[edk2-devel] [PATCH V4 07/10] MdeModulePkg/Variable: Add RT GetVariable() cache support
Kubacki, Michael A
michael.a.kubacki at intel.com
Thu Oct 17 17:44:06 UTC 2019
Jian, thanks a lot your analysis. The intention was very much to constrain the flow of information
from SMM to the non-SMM environment and not vice versa during runtime cache operation.
I agree that the buffers pointed to in SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT
should be checked with VariableSmmIsBufferOutsideSmmValid (). I will send a V5 with this change.
Thanks,
Michael
> -----Original Message-----
> From: Wang, Jian J <jian.j.wang at intel.com>
> Sent: Thursday, October 17, 2019 7:23 AM
> To: Wu, Hao A <hao.a.wu at intel.com>; 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>; Yao, Jiewen
> <jiewen.yao at intel.com>
> Subject: RE: [PATCH V4 07/10] MdeModulePkg/Variable: Add RT
> GetVariable() cache support
>
> >
> > Again, I would like to ask for help from other reviewers to look at this patch
> > (patch 7/10) and the next one (patch 8/10) (at least from the security
> > perspective). Any help will be appreciated, thanks in advance.
> >
>
> I'm trying to do a simple analysis below from security perspective. Please
> correct me
> if anything wrong.
>
> The patch added 3 new SMI variable Functions
> f(a):
> SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT
> f(b): SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE
> f(c): SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO
>
> f(a) communication buffer is type of
> SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT
>
> which is defined as
> 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;
>
> There're 6 fields (all pointers) in the buffer. SMM will handle them in
> following ways
> - ReadLock and PendingUpdate are used to avoid race condition between
> smm and
> non-smm code. I don't think there's security breach here.
> - RuntimeHobCache, RuntimeNvCache and RuntimeVolatileCache are buffers
> passed
> to smm code to simply store variable content. Smm code will not read its
> content.
> I think this won't bring any security risk.
>
> The SmmVariableHandler() will call VariableSmmIsBufferOutsideSmmValid()
> to make sure the communication buffer is outside of smram. But the handler
> will
> not check the above 6 pointers passed through communication buffer to see
> if they
> are in non-smram scope. This leaves potential security hole to allow smram
> buffer
> to be passed in from non-smm code.
>
> f(b) doesn't use communication buffer. It's just used to flush variable cache.
> Then
> no security risk here.
>
> f(c) uses communication buffer with type of
>
> typedef struct {
> UINTN TotalHobStorageSize;
> UINTN TotalNvStorageSize;
> UINTN TotalVolatileStorageSize;
> BOOLEAN AuthenticatedVariableUsage;
> } SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO;
>
> There's no pointer in the buffer and the SMI handler doesn't read its content
> but
> just store data into it. I think there's no security risk here.
>
> I also checked data flow newly introduced between smm and non-smm
> boundary.
> Most of the data flow is just from smm to non-smm. The only exception is
> ReadLock
> mentioned above. Generally speaking, I don't find security issue in this patch
> series
> except to above pointers passed by communication buffer.
>
> Regards,
> Jian
>
> > -----Original Message-----
> > From: Wu, Hao A <hao.a.wu at intel.com>
> > Sent: Wednesday, October 16, 2019 3:57 PM
> > 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 V4 07/10] MdeModulePkg/Variable: Add RT
> GetVariable()
> > cache support
> >
> > Again, I would like to ask for help from other reviewers to look at this patch
> > (patch 7/10) and the next one (patch 8/10) (at least from the security
> > perspective). Any help will be appreciated, thanks in advance.
> >
> >
> > One comment inherited from the feedback on the V2 series:
> > I saw AtRuntime() is still being added in file VariableSmmRuntimeDxe.c,
> could
> > you help to double confirm?
> >
> > Another general level comment is that:
> > Please help to update the MdeModulePkg.uni file as well for the introduce
> of
> > the new PCD.
> >
> > Inline comments below:
> >
> >
> > > -----Original Message-----
> > > From: Kubacki, Michael A
> > > Sent: Tuesday, October 15, 2019 7:30 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 V4 07/10] 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 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.
> > >
> > > The following are important points regarding the behavior of the
> > > variable drivers when the variable runtime cache is enabled.
> > >
> > > 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 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
> outside
> > > SMRAM.
> > >
> > > 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
> > > runtime
> > > cache if an SMM update occurs while the runtime cache is locked. Note
> that
> > > it is not expected a Runtime services call will interrupt SMM processing
> > > since all CPU cores rendezvous in SMM.
