From: Duke Zhai <duke.z...@amd.com> BZ #:4640 In V2: Improve coding style. 1.Remove the leading underscore and use double underscore at trailing in C header files. 2.Remove old tianocore licenses and redundant license description. 3.Improve coding style. For example: remove space between @param.
In V1: Initial SmmCpuFeaturesLibCommon module. The CPU specific programming for PiSmmCpuDxeSmm module when STM support is not included. Signed-off-by: Duke Zhai <duke.z...@amd.com> Cc: Eric Xing <eric.x...@amd.com> Cc: Ken Yao <ken....@amd.com> Cc: Igniculus Fu <igniculus...@amd.com> Cc: Abner Chang <abner.ch...@amd.com> --- .../SmmCpuFeaturesLibCommon.c | 623 ++++++++++++++++++ 1 file changed, 623 insertions(+) create mode 100644 Platform/AMD/VanGoghBoard/Override/edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c diff --git a/Platform/AMD/VanGoghBoard/Override/edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c b/Platform/AMD/VanGoghBoard/Override/edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c new file mode 100644 index 0000000000..f3615e2d9e --- /dev/null +++ b/Platform/AMD/VanGoghBoard/Override/edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c @@ -0,0 +1,623 @@ +/** @file +Implementation shared across all library instances. + +Copyright (C) 2024 Advanced Micro Devices, Inc. All rights reserved.<BR> +Copyright (c) 2010 - 2019, Intel Corporation. All rights reserved.<BR> +Copyright (c) Microsoft Corporation.<BR> +SPDX-License-Identifier: BSD-2-Clause-Patent + +**/ + +#include <PiMm.h> +#include <Library/SmmCpuFeaturesLib.h> +#include <Library/BaseLib.h> +#include <Library/MtrrLib.h> +#include <Library/PcdLib.h> +#include <Library/MemoryAllocationLib.h> +#include <Library/DebugLib.h> +#include <Register/Intel/Cpuid.h> +#include <Register/Intel/SmramSaveStateMap.h> +#include "CpuFeaturesLib.h" + +// +// Machine Specific Registers (MSRs) +// +#define SMM_FEATURES_LIB_IA32_MTRR_CAP 0x0FE +#define SMM_FEATURES_LIB_IA32_FEATURE_CONTROL 0x03A +#define SMM_FEATURES_LIB_IA32_SMRR_PHYSBASE 0x1F2 +#define SMM_FEATURES_LIB_IA32_SMRR_PHYSMASK 0x1F3 +#define SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSBASE 0x0A0 +#define SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSMASK 0x0A1 +#define EFI_MSR_SMRR_MASK 0xFFFFF000 +#define EFI_MSR_SMRR_PHYS_MASK_VALID BIT11 +#define SMM_FEATURES_LIB_SMM_FEATURE_CONTROL 0x4E0 + +// +// MSRs required for configuration of SMM Code Access Check +// +#define SMM_FEATURES_LIB_IA32_MCA_CAP 0x17D +#define SMM_CODE_ACCESS_CHK_BIT BIT58 + +extern UINT8 mSmmSaveStateRegisterLma; + +// +// Set default value to assume SMRR is not supported +// +BOOLEAN mSmrrSupported = FALSE; + +// +// Set default value to assume MSR_SMM_FEATURE_CONTROL is not supported +// +BOOLEAN mSmmFeatureControlSupported = FALSE; + +// +// Set default value to assume IA-32 Architectural MSRs are used +// +UINT32 mSmrrPhysBaseMsr = SMM_FEATURES_LIB_IA32_SMRR_PHYSBASE; +UINT32 mSmrrPhysMaskMsr = SMM_FEATURES_LIB_IA32_SMRR_PHYSMASK; + +// +// Set default value to assume MTRRs need to be configured on each SMI +// +BOOLEAN mNeedConfigureMtrrs = TRUE; + +// +// Array for state of SMRR enable on all CPUs +// +BOOLEAN *mSmrrEnabled; + +/** + Performs library initialization. + + This initialization function contains common functionality shared betwen all + library instance constructors. + +**/ +VOID +CpuFeaturesLibInitialization ( + VOID + ) +{ + UINT32 RegEax; + UINT32 RegEdx; + UINTN FamilyId; + UINTN ModelId; + + // + // Retrieve CPU Family and Model + // + AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, &RegEdx); + FamilyId = (RegEax >> 8) & 0xf; + ModelId = (RegEax >> 4) & 0xf; + if ((FamilyId == 0x06) || (FamilyId == 0x0f)) { + ModelId = ModelId | ((RegEax >> 12) & 0xf0); + } + + // + // Check CPUID(CPUID_VERSION_INFO).EDX[12] for MTRR capability + // + if ((RegEdx & BIT12) != 0) { + // + // Check MTRR_CAP MSR bit 11 for SMRR support + // + if ((AsmReadMsr64 (SMM_FEATURES_LIB_IA32_MTRR_CAP) & BIT11) != 0) { + mSmrrSupported = TRUE; + } + } + + // + // Intel(R) 64 and IA-32 Architectures Software Developer's Manual + // Volume 3C, Section 35.3 MSRs in the Intel(R) Atom(TM) Processor Family + // + // If CPU Family/Model is 06_1CH, 06_26H, 06_27H, 06_35H or 06_36H, then + // SMRR Physical Base and SMM Physical Mask MSRs are not available. + // + if (FamilyId == 0x06) { + if ((ModelId == 0x1C) || (ModelId == 0x26) || (ModelId == 0x27) || (ModelId == 0x35) || (ModelId == 0x36)) { + mSmrrSupported = FALSE; + } + } + + // + // Intel(R) 64 and IA-32 Architectures Software Developer's Manual + // Volume 3C, Section 35.2 MSRs in the Intel(R) Core(TM) 2 Processor Family + // + // If CPU Family/Model is 06_0F or 06_17, then use Intel(R) Core(TM) 2 + // Processor Family MSRs + // + if (FamilyId == 0x06) { + if ((ModelId == 0x17) || (ModelId == 0x0f)) { + mSmrrPhysBaseMsr = SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSBASE; + mSmrrPhysMaskMsr = SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSMASK; + } + } + + // + // Intel(R) 64 and IA-32 Architectures Software Developer's Manual + // Volume 3C, Section 34.4.2 SMRAM Caching + // An IA-32 processor does not automatically write back and invalidate its + // caches before entering SMM or before exiting SMM. Because of this behavior, + // care must be taken in the placement of the SMRAM in system memory and in + // the caching of the SMRAM to prevent cache incoherence when switching back + // and forth between SMM and protected mode operation. + // + // An IA-32 processor is a processor that does not support the Intel 64 + // Architecture. Support for the Intel 64 Architecture can be detected from + // CPUID(CPUID_EXTENDED_CPU_SIG).EDX[29] + // + // If an IA-32 processor is detected, then set mNeedConfigureMtrrs to TRUE, + // so caches are flushed on SMI entry and SMI exit, the interrupted code + // MTRRs are saved/restored, and MTRRs for SMM are loaded. + // + AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL); + if (RegEax >= CPUID_EXTENDED_CPU_SIG) { + AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &RegEdx); + if ((RegEdx & BIT29) != 0) { + mNeedConfigureMtrrs = FALSE; + } + } + + // + // Allocate array for state of SMRR enable on all CPUs + // + mSmrrEnabled = (BOOLEAN *)AllocatePool (sizeof (BOOLEAN) * GetCpuMaxLogicalProcessorNumber ()); + ASSERT (mSmrrEnabled != NULL); +} + +/** + Called during the very first SMI into System Management Mode to initialize + CPU features, including SMBASE, for the currently executing CPU. Since this + is the first SMI, the SMRAM Save State Map is at the default address of + SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET. The currently executing + CPU is specified by CpuIndex and CpuIndex can be used to access information + about the currently executing CPU in the ProcessorInfo array and the + HotPlugCpuData data structure. + + @param[in] CpuIndex The index of the CPU to initialize. The value + must be between 0 and the NumberOfCpus field in + the System Management System Table (SMST). + @param[in] IsMonarch TRUE if the CpuIndex is the index of the CPU that + was elected