[edk2-devel] [PATCH V2 7/9] MdeModulePkg/Variable: Add RT GetVariable() cache support
Wu, Hao A
hao.a.wu at intel.com
Tue Oct 8 02:12:24 UTC 2019
Inline replies below:
> -----Original Message-----
> From: Kubacki, Michael A
> Sent: Friday, October 04, 2019 5:54 AM
> To: Wu, Hao A; devel at edk2.groups.io
> Cc: Bi, Dandan; Ard Biesheuvel; Dong, Eric; Laszlo Ersek; Gao, Liming; Kinney,
> Michael D; Ni, Ray; Wang, Jian J; Yao, Jiewen
> Subject: RE: [PATCH V2 7/9] MdeModulePkg/Variable: Add RT GetVariable()
> cache support
>
> #1 - The plan is to remove the polling entirely in V3.
>
> #2 - I'd prefer to take a definitive direction and reduce validation and
> maintenance
> effort but you and Laszlo both requested this so I'll add a FeaturePCD to
> control
> activation of the runtime cache in this patch series. Perhaps this can be
> removed
> in the future.
>
> #3 - Will be done in V3.
>
> Other replies are inline.
>
> > -----Original Message-----
> > From: Wu, Hao A <hao.a.wu at intel.com>
> > Sent: Thursday, October 3, 2019 1:05 AM
> > To: Kubacki, Michael A <michael.a.kubacki at intel.com>;
> > devel at edk2.groups.io
> > Cc: Bi, Dandan <dandan.bi at intel.com>; Ard Biesheuvel
> > <ard.biesheuvel at linaro.org>; Dong, Eric <eric.dong at intel.com>; Laszlo
> Ersek
> > <lersek at redhat.com>; Gao, Liming <liming.gao at intel.com>; Kinney,
> Michael
> > D <michael.d.kinney at intel.com>; Ni, Ray <ray.ni at intel.com>; Wang, Jian J
> > <jian.j.wang at intel.com>; Yao, Jiewen <jiewen.yao at intel.com>
> > Subject: RE: [PATCH V2 7/9] MdeModulePkg/Variable: Add RT GetVariable()
> > cache support
> >
> > Before any comment on the patch, since I am not experienced in the
> > Variable
> > driver, I would like to ask for help from other reviewers to look into this
> > patch and provide feedbacks as well. Thanks in advance.
> >
> > With the above fact, some comments provided below maybe wrong. So
> > please help
> > to kindly correct me.
> >
> >
> > Some general comments:
> > 1. I am not sure if bringing the TimerLib dependency (delay in acquiring the
> > runtime cache read lock) to variable driver (a software driver for the most
> > part) is a good idea.
> >
> > Hope other reviewers can provide some feedbacks for this. Thanks in
> > advance.
> >
> > 2. In my opinion, I prefer a switch can be provided for platform owners to
> > choose between using the runtime cache and going through SMM for
> > GetVariable
> > (and for GetNextVariableName in the next patch as well).
> >
> > If platform owners feel uncomfortable with using the runtime cache with
> > regard to the security perspective, they can switch to the origin solution.
> >
> > 3. Please help to remove the 'EFIAPI' keyword for new driver internal
> > functions;
> >
> >
> > Inline comments below:
> >
> >
> > > -----Original Message-----
> > > From: Kubacki, Michael A
> > > Sent: Saturday, September 28, 2019 9:47 AM
> > > To: devel at edk2.groups.io
> > > Cc: Bi, Dandan; Ard Biesheuvel; Dong, Eric; Laszlo Ersek; Gao, Liming;
> > Kinney,
> > > Michael D; Ni, Ray; Wang, Jian J; Wu, Hao A; Yao, Jiewen
> > > Subject: [PATCH V2 7/9] MdeModulePkg/Variable: Add RT GetVariable()
> > > cache support
> > >
> > > REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2220
> > >
> > > 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.
> > >
> > > The following are important points regarding this change.
> > >
> > > 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.
> > >
> > > 2. SetVariable () requests will continue to always trigger an SMI.
> > > This occurs regardless of whether the variable is volatile or
> > > non-volatile.
> > >
> > > 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.
> > >
> > > 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.
> > >
> > > 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.
> > >
> > > When using SMM variables, 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
> outside
> > > SMRAM.
> > >
> > > It is possible to view UEFI variable read and write statistics by setting
> > > the gEfiMdeModulePkgTokenSpaceGuid.PcdVariableCollectStatistics
> > > FeaturePcd
> > > to TRUE and using the VariableInfo UEFI application in MdeModulePkg to
> > > dump
> > > variable statistics to the console. By doing so, a user can view the number
> > > of GetVariable () hits from the Runtime DXE variable driver (Runtime
> Cache
> > > hits) and the SMM variable driver (SMM Cache hits). SMM Cache hits for
> > > GetVariable () will occur when SMM modules invoke GetVariable ().
> > >
> > > Cc: Dandan Bi <dandan.bi at intel.com>
> > > Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> > > Cc: Eric Dong <eric.dong at intel.com>
> > > Cc: Laszlo Ersek <lersek at redhat.com>
> > > Cc: Liming Gao <liming.gao at intel.com>
> > > Cc: Michael D Kinney <michael.d.kinney at intel.com>
> > > Cc: Ray Ni <ray.ni at intel.com>
> > > Cc: Jian J Wang <jian.j.wang at intel.com>
> > > Cc: Hao A Wu <hao.a.wu at intel.com>
> > > Cc: Jiewen Yao <jiewen.yao at intel.com>
> > > Signed-off-by: Michael Kubacki <michael.a.kubacki at intel.com>
> > > ---
> > >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
> > > | 2 +
> > > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
> |
> > 2
> > > +
> > >
> > >
> >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.i
> > > nf | 31 +-
> > >
> > >
> >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
> > > | 2 +
> > > MdeModulePkg/Include/Guid/SmmVariableCommon.h | 29
> +-
> > > MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h | 39
> > +-
> > >
> > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.h
> > > | 47 ++
> > > MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c | 44
> > +-
> > >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.c
> > > | 153 +++++
> > > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c |
> > 114
> > > +++-
> > >
> > >
> >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.
> > > c | 608 +++++++++++++++++---
> > > 11 files changed, 966 insertions(+), 105 deletions(-)
> > >
> > > 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
> >
> >
> > Per my understanding, the module specified by VariableRuntimeDxe.inf
> > does not
> > involve SMM/SMI for variable services (like GetVariable). It looks weird to
> > me
> > for this INF to include the newly introduced runtime cache codes (below
> > source
> > header files):
> >
> > VariableRuntimeCache.c
> > VariableRuntimeCache.h
> >
> >
>
> This is because Variable.c is common to the runtime DXE and SMM variable
> driver and it contains the code to update variable caches. The runtime cache
> synchronization function (SynchronizeRuntimeVariableCache ()) will return
> if the runtime cache pointer is NULL.
Got it.
I was previously thinking whether it is possible to drop such dependency for
this non-SMM related runtime module. But if the dependency is coupled with
Variable.c as well, I am fine with the change above.
>
> > > 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/VariableSmmRuntimeDx
> > > e.inf
> > >
> >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.inf
> > > index 14894e6f13..70837ac6e0 100644
> > > ---
> > >
> >
> a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.inf
> > > +++
> > >
> >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.inf
> > > @@ -13,7 +13,7 @@
> > > # may not be modified without authorization. If platform fails to protect
> > > these resources,
> > > # the authentication service provided in this driver will be broken, and
> the
> > > behavior is undefined.
