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From:   "Kalra, Ashish" <Ashish.Kalra@amd.com>
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Subject: RE: [PATCH Part2 v6 05/49] x86/sev: Add RMP entry lookup helpers
Thread-Topic: [PATCH Part2 v6 05/49] x86/sev: Add RMP entry lookup helpers
Thread-Index: AQHYhkJMEjVRVcpx502HVSPCQUlAqK1bejcAgAACPYCAAD2E8IAAAkWAgAAEHtCAAALbAIAAEKeAgAACGACAAAZmMIABummAgAABGvCALNnqAIAAfWiAgAAF14CAD98qkA==
Date:   Mon, 1 Aug 2022 21:50:37 +0000
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[AMD Official Use Only - General]

>> I disagree.  Running an old kernel on new hardware with a different=20
>> RMP layout should refuse to use SNP, not read/write garbage and likely=20
>> corrupt the RMP and/or host memory.

>See my example below.

> And IMO, hiding the non-architectural RMP format in SNP-specific code=20
> so that we don't have to churn a bunch of call sites that don't _need_=20
> access to the raw RMP format is a good idea regardless of whether we=20
> want to be optimistic or pessimistic about future formats.

>I don't think I ever objected to that.

I agree with what Sean is recommending to do.=20

As I mentioned earlier, in the long term and with respect to future platfor=
ms, we are going to add architectural support
to read RMP table entries, so this structure will exist only for older plat=
form support.

Thanks,
Ashish