as monarch during System Management + Mode initialization. + FALSE if the CpuIndex is not the index of the CPU + that was elected as monarch during System + Management Mode initialization. + @param[in] ProcessorInfo Pointer to an array of EFI_PROCESSOR_INFORMATION + structures. ProcessorInfo[CpuIndex] contains the + information for the currently executing CPU. + @param[in] CpuHotPlugData Pointer to the CPU_HOT_PLUG_DATA structure that + contains the ApidId and SmBase arrays. +**/ +VOID +EFIAPI +SmmCpuFeaturesInitializeProcessor ( + IN UINTN CpuIndex, + IN BOOLEAN IsMonarch, + IN EFI_PROCESSOR_INFORMATION *ProcessorInfo, + IN CPU_HOT_PLUG_DATA *CpuHotPlugData + ) +{ + SMRAM_SAVE_STATE_MAP *CpuState; + UINT64 FeatureControl; + UINT32 RegEax; + UINT32 RegEdx; + UINTN FamilyId; + UINTN ModelId; + + // + // Configure SMBASE. + // + CpuState = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET); + if (mSmmSaveStateRegisterLma == EFI_SMM_SAVE_STATE_REGISTER_LMA_32BIT) { + CpuState->x86.SMBASE = (UINT32)CpuHotPlugData->SmBase[CpuIndex]; + } else { + CpuState->x64.SMBASE = (UINT32)CpuHotPlugData->SmBase[CpuIndex]; + } + + // + // Intel(R) 64 and IA-32 Architectures Software Developer's Manual + // Volume 3C, Section 35.2 MSRs in the Intel(R) Core(TM) 2 Processor Family + // + // If Intel(R) Core(TM) Core(TM) 2 Processor Family MSRs are being used, then + // make sure SMRR Enable(BIT3) of MSR_FEATURE_CONTROL MSR(0x3A) is set before + // accessing SMRR base/mask MSRs. If Lock(BIT0) of MSR_FEATURE_CONTROL MSR(0x3A) + // is set, then the MSR is locked and can not be modified. + // + if (mSmrrSupported && (mSmrrPhysBaseMsr == SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSBASE)) { + FeatureControl = AsmReadMsr64 (SMM_FEATURES_LIB_IA32_FEATURE_CONTROL); + if ((FeatureControl & BIT3) == 0) { + if ((FeatureControl & BIT0) == 0) { + AsmWriteMsr64 (SMM_FEATURES_LIB_IA32_FEATURE_CONTROL, FeatureControl | BIT3); + } else { + mSmrrSupported = FALSE; + } + } + } + + // + // If SMRR is supported, then program SMRR base/mask MSRs. + // The EFI_MSR_SMRR_PHYS_MASK_VALID bit is not set until the first normal SMI. + // The code that initializes SMM environment is running in normal mode + // from SMRAM region. If SMRR is enabled here, then the SMRAM region + // is protected and the normal mode code execution will fail. + // + if (mSmrrSupported) { + // + // SMRR size cannot be less than 4-KBytes + // SMRR size must be of length 2^n + // SMRR base alignment cannot be less than SMRR length + // + if ((CpuHotPlugData->SmrrSize < SIZE_4KB) || + (CpuHotPlugData->SmrrSize != GetPowerOfTwo32 (CpuHotPlugData->SmrrSize)) || + ((CpuHotPlugData->SmrrBase & ~(CpuHotPlugData->SmrrSize - 1)) != CpuHotPlugData->SmrrBase)) + { + // + // Print message and halt if CPU is Monarch + // + if (IsMonarch) { + DEBUG ((DEBUG_ERROR, "SMM Base/Size does not meet alignment/size requirement!\n")); + CpuDeadLoop (); + } + } else { + AsmWriteMsr64 (mSmrrPhysBaseMsr, CpuHotPlugData->SmrrBase | MTRR_CACHE_WRITE_BACK); + AsmWriteMsr64 (mSmrrPhysMaskMsr, (~(CpuHotPlugData->SmrrSize - 1) & EFI_MSR_SMRR_MASK)); + mSmrrEnabled[CpuIndex] = FALSE; + } + } + + // + // Retrieve CPU Family and Model + // + AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, &RegEdx); + FamilyId = (RegEax >> 8) & 0xf; + ModelId = (RegEax >> 4) & 0xf; + if ((FamilyId == 0x06) || (FamilyId == 0x0f)) { + ModelId = ModelId | ((RegEax >> 12) & 0xf0); + } + + // + // Intel(R) 64 and IA-32 Architectures Software Developer's Manual + // Volume 3C, Section 35.10.1 MSRs in 4th Generation