From mboxrd@z Thu Jan  1 00:00:00 1970
From: "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [RFC] CPUID usage for interaction between Hypervisors and Linux.
Date: Wed, 01 Oct 2008 10:47:48 -0700
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References: <1222881242.9381.17.camel@alok-dev1>
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Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
	"avi@redhat.com" <avi@redhat.com>,
	Rusty Russell <rusty@rustcorp.com.au>,
	Gerd Hoffmann <kraxel@redhat.com>, Ingo Molnar <mingo@elte.hu>,
	the arch/x86 maintainers <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	"Nakajima, Jun" <jun.nakajima@intel.com>,
	Dan Hecht <dhecht@vmware.com>,
	Zachary Amsden <zach@vmware.com>,
	virtualization@lists.linux-foundation.org, kvm@vger.kernel.org
To: akataria@vmware.com
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Alok Kataria wrote:
> 
> Hypervisor CPUID Interface Proposal
> -----------------------------------
> 
> Intel & AMD have reserved cpuid levels 0x40000000 - 0x400000FF for
> software use.  Hypervisors can use these levels to provide an interface
> to pass information from the hypervisor to the guest running inside a
> virtual machine.
> 
> This proposal defines a standard framework for the way in which the
> Linux and hypervisor communities incrementally define this CPUID space.
> 

I also observe that your proposal provides no mean of positive 
identification, i.e. that a hypervisor actually conforms to your proposal.

	-hpa