: "Bi, Dandan" , Ard Biesheuvel , "Dong, Eric" , Laszlo Ersek , "Gao, Liming" , "Kinney, Michael D" , "Ni, Ray" , "Wu, Hao A" , "Yao, Jiewen" Subject: Re: [PATCH V4 07/10] MdeModulePkg/Variable: Add RT GetVariable() cache support Thread-Topic: [PATCH V4 07/10] MdeModulePkg/Variable: Add RT GetVariable() cache support Thread-Index: AQHVgudkMkz3g1SQN02GSjHv0+Y2N6dcxgFA Date: Wed, 16 Oct 2019 06:46:16 +0000 Message-ID: References: <20191014233001.33024-1-michael.a.kubacki@intel.com> <20191014233001.33024-8-michael.a.kubacki@intel.com> In-Reply-To: <20191014233001.33024-8-michael.a.kubacki@intel.com> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiMjFiZTdmOTktMzQ4MS00MTBkLTg1YzgtMjVkNzE5ODI4YWUxIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiUGdqNFIwcmlLaXZFdkQwU0tkRnJiRXF5cEZSbHpPeDBtXC9Uc0ljOHN0UE11eUJVQW53VFRwd0lOWEwwN3Y0QWwifQ== x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.2.0.6 dlp-reaction: no-action x-originating-ip: [10.239.127.40] MIME-Version: 1.0 Return-Path: jian.j.wang@intel.com Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Hi Michael, Please see my inline comments. > -----Original Message----- > From: Kubacki, Michael A > Sent: Tuesday, October 15, 2019 7:30 AM > To: devel@edk2.groups.io > Cc: Bi, Dandan ; Ard Biesheuvel > ; Dong, Eric ; Laszlo Ers= ek > ; Gao, Liming ; Kinney, Michael = D > ; Ni, Ray ; Wang, Jian J > ; Wu, Hao A ; Yao, Jiewen > > Subject: [PATCH V4 07/10] MdeModulePkg/Variable: Add RT GetVariable() cac= he > support >=20 > REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3D2220 >=20 > This change reduces SMIs for GetVariable () by maintaining a > UEFI variable cache in Runtime DXE in addition to the pre- > existing cache in SMRAM. When the Runtime Service GetVariable() > is invoked, a Runtime DXE cache is used instead of triggering an > SMI to VariableSmm. This can improve overall system performance > by servicing variable read requests without rendezvousing all > cores into SMM. >=20 > The runtime cache can be disabled with by setting the FeaturePCD > gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache > to FALSE. If the PCD is set to FALSE, the runtime cache will not be > used and an SMI will be triggered for Runtime Service > GetVariable () and GetNextVariableName () invocations. >=20 > The following are important points regarding the behavior of the > variable drivers when the variable runtime cache is enabled. >=20 > 1. All of the non-volatile storage contents are loaded into the > cache upon driver load. This one time load operation from storage > is preferred as opposed to building the cache on demand. An on- > demand cache would require a fallback SMI to load data into the > cache as variables are requested. >=20 > 2. SetVariable () requests will continue to always trigger an SMI. > This occurs regardless of whether the variable is volatile or > non-volatile. >=20 > 3. Both volatile and non-volatile variables are cached in a runtime > buffer. As is the case in the current EDK II variable driver, they > continue to be cached in separate buffers. >=20 > 4. The cache in Runtime DXE and SMM are intended to be exact copies > of one another. All SMM variable accesses only return data from the > SMM cache. The runtime caches are only updated after the variable I/O > operation is successful in SMM. The runtime caches are only updated > from SMM. >=20 > 5. Synchronization mechanisms are in place to ensure the runtime cache > content integrity with the SMM cache. These may result in updates to > runtime cache that are the same in content but different in offset and > size from updates to the SMM cache. >=20 > When using SMM variables with runtime cache enabled, two caches will now > be present. > 1. "Runtime Cache" - Maintained in VariableSmmRuntimeDxe. Used to service > Runtime Services GetVariable () and GetNextVariableName () callers. > 2. "SMM Cache" - Maintained in VariableSmm to service SMM GetVariable () > and GetNextVariableName () callers. > a. This cache is retained so SMM modules do not operate on data outsid= e > SMRAM. >=20 > Because a race condition can occur if an SMI occurs during the execution > of runtime code reading from the runtime cache, a runtime cache read lock > is introduced that explicitly moves pending updates from SMM to the runti= me > cache if an SMM update occurs while the runtime cache is locked. Note tha= t > it is not expected a Runtime services call will interrupt SMM processing > since all CPU cores rendezvous in SMM. >=20 > It is possible to view UEFI variable read and write statistics by setting > the gEfiMdeModulePkgTokenSpaceGuid.PcdVariableCollectStatistics FeaturePc= d > to TRUE and using the VariableInfo UEFI application in MdeModulePkg to du= mp > variable statistics to the console. By doing so, a user can view the numb= er > of GetVariable () hits from the Runtime DXE variable driver (Runtime Cach= e > hits) and the SMM variable driver (SMM Cache hits). SMM Cache hits for > GetVariable () will occur when SMM modules invoke GetVariable (). >=20 > Cc: Dandan Bi > Cc: Ard Biesheuvel > Cc: Eric Dong > Cc: Laszlo Ersek > Cc: Liming Gao > Cc: Michael D Kinney > Cc: Ray Ni > Cc: Jian J Wang > Cc: Hao A Wu > Cc: Jiewen Yao > Signed-off-by: Michael Kubacki > --- > MdeModulePkg/MdeModulePkg.dec | = 12 + > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf | = 2 > + > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf | = 2 + > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.inf | > 20 +- > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf | > 2 + > MdeModulePkg/Include/Guid/SmmVariableCommon.h | = 29 +- > MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h | = 32 +- > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.h | > 51 ++ > MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c | = 50 +- > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.c | > 153 ++++++ > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c | 1= 14 > ++++- > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c | > 512 +++++++++++++++++++- > 12 files changed, 938 insertions(+), 41 deletions(-) >=20 > diff --git a/MdeModulePkg/MdeModulePkg.dec > b/MdeModulePkg/MdeModulePkg.dec > index 59b8c21713..a00835cb84 100644 > --- a/MdeModulePkg/MdeModulePkg.dec > +++ b/MdeModulePkg/MdeModulePkg.dec > @@ -641,6 +641,18 @@ > # @Prompt Enable Device Path From Text support. >=20 > gEfiMdeModulePkgTokenSpaceGuid.PcdDevicePathSupportDevicePathFromText > |TRUE|BOOLEAN|0x00010038 >=20 > + ## Indicates if the UEFI variable runtime cache should be enabled. > + # This setting only applies if SMM variables are enabled. When enable= d, all > variable > + # data for Runtime Service GetVariable () and GetNextVariableName () = calls is > retrieved > + # from a runtime data buffer referred to as the "runtime cache". An S= MI is not > triggered > + # at all for these requests. Variables writes still trigger an SMI. T= his can > greatly > + # reduce overall system SMM usage as most boots tend to issue far mor= e > variable reads > + # than writes.

> + # TRUE - The UEFI variable runtime cache is enabled.
> + # FALSE - The UEFI variable runtime cache is disabled.
> + # @Prompt Enable the UEFI variable runtime cache. > + > gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache|FALSE|B > OOLEAN|0x00010039 > + > ## Indicates if the statistics about variable usage will be collected.= This > information is > # stored as a vendor configuration table into the EFI system table. > # Set this PCD to TRUE to use VariableInfo application in > MdeModulePkg\Application directory to get > diff --git > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf > index 08a5490787..ceea5d1ff9 100644 > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf > @@ -40,6 +40,8 @@ > VariableNonVolatile.h > VariableParsing.c > VariableParsing.h > + VariableRuntimeCache.c > + VariableRuntimeCache.h > PrivilegePolymorphic.h > Measurement.c > TcgMorLockDxe.c > diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf > index 6dc2721b81..bc3033588d 100644 > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf > @@ -49,6 +49,8 @@ > VariableNonVolatile.h > VariableParsing.c > VariableParsing.h > + VariableRuntimeCache.c > + VariableRuntimeCache.h > VarCheck.c > Variable.h > PrivilegePolymorphic.h > diff --git > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.inf > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.inf > index 14894e6f13..b5a779a233 100644 > --- > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.inf > +++ > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.inf > @@ -13,7 +13,7 @@ > # may not be modified without authorization. If platform fails to prote= ct these > resources, > # the authentication service provided in this driver will be broken, an= d the > behavior is undefined. > # > -# Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.
