Hi Mike, Thanks the comments. Only IA-32 processor will check on every SMI since it needs configure Mtrr. Do you think the impact is acceptable or not?
For fixed PCD solution, the original concern: the fixed PCD will be treated as global variable. Should we need consider no compiler optimization case or it must be optimized away condition checks? Thanks, Jiaxin > -----Original Message----- > From: Kinney, Michael D <michael.d.kin...@intel.com> > Sent: Monday, July 18, 2022 8:13 AM > To: devel@edk2.groups.io; Wu, Jiaxin <jiaxin...@intel.com>; Kinney, Michael > D <michael.d.kin...@intel.com> > Cc: Dong, Eric <eric.d...@intel.com>; Ni, Ray <ray...@intel.com> > Subject: RE: [edk2-devel] [PATCH v1] UefiCpuPkg: Dynamic check SMRR enable > & SmmFeatureControl capability > > Are these checks made on every SMI? > > What is the impact to SMI latency to do the check dynamically? > > FeatureFlag and FixedAtBuild PCDs are declared as const global variables > which are used by optimizing compiler as constants in instructions or > optimize away condition checks all together. This option should still > be considered. > > Mike > > > -----Original Message----- > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Wu, > Jiaxin > > Sent: Sunday, July 17, 2022 1:38 AM > > To: devel@edk2.groups.io > > Cc: Dong, Eric <eric.d...@intel.com>; Ni, Ray <ray...@intel.com> > > Subject: [edk2-devel] [PATCH v1] UefiCpuPkg: Dynamic check SMRR enable & > SmmFeatureControl capability > > > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3962 > > > > Two SMM variables (mSmrrSupported & mSmmFeatureControlSupported) > are global > > variables, they control whether the SMRR and SMM Feature Control MSR will > > be restored respectively. > > To avoid the TOCTOU, dynamic check SMRR enable & SmmFeatureControl > capability. > > > > Change-Id: I6835e4b0e12c5e6f52effb60fd9224e3eb97fc0d > > Cc: Eric Dong <eric.d...@intel.com> > > Cc: Ray Ni <ray...@intel.com> > > Signed-off-by: Jiaxin Wu <jiaxin...@intel.com> > > --- > > .../SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c | 248 > ++++++++++++--------- > > 1 file changed, 141 insertions(+), 107 deletions(-) > > > > diff --git > a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c > > b/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c > > index 78de7f8407..b2f31c993f 100644 > > --- > a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c > > +++ > b/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c > > @@ -35,26 +35,10 @@ SPDX-License-Identifier: BSD-2-Clause-Patent > > // MSRs required for configuration of SMM Code Access Check > > // > > #define SMM_FEATURES_LIB_IA32_MCA_CAP 0x17D > > #define SMM_CODE_ACCESS_CHK_BIT BIT58 > > > > -// > > -// 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; > > > > @@ -62,26 +46,39 @@ BOOLEAN mNeedConfigureMtrrs = TRUE; > > // Array for state of SMRR enable on all CPUs > > // > > BOOLEAN *mSmrrEnabled; > > > > /** > > - Performs library initialization. > > + Return if SMRR is supported > > > > - This initialization function contains common functionality shared betwen > > all > > - library instance constructors. > > + @param[in] SmrrPhysBaseMsr Pointer to SmrrPhysBaseMsr. > > + @param[in] SmrrPhysMaskMsr Pointer to