Hi Gerd,
In v4 , InterlockedIncrement called is after RestoreVolatileRegisters to ensure
that "finished" reporting from the APs is as
later as possible.
Here is V3：
GetProcessorNumber (CpuMpData, &ProcessorNumber);
- RestoreVolatileRegisters (&CpuMpData->CpuData[0].VolatileRegisters, FALSE);
InterlockedIncrement ((UINT32 *)&CpuMpData->FinishedCount);
+
+ if (CpuMpData->EnableExecuteDisableForSwitchContext) {
+ EferMsr.Uint64 = AsmReadMsr64 (MSR_IA32_EFER);
+ EferMsr.Bits.NXE = 1;
+ AsmWriteMsr64 (MSR_IA32_EFER, EferMsr.Uint64);
+ }
+
+ RestoreVolatileRegisters (&CpuMpData->CpuData[0].VolatileRegisters, FALSE);
Regards,
Yuanhao
-----Original Message-----
From: Gerd Hoffmann <kra...@redhat.com>
Sent: Monday, November 13, 2023 6:54 PM
To: Xie, Yuanhao <yuanhao....@intel.com>
Cc: devel@edk2.groups.io; Dong, Eric <eric.d...@intel.com>; Ni, Ray
<ray...@intel.com>; Kumar, Rahul R <rahul.r.ku...@intel.com>
Subject: Re: [Patch V4] UefiCpuPkg/MpInitLib: Enable execute disable bit.
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> index 9a6ec5db5c..f29e66a14f 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> @@ -910,9 +910,16 @@ DxeApEntryPoint (
> CPU_MP_DATA *CpuMpData
> )
> {
> - UINTN ProcessorNumber;
> + UINTN ProcessorNumber;
> + MSR_IA32_EFER_REGISTER EferMsr;
>
> GetProcessorNumber (CpuMpData, &ProcessorNumber);
> + if (CpuMpData->EnableExecuteDisableForSwitchContext) {
> + EferMsr.Uint64 = AsmReadMsr64 (MSR_IA32_EFER);
> + EferMsr.Bits.NXE = 1;
> + AsmWriteMsr64 (MSR_IA32_EFER, EferMsr.Uint64); }
It helps reviewers if you document changes from one version to the next.
This code block was moved (compared to v3). Why?
take care,
Gerd
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