Re: [PATCH v4 1/6] x86: KVM: Advertise CMPccXADD CPUID to user space

[Jiaxi Chen]

On 11/21/2022 11:29 PM, Dave Hansen wrote:
> On 11/21/22 06:46, Jiaxi Chen wrote:
>> Features which has been enabled in kernel usually should be added to
>> /proc/cpuinfo.
> 
> Features that the kernel *itself* is actually using always get in there.
>  Things like "smep".
> 
> But, things that the kernel "enables" but that only get used by
> userspace don't generally show up in /proc/cpuinfo.
> 
> KVM is kinda a weird case.  The kernel is making the feature available
> to guests, but it's not _using_ it in any meaningful way.  To me, this
> seems much more akin to the features that are just available to
> userspace than something that the kernel is truly using.
> 
> Also, these feature names are just long and ugly, and the "flags" line
> is already a human-*un*readable mess.  I think we should just leave them
> out.

True and agree. As for these cpuids are not truly used by kernel except
for advertising to kvm userspace, we can hide them in /proc/cpuinfo by
overriding their name with "".

-- 
Regards,
Jiaxi