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Date: Wed, 1 Feb 2023 14:02:55 +0100
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: "Wu, Jiaxin" <jiaxin.wu@intel.com>
Cc: "Ni, Ray" <ray.ni@intel.com>,
	"devel@edk2.groups.io" <devel@edk2.groups.io>,
	"Dong, Eric" <eric.dong@intel.com>,
	"Zeng, Star" <star.zeng@intel.com>,
	Laszlo Ersek <lersek@redhat.com>,
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	"Kinney, Michael D" <michael.d.kinney@intel.com>,
	"Zimmer, Vincent" <vincent.zimmer@intel.com>
Subject: Re: [PATCH v3 1/5] UefiCpuPkg/SmmBaseHob.h: Add SMM Base HOB Data
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On Sun, Jan 29, 2023 at 05:08:49AM +0000, Wu, Jiaxin wrote:
> > 
> > For the smbase case it might also be possible to store the base
> > address and the per-cpu entry size, then use
> > 
> > 	smbase = base + size * cpuindex
> > 
> > to calculate the per-cpu base address.  Puts some restrictions on the
> > memory allocation (must be one big block), not sure this is possible,
> > that part of the code is not (yet?) posted for review.
> 
> 
> It's not a good idea that only store the start address of smbase and
> the per-cpu entry size. There are multiple algorithms to calculate
> each cpu's smbase, if hob producer (any peim) & consumer (SMM CPU
> driver) use different algorithm for each cpu's smbase, then there will
> be a big problem.

The algorithm needs to be part of the HOB specification of course.

take care,
  Gerd