Re: [RFC] Unify KVM kernel-space and user-space code into a single project

Anthony Liguori
2010-03-22T19:33:49Z

On 03/22/2010 02:31 PM, Daniel P. Berrange wrote:
> On Mon, Mar 22, 2010 at 02:15:35PM -0500, Anthony Liguori wrote:
>
>> On 03/22/2010 12:55 PM, Avi Kivity wrote:
>>
>>>> Lets look at the ${HOME}/.qemu/qmp/ enumeration method suggested by
>>>> Anthony.
>>>> There's numerous ways that this can break:
>>>>
>>> I don't like it either. We have libvirt for enumerating guests.
>>>
>> We're stuck in a rut with libvirt and I think a lot of the
>> dissatisfaction with qemu is rooted in that. It's not libvirt that's
>> the probably, but the relationship between qemu and libvirt.
>>
>> We add a feature to qemu and maybe after six month it gets exposed by
>> libvirt. Release time lines of the two projects complicate the
>> situation further. People that write GUIs are limited by libvirt
>> because that's what they're told to use and when they need something
>> simple, they're presented with first getting that feature implemented in
>> qemu, then plumbed through libvirt.
>>
> That is somewhat unfair as a blanket statement!
>

Sorry, you're certainly correct. Some features appear quickly, but
others can take an awfully long time.

>> It wouldn't be so bad if libvirt was basically a passthrough interface
>> to qemu but it tries to model everything in a generic way which is more
>> or less doomed to fail when you're adding lots of new features (as we are).
>>
>> The list of things that libvirt doesn't support and won't any time soon
>> is staggering.
>>
> As previously discussed, we want to improve both the set of features
> supported, and make it much easier to support new features promptly.
> The QMP& qdev stuff has been a very good step forward in making it
> easier to support QEMU management. There have been a proposals from
> several people, yourself included, on how to improve libvirt's support
> for the full range of QEMU features. We're committed to looking at this
> and figuring out which proposals are practical to support, so we can
> improve QEMU& libvirt interaction for everyone.
>

Regards,

Anthony Liguori

> Regards,
> Daniel
>