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Subject: Re: [PATCH Part1 v5 35/38] x86/sev: Register SNP guest request
 platform device
To:     Dov Murik <dovmurik@linux.ibm.com>, Borislav Petkov <bp@alien8.de>
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From:   Brijesh Singh <brijesh.singh@amd.com>
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Date:   Fri, 3 Sep 2021 07:08:06 -0500
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On 9/3/21 3:15 AM, Dov Murik wrote:
>> Unfortunately, the secrets page does not contain a magic header or uuid
>> which a guest can read to verify that the page is actually populated by
>> the PSP. 
> In the SNP FW ABI document section 8.14.2.5 there's a Table 61 titled
> Secrets Page Format, which states that the first field in that page is a
> u32 VERSION field which should equal 2h.
>
> While not as strict as GUID header, this can help detect early that the
> content of the SNP secrets page is invalid.

The description indicates that the field is a version number of the
secrets page format; it will get bumped every time the spec steals the
reserved bytes for something new. IMHO, we should not depend on the
version number.

thanks