> > > #
> > > -# Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.<BR>
> > > +# Copyright (c) 2010 - 2019, Intel Corporation. All rights reserved.<BR>
> > > # 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
> > >
> > > [Packages]
> > > MdePkg/MdePkg.dec
> > > @@ -49,6 +53,7 @@
> > > BaseLib
> > > UefiBootServicesTableLib
> > > DebugLib
> > > + TimerLib
> > > UefiRuntimeLib
> > > DxeServicesTableLib
> > > UefiDriverEntryPoint
> > > @@ -65,7 +70,29 @@
> > > gEdkiiVariableLockProtocolGuid ## PRODUCES
> > > gEdkiiVarCheckProtocolGuid ## PRODUCES
> > >
> > > +[Pcd]
> > > + gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize ##
> > > CONSUMES
> > > + gEfiMdeModulePkgTokenSpaceGuid.PcdMaxAuthVariableSize
> > ##
> > > CONSUMES
> > > +
> gEfiMdeModulePkgTokenSpaceGuid.PcdMaxHardwareErrorVariableSize
> > > ## CONSUMES
> > > + gEfiMdeModulePkgTokenSpaceGuid.PcdVariableStoreSize ##
> > > CONSUMES
> > > + gEfiMdeModulePkgTokenSpaceGuid.PcdHwErrStorageSize
> ##
> > > CONSUMES
> > > + gEfiMdeModulePkgTokenSpaceGuid.PcdMaxUserNvVariableSpaceSize
> > > ## CONSUMES
> > > +
> > >
> >
> gEfiMdeModulePkgTokenSpaceGuid.PcdBoottimeReservedNvVariableSpace
> > > Size ## CONSUMES
> >
> >
> > Not sure if the above PCDs are really needed by VariableSmmRuntimeDxe.
> >
> >
>
> I will double check and remove any not required.
>
> > > +
> > > +[FeaturePcd]
> > > + 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
> > > @@ -82,6 +109,8 @@
> > > ## SOMETIMES_CONSUMES ## Variable:L"dbt"
> > > gEfiImageSecurityDatabaseGuid
> > >
> > > + gEdkiiPiSmmCommunicationRegionTableGuid ##
> > > SOMETIMES_CONSUMES ## SystemTable
> > > +
> > > [Depex]
> > > gEfiSmmCommunicationProtocolGuid
> > >
> > > diff --git
> > >
> >
> a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.i
> > > nf
> > >
> >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.
> > > inf
> > > index ca9d23ce9f..95c5310c0b 100644
> > > ---
> > >
> >
> a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.i
> > > nf
> > > +++
> > >
> >
> 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.
> > >
> > > -Copyright (c) 2011 - 2015, Intel Corporation. All rights reserved.<BR>
> > > +Copyright (c) 2011 - 2019, Intel Corporation. All rights reserved.<BR>
> > > SPDX-License-Identifier: BSD-2-Clause-Patent
> > >
> > > **/
> > > @@ -9,6 +9,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> > > #ifndef _SMM_VARIABLE_COMMON_H_
> > > #define _SMM_VARIABLE_COMMON_H_
> > >
> > > +#include <Guid/VariableFormat.h>
> > > #include <Protocol/VarCheck.h>
> > >
> > > #define EFI_SMM_VARIABLE_WRITE_GUID \
> > > @@ -66,6 +67,16 @@ typedef struct {
> > > #define
> > > SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET 10
> > >
> > > #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
> > >
> > > ///
> > > /// Size of SMM communicate header, without including the payload.
> > > @@ -120,4 +131,20 @@ typedef struct {
> > > UINTN VariablePayloadSize;
> > > } SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE;
> > >
> > > +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..b9723c0250 100644
> > > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h
> > > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h
> > > @@ -57,6 +57,12 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> > > ///
> > > #define ISO_639_2_ENTRY_SIZE 3
> > >
> > > +///
> > > +/// The timeout to in 10us units to wait for the
> > > +/// variable runtime cache read lock to be acquired.
> > > +///
> > > +#define VARIABLE_RT_CACHE_READ_LOCK_TIMEOUT 200000
> > > +
> > > typedef enum {
> > > VariableStoreTypeVolatile,
> > > VariableStoreTypeHob,
> > > @@ -64,6 +70,21 @@ typedef enum {
> > > VariableStoreTypeMax
> > > } VARIABLE_STORE_TYPE;
> > >
> > > +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 +100,16 @@ typedef struct {
> > > } VARIABLE_POINTER_TRACK;
> > >
> > > 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 HobVariableBackupBase;
> >
> >
> > I do not see any usage of the new field "HobVariableBackupBase".
> > Could you help to double confirm?
> >
> >
>
> You are correct. I removed usage of this variable before sending the
> patch series and the global variable here needs to be cleaned up.
>
> > > + 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;
> > >
> > > typedef struct {
> > > diff --git
> > >
> >
> a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.h
> > >
> > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.
> > > h
> > > new file mode 100644
> > > index 0000000000..09b83eb215
> > > --- /dev/null
> > > +++
> > >
> > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.
> > > h
> > > @@ -0,0 +1,47 @@
> > > +/** @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.<BR>
> > > +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 not
> > > initialized properly.
> > > + @retval EFI_SUCCESS The volatile store was updated successfully.
> > > +
> > > +**/
> > > +EFI_STATUS
> > > +SynchronizeRuntimeVariableCacheEx (
> > > + VOID
> > > + );
> > > +
> > > +/**
> > > + Synchronizes the runtime variable caches with all pending updates
> > outside
> > > runtime.
> > > +
> > > + Ensures all conditions are met to maintain coherency for runtime cache
> > > updates.
> > > +
> > > + @param[in] VariableRuntimeCache Variable runtime cache structure
> for
> > > the 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_UNSUPPORTED The volatile store to be updated is not
> > > initialized properly.
> > > + @retval EFI_SUCCESS The volatile store was updated successfully.
> > > +
> > > +**/
> > > +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 5da2354aa5..bb2fa3fc19 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"
> > >
> > > VARIABLE_MODULE_GLOBAL *mVariableModuleGlobal;
> > >
> > > @@ -332,6 +333,12 @@ RecordVarErrorFlag (
> > > // Update the data in NV cache.
> > > //
> > > *VarErrFlag = TempFlag;
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + &mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCach
> e,
> > > + (UINTN) VarErrFlag - (UINTN) mNvVariableCache + (UINTN)
> > > mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase,
> > > + sizeof (TempFlag)
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > }
> > > }
> > > }
> > > @@ -755,12 +762,24 @@ Reclaim (
> > >
> > > Done:
> > > if (IsVolatile || mVariableModuleGlobal->VariableGlobal.EmuNvMode)
> {
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + &mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e,
> > > + 0,
> > > + VariableStoreHeader->Size
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > FreePool (ValidBuffer);
> > > } else {
> > > //
> > > // For NV variable reclaim, we use mNvVariableCache as the buffer, so
> > > copy the data back.
> > > //
> > > - CopyMem (mNvVariableCache, (UINT8 *)(UINTN)VariableBase,
> > > VariableStoreHeader->Size);
> > > + CopyMem (mNvVariableCache, (UINT8 *) (UINTN) VariableBase,
> > > VariableStoreHeader->Size);
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + &(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCach
> e),
> > > + 0,
> > > + VariableStoreHeader->Size
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > }
> > >
> > > return Status;
> > > @@ -1592,6 +1611,7 @@ UpdateVariable (
> > > VARIABLE_POINTER_TRACK *Variable;
> > > VARIABLE_POINTER_TRACK NvVariable;
> > > VARIABLE_STORE_HEADER *VariableStoreHeader;
> > > + VARIABLE_RUNTIME_CACHE *VolatileCacheInstance;
> > > UINT8 *BufferForMerge;
> > > UINTN MergedBufSize;
> > > BOOLEAN DataReady;
> > > @@ -2235,6 +2255,21 @@ UpdateVariable (
> > > }
> > >
> > > Done:
> > > + if (!EFI_ERROR (Status)) {
> > > + if (Variable->Volatile) {
> > > + VolatileCacheInstance = &(mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e);
> > > + } else {
> > > + VolatileCacheInstance = &(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCach
> e);
> > > + }
> > > +
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + VolatileCacheInstance,
> > > + 0,
> > > + VolatileCacheInstance->Store->Size
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > + }
> > > +
> > > return Status;
> > > }
> > >
> > > @@ -3409,6 +3444,12 @@ FlushHobVariableToFlash (
> > > ErrorFlag = TRUE;
> > > }
> > > }
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + &mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache,
> > > + 0,
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .S
> > > tore->Size
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > if (ErrorFlag) {
> > > //
> > > // We still have HOB variable(s) not flushed in flash.
