support for live migration with PCI passthrough devices

[Michal Privoznik]

On 8/26/20 8:27 AM, Erik Skultety wrote:
> 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.

Yeah that. That reminds me that at one of KVM Forums I've seen a demo of 
migration with a PCI device plugged in whole time, but it was all 
experimental. /me goes and tries to find it. à voilà:

https://www.youtube.com/watch?v=ZAzv0c-fdAc

Michal