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Date: Tue, 31 Aug 2021 12:45:40 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: devel@edk2.groups.io, min.m.xu@intel.com
Cc: Brijesh Singh <brijesh.singh@amd.com>, Eric Dong <eric.dong@intel.com>,
	Erdem Aktas <erdemaktas@google.com>, Hao A Wu <hao.a.wu@intel.com>,
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	Tom Lendacky <thomas.lendacky@amd.com>,
	Zhiguang Liu <zhiguang.liu@intel.com>
Subject: Re: [edk2-devel] [PATCH 00/23] Enable Intel TDX in OvmfPkg (SEC/PEI)
Message-ID: <20210831104540.4um7x5zz4aq3oaq6@sirius.home.kraxel.org>
References: <cover.1628767741.git.min.m.xu@intel.com>
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  Hi,

> [TDX]: https://software.intel.com/content/dam/develop/external/us/en/
> documents/tdx-whitepaper-final9-17.pdf

So, coming back to this after reading through a bunch of docs and
patches with some high-level questions.  The whitepaper lists two
ovmf configs:

  (1) config-a, supporting normal/sev/tdx with basic features.
  (2) config-b, supporting normal/tdx with more features.

What of this is implemented by this patch series?
config-a?  completely?  parts of it?

The whitepaper also doesn't explain very well why we have two
configurations in the first place.  It describes *what* are the
differences but not *why* they are there.

Apparently some of the additional features supported by config-b
are either more difficult or impossible to implement in config-a.
Is that correct?  Is that explained in more detail somewhere?

thanks,
  Gerd