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A comment on Intel Discloses Lakefield CPUs Specifications. Parent comment

Re:Intel Discloses Lakefield CPUs Specifications by loeg on Wednesday June 10, 2020 @02:11PM (#23480235)
The typical x86 extension query (cpuid) is an unpriviliged user-mode instruction — unless the application takes care to ask the OS, there's no real way for the OS to select the common denominator.

Edit: Also: AVX2 is a lot older than Skylake. You're probably thinking of AVX512.

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Re:Intel Discloses Lakefield CPUs Specifications by kllrnohj on Wednesday June 10, 2020 @02:21PM (#23480348)
The OS could still intercept CPUID - this is, after all, what VMs do.

But it looks like Intel is doing this anyway, as Sunny Cove in this application has had its AVX-512 removed anyway: "One thing we can confirm in advance – the Sunny Cove does not appear to be AVX-512 enabled."

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Re:Intel Discloses Lakefield CPUs Specifications by loeg on Wednesday June 10, 2020 @03:45PM (#23481211)
Running every thread in a hypervisor just to trap cpuid sounds like extreme overkill. And probably some applications want the features only available on the big core, and masking those out doesn't solve that end of the problem.
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Re:Intel Discloses Lakefield CPUs Specifications by saagarjha on Wednesday June 10, 2020 @03:25PM (#23481014)
Well then you need to set up a VMM for the OS…
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