Intel(R) Core(TM) + // Processor Family. + // + // If CPU Family/Model is 06_3C, 06_45, or 06_46 then use 4th Generation + // Intel(R) Core(TM) Processor Family MSRs. + // + if (FamilyId == 0x06) { + if ((ModelId == 0x3C) || (ModelId == 0x45) || (ModelId == 0x46) || + (ModelId == 0x3D) || (ModelId == 0x47) || (ModelId == 0x4E) || (ModelId == 0x4F) || + (ModelId == 0x3F) || (ModelId == 0x56) || (ModelId == 0x57) || (ModelId == 0x5C) || + (ModelId == 0x8C)) + { + // + // Check to see if the CPU supports the SMM Code Access Check feature + // Do not access this MSR unless the CPU supports the SmmRegFeatureControl + // + if ((AsmReadMsr64 (SMM_FEATURES_LIB_IA32_MCA_CAP) & SMM_CODE_ACCESS_CHK_BIT) != 0) { + mSmmFeatureControlSupported = TRUE; + } + } + } + + // + // Call internal worker function that completes the CPU initialization + // + FinishSmmCpuFeaturesInitializeProcessor (); +} + +/** + This function updates the SMRAM save state on the currently executing CPU + to resume execution at a specific address after an RSM instruction. This + function must evaluate the SMRAM save state to determine the execution mode + the RSM instruction resumes and update the resume execution address with + either NewInstructionPointer32 or NewInstructionPoint. The auto HALT restart + flag in the SMRAM save state must always be cleared. This function returns + the value of the instruction pointer from the SMRAM save state that was + replaced. If this function returns 0, then the SMRAM save state was not + modified. + + This function is called during the very first SMI on each CPU after + SmmCpuFeaturesInitializeProcessor() to set a flag in normal execution mode + to signal that the SMBASE of each CPU has been updated before the default + SMBASE address is used for the first SMI to the next CPU. + + @param[in] CpuIndex The index of the CPU to hook. The value + must be between 0 and the NumberOfCpus + field in the System Management System Table + (SMST). + @param[in] CpuState Pointer to SMRAM Save State Map for the + currently executing CPU. + @param[in] NewInstructionPointer32 Instruction pointer to use if resuming to + 32-bit execution mode from 64-bit SMM. + @param[in] NewInstructionPointer Instruction pointer to use if resuming to + same execution mode as SMM. + + @retval 0 This function did modify the SMRAM save state. + @retval > 0 The original instruction pointer value from the SMRAM save state + before it was replaced. +**/ +UINT64 +EFIAPI +SmmCpuFeaturesHookReturnFromSmm ( + IN UINTN CpuIndex, + IN SMRAM_SAVE_STATE_MAP *CpuState, + IN UINT64 NewInstructionPointer32, + IN UINT64 NewInstructionPointer + ) +{ + return 0; +} + +/** + Hook point in normal execution mode that allows the one CPU that was elected + as monarch during System Management Mode initialization to perform additional + initialization actions immediately after all of the CPUs have processed their + first SMI and called SmmCpuFeaturesInitializeProcessor() relocating SMBASE + into a buffer in SMRAM and called SmmCpuFeaturesHookReturnFromSmm(). +**/ +VOID +EFIAPI +SmmCpuFeaturesSmmRelocationComplete ( + VOID + ) +{ +} + +/** + Determines if MTRR registers must be configured to set SMRAM cache-ability + when executing in System Management Mode. + + @retval TRUE MTRR registers must be configured to set SMRAM cache-ability. + @retval FALSE MTRR registers do not need to be configured to set SMRAM + cache-ability. +**/ +BOOLEAN +EFIAPI +SmmCpuFeaturesNeedConfigureMtrrs ( + VOID + ) +{ + return mNeedConfigureMtrrs; +} + +/** + Disable SMRR register if SMRR is