SmrrPhysMaskMsr. > > + > > + @retval TRUE SMRR is supported. > > + @retval FALSE SMRR is not supported. > > > > **/ > > -VOID > > -CpuFeaturesLibInitialization ( > > - VOID > > +BOOLEAN > > +IsSmrrSupported ( > > + IN UINT32 *SmrrPhysBaseMsr OPTIONAL, > > + IN UINT32 *SmrrPhysMaskMsr OPTIONAL > > ) > > { > > + BOOLEAN ReturnValue; > > + > > UINT32 RegEax; > > UINT32 RegEdx; > > UINTN FamilyId; > > UINTN ModelId; > > > > + UINT64 FeatureControl; > > + > > + // > > + // Set default value to assume SMRR is not supported > > + // > > + ReturnValue = FALSE; > > + > > // > > // Retrieve CPU Family and Model > > // > > AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, &RegEdx); > > FamilyId = (RegEax >> 8) & 0xf; > > @@ -96,11 +93,11 @@ CpuFeaturesLibInitialization ( > > 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; > > + ReturnValue = TRUE; > > } > > } > > > > // > > // Intel(R) 64 and IA-32 Architectures Software Developer's Manual > > @@ -109,28 +106,79 @@ CpuFeaturesLibInitialization ( > > // 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; > > + ReturnValue = 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; > > + if (ReturnValue) { > > + // > > + // Return the SmrrPhysBaseMsr & SmrrPhysMaskMsr if required & Smrr > Supported > > + // > > + if (SmrrPhysBaseMsr != NULL) { > > + *SmrrPhysBaseMsr = SMM_FEATURES_LIB_IA32_SMRR_PHYSBASE; > > + } > > + > > + if (SmrrPhysBaseMsr != NULL) { > > + *SmrrPhysMaskMsr = SMM_FEATURES_LIB_IA32_SMRR_PHYSMASK; > > + } > > + > > + // > > + // 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)) { > > + if (SmrrPhysBaseMsr != NULL) { > > + *SmrrPhysBaseMsr = > SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSBASE; > > + } > > + > > + if (SmrrPhysMaskMsr != NULL) { > > + *SmrrPhysMaskMsr = > SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSMASK; > > + } > > + > > + // > > + // 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. > > + // > > + > > + FeatureControl = AsmReadMsr64 > (SMM_FEATURES_LIB_IA32_FEATURE_CONTROL); > > + if (((FeatureControl & BIT3) == 0) && ((FeatureControl & BIT0) == > > 1)) { > > + ReturnValue = FALSE; > > + } > > + } > > } > > } > > > > + return ReturnValue; > > +} > > + > > +/** > > + Performs library initialization. > > + > > + This initialization function contains common functionality shared betwen > > all > > + library instance constructors. > > + > > +**/ > > +VOID > > +CpuFeaturesLibInitialization ( > > + VOID > > + ) > > +{ > > + UINT32 RegEax; > > + UINT32 RegEdx; > > + > > // > > // 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, > > @@ -193,50 +241,27 @@ SmmCpuFeaturesInitializeProcessor ( > > 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; > > + UINT32 SmrrPhysBaseMsr; > > + UINT32 SmrrPhysMaskMsr; > > > > // > > // Configure SMBASE. > > // > > CpuState = (SMRAM_SAVE_STATE_MAP > *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET); > > CpuState->x86.