Re: [PATCH 0/5] KVM paravirt_ops implementation

Zachary Amsden
2007-06-20T20:46:18Z

Jeremy Fitzhardinge wrote:
>
> Hm, you need to quiesce the kernel in some way when you do a migrate,
> so making sure it isn't in a hypercall would be just part of that. In
> general you'd make sure all but one CPU is parked somewhere, and the
> remaining CPU is doing the suspend, right?
>
> The tricky part for Xen in all this is how to make sure all mfn
> references are visible to the hypervisor/toolstack so they can be
> remapped; hypercall page contents are not a concern by comparison.

You only need to quiesce if you have guest-visible data-structures that
have details about the underlying hardware. So Xen needs to quiesce,
but I don't know of any other VMM that would.

VMI, KVM and lhype should be capable of transparent migration without
guest involvement.

Zach