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

From: Kalra, Ashish
Date: Wed Jun 22 2022 - 14:34:45 EST


[AMD Official Use Only - General]

-----Original Message-----
From: Dave Hansen <dave.hansen@xxxxxxxxx>
Sent: Wednesday, June 22, 2022 1:18 PM
To: Kalra, Ashish <Ashish.Kalra@xxxxxxx>; x86@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; linux-coco@xxxxxxxxxxxxxxx; linux-mm@xxxxxxxxx; linux-crypto@xxxxxxxxxxxxxxx
Cc: tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; jroedel@xxxxxxx; Lendacky, Thomas <Thomas.Lendacky@xxxxxxx>; hpa@xxxxxxxxx; ardb@xxxxxxxxxx; pbonzini@xxxxxxxxxx; seanjc@xxxxxxxxxx; vkuznets@xxxxxxxxxx; jmattson@xxxxxxxxxx; luto@xxxxxxxxxx; dave.hansen@xxxxxxxxxxxxxxx; slp@xxxxxxxxxx; pgonda@xxxxxxxxxx; peterz@xxxxxxxxxxxxx; srinivas.pandruvada@xxxxxxxxxxxxxxx; rientjes@xxxxxxxxxx; dovmurik@xxxxxxxxxxxxx; tobin@xxxxxxx; bp@xxxxxxxxx; Roth, Michael <Michael.Roth@xxxxxxx>; vbabka@xxxxxxx; kirill@xxxxxxxxxxxxx; ak@xxxxxxxxxxxxxxx; tony.luck@xxxxxxxxx; marcorr@xxxxxxxxxx; sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx; alpergun@xxxxxxxxxx; dgilbert@xxxxxxxxxx; jarkko@xxxxxxxxxx
Subject: Re: [PATCH Part2 v6 05/49] x86/sev: Add RMP entry lookup helpers

On 6/22/22 11:15, Kalra, Ashish wrote:
> So actually this RPM entry definition is platform dependent and will
> need to be changed for different AMD processors and that change has to
> be handled correspondingly in the dump_rmpentry() code.

>So, if the RMP entry format changes in future processors, how do we make sure that the kernel does not try to use *this* code on those processors?

Functions snp_lookup_rmpentry() and dump_rmpentry() which rely on this structure definition will need to handle it accordingly.

Thanks,
Ashish