> > >
> > > 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/MdeModulePkg.dec | 12 +
> > >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
> > > | 2 +
> > > MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
> | 2
> > > +
> > >
> > >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.i
> > > nf | 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 |
> 114
> > > ++++-
> > >
> > >
> MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.
> > > c | 512 +++++++++++++++++++-
> > > 12 files changed, 938 insertions(+), 41 deletions(-)
> > >
> > > 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.
> > >
> > >
> gEfiMdeModulePkgTokenSpaceGuid.PcdDevicePathSupportDevicePathFrom
> > > Text|TRUE|BOOLEAN|0x00010038
> > >
> > > + ## Indicates if the UEFI variable runtime cache should be enabled.
> > > + # This setting only applies if SMM variables are enabled. When
> enabled, all
> > > variable
> > > + # data for Runtime Service GetVariable () and GetNextVariableName
> ()
> > > calls is retrieved
> > > + # from a runtime data buffer referred to as the "runtime cache". An
> SMI is
> > > not triggered
> > > + # at all for these requests. Variables writes still trigger an SMI. This can
> > > greatly
> > > + # reduce overall system SMM usage as most boots tend to issue far
> more
> > > variable reads
> > > + # than writes.<BR><BR>
> > > + # TRUE - The UEFI variable runtime cache is enabled.<BR>
> > > + # FALSE - The UEFI variable runtime cache is disabled.<BR>
> > > + # @Prompt Enable the UEFI variable runtime cache.
> > > +
> > >
> gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache|FALS
> > > E|BOOLEAN|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/VariableSmmRuntimeDx
> > > e.inf
> > >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDx
> > > e.inf
> > > index 14894e6f13..b5a779a233 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
> > > @@ -65,7 +69,21 @@
> > > gEdkiiVariableLockProtocolGuid ## PRODUCES
> > > gEdkiiVarCheckProtocolGuid ## PRODUCES
> > >
> > > +[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.i
> > > nf
> > >
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.
> > > inf
> > > index f8a3742959..6e17f6cdf5 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..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;
> > >
> > > +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;
> > >
> > > 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;
> > >
> > > 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.<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
> > > +FlushPendingRuntimeVariableCacheUpdates (
> > > + VOID
> > > + );
> > > +
> > > +/**
> > > + Synchronizes the runtime variable caches with all pending updates
> outside
> > > 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
> ReadLock
> > > is available. Otherwise, the
> > > + update is added as a pending update for the given variable store and it
> will
> > > be flushed to the runtime cache
> > > + at the next opportunity the ReadLock is available.
> > > +
> > > + @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_SUCCESS The update was added as a pending
> update
> > > successfully. If the variable runtime
> > > + cache ReadLock was available, the runtime cache was
> > > updated successfully.
> > > + @retval EFI_UNSUPPORTED The volatile store to be updated is not
> > > 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"
> > >
> > > VARIABLE_MODULE_GLOBAL *mVariableModuleGlobal;
> > >
> > > @@ -332,6 +333,12 @@ RecordVarErrorFlag (
> > > // Update the data in NV cache.
> > > //
> > > *VarErrFlag = TempFlag;
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + &mVariableModuleGlobal-
> > >
> >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache,
> > > + (UINTN) VarErrFlag - (UINTN) mNvVariableCache + (UINTN)
> > > mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase,
> > > + sizeof (TempFlag)
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > }
> > > }
> > > }
> > > @@ -766,12 +773,24 @@ Reclaim (
> > >
> > > Done:
> > > if (IsVolatile || mVariableModuleGlobal->VariableGlobal.EmuNvMode)
> {
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + &mVariableModuleGlobal-
> > >
> >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCach
> > > 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.VariableRuntimeNvCache,
> > > + 0,
> > > + VariableStoreHeader->Size
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > }
> > >
> > > 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 (
> > > }
> > >
> > > Done:
> > > + if (!EFI_ERROR (Status)) {
> > > + if (Variable->Volatile) {
> > > + VolatileCacheInstance = &(mVariableModuleGlobal-
> > >
> >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeVolatileCach
> > > e);
> > > + } else {
> > > + VolatileCacheInstance = &(mVariableModuleGlobal-
> > >
> >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeNvCache);
> > > + }
> > > +
> > > + if (VolatileCacheInstance->Store != NULL) {
> > > + Status = SynchronizeRuntimeVariableCache (
> > > + VolatileCacheInstance,
> > > + 0,
> > > + VolatileCacheInstance->Store->Size
> > > + );
> > > + ASSERT_EFI_ERROR (Status);
> > > + }
> > > + }
> > > +
> > > return Status;
> > > }
> > >
> > > @@ -3200,6 +3237,14 @@ FlushHobVariableToFlash (
> > > ErrorFlag = TRUE;
> > > }
> > > }
> > > + if (mVariableModuleGlobal-
> > >
> >VariableGlobal.VariableRuntimeCacheContext.VariableRuntimeHobCache.S
> > > tore != NULL) {
> > > + 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.
