This field is a pointer to an array of CPU_REGISTER_TABLE objects; one object per logical processor. Each table carries a variable number of CPU_REGISTER_TABLE_ENTRY objects; each entry prescribes a specific register setting for the CPU whose CPU_REGISTER_TABLE the entry is in.
Such entries are added to tables with the following CpuConfigLib functions: - WriteRegisterTableEx(): internal helper, - WriteRegisterTable(): public function for RegisterTable, - WritePreSmmInitRegisterTable(): public function for PreSmmInitRegisterTable. The driver Quark_EDKII_v1.1.0/IA32FamilyCpuBasePkg/CpuMpDxe/ allocates the array of CPU_REGISTER_TABLEs in AcpiNVS for ACPI_CPU_DATA.PreSmmInitRegisterTable, and sets the InitialApicID field of each table object. (This is then later used by PiSmmCpuDxeSmm to match a table against a logical CPU.) However, CpuMpDxe never adds any register entries to any processor's table in the PreSmmInitRegisterTable, either with WritePreSmmInitRegisterTable(), or manually. Therefore, rather than trying to replicate the super complex logic of CpuMpDxe in our CpuS3DataDxe, let's just remove ACPI_CPU_DATA.PreSmmInitRegisterTable altogether, along with its processing in PiSmmCpuDxeSmm. WARNING: this patch actually fixes a security bug. Namely, the processing being removed from PiSmmCpuDxeSmm happens on the S3 resume path, and it works directly off AcpiNVS memory, which the runtime OS may have tampered with. Unlike other AcpiNVS data pointed to by ACPI_CPU_DATA pointers, the PreSmmInitRegisterTable array has *not* been stashed into SMRAM from AcpiNVS, in the SmmReadyToLockEventNotify() function. The issue has been reported to <[email protected]> and <[email protected]> on 13 May 2015, Message-Id: <[email protected]>. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <[email protected]> --- OvmfPkg/QuarkPort/Include/AcpiCpuData.h | 1 - OvmfPkg/QuarkPort/PiSmmCpuDxeSmm/CpuS3.c | 28 -------------------- 2 files changed, 29 deletions(-) diff --git a/OvmfPkg/QuarkPort/Include/AcpiCpuData.h b/OvmfPkg/QuarkPort/Include/AcpiCpuData.h index dbecc1a..429c611 100644 --- a/OvmfPkg/QuarkPort/Include/AcpiCpuData.h +++ b/OvmfPkg/QuarkPort/Include/AcpiCpuData.h @@ -42,7 +42,6 @@ typedef struct { UINT32 StackSize; UINT32 NumberOfCpus; EFI_PHYSICAL_ADDRESS MtrrTable; - EFI_PHYSICAL_ADDRESS PreSmmInitRegisterTable; EFI_PHYSICAL_ADDRESS RegisterTable; EFI_PHYSICAL_ADDRESS ApMachineCheckHandlerBase; UINT32 ApMachineCheckHandlerSize; diff --git a/OvmfPkg/QuarkPort/PiSmmCpuDxeSmm/CpuS3.c b/OvmfPkg/QuarkPort/PiSmmCpuDxeSmm/CpuS3.c index 75eba6b..2072f1c 100644 --- a/OvmfPkg/QuarkPort/PiSmmCpuDxeSmm/CpuS3.c +++ b/OvmfPkg/QuarkPort/PiSmmCpuDxeSmm/CpuS3.c @@ -239,25 +239,9 @@ EarlyMPRendezvousProcedure ( VOID ) { - CPU_REGISTER_TABLE *RegisterTableList; - UINT32 InitApicId; - UINTN Index; - LoadMtrrData (mAcpiCpuData.MtrrTable); // - // Find processor number for this CPU. - // - RegisterTableList = (CPU_REGISTER_TABLE *) (UINTN) mAcpiCpuData.PreSmmInitRegisterTable; - InitApicId = GetInitialApicId (); - for (Index = 0; Index < mAcpiCpuData.NumberOfCpus; Index++) { - if (RegisterTableList[Index].InitialApicId == InitApicId) { - SetProcessorRegister (&RegisterTableList[Index]); - break; - } - } - - // // Count down the number with lock mechanism. // InterlockedDecrement (&mNumberToFinish); @@ -363,23 +347,11 @@ EarlyInitializeCpu ( VOID ) { - CPU_REGISTER_TABLE *RegisterTableList; - UINT32 InitApicId; - UINTN Index; - LoadMtrrData (mAcpiCpuData.MtrrTable); // // Find processor number for this CPU. // - RegisterTableList = (CPU_REGISTER_TABLE *) (UINTN) mAcpiCpuData.PreSmmInitRegisterTable; - InitApicId = GetInitialApicId (); - for (Index = 0; Index < mAcpiCpuData.NumberOfCpus; Index++) { - if (RegisterTableList[Index].InitialApicId == InitApicId) { - SetProcessorRegister (&RegisterTableList[Index]); - break; - } - } ProgramVirtualWireMode (); -- 1.8.3.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