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) { > > + if (IsSmrrSupported (&SmrrPhysBaseMsr, &SmrrPhysMaskMsr)) { > > // > > // 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 > > // > > @@ -250,50 +275,16 @@ SmmCpuFeaturesInitializeProcessor ( > > 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)); > > + AsmWriteMsr64 (SmrrPhysBaseMsr, CpuHotPlugData->SmrrBase | > MTRR_CACHE_WRITE_BACK); > > + AsmWriteMsr64 (SmrrPhysMaskMsr, (~(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 (); > > } > > @@ -381,12 +372,14 @@ VOID > > EFIAPI > > SmmCpuFeaturesDisableSmrr ( > > VOID > > ) > > { > > - if (mSmrrSupported && mNeedConfigureMtrrs) { > > - AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64 > (mSmrrPhysMaskMsr) & ~EFI_MSR_SMRR_PHYS_MASK_VALID); > > + UINT32 SmrrPhysMaskMsr; > > + > > + if (IsSmrrSupported (NULL, &SmrrPhysMaskMsr) && > mNeedConfigureMtrrs) { > > + AsmWriteMsr64 (SmrrPhysMaskMsr, AsmReadMsr64 (SmrrPhysMaskMsr) > & ~EFI_MSR_SMRR_PHYS_MASK_VALID); > > } > > } > > > > /** > > Enable SMRR register if SMRR is supported and > SmmCpuFeaturesNeedConfigureMtrrs() > > @@ -396,12 +389,14 @@ VOID > > EFIAPI > > SmmCpuFeaturesReenableSmrr ( > > VOID > > ) > > { > > - if (mSmrrSupported && mNeedConfigureMtrrs) { > > - AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64 > (mSmrrPhysMaskMsr) | EFI_MSR_SMRR_PHYS_MASK_VALID); > > + UINT32 SmrrPhysMaskMsr; > > + > > + if (IsSmrrSupported (NULL, &SmrrPhysMaskMsr) && > mNeedConfigureMtrrs) { > > + AsmWriteMsr64 (SmrrPhysMaskMsr, AsmReadMsr64 (SmrrPhysMaskMsr) > | EFI_MSR_SMRR_PHYS_MASK_VALID); > > } > > } > > > > /** > > Processor specific hook point each time a CPU enters System Management > Mode. > > @@ -414,15 +409,17 @@ VOID > > EFIAPI > > SmmCpuFeaturesRendezvousEntry ( > > IN UINTN CpuIndex > > ) > > { > > + UINT32 SmrrPhysMaskMsr; > > + > > // > > // 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); > > + if (!mSmrrEnabled[CpuIndex] && IsSmrrSupported (NULL, > &SmrrPhysMaskMsr)) { > > + AsmWriteMsr64 (SmrrPhysMaskMsr, AsmReadMsr64 (SmrrPhysMaskMsr) > | EFI_MSR_SMRR_PHYS_MASK_VALID); > > mSmrrEnabled[CpuIndex] = TRUE; > > } > > } > > > > /** > > @@ -458,12 +455,49 @@ EFIAPI > > SmmCpuFeaturesIsSmmRegisterSupported ( > > IN UINTN CpuIndex, > > IN SMM_REG_NAME RegName > > ) > > { > > - if (mSmmFeatureControlSupported && (RegName == > SmmRegFeatureControl)) { > > - return TRUE; > > + UINT32 RegEax; > > + UINT32 RegEdx; > > + UINTN FamilyId; > > + UINTN ModelId; > > + > > + if (RegName == SmmRegFeatureControl) { > > + // > > + // 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) { > > + return TRUE; > > + } > > + } > > + } > > } > > > > return FALSE; > > } > > > > @@ -484,11 +518,11 @@ EFIAPI > > SmmCpuFeaturesGetSmmRegister ( > > IN UINTN CpuIndex, > > IN SMM_REG_NAME RegName > > ) > > { > > - if (mSmmFeatureControlSupported && (RegName == > SmmRegFeatureControl)) { > > + if (SmmCpuFeaturesIsSmmRegisterSupported (CpuIndex, RegName)) { > > return AsmReadMsr64 (SMM_FEATURES_LIB_SMM_FEATURE_CONTROL); > > } > > > > return 0; > > } > > @@ -510,11 +544,11 @@ SmmCpuFeaturesSetSmmRegister ( > > IN UINTN CpuIndex, > > IN SMM_REG_NAME RegName, > > IN UINT64 Value > > ) > > { > > - if (mSmmFeatureControlSupported && (RegName == > SmmRegFeatureControl)) { > > + if (SmmCpuFeaturesIsSmmRegisterSupported (CpuIndex, RegName)) { > > AsmWriteMsr64 (SMM_FEATURES_LIB_SMM_FEATURE_CONTROL, Value); > > } > > } > > > > /** > > -- > > 2.16.2.windows.1 > > > > > > > > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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