From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexander Graf <agraf@suse.de>
Subject: Re: [RFC 0/2] GET_EMULATED_CPUID support with "allow-emulation" option
Date: Thu, 05 Jun 2014 18:58:17 +0200
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Cc: Borislav Petkov <bp@alien8.de>,
	"Gabriel L. Somlo" <gsomlo@gmail.com>, kvm@vger.kernel.org,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Michael Mueller <mimu@linux.vnet.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	"Jason J. Herne" <jjherne@linux.vnet.ibm.com>,
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To: Paolo Bonzini <pbonzini@redhat.com>,
	Eduardo Habkost <ehabkost@redhat.com>, qemu-devel@nongnu.org
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On 05.06.14 18:52, Paolo Bonzini wrote:
> Il 05/06/2014 18:45, Alexander Graf ha scritto:
>>>>
>>>
>>> Only if you were using "-cpu somethingThatHasAVX", though, no?
>>
>> Yes. The same argument goes the other way around. I want to use AVX
>> emulation, do "allow-emulation" and suddenly I get MONITOR/MWAIT 
>> emulation.
>
> What about:
>
> - letting "-cpu foo,+emulatedfeature" just work
>
> - adding emulated=yes that blindly enables all emulated features
>
> - making "-cpu ...,check" prints a warning for emulated features 
> unless emulated=yes

So:

   -cpu foo,+emulatedFeature just works

   -cpu foo,+notEmulatedFeature still sets the CPUID bit for that feature

   -cpu foo,check prints warnings for all cpuid bits not in the 
"allowed" bitmap. It prints different warnings depending on whether the 
bit is in "emulated" or not


Alex