> +# Copyright (c) 2010 - 2019, Intel Corporation. All rights reserved.
> # SPDX-License-Identifier: BSD-2-Clause-Patent > # > ## > @@ -39,6 +39,10 @@ > VariableSmmRuntimeDxe.c > PrivilegePolymorphic.h > Measurement.c > + VariableParsing.c > + VariableParsing.h > + VariableRuntimeCache.c > + VariableRuntimeCache.h >=20 > [Packages] > MdePkg/MdePkg.dec > @@ -65,7 +69,21 @@ > gEdkiiVariableLockProtocolGuid ## PRODUCES > gEdkiiVarCheckProtocolGuid ## PRODUCES >=20 > +[FeaturePcd] > + gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache > ## CONSUMES > + gEfiMdeModulePkgTokenSpaceGuid.PcdVariableCollectStatistics = ## > CONSUMES > + > [Guids] > + ## PRODUCES ## GUID # Signature of Variable store header > + ## CONSUMES ## GUID # Signature of Variable store header > + ## SOMETIMES_PRODUCES ## SystemTable > + gEfiAuthenticatedVariableGuid > + > + ## PRODUCES ## GUID # Signature of Variable store header > + ## CONSUMES ## GUID # Signature of Variable store header > + ## SOMETIMES_PRODUCES ## SystemTable > + gEfiVariableGuid > + > gEfiEventVirtualAddressChangeGuid ## CONSUMES ## Event > gEfiEventExitBootServicesGuid ## CONSUMES ## Event > ## CONSUMES ## GUID # Locate protocol > diff --git > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf > index f8a3742959..6e17f6cdf5 100644 > --- > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf > +++ > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf > @@ -49,6 +49,8 @@ > VariableNonVolatile.h > VariableParsing.c > VariableParsing.h > + VariableRuntimeCache.c > + VariableRuntimeCache.h > VarCheck.c > Variable.h > PrivilegePolymorphic.h > diff --git a/MdeModulePkg/Include/Guid/SmmVariableCommon.h > b/MdeModulePkg/Include/Guid/SmmVariableCommon.h > index c527a59891..ceef44dfd2 100644 > --- a/MdeModulePkg/Include/Guid/SmmVariableCommon.h > +++ b/MdeModulePkg/Include/Guid/SmmVariableCommon.h > @@ -1,7 +1,7 @@ > /** @file > The file defined some common structures used for communicating between > SMM variable module and SMM variable wrapper module. >=20 > -Copyright (c) 2011 - 2015, Intel Corporation. All rights reserved.
> +Copyright (c) 2011 - 2019, Intel Corporation. All rights reserved.
> SPDX-License-Identifier: BSD-2-Clause-Patent >=20 > **/ > @@ -9,6 +9,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent > #ifndef _SMM_VARIABLE_COMMON_H_ > #define _SMM_VARIABLE_COMMON_H_ >=20 > +#include > #include >=20 > #define EFI_SMM_VARIABLE_WRITE_GUID \ > @@ -66,6 +67,16 @@ typedef struct { > #define SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET > 10 >=20 > #define SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE 11 > +// > +// The payload for this function is > SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT > +// > +#define > SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT 12 > + > +#define SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE 13 > +// > +// The payload for this function is > SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO > +// > +#define SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO 14 >=20 > /// > /// Size of SMM communicate header, without including the payload. > @@ -120,4 +131,20 @@ typedef struct { > UINTN VariablePayloadSize; > } SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE; >=20 > +typedef struct { > + BOOLEAN *ReadLock; > + BOOLEAN *PendingUpdate; > + BOOLEAN *HobFlushComplete; > + VARIABLE_STORE_HEADER *RuntimeHobCache; > + VARIABLE_STORE_HEADER *RuntimeNvCache; > + VARIABLE_STORE_HEADER *RuntimeVolatileCache; > +} SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT; > + > +typedef struct { > + UINTN TotalHobStorageSize; > + UINTN TotalNvStorageSize; > + UINTN TotalVolatileStorageSize; > + BOOLEAN AuthenticatedVariableUsage; > +} SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO; > + > #endif // _SMM_VARIABLE_COMMON_H_ > diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h > b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h > index fb574b2e32..0b2bb6ae66 100644 > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h > @@ -64,6 +64,21 @@ typedef enum { > VariableStoreTypeMax > } VARIABLE_STORE_TYPE; >=20 > +typedef struct { > + UINT32 PendingUpdateOffset; > + UINT32 PendingUpdateLength; > + VARIABLE_STORE_HEADER *Store; > +} VARIABLE_RUNTIME_CACHE; > + > +typedef struct { > + BOOLEAN *ReadLock; > + BOOLEAN *PendingUpdate; > + BOOLEAN *HobFlushComplete; > + VARIABLE_RUNTIME_CACHE VariableRuntimeHobCache; > + VARIABLE_RUNTIME_CACHE VariableRuntimeNvCache; > + VARIABLE_RUNTIME_CACHE VariableRuntimeVolatileCache; > +} VARIABLE_RUNTIME_CACHE_CONTEXT; > + > typedef struct { > VARIABLE_HEADER *CurrPtr; > // > @@ -79,14 +94,15 @@ typedef struct { > } VARIABLE_POINTER_TRACK; >=20 > typedef struct { > - EFI_PHYSICAL_ADDRESS HobVariableBase; > - EFI_PHYSICAL_ADDRESS VolatileVariableBase; > - EFI_PHYSICAL_ADDRESS NonVolatileVariableBase; > - EFI_LOCK VariableServicesLock; > - UINT32 ReentrantState; > - BOOLEAN AuthFormat; > - BOOLEAN AuthSupport; > - BOOLEAN EmuNvMode; > + EFI_PHYSICAL_ADDRESS HobVariableBase; > + EFI_PHYSICAL_ADDRESS VolatileVariableBase; > + EFI_PHYSICAL_ADDRESS NonVolatileVariableBase; > + VARIABLE_RUNTIME_CACHE_CONTEXT VariableRuntimeCacheContext; > + EFI_LOCK VariableServicesLock; > + UINT32 ReentrantState; > + BOOLEAN AuthFormat; > + BOOLEAN AuthSupport; > + BOOLEAN EmuNvMode; > } VARIABLE_GLOBAL; >=20 > typedef struct { > diff --git > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.h > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.h > new file mode 100644 > index 0000000000..f9804a1d69 > --- /dev/null > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.h > @@ -0,0 +1,51 @@ > +/** @file > + The common variable volatile store routines shared by the DXE_RUNTIME > variable > + module and the DXE_SMM variable module. > + > +Copyright (c) 2019, Intel Corporation. All rights reserved.