> > > @@ -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 !=
> NULL)
> > > {
> > > + *(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..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 file
> > > 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 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
> > > +FlushPendingRuntimeVariableCacheUpdates (
> > > + VOID
> > > + )
> > > +{
> > > + VARIABLE_RUNTIME_CACHE_CONTEXT
> *VariableRuntimeCacheContext;
> > > +
> > > + VariableRuntimeCacheContext = &mVariableModuleGlobal-
> > > >VariableGlobal.VariableRuntimeCacheContext;
> > > +
> > > + if (VariableRuntimeCacheContext->VariableRuntimeNvCache.Store ==
> > > NULL ||
> > > + VariableRuntimeCacheContext-
> >VariableRuntimeVolatileCache.Store ==
> > > NULL ||
> > > + VariableRuntimeCacheContext->PendingUpdate == NULL) {
> > > + return EFI_UNSUPPORTED;
> > > + }
> > > +
> > > + if (*(VariableRuntimeCacheContext->PendingUpdate)) {
> > > + if (VariableRuntimeCacheContext->VariableRuntimeHobCache.Store
> !=
> > > 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 = 0;
> > > + VariableRuntimeCacheContext-
> > > >VariableRuntimeHobCache.PendingUpdateOffset = 0;
> > > + }
> > > +
> > > + CopyMem (
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) VariableRuntimeCacheContext-
> > > >VariableRuntimeNvCache.Store) +
> > > + VariableRuntimeCacheContext-
> > > >VariableRuntimeNvCache.PendingUpdateOffset
> > > + ),
> > > + (VOID *) (
> > > + ((UINT8 *) (UINTN) mNvVariableCache) +
> > > + VariableRuntimeCacheContext-
> > > >VariableRuntimeNvCache.PendingUpdateOffset
> > > + ),
> > > + VariableRuntimeCacheContext-
> > > >VariableRuntimeNvCache.PendingUpdateLength
> > > + );
> > > + VariableRuntimeCacheContext-
> > > >VariableRuntimeNvCache.PendingUpdateLength = 0;
> > > + VariableRuntimeCacheContext-
> > > >VariableRuntimeNvCache.PendingUpdateOffset = 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 = 0;
> > > + VariableRuntimeCacheContext-
> > > >VariableRuntimeVolatileCache.PendingUpdateOffset = 0;
> > > + *(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. This function will attempt
> > > + to write the given update (and any other pending updates) if the
> ReadLock
> > > is available. Otherwise, the
> > > + update is added as a pending update for the given variable store and it
> will
> > > be flushed to the runtime cache
> > > + at the next opportunity the ReadLock is available.
> > > +
> > > + @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_SUCCESS The update was added as a pending
> update
> > > successfully. If the variable runtime
> > > + cache ReadLock was available, the runtime cache was
> > > updated successfully.
> > > + @retval EFI_UNSUPPORTED The volatile store to be updated is not
> > > initialized properly.
> > > +
> > > +**/
> > > +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) {
> > > + // The runtime cache may not be active or allocated yet.
> > > + // In either case, return EFI_SUCCESS instead of
> EFI_NOT_AVAILABLE_YET.
> > > + 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 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 <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_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT)
> )
> > > {
> > > + 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;
> > > + 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 = 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 =
> > > (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..e236ddff33 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
> > >
> > > **/
> > > @@ -39,6 +39,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> > > #include <Guid/SmmVariableCommon.h>
> > >
> > > #include "PrivilegePolymorphic.h"
> > > +#include "VariableParsing.h"
> > >
> > > EFI_HANDLE mHandle = NULL;
> > > EFI_SMM_VARIABLE_PROTOCOL *mSmmVariable = NULL;
> > > @@ -46,8 +47,19 @@ 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 +119,72 @@ ReleaseLockOnlyAtBootTime (
> > > }
> > > }
> > >
> > > +/**
> > > + Return TRUE if ExitBootServices () has been called.
> > > +
> > > + @retval TRUE If ExitBootServices () has been called. FALSE if
> > > ExitBootServices () has not been called.
> > > +**/
> > > +BOOLEAN
> > > +AtRuntime (
> > > + VOID
> > > + )
> > > +{
> > > + 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
> > > +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.
> > >
> > > @@ -425,7 +503,169 @@ Done:
> > > }
> > >
> > > /**
> > > - This code finds variable in storage blocks (Volatile or Non-Volatile).
