Re: [edk2-devel] [PATCH 0/2] UefiCpuPkg/Library: Fix bug in MpInitLib

["Duran, Leo" <leo.duran@amd.com>]

> -----Original Message-----
> From: Gao, Liming [mailto:liming.gao@intel.com]
> Sent: Wednesday, February 26, 2020 3:56 AM
> To: devel@edk2.groups.io; Ni, Ray <ray.ni@intel.com>; Laszlo Ersek
> <lersek@redhat.com>; Duran, Leo <leo.duran@amd.com>; Wu, Hao A
> <hao.a.wu@intel.com>; Fu, Siyuan <siyuan.fu@intel.com>
> Cc: Dong, Eric <eric.dong@intel.com>; leif@nuviainc.com; Kinney, Michael D
> <michael.d.kinney@intel.com>; afish@apple.com; Gao, Liming
> <liming.gao@intel.com>
> Subject: RE: [edk2-devel] [PATCH 0/2] UefiCpuPkg/Library: Fix bug in
> MpInitLib
> 
> Leo:
>   Now, we enter into Hard Feature Freeze phase until edk2-stable202002 tag
> is created at 2020-02-28. Only critical bug fix is still allowed.
> 
>   Do you request to catch this fix into this stable tag? If yes, please work closely
> with UefiCpuPkg maintainers to catch the stable tag release schedule 2020-
> 02-28.
> 
> Thanks
> Liming
[Duran, Leo] 
I'm not sure I understand what my next steps are, perhaps I need to go back to the BUGZILLA?
(This issue is a "must-fix", so perhaps I can tag it as such in the BUG report.).

Thanks,
Leo.

> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ni, Ray
> > Sent: Wednesday, February 26, 2020 3:57 PM
> > To: Laszlo Ersek <lersek@redhat.com>; devel@edk2.groups.io;
> > leo.duran@amd.com; Wu, Hao A <hao.a.wu@intel.com>; Fu, Siyuan
> > <siyuan.fu@intel.com>
> > Cc: Dong, Eric <eric.dong@intel.com>
> > Subject: Re: [edk2-devel] [PATCH 0/2] UefiCpuPkg/Library: Fix bug in
> > MpInitLib
> >
> > Leo,
> >
> > > > BTW, reading the PlatformId MSR was already being done by
> > > > MicrocodeDetect(), but it never affected AMD-based platforms as
> > > > the flow never gets that far, since the Detect routine bails out early
> when it finds the size of the patch is zero.
> >
> > You are saying that PlatformId MSR access is not performed by CPU in old
> code because of the zero size uCode.
> > But now with Hao or Siyuan's change, the PlatformId MSR access is
> > always performed even when there is no uCode. It sounds like a regression
> to optimization to me.
> > Did you evaluate the path to avoid accessing PlatformID MSR when uCode
> > doesn't exist? So that the API to detect AMD processor is not needed at all.
> >
> > Thanks,
> > Ray
> >
> >