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Date: Thu, 2 Sep 2021 10:20:29 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: Brijesh Singh <brijesh.singh@amd.com>
Cc: devel@edk2.groups.io, James Bottomley <jejb@linux.ibm.com>,
	Min Xu <min.m.xu@intel.com>, Jiewen Yao <jiewen.yao@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Jordan Justen <jordan.l.justen@intel.com>,
	Ard Biesheuvel <ardb+tianocore@kernel.org>,
	Erdem Aktas <erdemaktas@google.com>,
	Michael Roth <Michael.Roth@amd.com>
Subject: Re: [PATCH v6 06/29] OvmfPkg/ResetVector: pre-validate the data pages used in SEC phase
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References: <20210901161646.24763-1-brijesh.singh@amd.com>
 <20210901161646.24763-7-brijesh.singh@amd.com>
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  Hi,

> During the guest creation time, the VMM encrypts the OVMF_CODE.fd using
> the SEV-SNP firmware provided LAUNCH_UPDATE_DATA command. In addition to
> encrypting the content, the command also validates the memory region.
> This allows us to execute the code without going through the validation
> sequence.

Hmm, tdx must handle this too.

> +  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpHypervisorPreValidatedStart|0x0|UINT32|0x56
> +  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpHypervisorPreValidatedEnd|0x0|UINT32|0x57

So maybe we should drop the "Snp" from the name here ...

>  ; GUID (SEV-SNP boot block): bd39c0c2-2f8e-4243-83e8-1b74cebcb7d9
>  ;
>  sevSnpBootBlockStart:
> +    DD      SNP_HV_VALIDATED_START
> +    DD      SNP_HV_VALIDATED_END

... and store the range which needs validation in another, not snp-specific block?

Jiewen? Min?

take care,
  Gerd