Re: [Qemu-devel] SLIRP migration?

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Jan Kiszka (jan.kiszka@siemens.com) wrote:
> On 2016-09-28 20:00, Dr. David Alan Gilbert wrote:
> > Hi Samuel, Jan,
> >   I'd like to convert SLIRPs migration code to VMState
> > and avoid all the qemu_put_/qemu_get_'s - but first I'd like to understand
> > when a lot of the slirp migration code makes sense.
> > 
> > I can see that migrating a VM with slirp makes sense (actually more
> > commonly saving a VM with slirp to a file); but when that happens
> > aren't you likely to lose all the network connections anyway?
> > If that's the case then why bother saving all the TCP state?
> > 
> > Under what circumstances do the network connections survive and
> > how can I test that?
> 
> I think I never tried this myself back then, nor do I remember any
> success story about slirp live migration from the top of my head.

It certainly survives - i.e. if you migrate a VM with slirp
the VM carries on running, and then you can make a new connection
to the VM and it works.

Maybe the issue here is that you need to store a lot of state
so that the guests view of the dieing connections after migration
is correct?

Dave

> Jan
> 
> -- 
> Siemens AG, Corporate Technology, CT RDA ITP SES-DE
> Corporate Competence Center Embedded Linux
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK