Re: [libvirt] [PATCH v3] Support for cpu64-rhel* qemu cpu models

[Jiri Denemark <jdenemar redhat com>]

On Tue, Feb 21, 2012 at 14:54:39 +0000, Daniel P. Berrange wrote:
> On Mon, Feb 13, 2012 at 03:32:26PM +0100, Jiri Denemark wrote:
> > It was designed to be okay. Libvirt checks what CPU models are supported by
> > qemu and avoids passing unsupported models to qemu. After all, we support
> > running libvirt with older releases of qemu (we don't force their git HEAD).
> 
> One day we should just stop using '-cpu', and simply write out a config
> file where we can put a full '[cpudef]' definition, and pass it to QEMU
> using -loadconfig. This will allow us to specify precise CPU models,
> without being tied to particular QEMU versions. It will also allow the
> end user / mgmt app to define new CPU models for libvirt to use.

Although, as someone already mentioned on this list, it's not so easy. Not
every combination we/user/mgmt come up with may actually be supported,
especially when migration comes into play. I guess we would need qemu to
verify the model we want to use is sane/supported.

Jirka