Re: [PATCH Part1 v5 35/38] x86/sev: Register SNP guest request platform device

From: Brijesh Singh
Date: Fri Sep 03 2021 - 08:08:18 EST



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