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Date: Mon, 30 Apr 2012 13:40:34 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Anthony Liguori <anthony@codemonkey.ws>
CC: "Michael S. Tsirkin" <mst@redhat.com>, Avi Kivity <avi@redhat.com>,
        Marcelo Tosatti <mtosatti@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        davej@redhat.com
Subject: Re: [PATCH] kvm: fix cpuid eax
References: <20120430143902.GA10181@redhat.com> <4F9EF7FA.3060007@codemonkey.ws>
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On 04/30/2012 01:37 PM, Anthony Liguori wrote:
> On 04/30/2012 09:39 AM, Michael S. Tsirkin wrote:
>> cpuid eax should return the max leaf so that
>> guests can find out the valid range.
>> This matches Xen et al.
> 
> What KVM does here predates Xen and Hyper-V.
> 
> This is an ABI breaker.
> 

What Intel and AMD have done here predates KVM...

What exactly relies on a zero here?

	-hpa