> +SPDX-License-Identifier: BSD-2-Clause-Patent > + > +**/ > + > +#ifndef _VARIABLE_RUNTIME_CACHE_H_ > +#define _VARIABLE_RUNTIME_CACHE_H_ > + > +#include "Variable.h" > + > +/** > + Copies any pending updates to runtime variable caches. > + > + @retval EFI_UNSUPPORTED The volatile store to be updated is no= t > initialized properly. > + @retval EFI_SUCCESS The volatile store was updated success= fully. > + > +**/ > +EFI_STATUS > +FlushPendingRuntimeVariableCacheUpdates ( > + VOID > + ); > + > +/** > + Synchronizes the runtime variable caches with all pending updates outs= ide > runtime. > + > + Ensures all conditions are met to maintain coherency for runtime cache > updates. This function will attempt > + to write the given update (and any other pending updates) if the ReadL= ock is > available. Otherwise, the > + update is added as a pending update for the given variable store and i= t will be > flushed to the runtime cache > + at the next opportunity the ReadLock is available. > + > + @param[in] VariableRuntimeCache Variable runtime cache structure for t= he > runtime cache being synchronized. > + @param[in] Offset Offset in bytes to apply the update. > + @param[in] Length Length of data in bytes of the update. > + > + @retval EFI_SUCCESS The update was added as a pending upda= te > successfully. If the variable runtime > + cache ReadLock was available, the runt= ime cache was > updated successfully. > + @retval EFI_UNSUPPORTED The volatile store to be updated is no= t > initialized properly. > + > +**/ > +EFI_STATUS > +SynchronizeRuntimeVariableCache ( > + IN VARIABLE_RUNTIME_CACHE *VariableRuntimeCache, > + IN UINTN Offset, > + IN UINTN Length > + ); > + > +#endif > diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c > b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c > index 0bd2f22e1a..29d6aca993 100644 > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c > @@ -25,6 +25,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent > #include "Variable.h" > #include "VariableNonVolatile.h" > #include "VariableParsing.h" > +#include "VariableRuntimeCache.h" >=20 > VARIABLE_MODULE_GLOBAL *mVariableModuleGlobal; >=20 > @@ -332,6 +333,12 @@ RecordVarErrorFlag ( > // Update the data in NV cache. > // > *VarErrFlag =3D TempFlag; > + Status =3D SynchronizeRuntimeVariableCache ( > + &mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache, > + (UINTN) VarErrFlag - (UINTN) mNvVariableCache + (UINTN= ) > mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase, > + sizeof (TempFlag) > + ); > + ASSERT_EFI_ERROR (Status); > } > } > } > @@ -766,12 +773,24 @@ Reclaim ( >=20 > Done: > if (IsVolatile || mVariableModuleGlobal->VariableGlobal.EmuNvMode) { > + Status =3D SynchronizeRuntimeVariableCache ( > + &mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCache, > + 0, > + VariableStoreHeader->Size > + ); > + ASSERT_EFI_ERROR (Status); > FreePool (ValidBuffer); > } else { > // > // For NV variable reclaim, we use mNvVariableCache as the buffer, s= o copy > the data back. > // > - CopyMem (mNvVariableCache, (UINT8 *)(UINTN)VariableBase, > VariableStoreHeader->Size); > + CopyMem (mNvVariableCache, (UINT8 *) (UINTN) VariableBase, > VariableStoreHeader->Size); > + Status =3D SynchronizeRuntimeVariableCache ( > + &mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache, > + 0, > + VariableStoreHeader->Size > + ); > + ASSERT_EFI_ERROR (Status); > } >=20 > return Status; > @@ -1614,6 +1633,7 @@ UpdateVariable ( > VARIABLE_POINTER_TRACK *Variable; > VARIABLE_POINTER_TRACK NvVariable; > VARIABLE_STORE_HEADER *VariableStoreHeader; > + VARIABLE_RUNTIME_CACHE *VolatileCacheInstance; > UINT8 *BufferForMerge; > UINTN MergedBufSize; > BOOLEAN DataReady; > @@ -2275,6 +2295,23 @@ UpdateVariable ( > } >=20 > Done: > + if (!EFI_ERROR (Status)) { > + if (Variable->Volatile) { > + VolatileCacheInstance =3D &(mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCache)= ; > + } else { > + VolatileCacheInstance =3D &(mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache); > + } > + > + if (VolatileCacheInstance->Store !=3D NULL) { > + Status =3D SynchronizeRuntimeVariableCache ( > + VolatileCacheInstance, > + 0, > + VolatileCacheInstance->Store->Size > + ); > + ASSERT_EFI_ERROR (Status); > + } > + } > + > return Status; > } >=20 > @@ -3200,6 +3237,14 @@ FlushHobVariableToFlash ( > ErrorFlag =3D TRUE; > } > } > + if (mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache.Stor > e !=3D NULL) { > + Status =3D SynchronizeRuntimeVariableCache ( > + &mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache, > + 0, > + mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache.Stor > e->Size > + ); > + ASSERT_EFI_ERROR (Status); > + } > if (ErrorFlag) { > // > // We still have HOB variable(s) not flushed in flash. > @@ -3210,6 +3255,9 @@ FlushHobVariableToFlash ( > // All HOB variables have been flushed in flash. > // > DEBUG ((EFI_D_INFO, "Variable driver: all HOB variables have been = flushed > in flash.\n")); > + if (mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.HobFlushComplete !=3D NULL) { > + *(mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.HobFlushComplete) =3D TRUE; > + } > if (!AtRuntime ()) { > FreePool ((VOID *) VariableStoreHeader); > } > diff --git > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.c > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.c > new file mode 100644 > index 0000000000..bc93cc07d2 > --- /dev/null > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.c > @@ -0,0 +1,153 @@ > +/** @file > + Functions related to managing the UEFI variable runtime cache. This fi= le > should only include functions > + used by the SMM UEFI variable driver. > + > + Caution: This module requires additional review when modified. > + This driver will have external input - variable data. They may be inpu= t in SMM > mode. > + This external input must be validated carefully to avoid security issu= e like > + buffer overflow, integer overflow. > + > +Copyright (c) 2019, Intel Corporation. All rights reserved.
> +SPDX-License-Identifier: BSD-2-Clause-Patent > + > +**/ > + > +#include "VariableParsing.h" > +#include "VariableRuntimeCache.h" > + > +extern VARIABLE_MODULE_GLOBAL *mVariableModuleGlobal; > +extern VARIABLE_STORE_HEADER *mNvVariableCache; > + > +/** > + Copies any pending updates to runtime variable caches. > + > + @retval EFI_UNSUPPORTED The volatile store to be updated is no= t > initialized properly. > + @retval EFI_SUCCESS The volatile store was updated success= fully. > + > +**/ > +EFI_STATUS > +FlushPendingRuntimeVariableCacheUpdates ( > + VOID > + ) > +{ > + VARIABLE_RUNTIME_CACHE_CONTEXT *VariableRuntimeCacheContext; > + > + VariableRuntimeCacheContext =3D &mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext; > + > + if (VariableRuntimeCacheContext->VariableRuntimeNvCache.Store =3D=3D N= ULL > || > + VariableRuntimeCacheContext->VariableRuntimeVolatileCache.Store = =3D=3D > NULL || > + VariableRuntimeCacheContext->PendingUpdate =3D=3D NULL) { > + return EFI_UNSUPPORTED; > + } > + > + if (*(VariableRuntimeCacheContext->PendingUpdate)) { > + if (VariableRuntimeCacheContext->VariableRuntimeHobCache.Store !