> > > @@ -3419,6 +3460,7 @@ FlushHobVariableToFlash (
> > > // All HOB variables have been flushed in flash.
> > > //
> > > DEBUG ((EFI_D_INFO, "Variable driver: all HOB variables have been
> > > flushed in flash.\n"));
> > > + *(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.HobFlushComplete) =
> > 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..2642d9b000
> > > --- /dev/null
> > > +++
> > >
> >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.c
> > > @@ -0,0 +1,153 @@
> > > +/** @file
> > > + The common variable volatile store routines shared by the
> > DXE_RUNTIME
> > > variable
> > > + module and the DXE_SMM variable module.
> > > +
> > > + Caution: This module requires additional review when modified.
> > > + This driver will have external input - variable data. They may be input in
> > > SMM mode.
> > > + This external input must be validated carefully to avoid security issue
> like
> > > + buffer overflow, integer overflow.
> > > +
> > > +Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
> > > +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 not
> > > initialized properly.
> > > + @retval EFI_SUCCESS The volatile store was updated successfully.
> > > +
> > > +**/
> > > +EFI_STATUS
> > > +SynchronizeRuntimeVariableCacheEx (
> >
> >
> > It is not clear to me why this function is named as the "Ex" version of
> function
> > SynchronizeRuntimeVariableCache(). For me, this function looks more like
> a
> > basic
> > version.
> >
> > I would suggest a name change for the functions provided in file
> > VariableRuntimeCache.c to better reflect their usage model.
> >
> >
>
> I'll rename it in V3.
>
> > > + VOID
> > > + )
> > > +{
> >
> >
> > I would recommend that at least a local variable should be introduced to
> > reduce
> > the duplications of:
> >
> > "mVariableModuleGlobal->VariableGlobal.VariableRuntimeCacheContext"
> >
> > in this function in order to make it easier to read.
> >
> >
>
> I'll add it in V3.
>
> > > + if (
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache.
> St
> > > ore == NULL ||
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e.Store == NULL ||
> > > + mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate == NULL
> > > + ) {
> > > + return EFI_UNSUPPORTED;
> > > + }
> > > +
> > > + if (*(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate)) {
> > > + if (
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .S
> > > tore != NULL &&
> > > + mVariableModuleGlobal->VariableGlobal.HobVariableBase > 0
> > > + ) {
> > > + CopyMem (
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .S
> > > tore) +
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .P
> > > endingUpdateOffset
> > > + ),
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) mVariableModuleGlobal-
> > > >VariableGlobal.HobVariableBase) +
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .P
> > > endingUpdateOffset
> > > + ),
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .P
> > > endingUpdateLength
> > > + );
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .P
> > > endingUpdateLength = 0;
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache
> .P
> > > endingUpdateOffset = 0;
> > > + }
> > > +
> > > + CopyMem (
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache.
> St
> > > ore) +
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache.
> Pe
> > > ndingUpdateOffset
> > > + ),
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) mNvVariableCache) +
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache.
> Pe
> > > ndingUpdateOffset
> > > + ),
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache.
> Pe
> > > ndingUpdateLength
> > > + );
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache.
> Pe
> > > ndingUpdateLength = 0;
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache.
> Pe
> > > ndingUpdateOffset = 0;
> > > +
> > > + CopyMem (
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e.Store) +
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e.PendingUpdateOffset
> > > + ),
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) mVariableModuleGlobal-
> > > >VariableGlobal.VolatileVariableBase) +
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e.PendingUpdateOffset
> > > + ),
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e.PendingUpdateLength
> > > + );
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e.PendingUpdateLength = 0;
> > > + mVariableModuleGlobal-
> > >
> > >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCa
> ch
> > > e.PendingUpdateOffset = 0;
> > > + *(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate) = FALSE;
> > > + }
> > > +
> > > + return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > + Synchronizes the runtime variable caches with all pending updates
> > outside
> > > runtime.
> > > +
> > > + Ensures all conditions are met to maintain coherency for runtime cache
> > > updates.
> > > +
> > > + @param[in] VariableRuntimeCache Variable runtime cache structure
> for
> > > the 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_UNSUPPORTED The volatile store to be updated is not
> > > initialized properly.
> > > + @retval EFI_SUCCESS The volatile store was updated successfully.
> > > +
> > > +**/
> > > +EFI_STATUS
> > > +SynchronizeRuntimeVariableCache (
> > > + IN VARIABLE_RUNTIME_CACHE *VariableRuntimeCache,
> > > + IN UINTN Offset,
> > > + IN UINTN Length
> > > + )
> > > +{
> > > + if (VariableRuntimeCache == NULL) {
> > > + return EFI_INVALID_PARAMETER;
> > > + } else if (VariableRuntimeCache->Store == NULL) {
> > > + // Runtime cache is not available yet at this point,
> > > + // Return EFI_SUCCESS instead of EFI_NOT_AVAILABLE_YET to let it
> > > progress
> > > + return EFI_SUCCESS;
> > > + }
> > > +
> > > + if (
> > > + mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate == NULL
> > ||
> > > + mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.ReadLock == NULL
> > > + ) {
> > > + return EFI_UNSUPPORTED;
> > > + }
> > > +
> > > + if (
> > > + *(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate) &&
> > > + VariableRuntimeCache->PendingUpdateLength > 0
> > > + ) {
> > > + VariableRuntimeCache->PendingUpdateLength =
> > > + (UINT32) (
> > > + MAX (
> > > + (UINTN) (VariableRuntimeCache->PendingUpdateOffset +
> > > VariableRuntimeCache->PendingUpdateLength),
> > > + Offset + Length
> > > + ) - MIN ((UINTN) VariableRuntimeCache->PendingUpdateOffset,
> > Offset)
> > > + );
> > > + VariableRuntimeCache->PendingUpdateOffset =
> > > + (UINT32) MIN ((UINTN) VariableRuntimeCache-
> > >PendingUpdateOffset,
> > > Offset);
> > > + } else {
> > > + VariableRuntimeCache->PendingUpdateLength = (UINT32) Length;
> > > + VariableRuntimeCache->PendingUpdateOffset = (UINT32) Offset;
> > > + }
> > > + *(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.PendingUpdate) = TRUE;
> > > +
> > > + if (*(mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext.ReadLock) == FALSE) {
> > > + return SynchronizeRuntimeVariableCacheEx ();
> > > + }
> > > +
> > > + return EFI_SUCCESS;
> > > +}
> > > diff --git
> > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c
> > > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c
> > > index ce409f22a3..8d767f75ac 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 <Guid/SmmVariableCommon.h>
> > > #include "Variable.h"
> > > #include "VariableParsing.h"
> > > +#include "VariableRuntimeCache.h"
> > > +
> > > +extern VARIABLE_STORE_HEADER *mNvVariableCache;
> > >
> > > BOOLEAN mAtRuntime = FALSE;
> > > UINT8 *mVariableBufferPayload = 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 *RegisterContext,
> > > + IN OUT VOID *CommBuffer,
> > > + IN OUT UINTN *CommBufferSize
> > > )
> > > {
> > > - 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
> > > *VariableToLock;
> > > + SMM_VARIABLE_COMMUNICATE_VAR_CHECK_VARIABLE_PROPERTY
> > > *CommVariableProperty;
> > > + VARIABLE_INFO_ENTRY *VariableInfo;
> > > + VARIABLE_RUNTIME_CACHE_CONTEXT
> > > *VariableCacheContext;
> > > + VARIABLE_STORE_HEADER *VariableCache;
> > > + UINTN InfoSize;
> > > + UINTN NameBufferSize;
> > > + UINTN CommBufferPayloadSize;
> > > + UINTN TempCommBufferSize;
> > >
> > > //
> > > // 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_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT)
> > )
> > > {
> >
> >
> > The above check is not correct, I think it should be:
> >
> > if (CommBufferPayloadSize < sizeof
> >
> (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT)
> > ) {
> >
> > Please help to double confirm.
> > Also, I recommend some security tests should be performed to these new
> > cases in
> > the variable SMI handler.
