Re: [PATCH v3 1/7] x86: KVM: Move existing x86 CPUID leaf [CPUID_7_1_EAX] to kvm-only leaf

Jiaxi Chen
2022-11-16T02:27:43Z

On 11/16/2022 12:16 AM, Borislav Petkov wrote:
> On Tue, Nov 15, 2022 at 03:29:45PM +0000, Sean Christopherson wrote:
>> Heh, are any of the bits you believe Intel will add publicly documented? :-)
>>
>> LAM could be scattered, but if more bits are expected that's probably a waste of
>> time and effort.
>
> I'm being told the bigger part of that word is going to be used for
> either kernel or KVM bits so we might as well use it the "normal" way
> instead of doing KVM-only or scattered bits after all.
>
> Thx.
>
Intel published ISE spec
[https://cdrdv2.intel.com/v1/dl/getContent/671368] has documented 11
instructions for this leaf CPUID.7.1.EAX by now. Given that more bits
are going to be defined, I will enable these bits in the patch series as
v1 did and will not move them to kvm-only leaves.

By the way, Boris, what about CPUID.7.1.EDX, whether bigger part of it
is expected to be used? In intel ISE, 3 bits are defined for this word.
For now, I think put them in kvm-only subleaves as this patch series did
is a better choice. What's your opinion?

--
Regards,
Jiaxi