Re: [RFC Part1 PATCH v3 02/17] x86/CPU/AMD: Add the Secure Encrypted Virtualization CPU feature

Tom Lendacky
2017-08-09T18:17:54Z

On 7/25/2017 10:33 AM, Borislav Petkov wrote:
> On Tue, Jul 25, 2017 at 10:29:40AM -0500, Tom Lendacky wrote:
>> But early_identify_cpu() calls get_cpu_cap() which will check for cpuid
>> leaf 0x80000008 support and set x86_phys_bits.
>
> Right, but it can't be less than 32, can it? And if it is more than 32
> bits, then it probably doesn't really matter on 32-bit. Unless it is
> less than 36 bits and you do PAE...
>
>> I'll try to build and run a 32-bit kernel and see how this all flows.
>
> Yeah, that would be good.

Ok, finally got around to running a 32-bit kernel and it reports
x86_phys_bits as 48.

Thanks,
Tom

>
> Thanks.
>