> >
> >
>
> You're right. The wrong macro was simply copied.
>
> > > + DEBUG ((DEBUG_ERROR, "InitRuntimeVariableCacheContext: SMM
> > > communication buffer size invalid!\n"));
> > > + } else if (mEndOfDxe) {
> > > + DEBUG ((DEBUG_ERROR, "InitRuntimeVariableCacheContext:
> Cannot
> > > init context after end of DXE!\n"));
> > > + } else {
> > > + RuntimeVariableCacheContext =
> > >
> >
> (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT
> > > *) SmmVariableFunctionHeader->Data;
> >
> >
> > Not sure on this one:
> >
> > Do you think it is necessary to copy the contents in the comm buffer to the
> > pre-allocated SMM variable buffer payload 'mVariableBufferPayload' to
> > avoid
> > TOCTOU issue? Since there are some tests (sort of, a couple of ASSERTs)
> > based
> > on the comm buffer content.
> >
> >
>
> I understand the TOCTOU observation. But is this still a concern with all the
> cores rendezvoused in SMM prior to end of DXE?
Hello Jian and Jiewen,
Could you help to provide your comments on this one? Thanks in advance.
>
> > > + VariableCacheContext = &mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext;
> > > +
> > > + ASSERT (RuntimeVariableCacheContext->RuntimeVolatileCache !=
> > > NULL);
> > > + ASSERT (RuntimeVariableCacheContext->RuntimeNvCache != NULL);
> > > + ASSERT (RuntimeVariableCacheContext->PendingUpdate != NULL);
> > > + ASSERT (RuntimeVariableCacheContext->ReadLock != NULL);
> > > + ASSERT (RuntimeVariableCacheContext->HobFlushComplete !=
> > NULL);
> > > +
> > > + VariableCacheContext->VariableRuntimeHobCache.Store =
> > > RuntimeVariableCacheContext->RuntimeHobCache;
> > > + VariableCacheContext->VariableRuntimeVolatileCache.Store =
> > > RuntimeVariableCacheContext->RuntimeVolatileCache;
> > > + VariableCacheContext->VariableRuntimeNvCache.Store =
> > > RuntimeVariableCacheContext->RuntimeNvCache;
> > > + VariableCacheContext->PendingUpdate =
> > > RuntimeVariableCacheContext->PendingUpdate;
> > > + VariableCacheContext->ReadLock =
> > > RuntimeVariableCacheContext->ReadLock;
> > > + VariableCacheContext->HobFlushComplete =
> > > RuntimeVariableCacheContext->HobFlushComplete;
> > > +
> > > + // Set up the intial pending request since the RT cache needs to be
> in
> > > sync with SMM cache
> > > + if (mVariableModuleGlobal->VariableGlobal.HobVariableBase == 0)
> {
> > > + VariableCacheContext-
> > > >VariableRuntimeHobCache.PendingUpdateOffset = 0;
> > > + VariableCacheContext-
> > > >VariableRuntimeHobCache.PendingUpdateLength = 0;
> > > + } else {
> > > + VariableCache = (VARIABLE_STORE_HEADER *) (UINTN)
> > > mVariableModuleGlobal->VariableGlobal.HobVariableBase;
> > > + VariableCacheContext-
> > > >VariableRuntimeHobCache.PendingUpdateOffset = 0;
> > > + VariableCacheContext-
> > > >VariableRuntimeHobCache.PendingUpdateLength = (UINT32) ((UINTN)
> > > GetEndPointer (VariableCache) - (UINTN) VariableCache);
> > > + CopyGuid (&(VariableCacheContext-
> > > >VariableRuntimeHobCache.Store->Signature), &(VariableCache-
> > > >Signature));
> > > + }
> > > + VariableCache = (VARIABLE_STORE_HEADER *) (UINTN)
> > > mVariableModuleGlobal->VariableGlobal.VolatileVariableBase;
> > > + VariableCacheContext-
> > > >VariableRuntimeVolatileCache.PendingUpdateOffset = 0;
> > > + VariableCacheContext-
> > > >VariableRuntimeVolatileCache.PendingUpdateLength = (UINT32)
> > ((UINTN)
> > > GetEndPointer (VariableCache) - (UINTN) VariableCache);
> > > + CopyGuid (&(VariableCacheContext-
> > > >VariableRuntimeVolatileCache.Store->Signature), &(VariableCache-
> > > >Signature));
> > > +
> > > + VariableCache = (VARIABLE_STORE_HEADER *) (UINTN)
> > > mNvVariableCache;
> > > + VariableCacheContext-
> > > >VariableRuntimeNvCache.PendingUpdateOffset = 0;
> > > + VariableCacheContext-
> > > >VariableRuntimeNvCache.PendingUpdateLength = (UINT32) ((UINTN)
> > > GetEndPointer (VariableCache) - (UINTN) VariableCache);
> > > + CopyGuid (&(VariableCacheContext-
> > >VariableRuntimeNvCache.Store-
> > > >Signature), &(VariableCache->Signature));
> > > +
> > > + *(VariableCacheContext->PendingUpdate) = TRUE;
> > > + *(VariableCacheContext->ReadLock) = FALSE;
> > > + *(VariableCacheContext->HobFlushComplete) = FALSE;
> > > + }
> > > + Status = EFI_SUCCESS;
> > > + break;
> > > + case SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE:
> > > + Status = SynchronizeRuntimeVariableCacheEx ();
> > > + 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 =
> > > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO *)
> > > SmmVariableFunctionHeader->Data;
> > > +
> > > + if (mVariableModuleGlobal->VariableGlobal.HobVariableBase > 0) {
> > > + VariableCache = (VARIABLE_STORE_HEADER *) (UINTN)
> > > mVariableModuleGlobal->VariableGlobal.HobVariableBase;
> > > + GetRuntimeCacheInfo->TotalHobStorageSize = VariableCache->Size;
> > > + } else {
> > > + GetRuntimeCacheInfo->TotalHobStorageSize = 0;
> > > + }
> > > +
> > > + VariableCache = (VARIABLE_STORE_HEADER *) (UINTN)
> > > mVariableModuleGlobal->VariableGlobal.VolatileVariableBase;
> > > + GetRuntimeCacheInfo->TotalVolatileStorageSize = VariableCache-
> > >Size;
> > > + VariableCache = (VARIABLE_STORE_HEADER *) (UINTN)
> > > mNvVariableCache;
> > > + GetRuntimeCacheInfo->TotalNvStorageSize = (UINTN)
> VariableCache-
> > > >Size;
> > > + GetRuntimeCacheInfo->AuthenticatedVariableUsage =
> > > mVariableModuleGlobal->VariableGlobal.AuthFormat;
> > > +
> > > + Status = EFI_SUCCESS;
> > > + break;
> > >
> > > default:
> > > Status = EFI_UNSUPPORTED;
> > > diff --git
> > >
> >
> a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.c
> > >
> >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.c
> > > index 0a1888e5ef..46f69765a4 100644
> > > ---
> > >
> >
> a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.c
> > > +++
> > >
> >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.c
> > > @@ -13,7 +13,7 @@
> > >
> > > InitCommunicateBuffer() is really function to check the variable data
> size.
