Re: [RFC PATCH] tools/x86: add kcpuid tool to show raw CPU features

From: peterz
Date: Wed Sep 02 2020 - 12:45:59 EST


On Thu, Aug 27, 2020 at 03:49:03PM +0800, Feng Tang wrote:
> End users frequently want to know what features their processor
> supports, independent of what the kernel supports.
>
> /proc/cpuinfo is great. It is omnipresent and since it is provided by
> the kernel it is always as up to date as the kernel. But, it can be
> ambiguous about processor features which can be disabled by the kernel
> at boot-time or compile-time.

Let me once again suggest we use CPUID faulting to 'fix' this.

We really should clear the CPUID bits when the kernel explicitly
disables things.

https://lkml.kernel.org/r/1552431636-31511-18-git-send-email-fenghua.yu@xxxxxxxxx