Re: [PATCH Part2 v6 05/49] x86/sev: Add RMP entry lookup helpers

Dave Hansen
2022-06-22T19:50:19Z

On 6/22/22 12:43, Kalra, Ashish wrote:
>> I think that needs to be fixed. It should be as simple as a
>> model/family check, though. If someone (for example) attempts to
>> use SNP (and thus snp_lookup_rmpentry() and dump_rmpentry()) code
>> on a newer CPU, the kernel should refuse.
> More specifically I am thinking of adding RMP entry field accessors
> so that they can do this cpu model/family check and return the
> correct field as per processor architecture.

That will be helpful down the road when there's more than one format.
But, the real issue is that the kernel doesn't *support* a different RMP
format. So, the SNP support should be disabled when encountering a
model/family other than the known good one.