> > >
> > > -Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.<BR>
> > > +Copyright (c) 2010 - 2019, Intel Corporation. All rights reserved.<BR>
> > > SPDX-License-Identifier: BSD-2-Clause-Patent
> > >
> > > **/
> > > @@ -32,13 +32,16 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> > > #include <Library/UefiRuntimeLib.h>
> > > #include <Library/BaseMemoryLib.h>
> > > #include <Library/DebugLib.h>
> > > +#include <Library/TimerLib.h>
> > > #include <Library/UefiLib.h>
> > > #include <Library/BaseLib.h>
> > >
> > > #include <Guid/EventGroup.h>
> > > +#include <Guid/PiSmmCommunicationRegionTable.h>
> > > #include <Guid/SmmVariableCommon.h>
> > >
> > > #include "PrivilegePolymorphic.h"
> > > +#include "VariableParsing.h"
> > >
> > > EFI_HANDLE mHandle = NULL;
> > > EFI_SMM_VARIABLE_PROTOCOL *mSmmVariable = NULL;
> > > @@ -46,8 +49,19 @@ EFI_EVENT
> mVirtualAddressChangeEvent
> > =
> > > NULL;
> > > EFI_SMM_COMMUNICATION_PROTOCOL *mSmmCommunication
> =
> > > NULL;
> > > UINT8 *mVariableBuffer = NULL;
> > > UINT8 *mVariableBufferPhysical = NULL;
> > > +VARIABLE_INFO_ENTRY *mVariableInfo = NULL;
> > > +VARIABLE_STORE_HEADER *mVariableRuntimeHobCacheBuffer
> > =
> > > NULL;
> > > +VARIABLE_STORE_HEADER *mVariableRuntimeNvCacheBuffer
> > =
> > > NULL;
> > > +VARIABLE_STORE_HEADER
> *mVariableRuntimeVolatileCacheBuffer
> > > = 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 +121,73 @@ ReleaseLockOnlyAtBootTime (
> > > }
> > > }
> > >
> > > +/**
> > > + Return TRUE if ExitBootServices () has been called.
> > > +
> > > + @retval TRUE If ExitBootServices () has been called.
> > > +**/
> > > +BOOLEAN
> > > +AtRuntime (
> > > + VOID
> > > + )
> >
> >
> > I think we can either:
> > 1. Use EfiAtRuntime() for VariableSmmRuntimeDxe
> > 2. Move AtRuntime() to VariableParsing.c so that the function can be
> shared
> > with VariableRuntimeDxe & VariableSmmRuntimeDxe. And then update
> > the
> > EfiAtRuntime() usages to AtRuntime() for VariableSmmRuntimeDxe.
> >
> >
>
> #1 will work fine.
>
> > > +{
> > > + return EfiAtRuntime ();
> > > +}
> > > +
> > > +/**
> > > + Initialize the variable cache buffer as an empty variable store.
> > > +
> > > + @param[out] VariableCacheBuffer A pointer to pointer of a cache
> > > variable store.
> > > + @param[in,out] TotalVariableCacheSize On input, the minimum size
> > > needed for the UEFI variable store cache
> > > + buffer that is allocated. On output, the actual size
> of
> > > the buffer allocated.
> > > + If TotalVariableCacheSize is zero, a buffer will not
> be
> > > allocated and the
> > > + function will return with EFI_SUCCESS.
> > > +
> > > + @retval EFI_SUCCESS The variable cache was allocated and
> > initialized
> > > 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
> > to
> > > allocate the variable store cache buffer.
> > > +
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +InitVariableCache (
> > > + OUT VARIABLE_STORE_HEADER **VariableCacheBuffer,
> > > + IN OUT UINTN *TotalVariableCacheSize
> > > + )
> > > +{
> > > + VARIABLE_STORE_HEADER *VariableCacheStorePtr;
> > > +
> > > + if (TotalVariableCacheSize == NULL) {
> > > + return EFI_INVALID_PARAMETER;
> > > + }
> > > + if (*TotalVariableCacheSize == 0) {
> > > + return EFI_SUCCESS;
> > > + }
> > > + if (VariableCacheBuffer == NULL || *TotalVariableCacheSize < sizeof
> > > (VARIABLE_STORE_HEADER)) {
> > > + return EFI_INVALID_PARAMETER;
> > > + }
> > > + *TotalVariableCacheSize = ALIGN_VALUE (*TotalVariableCacheSize,
> > sizeof
> > > (UINT32));
> > > +
> > > + //
> > > + // Allocate NV Storage Cache and initialize it to all 1's (like an erased FV)
> > > + //
> > > + *VariableCacheBuffer = (VARIABLE_STORE_HEADER *)
> > > AllocateRuntimePages (
> > > + EFI_SIZE_TO_PAGES (*TotalVariableCacheSize)
> > > + );
> > > + if (*VariableCacheBuffer == NULL) {
> > > + return EFI_OUT_OF_RESOURCES;
> > > + }
> > > + VariableCacheStorePtr = *VariableCacheBuffer;
> > > + SetMem32 ((VOID *) VariableCacheStorePtr, *TotalVariableCacheSize,
> > > (UINT32) 0xFFFFFFFF);
> > > +
> > > + ZeroMem ((VOID *) VariableCacheStorePtr, sizeof
> > > (VARIABLE_STORE_HEADER));
> > > + VariableCacheStorePtr->Size = (UINT32) *TotalVariableCacheSize;
> > > + VariableCacheStorePtr->Format = VARIABLE_STORE_FORMATTED;
> > > + VariableCacheStorePtr->State = VARIABLE_STORE_HEALTHY;
> > > +
> > > + return EFI_SUCCESS;
> > > +}
> > > +
> > > /**
> > > Initialize the communicate buffer using DataSize and Function.
> > >
> > > @@ -153,6 +234,69 @@ InitCommunicateBuffer (
> > > }
> > >
> > >
> > > +/**
> > > + Gets a SMM communicate buffer from the
> > > EDKII_PI_SMM_COMMUNICATION_REGION_TABLE installed as an entry
> in
> > > the UEFI
> > > + system configuration table. A generic SMM communication buffer DXE
> > > driver may install the table or a custom table
> > > + may be installed by a platform-specific driver.
> > > +
> > > + The communicate size is: SMM_COMMUNICATE_HEADER_SIZE +
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE +
> > > + DataSize.
> > > +
> > > + @param[in,out] CommBufferSize On input, the minimum size
> needed
> > > for the communication buffer.
> > > + On output, the SMM buffer size available at
> > CommBuffer.
> > > + @param[out] CommBuffer A pointer to an SMM communication
> > > buffer pointer.
> > > +
> > > + @retval EFI_SUCCESS The communication buffer was found
> > > successfully.
> > > + @retval EFI_INVALID_PARAMETER A given pointer is NULL or the
> > > CommBufferSize is zero.
> > > + @retval EFI_NOT_FOUND The
> > > EDKII_PI_SMM_COMMUNICATION_REGION_TABLE was not found.
> > > + @retval EFI_OUT_OF_RESOURCES A valid SMM communicate buffer
> > for
> > > the requested size is not available.
> > > +
> > > +**/
> > > +EFI_STATUS
> > > +GetCommunicateBuffer (
> > > + IN OUT UINTN *CommBufferSize,
> > > + OUT UINT8 **CommBuffer
> > > + )
> >
> >
> > Minor comment:
> >
> > I found that the consumers of the above function are:
> > GetRuntimeCacheInfo()
> > SendRuntimeVariableCacheContextToSmm()
> >
> > Both of them get called within SmmVariableReady() when the SMM
> variable
> > driver
> > finished initialization. I am wondering if they can simply use the pre-
> allocated
> > comm buffer (via InitCommunicateBuffer() and using 'mVariableBuffer'),
> > instead
> > of looking into the configuration table.
> >
> > In my opinion, this function can be dropped.
> >
> >
>
> I did that initially. It was recommended to use this method.
After this patch, the driver will have 2 approaches for constructing the SMM
communication buffer:
A). Pre-allocate a buffer 'mVariableBuffer' as subsequent usage as SMM
communication buffer via function calls InitCommunicateBuffer() and then
SendCommunicateBuffer();
This approach is used by functions like:
VariableLockRequestToLock()
VarCheckVariablePropertySet()
VarCheckVariablePropertyGet()
RuntimeServiceGetVariable()
RuntimeServiceGetNextVariableName()
RuntimeServiceSetVariable()
RuntimeServiceQueryVariableInfo()
OnExitBootServices()
OnReadyToBoot()
B). Lookup in the system configuration table for memory ranges as SMM
communication buffer.
This approach is used by functions:
GetRuntimeCacheInfo()
SendRuntimeVariableCacheContextToSmm()
Could you help to confirm with the people who gave you the recommendation that
whether the driver should keep these 2 approaches or should align with 1
unified approach? Thanks.
