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Date: Thu, 05 Jun 2014 18:24:22 +0200
From: Alexander Graf <agraf@suse.de>
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Subject: Re: [Qemu-devel] [RFC 0/2] GET_EMULATED_CPUID support with
	"allow-emulation" option
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To: Eduardo Habkost <ehabkost@redhat.com>, qemu-devel@nongnu.org
Cc: Michael Mueller <mimu@linux.vnet.ibm.com>, kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>, Christian Borntraeger <borntraeger@de.ibm.com>, "Gabriel L. Somlo" <gsomlo@gmail.com>, Borislav Petkov <bp@alien8.de>, "Jason J. Herne" <jjherne@linux.vnet.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= <afaerber@suse.de>


On 05.06.14 18:12, Eduardo Habkost wrote:
> This implements GET_SUPPORTED_CPUID support using an explicit option for it:
> "allow-emulation". We don't want any emulated feature to be enabled by accident,
> so they will be enabled only if the user explicitly wants to allow them.

So is this an all-or-nothing approach? I would really prefer to override 
individual bits.

Also, I don't think the line "emulated" is the right one to draw. We 
"emulate" SVM or VMX too, but still enable them by default as soon as we 
think they're ready enough.

So could we add a new flag specifier instead? Today we have -flag and 
+flag. How about *flag to "force enable if the kernel can handle it, but 
doesn't do so by default"?


Alex