RE: [PATCH Part2 v6 06/49] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction

Kalra, Ashish
2022-06-21T17:38:40Z

[AMD Official Use Only - General]

Hello Dave,

>> /*
>> * The RMP entry format is not architectural. The format is defined
>> in PPR @@ -126,6 +128,15 @@ struct snp_guest_platform_data {
>> u64 secrets_gpa;
>> };
>>
>> +struct rmpupdate {
>> + u64 gpa;
>> + u8 assigned;
>> + u8 pagesize;
>> + u8 immutable;
>> + u8 rsvd;
>> + u32 asid;
>> +} __packed;

>I see above it says the RMP entry format isn't architectural; is this 'rmpupdate' structure? If not how is this going to get handled when we have a couple of SNP capable CPUs with different layouts?

Architectural implies that it is defined in the APM and shouldn't change in such a way as to not be backward compatible.
I probably think the wording here should be architecture independent or more precisely platform independent.

Thanks,
Ashish