Which CPUID features are “hidden” or “masked” from the native hardware in KVM implementation. Why does the KVM hypervisor hide / mask such features?
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These are hidden so the guest OS doesn't rely on them, which allows to migrate the VM to another machine that might implement fewer features. You can configure KVM to expose more features to the guest. – Simon Richter Dec 16 '15 at 10:55
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@SimonRichter thanks a lot for your reply but what are those features. Would really appreciate if you could name few? – user3073180 Dec 16 '15 at 11:50
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There is a good list on the [Unix&Linux SE](http://unix.stackexchange.com/questions/43539/what-do-the-flags-in-proc-cpuinfo-mean) – Simon Richter Dec 16 '15 at 12:41
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@SimonRichter But these are all the supported ones. How to find out which ones are masked/hidden by KVM? Thanks in advance. – user3073180 Dec 16 '15 at 16:41
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From inside the VM, you can't, and it wouldn't be useful anyway (because the admin may choose to migrate the VM to another machine at any time). If you have access to the host system as well, get both lists and compare. – Simon Richter Dec 16 '15 at 21:11
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@SimonRichter Thanks will do that.. but do u know 1 or 2 such features? – user3073180 Dec 16 '15 at 23:16