=3D = NULL > && > + mVariableModuleGlobal->VariableGlobal.HobVariableBase > 0) { > + CopyMem ( > + (VOID *) ( > + ((UINT8 *) (UINTN) VariableRuntimeCacheContext- > >VariableRuntimeHobCache.Store) + > + VariableRuntimeCacheContext- > >VariableRuntimeHobCache.PendingUpdateOffset > + ), > + (VOID *) ( > + ((UINT8 *) (UINTN) mVariableModuleGlobal- > >VariableGlobal.HobVariableBase) + > + VariableRuntimeCacheContext- > >VariableRuntimeHobCache.PendingUpdateOffset > + ), > + VariableRuntimeCacheContext- > >VariableRuntimeHobCache.PendingUpdateLength > + ); > + VariableRuntimeCacheContext- > >VariableRuntimeHobCache.PendingUpdateLength =3D 0; > + VariableRuntimeCacheContext- > >VariableRuntimeHobCache.PendingUpdateOffset =3D 0; > + } > + > + CopyMem ( > + (VOID *) ( > + ((UINT8 *) (UINTN) VariableRuntimeCacheContext- > >VariableRuntimeNvCache.Store) + > + VariableRuntimeCacheContext- > >VariableRuntimeNvCache.PendingUpdateOffset > + ), > + (VOID *) ( > + ((UINT8 *) (UINTN) mNvVariableCache) + > + VariableRuntimeCacheContext- > >VariableRuntimeNvCache.PendingUpdateOffset > + ), > + VariableRuntimeCacheContext- > >VariableRuntimeNvCache.PendingUpdateLength > + ); > + VariableRuntimeCacheContext- > >VariableRuntimeNvCache.PendingUpdateLength =3D 0; > + VariableRuntimeCacheContext- > >VariableRuntimeNvCache.PendingUpdateOffset =3D 0; > + > + CopyMem ( > + (VOID *) ( > + ((UINT8 *) (UINTN) VariableRuntimeCacheContext- > >VariableRuntimeVolatileCache.Store) + > + VariableRuntimeCacheContext- > >VariableRuntimeVolatileCache.PendingUpdateOffset > + ), > + (VOID *) ( > + ((UINT8 *) (UINTN) mVariableModuleGlobal- > >VariableGlobal.VolatileVariableBase) + > + VariableRuntimeCacheContext- > >VariableRuntimeVolatileCache.PendingUpdateOffset > + ), > + VariableRuntimeCacheContext- > >VariableRuntimeVolatileCache.PendingUpdateLength > + ); > + VariableRuntimeCacheContext- > >VariableRuntimeVolatileCache.PendingUpdateLength =3D 0; > + VariableRuntimeCacheContext- > >VariableRuntimeVolatileCache.PendingUpdateOffset =3D 0; > + *(VariableRuntimeCacheContext->PendingUpdate) =3D FALSE; > + } > + > + return EFI_SUCCESS; > +} > + > +/** > + Synchronizes the runtime variable caches with all pending updates outs= ide > runtime. > + > + Ensures all conditions are met to maintain coherency for runtime cache > updates. This function will attempt > + to write the given update (and any other pending updates) if the ReadL= ock is > available. Otherwise, the > + update is added as a pending update for the given variable store and i= t will be > flushed to the runtime cache > + at the next opportunity the ReadLock is available. > + > + @param[in] VariableRuntimeCache Variable runtime cache structure for t= he > runtime cache being synchronized. > + @param[in] Offset Offset in bytes to apply the update. > + @param[in] Length Length of data in bytes of the update. > + > + @retval EFI_SUCCESS The update was added as a pending upda= te > successfully. If the variable runtime > + cache ReadLock was available, the runt= ime cache was > updated successfully. > + @retval EFI_UNSUPPORTED The volatile store to be updated is no= t > initialized properly. > + > +**/ > +EFI_STATUS > +SynchronizeRuntimeVariableCache ( > + IN VARIABLE_RUNTIME_CACHE *VariableRuntimeCache, > + IN UINTN Offset, > + IN UINTN Length > + ) > +{ > + if (VariableRuntimeCache =3D=3D NULL) { > + return EFI_INVALID_PARAMETER; > + } else if (VariableRuntimeCache->Store =3D=3D NULL) { > + // The runtime cache may not be active or allocated yet. > + // In either case, return EFI_SUCCESS instead of EFI_NOT_AVAILABLE_Y= ET. > + return EFI_SUCCESS; > + } > + > + if (mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate =3D=3D NULL || > + mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.ReadLock =3D=3D NULL) { > + return EFI_UNSUPPORTED; > + } > + > + if (*(mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate) && > + VariableRuntimeCache->PendingUpdateLength > 0) { > + VariableRuntimeCache->PendingUpdateLength =3D > + (UINT32) ( > + MAX ( > + (UINTN) (VariableRuntimeCache->PendingUpdateOffset + > VariableRuntimeCache->PendingUpdateLength), > + Offset + Length > + ) - MIN ((UINTN) VariableRuntimeCache->PendingUpdateOffset, Offs= et) > + ); > + VariableRuntimeCache->PendingUpdateOffset =3D > + (UINT32) MIN ((UINTN) VariableRuntimeCache->PendingUpdateOffset, > Offset); > + } else { > + VariableRuntimeCache->PendingUpdateLength =3D (UINT32) Length; > + VariableRuntimeCache->PendingUpdateOffset =3D (UINT32) Offset; > + } > + *(mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate) =3D TRUE; > + > + if (*(mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext.ReadLock) =3D=3D FALSE) { > + return FlushPendingRuntimeVariableCacheUpdates (); > + } > + > + return EFI_SUCCESS; > +} > diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c > index 5e24bc4a62..45814b8996 100644 > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c > @@ -31,6 +31,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent > #include > #include "Variable.h" > #include "VariableParsing.h" > +#include "VariableRuntimeCache.h" > + > +extern VARIABLE_STORE_HEADER *mNvVariableCache; >=20 > BOOLEAN mAtRuntime = =3D FALSE; > UINT8 *mVariableBufferPay= load =3D NULL; > @@ -451,25 +454,29 @@ SmmVariableGetStatistics ( > EFI_STATUS > EFIAPI > SmmVariableHandler ( > - IN EFI_HANDLE DispatchHandle, > - IN CONST VOID *RegisterContext, > - IN OUT VOID *CommBuffer, > - IN OUT UINTN *CommBufferSize > + IN EFI_HANDLE DispatchHandle= , > + IN CONST VOID *RegisterConte= xt, > + IN OUT VOID *CommBuffer, > + IN OUT UINTN *CommBufferSiz= e > ) > { > - EFI_STATUS Status; > - SMM_VARIABLE_COMMUNICATE_HEADER > *SmmVariableFunctionHeader; > - SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE > *SmmVariableHeader; > - SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME > *GetNextVariableName; > - SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO > *QueryVariableInfo; > - SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE *GetPayloadSize; > - VARIABLE_INFO_ENTRY *VariableInfo; > - SMM_VARIABLE_COMMUNICATE_LOCK_VARIABLE *VariableToLock; > - SMM_VARIABLE_COMMUNICATE_VAR_CHECK_VARIABLE_PROPERTY > *CommVariableProperty; > - UINTN InfoSize; > - UINTN NameBufferSize; > - UINTN CommBufferPayloadSize= ; > - UINTN TempCommBufferSize; > + EFI_STATUS Status; > + SMM_VARIABLE_COMMUNICATE_HEADER > *SmmVariableFunctionHeader; > + SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE > *SmmVariableHeader; > + SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME > *GetNextVariableName; > + SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO > *QueryVariableInfo; > + SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE > *GetPayloadSize; > + SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT > *RuntimeVariableCacheContext; > + SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO > *GetRuntimeCacheInfo; > + SMM_VARIABLE_COMMUNICATE_LOCK_VARIABLE *VariableToLoc= k; > + SMM_VARIABLE_COMMUNICATE_VAR_CHECK_VARIABLE_PROPERTY > *CommVariableProperty; > + VARIABLE_INFO_ENTRY *VariableInfo; > + VARIABLE_RUNTIME_CACHE_CONTEXT *VariableCache= Context; > + VARIABLE_STORE_HEADER *VariableCache= ; > + UINTN InfoSize; > + UINTN NameBufferSize= ; > + UINTN CommBufferPayl= oadSize; > + UINTN TempCommBuffer= Size; >=20 > // > // If input is invalid, stop processing this SMI > @@ -789,6 +796,79 @@ SmmVariableHandler ( > ); > CopyMem (SmmVariableFunctionHeader->Data, mVariableBufferPayload, > CommBufferPayloadSize); > break; > + case > SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT: > + if (CommBufferPayloadSize < sizeof > (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT)) { > + DEBUG ((DEBUG_ERROR, "InitRuntimeVariableCacheContext: SMM > communication buffer size invalid!