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

Anthony Liguori
2010-03-22T19:15:35Z

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.

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.

libvirt serves an important purpose, but we need to do a better job in
qemu with respect to usability. We can't just punt to libvirt.

Regards,

Anthony Liguori