diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c index 40c1bf407a..e832c16eca 100644 --- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c @@ -295,6 +295,7 @@ InitMpGlobalData ( UINTN Index; EFI_GCD_MEMORY_SPACE_DESCRIPTOR MemDesc; UINTN StackBase; + CPU_INFO_IN_HOB *CpuInfoInHob; SaveCpuMpData (CpuMpData); @@ -314,8 +315,21 @@ InitMpGlobalData ( ASSERT (FALSE); } + // + // DXE will reuse stack allocated for APs at PEI phase if it's available. + // Let's check it here. + // + // Note: BSP's stack guard is set at DxeIpl phase. But for the sake of + // BSP/AP exchange, stack guard for ApTopOfStack of cpu 0 will still be + // set here. + // + CpuInfoInHob = (CPU_INFO_IN_HOB *)(UINTN)CpuMpData->CpuInfoInHob; for (Index = 0; Index < CpuMpData->CpuCount; ++Index) { - StackBase = CpuMpData->Buffer + Index * CpuMpData->CpuApStackSize; + if (CpuInfoInHob != NULL && CpuInfoInHob[Index].ApTopOfStack != 0) { + StackBase = CpuInfoInHob[Index].ApTopOfStack - CpuMpData->CpuApStackSize; + } else { + StackBase = CpuMpData->Buffer + Index * CpuMpData->CpuApStackSize; + } Status = gDS->GetMemorySpaceDescriptor (StackBase, &MemDesc); ASSERT_EFI_ERROR (Status); @@ -326,6 +340,9 @@ InitMpGlobalData ( MemDesc.Attributes | EFI_MEMORY_RP ); ASSERT_EFI_ERROR (Status); + + DEBUG ((DEBUG_INFO, "Stack Guard set at %lx [cpu%lu]!\n", + (UINT64)StackBase, (UINT64)Index)); } }