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Date: Thu, 08 Oct 2009 09:23:14 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] Re: [PATCH v2 9/9] Add -kvm option
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To: Avi Kivity <avi@redhat.com>
Cc: Andre Przywara <andre.przywara@amd.com>, Anthony Liguori <aliguori@us.ibm.com>, Gerd Hoffmann <kraxel@redhat.com>, Glauber Costa <glommer@redhat.com>, qemu-devel@nongnu.org

Avi Kivity wrote:
> On 10/08/2009 01:00 AM, Anthony Liguori wrote:
>> Glauber Costa wrote:
>>> This option deprecates --enable-kvm. It is a more flexible option,
>>> that makes use of qemu-opts, and allow us to pass on options to 
>>> enable or
>>> disable kernel irqchip, for example.
>>
>> With proper qdev support, you could select kvm device models based on 
>> -device so I think this option isn't all that useful.
>
> qdev (mostly?) is about the guest interface; this is more about the 
> host implementation, so akin to -drive file= and cache=.

If we make the kvm device a separate device, then it's about choosing 
which device to use.

Regardless, even if it were a single device, it's still a property of 
the device so a qdev property would be the logical way to expose it.

>> What I'd like to see in the interim is a kvm specific machine type 
>> that's defaulted to if kvm is enabled.  I think this would be useful 
>> not only for enabling things like in-kernel apic, but also for 
>> selecting a default cpu model.
>
> We should make a distinction between guest-visible changes and 
> accelerators like kvm-irqchip and vhost.

They are different device models that happen to implement the same 
guest-visible device.

Regards,

Anthony Liguori