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Date: Tue, 12 Oct 2021 09:22:28 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: Min Xu <min.m.xu@intel.com>
Cc: devel@edk2.groups.io, 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: [PATCH V9 3/4] OvmfPkg: Add IntelTdxMetadata.asm
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  Hi,

> +; - Type field means this section is of BFV. This field is designed for the
> +;   purpose that in some case host VMM may do some additional processing based
> +;   upon the section type. TdHob section is an example. Host VMM pass the
> +;   physical memory information to the guest firmware by writing the data in
> +;   the memory region designated by TdHob section.

Brijesh?  What are your plans?  Do you want use this too?

If so, then the section types need some more structure.  I think best
would be reserve blocks, something like 0x00 -> 0xff common types (bfv,
cfv, temp_mem), 0x100 -> 0x1ff tdx (td_hob), 0x200 -> 0x2ff sev (cpuid,
secrets, ...).

take care,
  Gerd