supported and SmmCpuFeaturesNeedConfigureMtrrs() + returns TRUE. +**/ +VOID +EFIAPI +SmmCpuFeaturesDisableSmrr ( + VOID + ) +{ + if (mSmrrSupported && mNeedConfigureMtrrs) { + AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64 (mSmrrPhysMaskMsr) & ~EFI_MSR_SMRR_PHYS_MASK_VALID); + } +} + +/** + Enable SMRR register if SMRR is supported and SmmCpuFeaturesNeedConfigureMtrrs() + returns TRUE. +**/ +VOID +EFIAPI +SmmCpuFeaturesReenableSmrr ( + VOID + ) +{ + if (mSmrrSupported && mNeedConfigureMtrrs) { + AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64 (mSmrrPhysMaskMsr) | EFI_MSR_SMRR_PHYS_MASK_VALID); + } +} + +/** + Processor specific hook point each time a CPU enters System Management Mode. + + @param[in] CpuIndex The index of the CPU that has entered SMM. The value + must be between 0 and the NumberOfCpus field in the + System Management System Table (SMST). +**/ +VOID +EFIAPI +SmmCpuFeaturesRendezvousEntry ( + IN UINTN CpuIndex + ) +{ + // + // If SMRR is supported and this is the first normal SMI, then enable SMRR + // + if (mSmrrSupported && !mSmrrEnabled[CpuIndex]) { + AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64 (mSmrrPhysMaskMsr) | EFI_MSR_SMRR_PHYS_MASK_VALID); + mSmrrEnabled[CpuIndex] = TRUE; + } +} + +/** + Processor specific hook point each time a CPU exits System Management Mode. + + @param[in] CpuIndex The index of the CPU that is exiting SMM. The value must + be between 0 and the NumberOfCpus field in the System + Management System Table (SMST). +**/ +VOID +EFIAPI +SmmCpuFeaturesRendezvousExit ( + IN UINTN CpuIndex + ) +{ +} + +/** + Check to see if an SMM register is supported by a specified CPU. + + @param[in] CpuIndex The index of the CPU to check for SMM register support. + The value must be between 0 and the NumberOfCpus field + in the System Management System Table (SMST). + @param[in] RegName Identifies the SMM register to check for support. + + @retval TRUE The SMM register specified by RegName is supported by the CPU + specified by CpuIndex. + @retval FALSE The SMM register specified by RegName is not supported by the + CPU specified by CpuIndex. +**/ +BOOLEAN +EFIAPI +SmmCpuFeaturesIsSmmRegisterSupported ( + IN UINTN CpuIndex, + IN SMM_REG_NAME RegName + ) +{ + if (mSmmFeatureControlSupported && (RegName == SmmRegFeatureControl)) { + return TRUE; + } + + return FALSE; +} + +/** + Returns the current value of the SMM register for the specified CPU. + If the SMM register is not supported, then 0 is returned. + + @param[in] CpuIndex The index of the CPU to read the SMM register. The + value must be between 0 and the NumberOfCpus field in + the System Management System Table (SMST). + @param[in] RegName Identifies the SMM register to read. + + @return The value of the SMM register specified by RegName from the CPU + specified by CpuIndex. +**/ +UINT64 +EFIAPI +SmmCpuFeaturesGetSmmRegister ( + IN UINTN CpuIndex, + IN SMM_REG_NAME RegName + ) +{ + if (mSmmFeatureControlSupported && (RegName == SmmRegFeatureControl)) { + return AsmReadMsr64 (SMM_FEATURES_LIB_SMM_FEATURE_CONTROL); + } + + return 0; +} + +/** + Sets the value of an SMM register on a specified CPU. + If the SMM register is not supported, then no action is performed. + + @param[in] CpuIndex The index of the CPU to write the SMM register. The + value must be between 0 and the NumberOfCpus field in + the System Management System Table (SMST). + @param[in] RegName Identifies the SMM register to write. + registers are read-only. + @param[in] Value The value to write to the SMM register. +**/ +VOID +EFIAPI +SmmCpuFeaturesSetSmmRegister ( + IN UINTN CpuIndex, + IN SMM_REG_NAME RegName, + IN UINT64 Value + ) +{ + if (mSmmFeatureControlSupported && (RegName == SmmRegFeatureControl)) { + AsmWriteMsr64 (SMM_FEATURES_LIB_SMM_FEATURE_CONTROL, Value); + } +} + +/** + Read an SMM Save State register on the target processor. If this function + returns EFI_UNSUPPORTED, then the caller is responsible for reading the + SMM Save Sate register. + + @param[in] CpuIndex The index of the CPU to read the SMM Save State. The + value must be between 0 and the NumberOfCpus field in + the System Management System Table (SMST). + @param[in] Register The SMM Save State register to read. + @param[in] Width The number of bytes to read from the CPU save state. + @param[out] Buffer Upon return, this holds the CPU register value read + from the save state. + + @retval EFI_SUCCESS The register was read from Save State. + @retval EFI_INVALID_PARAMETER Buffer is NULL. + @retval EFI_UNSUPPORTED This function does not support reading Register. + +**/ +EFI_STATUS +EFIAPI +SmmCpuFeaturesReadSaveStateRegister ( + IN UINTN CpuIndex, + IN EFI_SMM_SAVE_STATE_REGISTER Register, + IN UINTN Width, + OUT VOID *Buffer + ) +{ + return EFI_UNSUPPORTED; +} + +/** + Writes an SMM Save State register on the target processor. If this function + returns EFI_UNSUPPORTED, then the caller is responsible for writing the + SMM Save Sate register. + + @param[in] CpuIndex The index of the CPU to write the SMM Save State. The + value must be between 0 and the NumberOfCpus field in + the System Management System Table (SMST). + @param[in] Register The SMM Save State register to write. + @param[in] Width The number of bytes to write to the CPU save state. + @param[in] Buffer Upon entry, this holds the new CPU register value. + + @retval EFI_SUCCESS The register was written to Save State. + @retval EFI_INVALID_PARAMETER Buffer is NULL. + @retval EFI_UNSUPPORTED This function does not support writing Register. +**/ +EFI_STATUS +EFIAPI +SmmCpuFeaturesWriteSaveStateRegister ( + IN UINTN CpuIndex, + IN EFI_SMM_SAVE_STATE_REGISTER Register, + IN UINTN Width, + IN CONST VOID *Buffer + ) +{ + return EFI_UNSUPPORTED; +} + +/** + This function is hook point called after the gEfiSmmReadyToLockProtocolGuid + notification is completely processed. +**/ +VOID +EFIAPI +SmmCpuFeaturesCompleteSmmReadyToLock ( + VOID + ) +{ +} + +/** + This API provides a method for a CPU to allocate a specific region for storing page tables. + + This API can be called more once to allocate memory for page tables. + + Allocates the number of 4KB pages of type EfiRuntimeServicesData and returns a pointer to the + allocated buffer. The buffer returned is aligned on a 4KB boundary. If Pages is 0, then NULL + is returned. If there is not enough memory remaining to satisfy the request, then NULL is + returned. + + This function can also return NULL if there is no preference on where the page tables are allocated in SMRAM. + + @param Pages The number of 4 KB pages to allocate. + + @return A pointer to the allocated buffer for page tables. + @retval NULL Fail to allocate a specific region for storing page tables, + Or there is no preference on where the page tables are allocated in SMRAM. + +**/ +VOID * +EFIAPI +SmmCpuFeaturesAllocatePageTableMemory ( + IN UINTN Pages + ) +{ + return NULL; +} -- 2.31.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#114521): https://edk2.groups.io/g/devel/message/114521 Mute This Topic: https://groups.io/mt/103971423/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-