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Date: Fri, 26 Sep 2008 17:32:26 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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CC: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
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       Daniel Hecht <dhecht@vmware.com>,
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Subject: Re: Use CPUID to communicate with the hypervisor.
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Alok Kataria wrote:
>>>
>> This is great, obviously... although we'll have to deal with legacy
>> methods for a while if not indefinitely (just as we have to for
>> pre-CPUID processors).
> 
> Ok, do you think we should keep those (legacy) interfaces separate so
> that they can be phased out whenever the time is right. 
> 

I don't, realistically, think we can phase them out for a very long 
time, and then it's usually a "why bother".  What we want to do is 
abstract them so they don't make the rest of the code suck.

> 
> I would like to see this as a generic hypervisor way to get frequency
> rather than a VMware specific thingy. 
>> In order for *that* to be safe, you'd have to have well-defined ranges
>> for different virtualization vendors where each of them can define their
>> own stuff.
> 
> My motivation for doing this is to have a standard across all the
> hypervisor's. If all the different hypervisor guys can come to some
> sought of consensus on the various hypervisor leafs that would help keep
> this simple and a lot more maintainable.
> 

Agreed.  However, that's obviously beyond our immediate control.

	-hpa