> > > + Signals SMM to synchronize any pending variable updates with the
> > > runtime 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
> 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
> > > +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 (!EfiAtRuntime ()) {
> > > + FreePool (mVariableRuntimeHobCacheBuffer);
> > > + }
> > > + mVariableRuntimeHobCacheBuffer = 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 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
> > > +FindVariableInRuntimeCache (
> > > + IN CHAR16 *VariableName,
> > > + IN EFI_GUID *VendorGuid,
> > > + OUT UINT32 *Attributes OPTIONAL,
> > > + IN OUT UINTN *DataSize,
> > > + OUT VOID *Data OPTIONAL
> > > + )
> > > +{
> > > + EFI_STATUS Status;
> > > + 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;
> > > + }
> > > +
> > > + //
> > > + // The UEFI specification restricts Runtime Services callers from
> invoking
> > > the same or certain other Runtime Service
> > > + // functions prior to completion and return from a previous Runtime
> > > Service 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 = 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,
> > > mVariableAuthFormat);
> > > + if (!EFI_ERROR (Status)) {
> > > + break;
> > > + }
> > > + }
> > > +
> > > + if (!EFI_ERROR (Status)) {
> > > + //
> > > + // Get data size
> > > + //
> > > + TempDataSize = DataSizeOfVariable (RtPtrTrack.CurrPtr,
> > > mVariableAuthFormat);
> > > + ASSERT (TempDataSize != 0);
> > > +
> > > + if (*DataSize >= TempDataSize) {
> > > + if (Data == NULL) {
> > > + Status = EFI_INVALID_PARAMETER;
> > > + goto Done;
> > > + }
> > > +
> > > + CopyMem (Data, GetVariableDataPtr (RtPtrTrack.CurrPtr,
> > > mVariableAuthFormat), 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;
> > > +
> > > + return Status;
> > > +}
> > > +
> > > +/**
> > > + Finds the given variable in a variable store in SMM.
> > >
> > > Caution: This function may receive untrusted input.
> > > The data size is external input, so this function will validate it carefully to
> > > avoid buffer overflow.
> > > @@ -437,20 +677,18 @@ Done:
> > > 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_SUCCESS Find the specified variable.
> > > - @retval EFI_NOT_FOUND Not found.
> > > - @retval EFI_BUFFER_TO_SMALL DataSize is too small for the result.
> > > + @retval EFI_NOT_FOUND The specified variable could not be
> found.
> > >
> > > **/
> > > 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;
> > > }
> > >
> > > - 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 = OFFSET_OF
> > > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) +
> > > VariableNameSize + TempDataSize;
> > >
> > > - Status = InitCommunicateBuffer ((VOID **)&SmmVariableHeader,
> > > PayloadSize, SMM_VARIABLE_FUNCTION_GET_VARIABLE);
> > > + Status = InitCommunicateBuffer ((VOID **) &SmmVariableHeader,
> > > PayloadSize, SMM_VARIABLE_FUNCTION_GET_VARIABLE);
> > > if (EFI_ERROR (Status)) {
> > > goto Done;
> > > }
> > > @@ -534,11 +770,58 @@ RuntimeServiceGetVariable (
> > > }
> > >
> > > 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 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_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 result.
> > > +
> > > +**/
> > > +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 == NULL || VendorGuid == NULL || DataSize ==
> NULL) {
> > > + return EFI_INVALID_PARAMETER;
> > > + }
> > > + if (VariableName[0] == 0) {
> > > + return EFI_NOT_FOUND;
> > > + }
> > > +
> > > + AcquireLockOnlyAtBootTime (&mVariableServicesLock);
> > > + if (FeaturePcdGet (PcdEnableVariableRuntimeCache)) {
> > > + Status = FindVariableInRuntimeCache (VariableName, VendorGuid,
> > > Attributes, DataSize, Data);
> > > + } else {
> > > + Status = FindVariableInSmm (VariableName, VendorGuid, Attributes,
> > > DataSize, Data);
> > > + }
> > > ReleaseLockOnlyAtBootTime (&mVariableServicesLock);
> > > +
> > > return Status;
> > > }
> > >
> > > -
> > > /**
> > > This code Finds the Next available variable.