Best Regards,
Hao Wu
>
> > > +{
> > > + EFI_STATUS Status;
> > > + EDKII_PI_SMM_COMMUNICATION_REGION_TABLE
> > > *PiSmmCommunicationRegionTable;
> > > + EFI_MEMORY_DESCRIPTOR *Entry;
> > > + UINTN EntrySize;
> > > + UINT32 Index;
> > > +
> > > + if (CommBuffer == NULL || CommBufferSize == NULL ||
> > > *CommBufferSize == 0) {
> > > + return EFI_INVALID_PARAMETER;
> > > + }
> > > +
> > > + Status = EfiGetSystemConfigurationTable (
> > > + &gEdkiiPiSmmCommunicationRegionTableGuid,
> > > + (VOID **) &PiSmmCommunicationRegionTable
> > > + );
> > > + if (EFI_ERROR (Status) || PiSmmCommunicationRegionTable == NULL) {
> > > + return EFI_NOT_FOUND;
> > > + }
> > > +
> > > + Entry = (EFI_MEMORY_DESCRIPTOR *)
> > (PiSmmCommunicationRegionTable
> > > + 1);
> > > + EntrySize = 0;
> > > + for (Index = 0; Index < PiSmmCommunicationRegionTable-
> > > >NumberOfEntries; Index++) {
> > > + if (Entry->Type == EfiConventionalMemory) {
> > > + EntrySize = EFI_PAGES_TO_SIZE ((UINTN) Entry->NumberOfPages);
> > > + if (EntrySize >= *CommBufferSize) {
> > > + break;
> > > + }
> > > + }
> > > + Entry = (EFI_MEMORY_DESCRIPTOR *) ((UINT8 *) Entry +
> > > PiSmmCommunicationRegionTable->DescriptorSize);
> > > + }
> > > +
> > > + if (Index < PiSmmCommunicationRegionTable->NumberOfEntries) {
> > > + *CommBufferSize = EntrySize;
> > > + *CommBuffer = (UINT8 *) (UINTN) Entry->PhysicalStart;
> > > + return EFI_SUCCESS;
> > > + }
> > > +
> > > + return EFI_OUT_OF_RESOURCES;
> > > +}
> > > +
> > > /**
> > > Send the data in communicate buffer to SMM.
> > >
> > > @@ -424,6 +568,171 @@ Done:
> > > return Status;
> > > }
> > >
> > > +/**
> > > + Signals SMM to synchronize any pending variable updates with the
> > > runtime cache(s).
> > > +
> > > +**/
> > > +VOID
> > > +EFIAPI
> > > +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
> > updates.
> > > +
> > > + If the variable HOB was finished being flushed since the last check for a
> > > runtime cache update, this function
> > > + will prevent the HOB cache from being used for future runtime cache
> > hits.
> > > +
> > > +**/
> > > +VOID
> > > +EFIAPI
> > > +CheckForRuntimeCacheSync (
> > > + VOID
> > > + )
> > > +{
> > > + if (mVariableRuntimeCachePendingUpdate) {
> > > + SyncRuntimeCache ();
> > > + }
> > > + ASSERT (!mVariableRuntimeCachePendingUpdate);
> > > +
> > > + //
> > > + // The HOB variable data may have finished being flushed in the
> runtime
> > > cache sync update
> > > + //
> > > + if (mHobFlushComplete && mVariableRuntimeHobCacheBuffer !=
> NULL)
> > {
> > > + if (!AtRuntime ()) {
> > > + FreePool (mVariableRuntimeHobCacheBuffer);
> > > + }
> > > + mVariableRuntimeHobCacheBuffer = NULL;
> > > + }
> > > +}
> > > +
> > > +/**
> > > + This code finds variable in a volatile memory store.
> > > +
> > > + Caution: This function may receive untrusted input.
> > > + The data size is external input, so this function will validate it carefully
> 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 found.
> > > + @param[in, out] DataSize Size of Data found. If size is less than
> the
> > > + data, this value contains the required 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
> > > +EFIAPI
> > > +FindVariableInRuntimeCache (
> > > + IN CHAR16 *VariableName,
> > > + IN EFI_GUID *VendorGuid,
> > > + OUT UINT32 *Attributes OPTIONAL,
> > > + IN OUT UINTN *DataSize,
> > > + OUT VOID *Data OPTIONAL
> > > + )
> > > +{
> > > + EFI_STATUS Status;
> > > + UINTN DelayIndex;
> > > + UINTN TempDataSize;
> > > + VARIABLE_POINTER_TRACK RtPtrTrack;
> > > + VARIABLE_STORE_TYPE StoreType;
> > > + VARIABLE_STORE_HEADER *VariableStoreList[VariableStoreTypeMax];
> > > +
> > > + Status = EFI_NOT_FOUND;
> > > +
> > > + if (VariableName == NULL || VendorGuid == NULL || DataSize == NULL)
> {
> > > + return EFI_INVALID_PARAMETER;
> > > + }
> > > +
> > > + for (DelayIndex = 0; mVariableRuntimeCacheReadLock && DelayIndex
> <
> > > VARIABLE_RT_CACHE_READ_LOCK_TIMEOUT; DelayIndex++) {
> > > + MicroSecondDelay (10);
> > > + }
> > > + if (DelayIndex < VARIABLE_RT_CACHE_READ_LOCK_TIMEOUT) {
> > > + ASSERT (!mVariableRuntimeCacheReadLock);
> > > +
> > > + mVariableRuntimeCacheReadLock = 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] =
> > > mVariableRuntimeVolatileCacheBuffer;
> > > + VariableStoreList[VariableStoreTypeHob] =
> > > mVariableRuntimeHobCacheBuffer;
> > > + VariableStoreList[VariableStoreTypeNv] =
> > > mVariableRuntimeNvCacheBuffer;
> > > +
> > > + for (StoreType = (VARIABLE_STORE_TYPE) 0; StoreType <
> > > VariableStoreTypeMax; StoreType++) {
> > > + if (VariableStoreList[StoreType] == NULL) {
> > > + continue;
> > > + }
> > > +
> > > + RtPtrTrack.StartPtr = GetStartPointer (VariableStoreList[StoreType]);
> > > + RtPtrTrack.EndPtr = GetEndPointer (VariableStoreList[StoreType]);
> > > + RtPtrTrack.Volatile = (BOOLEAN) (StoreType ==
> > > VariableStoreTypeVolatile);
> > > +
> > > + Status = FindVariableEx (VariableName, VendorGuid, FALSE,
> > > &RtPtrTrack);
> > > + if (!EFI_ERROR (Status)) {
> > > + break;
> > > + }
> > > + }
> > > +
> > > + if (!EFI_ERROR (Status)) {
> > > + //
> > > + // Get data size
> > > + //
> > > + TempDataSize = DataSizeOfVariable (RtPtrTrack.CurrPtr);
> > > + ASSERT (TempDataSize != 0);
> > > +
> > > + if (*DataSize >= TempDataSize) {
> > > + if (Data == NULL) {
> > > + Status = EFI_INVALID_PARAMETER;
> > > + goto Done;
> > > + }
> > > +
> > > + CopyMem (Data, GetVariableDataPtr (RtPtrTrack.CurrPtr),
> > > TempDataSize);
> > > + if (Attributes != NULL) {
> > > + *Attributes = RtPtrTrack.CurrPtr->Attributes;
> > > + }
> > > +
> > > + *DataSize = TempDataSize;
> > > +
> > > + UpdateVariableInfo (VariableName, VendorGuid,
> > RtPtrTrack.Volatile,
> > > TRUE, FALSE, FALSE, TRUE, &mVariableInfo);
> > > +
> > > + Status = EFI_SUCCESS;
> > > + goto Done;
> > > + } else {
> > > + *DataSize = TempDataSize;
> > > + Status = EFI_BUFFER_TOO_SMALL;
> > > + goto Done;
> > > + }
> > > + }
> > > + }
> > > + }
> > > +
> > > +Done:
> > > + mVariableRuntimeCacheReadLock = FALSE;
> >
> >
> > If timeout occurs when acquiring the read lock, should this flag be set to
> > FALSE
> > in such case?
> >
>
> Please see reply to patch #8.
