support for live migration with PCI passthrough devices

[Erik Skultety]

On Tue, Aug 25, 2020 at 02:56:49PM +0200, Michal Privoznik wrote:
> On 8/25/20 1:40 PM, Henry lol wrote:
> > Hi guys,
> >
> > I'm wondering whether libvirt supports live migration for the VM with
> > PCI passthrough devices.
> > or it must be assumed before live migration that all passthrough devices
> > be unplugged?
>
> Unfortunately, this is still not supported. The problem is that PCI devices
> themselves are not capable of dumping their internal state and restoring
> from it on destination.
>
> There is a long thread started last month that discuss what the interface
> should look like, but at this point I guess we are still far away from it:
>
> https://www.redhat.com/archives/libvir-list/2020-July/msg00675.html

Just a little note, even with such an interface in place it will still take
time for vendors of conventional physical devices to adopt it, so realistically
the main focus here are mediated devices and SRIOV-capable devices.

Erik