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

Joerg Roedel
2010-03-23T14:06:09Z

On Mon, Mar 22, 2010 at 05:06:17PM -0500, Anthony Liguori wrote:
> There always needs to be a system wide entity. There are two ways to
> enumerate instances from that system wide entity. You can centralize
> the creation of instances and there by maintain an list of current
> instances. You can also allow instances to be created in a
> decentralized manner and provide a standard mechanism for instances to
> register themselves with the system wide entity.

And this system wide entity is the kvm module. It creates instances of
'struct kvm' and destroys them. I see no problem if we just attach a
name to every instance with a good default value like kvm0, kvm1 ... or
guest0, guest1 ... User-space can override the name if it wants. The kvm
module takes care about the names being unique.
This is very much the same as network card numbering is implemented in
the kernel.
Forcing perf to talk to qemu or even libvirt produces to much overhead
imho. Instrumentation only produces useful results with low overhead.

Joerg