Today's MpInitLib PEI implementation directly calls PeiServices->GetHobList() from AP which may cause racing issue.
This patch fixes this issue by duplicating IDT for APs. Because CpuMpData structure is stored just after IDT, the CpuMPData address equals to IDTR.BASE + IDTR.LIMIT + 1. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni <[email protected]> Cc: Jeff Fan <[email protected]> Cc: Eric Dong <[email protected]> Cc: Jiewen Yao <[email protected]> Cc: Fish Andrew <[email protected]> Cc: Laszlo Ersek <[email protected]> --- UefiCpuPkg/Library/MpInitLib/MpLib.c | 41 +++++++++++++++++++++++++++++---- UefiCpuPkg/Library/MpInitLib/PeiMpLib.c | 18 +++++++++++---- 2 files changed, 51 insertions(+), 8 deletions(-) diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c index eb2765910c..e8ecad870c 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c @@ -1506,6 +1506,7 @@ MpInitLibInitialize ( UINT32 MaxLogicalProcessorNumber; UINT32 ApStackSize; MP_ASSEMBLY_ADDRESS_MAP AddressMap; + CPU_VOLATILE_REGISTERS VolatileRegisters; UINTN BufferSize; UINT32 MonitorFilterSize; VOID *MpBuffer; @@ -1516,6 +1517,7 @@ MpInitLibInitialize ( UINTN Index; UINTN ApResetVectorSize; UINTN BackupBufferAddr; + UINTN ApIdtBase; OldCpuMpData = GetCpuMpDataFromGuidedHob (); if (OldCpuMpData == NULL) { @@ -1530,19 +1532,46 @@ MpInitLibInitialize ( ApStackSize = PcdGet32(PcdCpuApStackSize); ApLoopMode = GetApLoopMode (&MonitorFilterSize); + // + // Save BSP's Control registers for APs + // + SaveVolatileRegisters (&VolatileRegisters); + BufferSize = ApStackSize * MaxLogicalProcessorNumber; BufferSize += MonitorFilterSize * MaxLogicalProcessorNumber; - BufferSize += sizeof (CPU_MP_DATA); BufferSize += ApResetVectorSize; + BufferSize += VolatileRegisters.Idtr.Limit + 1; + BufferSize += sizeof (CPU_MP_DATA); BufferSize += (sizeof (CPU_AP_DATA) + sizeof (CPU_INFO_IN_HOB))* MaxLogicalProcessorNumber; MpBuffer = AllocatePages (EFI_SIZE_TO_PAGES (BufferSize)); ASSERT (MpBuffer != NULL); ZeroMem (MpBuffer, BufferSize); Buffer = (UINTN) MpBuffer; + /* + The layout of the Buffer is as below: + + +--------------------+ <-- Buffer + AP Stacks (N) + +--------------------+ <-- MonitorBuffer + AP Monitor Filters (N) + +--------------------+ <-- BackupBuffer + Backup Buffer + +--------------------+ <-- ApIdtBase (8-byte boundary) + AP IDT All APs share one separate IDT. So AP can get address of CPU_MP_DATA from IDT Base. + +--------------------+ <-- CpuMpData + CPU_MP_DATA + +--------------------+ <-- CpuMpData->CpuData + CPU_AP_DATA (N) + +--------------------+ <-- CpuMpData->CpuInfoHob + CPU_INFO_IN_HOB (N) + +--------------------+ + + */ MonitorBuffer = (UINT8 *) (Buffer + ApStackSize * MaxLogicalProcessorNumber); BackupBufferAddr = (UINTN) MonitorBuffer + MonitorFilterSize * MaxLogicalProcessorNumber; - CpuMpData = (CPU_MP_DATA *) (BackupBufferAddr + ApResetVectorSize); + ApIdtBase = ALIGN_VALUE (BackupBufferAddr + ApResetVectorSize, 8); + CpuMpData = (CPU_MP_DATA *) (ApIdtBase + VolatileRegisters.Idtr.Limit + 1); CpuMpData->Buffer = Buffer; CpuMpData->CpuApStackSize = ApStackSize; CpuMpData->BackupBuffer = BackupBufferAddr; @@ -1557,10 +1586,14 @@ MpInitLibInitialize ( CpuMpData->MicrocodePatchAddress = PcdGet64 (PcdCpuMicrocodePatchAddress); CpuMpData->MicrocodePatchRegionSize = PcdGet64 (PcdCpuMicrocodePatchRegionSize); InitializeSpinLock(&CpuMpData->MpLock); + // - // Save BSP's Control registers to APs + // Duplicate BSP's IDT to APs. + // All APs share one separate IDT. So AP can get the address of CpuMpData by using IDTR.BASE + IDTR.LIMIT + 1 // - SaveVolatileRegisters (&CpuMpData->CpuData[0].VolatileRegisters); + CopyMem ((VOID *)ApIdtBase, (VOID *)VolatileRegisters.Idtr.Base, VolatileRegisters.Idtr.Limit + 1); + VolatileRegisters.Idtr.Base = ApIdtBase; + CopyMem (&CpuMpData->CpuData[0].VolatileRegisters, &VolatileRegisters, sizeof (VolatileRegisters)); // // Set BSP basic information // diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c index 791ae9db6e..92f28681e4 100644 --- a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c @@ -27,6 +27,8 @@ EnableDebugAgent ( /** Get pointer to CPU MP Data structure. + For BSP, the pointer is retrieved from HOB. + For AP, the structure is just after IDT. @return The pointer to CPU MP Data structure. **/ @@ -35,10 +37,18 @@ GetCpuMpData ( VOID ) { - CPU_MP_DATA *CpuMpData; - - CpuMpData = GetCpuMpDataFromGuidedHob (); - ASSERT (CpuMpData != NULL); + CPU_MP_DATA *CpuMpData; + MSR_IA32_APIC_BASE_REGISTER ApicBaseMsr; + IA32_DESCRIPTOR Idtr; + + ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE); + if (ApicBaseMsr.Bits.BSP == 1) { + CpuMpData = GetCpuMpDataFromGuidedHob (); + ASSERT (CpuMpData != NULL); + } else { + AsmReadIdtr (&Idtr); + CpuMpData = (CPU_MP_DATA *) (Idtr.Base + Idtr.Limit + 1); + } return CpuMpData; } -- 2.16.1.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
