Re: [Xen-devel] Re: [Qemu-devel] [PATCH 05/13] xen: groundwork for xen support

[Daniel P. Berrange]

On Tue, Aug 26, 2008 at 03:20:06PM +0200, Gerd Hoffmann wrote:
> Daniel P. Berrange wrote:
> > Probing for whether a domain ID exists in the hypervisor, and if not, then
> > creating it, has a nasty race condition, where XenD could launch QEMU
> > and then (for whatever reason) decide to kill off the domain, but QEMU
> > then re-creates it during its startup procedure.
> 
> Oops.  Yes, that needs to be addressed.
> 
> > If we want QEMU to explicitly created Xen domains from scratch, rather than
> > attaching to an existing one, then there needs to be a way to reliably 
> > specify this behaviour via the CLI.
> 
> So we are scoring at three options for xen now:
> 
>   -xen-domid <nr>  specify xen domain id.
>   -xen-create      ask qemu to create the domain.

Actually I'd invert that, eg   -xen-attach  since common QEMU semantics
are that it is completely in charge of creation. Attaching to an externally
created VM is the xen additional semantics.

Regards,
Daniel
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