\n")); > + } else if (mEndOfDxe) { > + DEBUG ((DEBUG_ERROR, "InitRuntimeVariableCacheContext: Cannot in= it > context after end of DXE!\n")); > + } else { > + RuntimeVariableCacheContext =3D > (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT *) > SmmVariableFunctionHeader->Data; > + VariableCacheContext =3D &mVariableModuleGlobal- > >VariableGlobal.VariableRuntimeCacheContext; > + > + ASSERT (RuntimeVariableCacheContext->RuntimeVolatileCache !=3D N= ULL); > + ASSERT (RuntimeVariableCacheContext->RuntimeNvCache !=3D NULL); > + ASSERT (RuntimeVariableCacheContext->PendingUpdate !=3D NULL); > + ASSERT (RuntimeVariableCacheContext->ReadLock !=3D NULL); > + ASSERT (RuntimeVariableCacheContext->HobFlushComplete !=3D NULL)= ; > + > + VariableCacheContext->VariableRuntimeHobCache.Store =3D > RuntimeVariableCacheContext->RuntimeHobCache; > + VariableCacheContext->VariableRuntimeVolatileCache.Store =3D > RuntimeVariableCacheContext->RuntimeVolatileCache; > + VariableCacheContext->VariableRuntimeNvCache.Store =3D > RuntimeVariableCacheContext->RuntimeNvCache; > + VariableCacheContext->PendingUpdate =3D > RuntimeVariableCacheContext->PendingUpdate; > + VariableCacheContext->ReadLock =3D > RuntimeVariableCacheContext->ReadLock; > + VariableCacheContext->HobFlushComplete =3D > RuntimeVariableCacheContext->HobFlushComplete; > + > + // Set up the intial pending request since the RT cache needs to= be in sync > with SMM cache > + if (mVariableModuleGlobal->VariableGlobal.HobVariableBase =3D=3D= 0) { > + VariableCacheContext->VariableRuntimeHobCache.PendingUpdateOff= set > =3D 0; > + VariableCacheContext- > >VariableRuntimeHobCache.PendingUpdateLength =3D 0; > + } else { > + VariableCache =3D (VARIABLE_STORE_HEADER *) (UINTN) > mVariableModuleGlobal->VariableGlobal.HobVariableBase; > + VariableCacheContext->VariableRuntimeHobCache.PendingUpdateOff= set > =3D 0; > + VariableCacheContext- > >VariableRuntimeHobCache.PendingUpdateLength =3D (UINT32) ((UINTN) > GetEndPointer (VariableCache) - (UINTN) VariableCache); > + CopyGuid (&(VariableCacheContext->VariableRuntimeHobCache.Stor= e- > >Signature), &(VariableCache->Signature)); > + } > + VariableCache =3D (VARIABLE_STORE_HEADER *) (UINTN) > mVariableModuleGlobal->VariableGlobal.VolatileVariableBase; > + VariableCacheContext- > >VariableRuntimeVolatileCache.PendingUpdateOffset =3D 0; > + VariableCacheContext- > >VariableRuntimeVolatileCache.PendingUpdateLength =3D (UINT32) ((UINTN) > GetEndPointer (VariableCache) - (UINTN) VariableCache); > + CopyGuid (&(VariableCacheContext->VariableRuntimeVolatileCache.S= tore- > >Signature), &(VariableCache->Signature)); > + > + VariableCache =3D (VARIABLE_STORE_HEADER *) (UINTN) > mNvVariableCache; > + VariableCacheContext->VariableRuntimeNvCache.PendingUpdateOffset= =3D > 0; > + VariableCacheContext->VariableRuntimeNvCache.PendingUpdateLength= =3D > (UINT32) ((UINTN) GetEndPointer (VariableCache) - (UINTN) VariableCache); > + CopyGuid (&(VariableCacheContext->VariableRuntimeNvCache.Store- > >Signature), &(VariableCache->Signature)); > + > + *(VariableCacheContext->PendingUpdate) =3D TRUE; > + *(VariableCacheContext->ReadLock) =3D FALSE; > + *(VariableCacheContext->HobFlushComplete) =3D FALSE; > + } > + Status =3D EFI_SUCCESS; > + break; > + case SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE: > + Status =3D FlushPendingRuntimeVariableCacheUpdates (); > + break; > + case SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO: > + if (CommBufferPayloadSize < sizeof > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO)) { > + DEBUG ((DEBUG_ERROR, "GetRuntimeCacheInfo: SMM communication > buffer size invalid!\n")); > + return EFI_SUCCESS; > + } > + GetRuntimeCacheInfo =3D > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO *) > SmmVariableFunctionHeader->Data; > + > + if (mVariableModuleGlobal->VariableGlobal.HobVariableBase > 0) { > + VariableCache =3D (VARIABLE_STORE_HEADER *) (UINTN) > mVariableModuleGlobal->VariableGlobal.HobVariableBase; > + GetRuntimeCacheInfo->TotalHobStorageSize =3D VariableCache->Size= ; > + } else { > + GetRuntimeCacheInfo->TotalHobStorageSize =3D 0; > + } > + > + VariableCache =3D (VARIABLE_STORE_HEADER *) (UINTN) > mVariableModuleGlobal->VariableGlobal.VolatileVariableBase; > + GetRuntimeCacheInfo->TotalVolatileStorageSize =3D VariableCache->S= ize; > + VariableCache =3D (VARIABLE_STORE_HEADER *) (UINTN) mNvVariableCa= che; > + GetRuntimeCacheInfo->TotalNvStorageSize =3D (UINTN) VariableCache-= >Size; > + GetRuntimeCacheInfo->AuthenticatedVariableUsage =3D > mVariableModuleGlobal->VariableGlobal.AuthFormat; > + > + Status =3D EFI_SUCCESS; > + break; >=20 > default: > Status =3D EFI_UNSUPPORTED; > diff --git > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c > index 0a1888e5ef..e236ddff33 100644 > --- > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c > +++ > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c > @@ -13,7 +13,7 @@ >=20 > InitCommunicateBuffer() is really function to check the variable data = size. >=20 > -Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.
> +Copyright (c) 2010 - 2019, Intel Corporation. All rights reserved.
> SPDX-License-Identifier: BSD-2-Clause-Patent >=20 > **/ > @@ -39,6 +39,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent > #include >=20 > #include "PrivilegePolymorphic.h" > +#include "VariableParsing.h" >=20 > EFI_HANDLE mHandle =3D NULL; > EFI_SMM_VARIABLE_PROTOCOL *mSmmVariable =3D NULL; > @@ -46,8 +47,19 @@ EFI_EVENT mVirtualAddressChange= Event =3D > NULL; > EFI_SMM_COMMUNICATION_PROTOCOL *mSmmCommunication =3D NULL; > UINT8 *mVariableBuffer =3D NULL; > UINT8 *mVariableBufferPhysical =3D NULL; > +VARIABLE_INFO_ENTRY *mVariableInfo =3D NULL; > +VARIABLE_STORE_HEADER *mVariableRuntimeHobCacheBuffer = =3D > NULL; > +VARIABLE_STORE_HEADER *mVariableRuntimeNvCacheBuffer = =3D > NULL; > +VARIABLE_STORE_HEADER *mVariableRuntimeVolatileCacheBuffer = =3D > NULL; > UINTN mVariableBufferSize; > +UINTN mVariableRuntimeHobCacheBufferSize; > +UINTN mVariableRuntimeNvCacheBufferSize; > +UINTN mVariableRuntimeVolatileCacheBufferSize= ; > UINTN mVariableBufferPayloadSize; > +BOOLEAN mVariableRuntimeCachePendingUpdate; > +BOOLEAN mVariableRuntimeCacheReadLock; > +BOOLEAN mVariableAuthFormat; > +BOOLEAN mHobFlushComplete; > EFI_LOCK mVariableServicesLock; > EDKII_VARIABLE_LOCK_PROTOCOL mVariableLock; > EDKII_VAR_CHECK_PROTOCOL mVarCheck; > @@ -107,6 +119,72 @@ ReleaseLockOnlyAtBootTime ( > } > } >=20 > +/** > + Return TRUE if ExitBootServices () has been called. > + > + @retval TRUE If ExitBootServices () has been called. FALSE if ExitBoot= Services > () has not been called. > +**/ > +BOOLEAN > +AtRuntime ( > + VOID > + ) > +{ > + return EfiAtRuntime (); > +} > + AtRuntime() is kept here. But EfiAtRuntime() is still used elsewhere in thi= s file. > +/** > + Initialize the variable cache buffer as an empty variable store. > + > + @param[out] VariableCacheBuffer A pointer to pointer of a cach= e > variable