On Wed, Oct 26, 2022 at 11:40:31AM +0800, Jiaxi Chen wrote: > > What do you think about moving CPUID_7_1_EAX to be a KVM-only leaf too? AFAICT, > > KVM passthrough is the only reason the existing features are defined. Yap, looking at the patches which added those 2 feature flags upstream, they don't look like some particular use was the goal but rather to expose it to guests. Besides, AVX512 apps do their own CPUID detection. > Since CPUID_7_1_EAX has only 5 features now, it is a big waste, > should we move it to KVM-only leaf as Sean suggested. What's your > opinion about this? Yes, pls do. And when you do, make sure to undo what b302e4b176d0 ("x86/cpufeatures: Enumerate the new AVX512 BFLOAT16 instructions") added. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette