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Date: Thu, 19 Aug 2021 08:49:37 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: devel@edk2.groups.io, min.m.xu@intel.com
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>,
	Jordan Justen <jordan.l.justen@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 18/23] OvmfPkg: Enable Tdx in SecMain.c
Message-ID: <20210819064937.o646vxjebwzgfgoz@sirius.home.kraxel.org>
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  Hi,

> +/**
> +  In Tdx guest, some information need to be passed from host VMM to guest
> +  firmware. For example, the memory resource, etc. These information are
> +  prepared by host VMM and put in HobList which is described in TdxMetadata.

What kind of information is passed to the guest here?

qemu has fw_cfg to pass information from the VMM to the guest firmware.
What are the reasons to not use fw_cfg?

thanks,
  Gerd