Re: [PATCH 2/2] cpu: intel, amd: mask cleared cpuid features

From: H. Peter Anvin
Date: Wed Jul 25 2012 - 10:14:10 EST


With the necessary infrastructure, yes. Trap and emulate is montrivial work.

Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> wrote:

>On 07/25/2012 04:57 AM, H. Peter Anvin wrote:
>> On 07/24/2012 04:09 AM, Vladimir Davydov wrote:
>>> We have not encountered this situation in our environments and I
>hope we
>>> won't :-)
>>>
>>> But look, these CPUID functions cover majority of CPU features,
>don't
>>> they? So, most of "normal" apps inside VM will survive migration.
>>> Perhaps, some low-level utils won't. I guess that's why there are no
>>> MSRs for other levels provided by vendors.
>>>
>> You will once Ivy Bridge becomes common.
>
>Ivy Bridge has CPUID faulting, which allows masking all CPUID
>levels/functions.
>
>> -hpa
>>

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