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Date: Wed, 3 May 2023 09:24:11 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: "Ni, Ray" <ray.ni@intel.com>
Cc: "devel@edk2.groups.io" <devel@edk2.groups.io>, 
	Pawel Polawski <ppolawsk@redhat.com>, "Kumar, Rahul R" <rahul.r.kumar@intel.com>, 
	Oliver Steffen <osteffen@redhat.com>, "Dong, Eric" <eric.dong@intel.com>
Subject: Re: [edk2-devel] [PATCH 1/1] UefiCpuPkg/MpInitLib: fix apic mode for cpu hotplug
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On Tue, Mar 21, 2023 at 07:28:44AM +0000, Ni, Ray wrote:
> > +  } else if ((PcdGet32 (PcdCpuBootLogicalProcessorNumber) > 0) &&
> > +             (PcdGet32 (PcdCpuMaxLogicalProcessorNumber) > 255))
> > +  {
> > +    X2Apic = TRUE;
> 
> Gerd,
> I agree with your needs that want X2 APIC even the actual processor number in BIOS phase <= 255.
> 
> Question: Is it possible that BIOS stays at XAPIC, and later OS switches to X2 APIC when the maximum CPU count > 255?
> 
> I am thinking about adding a new PCD to tell MP code switch to x2 apic in the first time AP wakes up. Possible timeline for the code change is
> about within 1 month. Do you think it can meet your needs?

Ping.  What is the status here?  I'd like to see that fixed for OVMF
for the next stable release, and freeze is coming closer ...

take care,
  Gerd