>
> > Best Regards,
> > Hao Wu
> >
> >
> > > +
> > > + return Status;
> > > +}
> > > +
> > > /**
> > > This code finds variable in storage blocks (Volatile or Non-Volatile).
> > >
> > > @@ -454,91 +763,21 @@ RuntimeServiceGetVariable (
> > > )
> > > {
> > > EFI_STATUS Status;
> > > - UINTN PayloadSize;
> > > - SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE
> > > *SmmVariableHeader;
> > > - UINTN TempDataSize;
> > > - UINTN VariableNameSize;
> > >
> > > if (VariableName == NULL || VendorGuid == NULL || DataSize == NULL)
> {
> > > return EFI_INVALID_PARAMETER;
> > > }
> > > -
> > > - TempDataSize = *DataSize;
> > > - VariableNameSize = StrSize (VariableName);
> > > - SmmVariableHeader = NULL;
> > > -
> > > - //
> > > - // If VariableName exceeds SMM payload limit. Return failure
> > > - //
> > > - if (VariableNameSize > mVariableBufferPayloadSize - OFFSET_OF
> > > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name)) {
> > > - return EFI_INVALID_PARAMETER;
> > > - }
> > > -
> > > - AcquireLockOnlyAtBootTime(&mVariableServicesLock);
> > > -
> > > - //
> > > - // Init the communicate buffer. The buffer data size is:
> > > - // SMM_COMMUNICATE_HEADER_SIZE +
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + PayloadSize.
> > > - //
> > > - if (TempDataSize > mVariableBufferPayloadSize - OFFSET_OF
> > > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) -
> > > VariableNameSize) {
> > > - //
> > > - // If output data buffer exceed SMM payload limit. Trim output buffer
> to
> > > SMM payload size
> > > - //
> > > - TempDataSize = mVariableBufferPayloadSize - OFFSET_OF
> > > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) -
> > > VariableNameSize;
> > > - }
> > > - PayloadSize = OFFSET_OF
> > > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) +
> > > VariableNameSize + TempDataSize;
> > > -
> > > - Status = InitCommunicateBuffer ((VOID **)&SmmVariableHeader,
> > > PayloadSize, SMM_VARIABLE_FUNCTION_GET_VARIABLE);
> > > - if (EFI_ERROR (Status)) {
> > > - goto Done;
> > > - }
> > > - ASSERT (SmmVariableHeader != NULL);
> > > -
> > > - CopyGuid (&SmmVariableHeader->Guid, VendorGuid);
> > > - SmmVariableHeader->DataSize = TempDataSize;
> > > - SmmVariableHeader->NameSize = VariableNameSize;
> > > - if (Attributes == NULL) {
> > > - SmmVariableHeader->Attributes = 0;
> > > - } else {
> > > - SmmVariableHeader->Attributes = *Attributes;
> > > - }
> > > - CopyMem (SmmVariableHeader->Name, VariableName,
> > > SmmVariableHeader->NameSize);
> > > -
> > > - //
> > > - // Send data to SMM.
> > > - //
> > > - Status = SendCommunicateBuffer (PayloadSize);
> > > -
> > > - //
> > > - // Get data from SMM.
> > > - //
> > > - if (Status == EFI_SUCCESS || Status == EFI_BUFFER_TOO_SMALL) {
> > > - //
> > > - // SMM CommBuffer DataSize can be a trimed value
> > > - // Only update DataSize when needed
> > > - //
> > > - *DataSize = SmmVariableHeader->DataSize;
> > > - }
> > > - if (Attributes != NULL) {
> > > - *Attributes = SmmVariableHeader->Attributes;
> > > - }
> > > -
> > > - if (EFI_ERROR (Status)) {
> > > - goto Done;
> > > - }
> > > -
> > > - if (Data != NULL) {
> > > - CopyMem (Data, (UINT8 *)SmmVariableHeader->Name +
> > > SmmVariableHeader->NameSize, SmmVariableHeader->DataSize);
> > > - } else {
> > > - Status = EFI_INVALID_PARAMETER;
> > > + if (VariableName[0] == 0) {
> > > + return EFI_NOT_FOUND;
> > > }
> > >
> > > -Done:
> > > + AcquireLockOnlyAtBootTime (&mVariableServicesLock);
> > > + Status = FindVariableInRuntimeCache (VariableName, VendorGuid,
> > > Attributes, DataSize, Data);
> > > ReleaseLockOnlyAtBootTime (&mVariableServicesLock);
> > > +
> > > return Status;
> > > }
> > >
> > > -
> > > /**
> > > This code Finds the Next available variable.
> > >
> > > @@ -870,6 +1109,17 @@ OnReadyToBoot (
> > > //
> > > SendCommunicateBuffer (0);
> > >
> > > + //
> > > + // Install the system configuration table for variable info data captured
> > > + //
> > > + if (FeaturePcdGet (PcdVariableCollectStatistics)) {
> > > + if (mVariableAuthFormat) {
> > > + gBS->InstallConfigurationTable (&gEfiAuthenticatedVariableGuid,
> > > mVariableInfo);
> > > + } else {
> > > + gBS->InstallConfigurationTable (&gEfiVariableGuid, mVariableInfo);
> > > + }
> > > + }
> > > +
> > > gBS->CloseEvent (Event);
> > > }
> > >
> > > @@ -893,6 +1143,9 @@ VariableAddressChangeEvent (
> > > {
> > > EfiConvertPointer (0x0, (VOID **) &mVariableBuffer);
> > > EfiConvertPointer (0x0, (VOID **) &mSmmCommunication);
> > > + EfiConvertPointer (0x0, (VOID **)
> &mVariableRuntimeHobCacheBuffer);
> > > + EfiConvertPointer (0x0, (VOID **) &mVariableRuntimeNvCacheBuffer);
> > > + EfiConvertPointer (0x0, (VOID **)
> > > &mVariableRuntimeVolatileCacheBuffer);
> > > }
> > >
> > > /**
> > > @@ -969,6 +1222,173 @@ Done:
> > > return Status;
> > > }
> > >
> > > +/**
> > > + This code gets information needed from SMM for runtime cache
> > > initialization.
> > > +
> > > + @param[out] TotalHobStorageSize Output pointer for the total
> HOB
> > > storage size in bytes.
> > > + @param[out] TotalNvStorageSize Output pointer for the total non-
> > > volatile storage size in bytes.
> > > + @param[out] TotalVolatileStorageSize Output pointer for the total
> > > volatile storage size in bytes.
> > > + @param[out] AuthenticatedVariableUsage Output pointer that
> indicates
> > if
> > > authenticated variables are to be used.
> > > +
> > > + @retval EFI_SUCCESS Retrieved the size successfully.
> > > + @retval EFI_INVALID_PARAMETER TotalNvStorageSize parameter
> is
> > > NULL.
> > > + @retval EFI_OUT_OF_RESOURCES Could not allocate a
> > CommBuffer.
> > > + @retval Others Could not retrieve the size successfully.;
> > > +
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +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
> > > *SmmCommunicateHeader;
> > > + SMM_VARIABLE_COMMUNICATE_HEADER
> > > *SmmVariableFunctionHeader;
> > > + UINTN CommSize;
> > > + UINTN CommBufferSize;
> > > + UINT8 *CommBuffer;
> > > +
> > > + SmmGetRuntimeCacheInfo = NULL;
> > > + CommBuffer = NULL;
> > > +
> > > + if (TotalHobStorageSize == NULL || TotalNvStorageSize == NULL ||
> > > TotalVolatileStorageSize == NULL || AuthenticatedVariableUsage ==
> NULL)
> > {
> > > + return EFI_INVALID_PARAMETER;
> > > + }
> > > +
> > > + AcquireLockOnlyAtBootTime (&mVariableServicesLock);
> > > +
> > > + CommSize = SMM_COMMUNICATE_HEADER_SIZE +
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof
> > > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO);
> > > + CommBufferSize = CommSize;
> > > + Status = GetCommunicateBuffer (&CommBufferSize, &CommBuffer);
> > > + if (EFI_ERROR (Status)) {
> > > + goto Done;
> > > + }
> > > + if (CommBuffer == NULL) {
> > > + Status = EFI_OUT_OF_RESOURCES;
> > > + goto Done;
> > > + }
> > > + ZeroMem (CommBuffer, CommBufferSize);
> > > +
> > > + SmmCommunicateHeader = (EFI_SMM_COMMUNICATE_HEADER *)
> > > CommBuffer;
> > > + CopyGuid (&SmmCommunicateHeader->HeaderGuid,
> > > &gEfiSmmVariableProtocolGuid);
> > > + SmmCommunicateHeader->MessageLength =
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof
> > > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO);
> > > +
> > > + SmmVariableFunctionHeader =
> > > (SMM_VARIABLE_COMMUNICATE_HEADER *)
> SmmCommunicateHeader-
> > > >Data;
> > > + SmmVariableFunctionHeader->Function =
> > > SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO;
> > > + SmmGetRuntimeCacheInfo =
> > > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO *)
> > > SmmVariableFunctionHeader->Data;
> > > +
> > > + //
> > > + // Send data to SMM.
