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Date: Tue, 17 Aug 2021 10:38:22 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: devel@edk2.groups.io, min.m.xu@intel.com
Cc: Michael D Kinney <michael.d.kinney@intel.com>,
	Liming Gao <gaoliming@byosoft.com.cn>,
	Zhiguang Liu <zhiguang.liu@intel.com>,
	Brijesh Singh <brijesh.singh@amd.com>,
	Erdem Aktas <erdemaktas@google.com>,
	James Bottomley <jejb@linux.ibm.com>,
	Jiewen Yao <jiewen.yao@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>
Subject: Re: [edk2-devel] [PATCH 07/23] MdePkg: Update BaseIoLibIntrinsicSev to support Tdx
Message-ID: <20210817083822.vx2ts6twmm2fspqc@sirius.home.kraxel.org>
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  Hi,

> In the I/O functions of above files, if IsTdxGuest() returns TRUE, then
> Td I/O routine is called, otherwise the legacy I/O routine is called.
> Td I/O routines are declared in IoLibTdx.h and implemented in
> IoLibInternalTdx.c.

Sorry, I'm a bit late to the party, but what is the overall long plan
here?

IIRC some of the TDX features require a separate firmware binary.  So,
if we need a separate binary anyway at some point in the future, isn't
it simpler then to use a separate firmware binary right from the start?

You can simply add a Tdx-specific variant of the library
(BaseIoLibIntrinsicTdx.inf) and switch at compile time instead of
having runtime switches all over the place.

take care,
  Gerd