On 9/2/20 9:45 AM, pet...@infradead.org wrote: > 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...@intel.com
Wouldn't we also have to turn on faulting for all the bits that are enumerated, but of which the kernel is unaware? Right now, a bit that we clearcpuid= and one about which the kernel is totally unaware look the same.