> > > + //
> > > + Status = mSmmCommunication->Communicate
> (mSmmCommunication,
> > > CommBuffer, &CommSize);
> > > + ASSERT_EFI_ERROR (Status);
> > > + if (CommSize <= SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) {
> > > + Status = EFI_BAD_BUFFER_SIZE;
> > > + goto Done;
> > > + }
> > > +
> > > + Status = SmmVariableFunctionHeader->ReturnStatus;
> > > + if (EFI_ERROR (Status)) {
> > > + goto Done;
> > > + }
> > > +
> > > + //
> > > + // Get data from SMM.
> > > + //
> > > + *TotalHobStorageSize = SmmGetRuntimeCacheInfo-
> > >TotalHobStorageSize;
> > > + *TotalNvStorageSize = SmmGetRuntimeCacheInfo-
> >TotalNvStorageSize;
> > > + *TotalVolatileStorageSize = SmmGetRuntimeCacheInfo-
> > > >TotalVolatileStorageSize;
> > > + *AuthenticatedVariableUsage = 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 Could not allocate a CommBuffer.
> > > + @retval Others Could not retrieve the size successfully.;
> > > +
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +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;
> > > + UINTN CommBufferSize;
> > > + UINT8 *CommBuffer;
> > > +
> > > + SmmRuntimeVarCacheContext = NULL;
> > > + CommBuffer = NULL;
> > > +
> > > + 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 = SMM_COMMUNICATE_HEADER_SIZE +
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof
> > >
> >
> (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT)
> > ;
> > > + CommBufferSize = CommSize;
> > > + Status = GetCommunicateBuffer (&CommBufferSize, &CommBuffer);
> > > + if (EFI_ERROR (Status)) {
> > > + goto Done;
> > > + }
> > > + if (CommBuffer == NULL) {
> > > + Status = EFI_OUT_OF_RESOURCES;
> > > + goto Done;
> > > + }
> > > + ZeroMem (CommBuffer, CommBufferSize);
> > > +
> > > + SmmCommunicateHeader = (EFI_SMM_COMMUNICATE_HEADER *)
> > > CommBuffer;
> > > + CopyGuid (&SmmCommunicateHeader->HeaderGuid,
> > > &gEfiSmmVariableProtocolGuid);
> > > + SmmCommunicateHeader->MessageLength =
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof
> > >
> >
> (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT)
> > ;
> > > +
> > > + SmmVariableFunctionHeader =
> > > (SMM_VARIABLE_COMMUNICATE_HEADER *)
> SmmCommunicateHeader-
> > > >Data;
> > > + SmmVariableFunctionHeader->Function =
> > >
> > SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT;
> > > + SmmRuntimeVarCacheContext =
> > >
> >
> (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT
> > > *) SmmVariableFunctionHeader->Data;
> > > +
> > > + SmmRuntimeVarCacheContext->RuntimeHobCache =
> > > mVariableRuntimeHobCacheBuffer;
> > > + SmmRuntimeVarCacheContext->RuntimeVolatileCache =
> > > mVariableRuntimeVolatileCacheBuffer;
> > > + SmmRuntimeVarCacheContext->RuntimeNvCache =
> > > mVariableRuntimeNvCacheBuffer;
> > > + SmmRuntimeVarCacheContext->PendingUpdate =
> > > &mVariableRuntimeCachePendingUpdate;
> > > + SmmRuntimeVarCacheContext->ReadLock =
> > > &mVariableRuntimeCacheReadLock;
> > > + SmmRuntimeVarCacheContext->HobFlushComplete =
> > > &mHobFlushComplete;
> > > +
> > > + //
> > > + // Send data to SMM.
> > > + //
> > > + Status = mSmmCommunication->Communicate
> (mSmmCommunication,
> > > CommBuffer, &CommSize);
> > > + ASSERT_EFI_ERROR (Status);
> > > + if (CommSize <= SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) {
> > > + Status = EFI_BAD_BUFFER_SIZE;
> > > + goto Done;
> > > + }
> > > +
> > > + Status = SmmVariableFunctionHeader->ReturnStatus;
> > > + if (EFI_ERROR (Status)) {
> > > + goto Done;
> > > + }
> > > +
> > > +Done:
> > > + ReleaseLockOnlyAtBootTime (&mVariableServicesLock);
> > > + return Status;
> > > +}
> > > +
> > > /**
> > > Initialize variable service and install Variable Architectural protocol.
> > >
> > > @@ -985,7 +1405,7 @@ SmmVariableReady (
> > > {
> > > EFI_STATUS Status;
> > >
> > > - Status = gBS->LocateProtocol (&gEfiSmmVariableProtocolGuid, NULL,
> > > (VOID **)&mSmmVariable);
> > > + Status = gBS->LocateProtocol (&gEfiSmmVariableProtocolGuid, NULL,
> > > (VOID **) &mSmmVariable);
> > > if (EFI_ERROR (Status)) {
> > > return;
> > > }
> > > @@ -1007,6 +1427,40 @@ SmmVariableReady (
> > > //
> > > mVariableBufferPhysical = mVariableBuffer;
> > >
> > > + //
> > > + // Allocate runtime variable cache memory buffers.
> > > + //
> > > + Status = GetRuntimeCacheInfo (
> > > + &mVariableRuntimeHobCacheBufferSize,
> > > + &mVariableRuntimeNvCacheBufferSize,
> > > + &mVariableRuntimeVolatileCacheBufferSize,
> > > + &mVariableAuthFormat
> > > + );
> > > + if (!EFI_ERROR (Status)) {
> > > + Status = InitVariableCache (&mVariableRuntimeHobCacheBuffer,
> > > &mVariableRuntimeHobCacheBufferSize);
> > > + if (!EFI_ERROR (Status)) {
> > > + Status = InitVariableCache (&mVariableRuntimeNvCacheBuffer,
> > > &mVariableRuntimeNvCacheBufferSize);
> > > + if (!EFI_ERROR (Status)) {
> > > + Status = InitVariableCache (&mVariableRuntimeVolatileCacheBuffer,
> > > &mVariableRuntimeVolatileCacheBufferSize);
> > > + if (!EFI_ERROR (Status)) {
> > > + Status = InitVariableParsing (mVariableAuthFormat);
> > > + ASSERT_EFI_ERROR (Status);
> > > +
> > > + Status = SendRuntimeVariableCacheContextToSmm ();
> > > + if (!EFI_ERROR (Status)) {
> > > + SyncRuntimeCache ();
> > > + }
> > > + }
> > > + }
> > > + }
> > > + if (EFI_ERROR (Status)) {
> > > + mVariableRuntimeHobCacheBuffer = NULL;
> > > + mVariableRuntimeNvCacheBuffer = NULL;
> > > + mVariableRuntimeVolatileCacheBuffer = NULL;
> > > + }
> > > + }
> > > + ASSERT_EFI_ERROR (Status);
> > > +
> > > gRT->GetVariable = RuntimeServiceGetVariable;
> > > gRT->GetNextVariableName = RuntimeServiceGetNextVariableName;
> > > gRT->SetVariable = RuntimeServiceSetVariable;
> > > --
> > > 2.16.2.windows.1
> >
>
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