Re: [Xen-devel] [xen vMCE RFC V0.2] xen vMCE design

From: Christoph Egger
Date: Tue Jul 03 2012 - 11:32:17 EST


On 07/03/12 17:08, Jan Beulich wrote:

>>>> On 03.07.12 at 16:50, Christoph Egger <Christoph.Egger@xxxxxxx> wrote:
>> On 07/03/12 15:26, Luck, Tony wrote:
>>
>>>> I'm not convinced of the need, and would prefer aiming at a
>>>> shared implementation unless issues arise that make this
>>>> impossible.
>>>
>>> It does sound odd. Yes, Intel and AMD have differences around CMCI ... but
>> we are never
>>> going to send a CMCI to a guest (there is no point, it can't do anything
>> useful with the
>>> information, it may do something pointlessly stupid like stop using a guest
>> physical page).
>>> The only reason I suggested making MCG_CAP pretend that CMCI was supported
>> was a
>>> small optimization ... if a Linux guest sees that CMCI is supported, it will
>> not poll the machine
>>> check banks looking for corrected errors.
>>
>>
>> Are you talking about PV or HVM guest?
>>
>> For HVM guests yes it makes sense to disable CMCI in MCG_CAP for both
>> AMD and Intel.
>
> "enable" you mean?


Oh, sorry. I misread one sentence.
If CMCI for the guest is really just emulated (= 100% software)
then yes, enable for both AMD and Intel is fine.

Christoph

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