store. > + @param[in,out] TotalVariableCacheSize On input, the minimum size nee= ded > for the UEFI variable store cache > + buffer that is allocated. On o= utput, the actual size of the > buffer allocated. > + If TotalVariableCacheSize is z= ero, a buffer will not be > allocated and the > + function will return with EFI_= SUCCESS. > + > + @retval EFI_SUCCESS The variable cache was allocated and i= nitialized > successfully. > + @retval EFI_INVALID_PARAMETER A given pointer is NULL or an invalid > variable store size was specified. > + @retval EFI_OUT_OF_RESOURCES Insufficient resources are available t= o > allocate the variable store cache buffer. > + > +**/ > +EFI_STATUS > +InitVariableCache ( > + OUT VARIABLE_STORE_HEADER **VariableCacheBuffer, > + IN OUT UINTN *TotalVariableCacheSize > + ) > +{ > + VARIABLE_STORE_HEADER *VariableCacheStorePtr; > + > + if (TotalVariableCacheSize =3D=3D NULL) { > + return EFI_INVALID_PARAMETER; > + } > + if (*TotalVariableCacheSize =3D=3D 0) { > + return EFI_SUCCESS; > + } > + if (VariableCacheBuffer =3D=3D NULL || *TotalVariableCacheSize < sizeo= f > (VARIABLE_STORE_HEADER)) { > + return EFI_INVALID_PARAMETER; > + } > + *TotalVariableCacheSize =3D ALIGN_VALUE (*TotalVariableCacheSize, size= of > (UINT32)); > + > + // > + // Allocate NV Storage Cache and initialize it to all 1's (like an era= sed FV) > + // > + *VariableCacheBuffer =3D (VARIABLE_STORE_HEADER *) AllocateRuntimePag= es > ( > + EFI_SIZE_TO_PAGES (*TotalVariableCacheSize) > + ); > + if (*VariableCacheBuffer =3D=3D NULL) { > + return EFI_OUT_OF_RESOURCES; > + } > + VariableCacheStorePtr =3D *VariableCacheBuffer; > + SetMem32 ((VOID *) VariableCacheStorePtr, *TotalVariableCacheSize, > (UINT32) 0xFFFFFFFF); > + > + ZeroMem ((VOID *) VariableCacheStorePtr, sizeof > (VARIABLE_STORE_HEADER)); > + VariableCacheStorePtr->Size =3D (UINT32) *TotalVariableCacheSize; > + VariableCacheStorePtr->Format =3D VARIABLE_STORE_FORMATTED; > + VariableCacheStorePtr->State =3D VARIABLE_STORE_HEALTHY; > + > + return EFI_SUCCESS; > +} > + > /** > Initialize the communicate buffer using DataSize and Function. >=20 > @@ -425,7 +503,169 @@ Done: > } >=20 > /** > - This code finds variable in storage blocks (Volatile or Non-Volatile). > + Signals SMM to synchronize any pending variable updates with the runti= me > cache(s). > + > +**/ > +VOID > +SyncRuntimeCache ( > + VOID > + ) > +{ > + // > + // Init the communicate buffer. The buffer data size is: > + // SMM_COMMUNICATE_HEADER_SIZE + > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE. > + // > + InitCommunicateBuffer (NULL, 0, > SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE); > + > + // > + // Send data to SMM. > + // > + SendCommunicateBuffer (0); > +} > + > +/** > + Check whether a SMI must be triggered to retrieve pending cache update= s. > + > + If the variable HOB was finished being flushed since the last check fo= r a > runtime cache update, this function > + will prevent the HOB cache from being used for future runtime cache hi= ts. > + > +**/ > +VOID > +CheckForRuntimeCacheSync ( > + VOID > + ) > +{ > + if (mVariableRuntimeCachePendingUpdate) { > + SyncRuntimeCache (); > + } > + ASSERT (!mVariableRuntimeCachePendingUpdate); > + > + // > + // The HOB variable data may have finished being flushed in the runtim= e cache > sync update > + // > + if (mHobFlushComplete && mVariableRuntimeHobCacheBuffer !=3D NULL) { > + if (!EfiAtRuntime ()) { > + FreePool (mVariableRuntimeHobCacheBuffer); > + } > + mVariableRuntimeHobCacheBuffer =3D NULL; > + } > +} > + > +/** > + Finds the given variable in a runtime cache variable store. > + > + Caution: This function may receive untrusted input. > + The data size is external input, so this function will validate it car= efully to > avoid buffer overflow. > + > + @param[in] VariableName Name of Variable to be found. > + @param[in] VendorGuid Variable vendor GUID. > + @param[out] Attributes Attribute value of the variable fou= nd. > + @param[in, out] DataSize Size of Data found. If size is less= than the > + data, this value contains the requi= red size. > + @param[out] Data Data pointer. > + > + @retval EFI_SUCCESS Found the specified variable. > + @retval EFI_INVALID_PARAMETER Invalid parameter. > + @retval EFI_NOT_FOUND The specified variable could not be= found. > + > +**/ > +EFI_STATUS > +FindVariableInRuntimeCache ( > + IN CHAR16 *VariableName, > + IN EFI_GUID *VendorGuid, > + OUT UINT32 *Attributes OPTIONAL, > + IN OUT UINTN *DataSize, > + OUT VOID *Data OPTIONAL I'm not sure the newly added OPTIONAL to last parameter 'Data' is correct. Per my understanding on below code, 'Data' is always required when mVariableRuntimeCachePendingUpdate is FALSE. In other words, 'Data' passing with NULL has no meaning. In my opinion it's should not be 'optional'.=20 > + ) > +{ > + EFI_STATUS Status; > + UINTN TempDataSize; > + VARIABLE_POINTER_TRACK RtPtrTrack; > + VARIABLE_STORE_TYPE StoreType; > + VARIABLE_STORE_HEADER *VariableStoreList[VariableStoreTypeMax]; > + > + Status =3D EFI_NOT_FOUND; > + > + if (VariableName =3D=3D NULL || VendorGuid =3D=3D NULL || DataSize =3D= =3D NULL) { > + return EFI_INVALID_PARAMETER; > + } > + > + // > + // The UEFI specification restricts Runtime Services callers from invo= king the > same or certain other Runtime Service > + // functions prior to completion and return from a previous Runtime Se= rvice > call. These restrictions prevent > + // a GetVariable () or GetNextVariable () call from being issued until= a prior call > has returned. The runtime > + // cache read lock should always be free when entering this function. > + // > + ASSERT (!mVariableRuntimeCacheReadLock); > + > + mVariableRuntimeCacheReadLock =3D TRUE; > + CheckForRuntimeCacheSync (); > + > + if (!mVariableRuntimeCachePendingUpdate) { > + // > + // 0: Volatile, 1: HOB, 2: Non-Volatile. > + // The index and attributes mapping must be kept in this order as > FindVariable > + // makes use of this mapping to implement search algorithm. > + // > + VariableStoreList[VariableStoreTypeVolatile] =3D > mVariableRuntimeVolatileCacheBuffer; > + VariableStoreList[VariableStoreTypeHob] =3D > mVariableRuntimeHobCacheBuffer; > + VariableStoreList[VariableStoreTypeNv] =3D > mVariableRuntimeNvCacheBuffer; > + > + for (StoreType =3D (VARIABLE_STORE_TYPE) 0; StoreType < > VariableStoreTypeMax; StoreType++) { > + if (VariableStoreList[StoreType] =3D=3D NULL) { > + continue; > + } > + > + RtPtrTrack.StartPtr =3D GetStartPointer (VariableStoreList[StoreTy= pe]); > + RtPtrTrack.EndPtr =3D GetEndPointer (VariableStoreList[StoreTy= pe]); > + RtPtrTrack.Volatile =3D (BOOLEAN) (StoreType =3D=3D VariableStoreT= ypeVolatile); > + > + Status =3D FindVariableEx (VariableName, VendorGuid, FALSE, &RtPtr= Track, > mVariableAuthFormat); > + if (!EFI_ERROR (Status)) { > + break; > + } > + } > + > + if (!EFI_ERROR (Status)) { > + // > + // Get data size > + // > + TempDataSize =3D DataSizeOfVariable (RtPtrTrack.CurrPtr, > mVariableAuthFormat); > + ASSERT (TempDataSize !=3D 0); > + > + if (*DataSize >=3D TempDataSize) { > + if (Data =3D=3D NULL) { > + Status =3D EFI_INVALID_PARAMETER; > + goto Done; > + } > + > + CopyMem (Data, GetVariableDataPtr (RtPtrTrack.CurrPtr, > mVariableAuthFormat), TempDataSize); > + if (Attributes !