> > >
> > > @@ -870,6 +1153,17 @@ OnReadyToBoot (
> > > //
> > > SendCommunicateBuffer (0);
> > >
> > > + //
> > > + // Install the system configuration table for variable info data captured
> > > + //
> > > + if (FeaturePcdGet (PcdEnableVariableRuntimeCache) &&
> FeaturePcdGet
> > > (PcdVariableCollectStatistics)) {
> > > + if (mVariableAuthFormat) {
> > > + gBS->InstallConfigurationTable (&gEfiAuthenticatedVariableGuid,
> > > mVariableInfo);
> > > + } else {
> > > + gBS->InstallConfigurationTable (&gEfiVariableGuid, mVariableInfo);
> > > + }
> > > + }
> > > +
> > > gBS->CloseEvent (Event);
> > > }
> > >
> > > @@ -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);
> > > }
> > >
> > > /**
> > > @@ -969,6 +1266,159 @@ 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 The memory resources
> needed
> > > for a CommBuffer are not available.
> > > + @retval Others Could not retrieve the size successfully.
> > > +
> > > +**/
> > > +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
> > > *SmmCommunicateHeader;
> > > + SMM_VARIABLE_COMMUNICATE_HEADER
> > > *SmmVariableFunctionHeader;
> > > + UINTN CommSize;
> > > + UINT8 *CommBuffer;
> > > +
> > > + SmmGetRuntimeCacheInfo = NULL;
> > > + CommBuffer = mVariableBuffer;
> > > +
> > > + if (TotalHobStorageSize == NULL || TotalNvStorageSize == NULL ||
> > > TotalVolatileStorageSize == NULL || AuthenticatedVariableUsage ==
> NULL) {
> > > + return EFI_INVALID_PARAMETER;
> > > + }
> > > +
> > > + if (CommBuffer == NULL) {
> > > + return EFI_OUT_OF_RESOURCES;
> > > + }
> > > +
> > > + AcquireLockOnlyAtBootTime (&mVariableServicesLock);
> > > +
> > > + CommSize = SMM_COMMUNICATE_HEADER_SIZE +
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof
> > > (SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO);
> > > + ZeroMem (CommBuffer, CommSize);
> >
> >
> > I would suggest to align with the approach of using the pre-alloacted
> > communication buffer like those existing functions:
> >
> > VariableLockRequestToLock()
> > VarCheckVariablePropertySet()
> > VarCheckVariablePropertyGet()
> > RuntimeServiceGetVariable()
> > RuntimeServiceGetNextVariableName()
> > RuntimeServiceSetVariable()
> > RuntimeServiceQueryVariableInfo()
> > OnExitBootServices()
> > OnReadyToBoot()
> >
> > They will:
> > 1. Use InitCommunicateBuffer() to get the communication buffer (a data
> size
> > check will be performed in InitCommunicateBuffer);
> > 2. Update the communication buffer content;
> > 3. Use SendCommunicateBuffer() to send the data to SMM.
> >
> > There is a similar case for SendRuntimeVariableCacheContextToSmm() as
> well.
> >
> > Best Regards,
> > Hao Wu
> >
> >
> > > +
> > > + 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 The memory resources needed
> for a
> > > CommBuffer are not available.
> > > + @retval Others Could not retrieve the size successfully.;
> > > +
> > > +**/
> > > +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 = NULL;
> > > + CommBuffer = mVariableBuffer;
> > > +
> > > + if (CommBuffer == 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 = SMM_COMMUNICATE_HEADER_SIZE +
> > > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + sizeof
> > >
> (SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT)
> ;
> > > + ZeroMem (CommBuffer, CommSize);
> > > +
> > > + 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 +1435,7 @@ 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 +1457,42 @@ SmmVariableReady (
> > > //
> > > mVariableBufferPhysical = mVariableBuffer;
> > >
> > > + if (FeaturePcdGet (PcdEnableVariableRuntimeCache)) {
> > > + DEBUG ((DEBUG_INFO, "Variable driver runtime cache is
> enabled.\n"));
> > > + //
> > > + // 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 = SendRuntimeVariableCacheContextToSmm ();
> > > + if (!EFI_ERROR (Status)) {
> > > + SyncRuntimeCache ();
> > > + }
> > > + }
> > > + }
> > > + }
> > > + if (EFI_ERROR (Status)) {
> > > + mVariableRuntimeHobCacheBuffer = NULL;
> > > + mVariableRuntimeNvCacheBuffer = NULL;
> > > + mVariableRuntimeVolatileCacheBuffer = NULL;
> > > + }
> > > + }
> > > + ASSERT_EFI_ERROR (Status);
> > > + } else {
> > > + DEBUG ((DEBUG_INFO, "Variable driver runtime cache is
> disabled.\n"));
> > > + }
> > > +
> > > gRT->GetVariable = RuntimeServiceGetVariable;
> > > gRT->GetNextVariableName = RuntimeServiceGetNextVariableName;
> > > gRT->SetVariable = RuntimeServiceSetVariable;
> > > --
> > > 2.16.2.windows.1
>
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