=3D NULL) { > + *Attributes =3D RtPtrTrack.CurrPtr->Attributes; > + } > + > + *DataSize =3D TempDataSize; > + > + UpdateVariableInfo (VariableName, VendorGuid, RtPtrTrack.Volatil= e, > TRUE, FALSE, FALSE, TRUE, &mVariableInfo); > + > + Status =3D EFI_SUCCESS; > + goto Done; > + } else { > + *DataSize =3D TempDataSize; > + Status =3D EFI_BUFFER_TOO_SMALL; > + goto Done; > + } > + } > + } > + > +Done: > + mVariableRuntimeCacheReadLock =3D FALSE; > + > + return Status; > +} > + > +/** > + Finds the given variable in a variable store in SMM. >=20 > Caution: This function may receive untrusted input. > The data size is external input, so this function will validate it car= efully to avoid > buffer overflow. > @@ -437,20 +677,18 @@ Done: > data, this value contains the requi= red size. > @param[out] Data Data pointer. >=20 > + @retval EFI_SUCCESS Found the specified variable. > @retval EFI_INVALID_PARAMETER Invalid parameter. > - @retval EFI_SUCCESS Find the specified variable. > - @retval EFI_NOT_FOUND Not found. > - @retval EFI_BUFFER_TO_SMALL DataSize is too small for the resul= t. > + @retval EFI_NOT_FOUND The specified variable could not be= found. >=20 > **/ > EFI_STATUS > -EFIAPI > -RuntimeServiceGetVariable ( > +FindVariableInSmm ( > IN CHAR16 *VariableName, > IN EFI_GUID *VendorGuid, > OUT UINT32 *Attributes OPTIONAL, > IN OUT UINTN *DataSize, > - OUT VOID *Data > + OUT VOID *Data OPTIONAL > ) > { > EFI_STATUS Status; > @@ -474,8 +712,6 @@ RuntimeServiceGetVariable ( > return EFI_INVALID_PARAMETER; > } >=20 > - AcquireLockOnlyAtBootTime(&mVariableServicesLock); > - > // > // Init the communicate buffer. The buffer data size is: > // SMM_COMMUNICATE_HEADER_SIZE + > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + PayloadSize. > @@ -488,7 +724,7 @@ RuntimeServiceGetVariable ( > } > PayloadSize =3D OFFSET_OF > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) + > VariableNameSize + TempDataSize; >=20 > - Status =3D InitCommunicateBuffer ((VOID **)&SmmVariableHeader, Payload= Size, > SMM_VARIABLE_FUNCTION_GET_VARIABLE); > + Status =3D InitCommunicateBuffer ((VOID **) &SmmVariableHeader, > PayloadSize, SMM_VARIABLE_FUNCTION_GET_VARIABLE); > if (EFI_ERROR (Status)) { > goto Done; > } > @@ -534,11 +770,58 @@ RuntimeServiceGetVariable ( > } >=20 > Done: > + return Status; > +} > + > +/** > + This code finds variable in storage blocks (Volatile or Non-Volatile). > + > + Caution: This function may receive untrusted input. > + The data size is external input, so this function will validate it car= efully to > avoid buffer overflow. > + > + @param[in] VariableName Name of Variable to be found. > + @param[in] VendorGuid Variable vendor GUID. > + @param[out] Attributes Attribute value of the variable fou= nd. > + @param[in, out] DataSize Size of Data found. If size is less= than the > + data, this value contains the requi= red size. > + @param[out] Data Data pointer. > + > + @retval EFI_INVALID_PARAMETER Invalid parameter. > + @retval EFI_SUCCESS Find the specified variable. > + @retval EFI_NOT_FOUND Not found. > + @retval EFI_BUFFER_TO_SMALL DataSize is too small for the resul= t. > + > +**/ > +EFI_STATUS > +EFIAPI > +RuntimeServiceGetVariable ( > + IN CHAR16 *VariableName, > + IN EFI_GUID *VendorGuid, > + OUT UINT32 *Attributes OPTIONAL, > + IN OUT UINTN *DataSize, > + OUT VOID *Data > + ) > +{ > + EFI_STATUS Status; > + > + if (VariableName =3D=3D NULL || VendorGuid =3D=3D NULL || DataSize =3D= =3D NULL) { > + return EFI_INVALID_PARAMETER; > + } > + if (VariableName[0] =3D=3D 0) { > + return EFI_NOT_FOUND; > + } > + > + AcquireLockOnlyAtBootTime (&mVariableServicesLock); > + if (FeaturePcdGet (PcdEnableVariableRuntimeCache)) { > + Status =3D FindVariableInRuntimeCache (VariableName, VendorGuid, Att= ributes, > DataSize, Data); > + } else { > + Status =3D FindVariableInSmm (VariableName, VendorGuid, Attributes, = DataSize, > Data); > + } > ReleaseLockOnlyAtBootTime (&mVariableServicesLock); > + > return Status; > } >=20 > - > /** > This code Finds the Next available variable. >=20 > @@ -870,6 +1153,17 @@ OnReadyToBoot ( > // > SendCommunicateBuffer (0); >=20 > + // > + // Install the system configuration table for variable info data captu= red > + // > + if (FeaturePcdGet (PcdEnableVariableRuntimeCache) && FeaturePcdGet > (PcdVariableCollectStatistics)) { > + if (mVariableAuthFormat) { > + gBS->InstallConfigurationTable (&gEfiAuthenticatedVariableGuid, > mVariableInfo); > + } else { > + gBS->InstallConfigurationTable (&gEfiVariableGuid, mVariableInfo); > + } > + } > + > gBS->CloseEvent (Event); > } >=20 > @@ -893,6 +1187,9 @@ VariableAddressChangeEvent ( > { > EfiConvertPointer (0x0, (VOID **) &mVariableBuffer); > EfiConvertPointer (0x0, (VOID **) &mSmmCommunication); > + EfiConvertPointer (0x0, (VOID **) &mVariableRuntimeHobCacheBuffer); > + EfiConvertPointer (0x0, (VOID **) &mVariableRuntimeNvCacheBuffer); > + EfiConvertPointer (0x0, (VOID **) &mVariableRuntimeVolatileCacheBuffer= ); > } >=20 > /** > @@ -969,6 +1266,159 @@ Done: > return Status; > } >=20 > +/** > + This code gets information needed from SMM for runtime cache initializ= ation. > + > + @param[out] TotalHobStorageSize Output pointer for the total H= OB > storage size in bytes. > + @param[out] TotalNvStorageSize Output pointer for the total n= on- > volatile storage size in bytes. > + @param[out] TotalVolatileStorageSize Output pointer for the total v= olatile > storage size in bytes. > + @param[out] AuthenticatedVariableUsage Output pointer that indicates = if > authenticated variables are to be used. > + > + @retval EFI_SUCCESS Retrieved the size successfull= y. > + @retval EFI_INVALID_PARAMETER TotalNvStorageSize parameter i= s > NULL. > + @retval EFI_OUT_OF_RESOURCES The memory resources needed fo= r a > CommBuffer are not available. > + @retval Others Could not retrieve the size su= ccessfully. > + > +**/ > +EFI_STATUS > +GetRuntimeCacheInfo ( > + OUT UINTN *TotalHobStorageSize, > + OUT UINTN *TotalNvStorageSize, > + OUT UINTN *TotalVolatileStorageSize, > + OUT BOOLEAN *AuthenticatedVariableUsage > + ) > +{ > + EFI_STATUS Status; > + SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO > *SmmGetRuntimeCacheInfo; > + EFI_SMM_COMMUNICATE_HEADER *SmmCommunicateHea= der; > + SMM_VARIABLE_COMMUNICATE_HEADER > *SmmVariableFunctionHeader; > + UINTN CommSize; > + UINT8 *CommBuffer; > + > + SmmGetRuntimeCacheInfo =3D NULL; > + CommBuffer =3D mVariableBuffer; > + > + if (TotalHobStorageSize =3D=3D NULL || TotalNvStorageSize =3D=3D NULL = || > TotalVolatileStorageSize =3D=3D NULL || AuthenticatedVariableUsage =3D=3D= NULL) { > + return EFI_INVALID_PARAMETER; > + } > + > + if (CommBuffer =3D=3D NULL) { > + return EFI_OUT_OF_RESOURCES; > + } > + > + AcquireLockOnlyAtBootTime (&mVariableServicesLock); > + > + CommSize =3D SMM_COMMUNICATE_HEADER_SIZE + > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO); > + ZeroMem (CommBuffer, CommSize); > + > + SmmCommunicateHeader =3D (EFI_SMM_COMMUNICATE_HEADER *) > CommBuffer; > + CopyGuid (&SmmCommunicateHeader->HeaderGuid, > &gEfiSmmVariableProtocolGuid); > + SmmCommunicateHeader->MessageLength =3D > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO); > + > + SmmVariableFunctionHeader =3D (SMM_VARIABLE_COMMUNICATE_HEADER *) > SmmCommunicateHeader->Data; > + SmmVariableFunctionHeader->Function =3D > SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO; > + SmmGetRuntimeCacheInfo =3D > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO *) > SmmVariableFunctionHeader->Data; > + > + // > + // Send data to SMM. > + // > + Status =3D mSmmCommunication->Communicate (mSmmCommunication, > CommBuffer, &CommSize); > + ASSERT_EFI_ERROR (Status); > + if (CommSize <=3D SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) { > + Status =3D EFI_BAD_BUFFER_SIZE; > + goto Done; > + } > + > + Status =3D SmmVariableFunctionHeader->ReturnStatus; > + if (EFI_ERROR (Status)) { > + goto Done; > + } > + > + // > + // Get data from SMM. > + // > + *TotalHobStorageSize =3D SmmGetRuntimeCacheInfo->TotalHobStorageSize; > + *TotalNvStorageSize =3D SmmGetRuntimeCacheInfo->TotalNvStorageSize; > + *TotalVolatileStorageSize =3D SmmGetRuntimeCacheInfo- > >TotalVolatileStorageSize; > + *AuthenticatedVariableUsage =3D SmmGetRuntimeCacheInfo- > >AuthenticatedVariableUsage; > + > +Done: > + ReleaseLockOnlyAtBootTime (&mVariableServicesLock); > + return Status; > +} > + > +/** > + Sends the runtime variable cache context information to SMM. > + > + @retval EFI_SUCCESS Retrieved the size successfully. > + @retval EFI_INVALID_PARAMETER TotalNvStorageSize parameter is NULL= . > + @retval EFI_OUT_OF_RESOURCES The memory resources needed for a > CommBuffer are not available. > + @retval Others Could not retrieve the size successf= ully.; > + > +**/ > +EFI_STATUS > +SendRuntimeVariableCacheContextToSmm ( > + VOID > + ) > +{ > + EFI_STATUS Status; > + SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT > *SmmRuntimeVarCacheContext; > + EFI_SMM_COMMUNICATE_HEADER > *SmmCommunicateHeader; > + SMM_VARIABLE_COMMUNICATE_HEADER > *SmmVariableFunctionHeader; > + UINTN CommSize; > + UINT8 *CommBuffer; > + > + SmmRuntimeVarCacheContext =3D NULL; > + CommBuffer =3D mVariableBuffer; > + > + if (CommBuffer =3D=3D NULL) { > + return EFI_OUT_OF_RESOURCES; > + } > + > + AcquireLockOnlyAtBootTime (&mVariableServicesLock); > + > + // > + // Init the communicate buffer. The buffer data size is: > + // SMM_COMMUNICATE_HEADER_SIZE + > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof > (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT); > + // > + CommSize =3D SMM_COMMUNICATE_HEADER_SIZE + > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof > (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT); > + ZeroMem (CommBuffer, CommSize); > + > + SmmCommunicateHeader =3D (EFI_SMM_COMMUNICATE_HEADER *) > CommBuffer; > + CopyGuid (&SmmCommunicateHeader->HeaderGuid, > &gEfiSmmVariableProtocolGuid); > + SmmCommunicateHeader->MessageLength =3D > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof > (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT); > + > + SmmVariableFunctionHeader =3D (SMM_VARIABLE_COMMUNICATE_HEADER *) > SmmCommunicateHeader->Data; > + SmmVariableFunctionHeader->Function =3D > SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT; > + SmmRuntimeVarCacheContext =3D > (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT *) > SmmVariableFunctionHeader->Data; > + > + SmmRuntimeVarCacheContext->RuntimeHobCache =3D > mVariableRuntimeHobCacheBuffer; > + SmmRuntimeVarCacheContext->RuntimeVolatileCache =3D > mVariableRuntimeVolatileCacheBuffer; > + SmmRuntimeVarCacheContext->RuntimeNvCache =3D > mVariableRuntimeNvCacheBuffer; > + SmmRuntimeVarCacheContext->PendingUpdate =3D > &mVariableRuntimeCachePendingUpdate; > + SmmRuntimeVarCacheContext->ReadLock =3D > &mVariableRuntimeCacheReadLock; > + SmmRuntimeVarCacheContext->HobFlushComplete =3D &mHobFlushComplete; > + > + // > + // Send data to SMM. > + // > + Status =3D mSmmCommunication->Communicate (mSmmCommunication, > CommBuffer, &CommSize); > + ASSERT_EFI_ERROR (Status); > + if (CommSize <=3D SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) { > + Status =3D EFI_BAD_BUFFER_SIZE; > + goto Done; > + } > + > + Status =3D SmmVariableFunctionHeader->ReturnStatus; > + if (EFI_ERROR (Status)) { > + goto Done; > + } > + > +Done: > + ReleaseLockOnlyAtBootTime (&mVariableServicesLock); > + return Status; > +} > + > /** > Initialize variable service and install Variable Architectural protoco= l. >=20 > @@ -985,7 +1435,7 @@ SmmVariableReady ( > { > EFI_STATUS Status; >=20 > - Status =3D gBS->LocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (V= OID > **)&mSmmVariable); > + Status =3D gBS->LocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (V= OID > **) &mSmmVariable); > if (EFI_ERROR (Status)) { > return; > } > @@ -1007,6 +1457,42 @@ SmmVariableReady ( > // > mVariableBufferPhysical =3D mVariableBuffer; >=20 > + if (FeaturePcdGet (PcdEnableVariableRuntimeCache)) { > + DEBUG ((DEBUG_INFO, "Variable driver runtime cache is enabled.\n")); > + // > + // Allocate runtime variable cache memory buffers. > + // > + Status =3D GetRuntimeCacheInfo ( > + &mVariableRuntimeHobCacheBufferSize, > + &mVariableRuntimeNvCacheBufferSize, > + &mVariableRuntimeVolatileCacheBufferSize, > + &mVariableAuthFormat > + ); > + if (!EFI_ERROR (Status)) { > + Status =3D InitVariableCache (&mVariableRuntimeHobCacheBuffer, > &mVariableRuntimeHobCacheBufferSize); > + if (!EFI_ERROR (Status)) { > + Status =3D InitVariableCache (&mVariableRuntimeNvCacheBuffer, > &mVariableRuntimeNvCacheBufferSize); > + if (!EFI_ERROR (Status)) { > + Status =3D InitVariableCache (&mVariableRuntimeVolatileCacheBu= ffer, > &mVariableRuntimeVolatileCacheBufferSize); > + if (!EFI_ERROR (Status)) { > + Status =3D SendRuntimeVariableCacheContextToSmm (); > + if (!EFI_ERROR (Status)) { > + SyncRuntimeCache (); > + } > + } > + } > + } > + if (EFI_ERROR (Status)) { > + mVariableRuntimeHobCacheBuffer =3D NULL; > + mVariableRuntimeNvCacheBuffer =3D NULL; > + mVariableRuntimeVolatileCacheBuffer =3D NULL; > + } > + } Above code uses a little bit deep of nested if-statement, and is a little b= it harder to read. What about flatten it? For example, one of the ways is using short-ci= rcuiting expression in one if-statement. Using 'goto' is another option. if (GetRuntimeCacheInfo (&mVariableRuntimeHobCacheBufferSize, &mVariableRuntimeNvCacheBufferSize, &mVariableRuntimeVolatileCacheBufferSize, &mVariableAuthFormat) =3D=3D EFI_SUCCESS && InitVariableCache (&mVariableRuntimeHobCacheBuffer, &mVariableRuntimeHobCacheBufferSize) =3D=3D EFI_= SUCCESS && InitVariableCache (&mVariableRuntimeNvCacheBuffer, &mVariableRuntimeNvCacheBufferSize) =3D=3D EFI_S= UCCESS && InitVariableCache (&mVariableRuntimeVolatileCacheBuffer, &mVariableRuntimeVolatileCacheBufferSize) =3D=3D= EFI_SUCCESS && SendRuntimeVariableCacheContextToSmm () =3D=3D EFI_SUCCESS) { SyncRuntimeCache (); } else { Status =3D EFI_OUT_OF_RESOURCES; mVariableRuntimeHobCacheBuffer =3D NULL; mVariableRuntimeNvCacheBuffer =3D NULL; mVariableRuntimeVolatileCacheBuffer =3D NULL; } Your code is not wrong, except that the memory already allocated is not fre= ed due to later error. But maybe there's no need to free in such fatal situation. Anyway, y= ou don't have to do above change. I'll leave it to you to make decision. Regards, Jian > + ASSERT_EFI_ERROR (Status); > + } else { > + DEBUG ((DEBUG_INFO, "Variable driver runtime cache is disabled.\n"))= ; > + } > + > gRT->GetVariable =3D RuntimeServiceGetVariable; > gRT->GetNextVariableName =3D RuntimeServiceGetNextVariableName; > gRT->SetVariable =3D RuntimeServiceSetVariable; > -- > 2.16.2.windows.1