On Thu, Nov 26, 2015 at 12:02:33AM +0800, Lan, Tianyu wrote:

On 11/25/2015 8:28 PM, Michael S. Tsirkin wrote:

quoted

Frankly, I don't really see what this short term hack buys us,
and if it goes in, we'll have to maintain it forever.

The framework of how to notify VF about migration status won't be
changed regardless of stopping VF or not before doing migration.
We hope to reach agreement on this first.

Well it's bi-directional, the framework won't work if it's
uni-directional.
Further, if you use this interface to stop the interface
at the moment, you won't be able to do anything else
with it, and will need a new one down the road.

Tracking dirty memory still
need to more discussions and we will continue working on it. Stop VF may
help to work around the issue and make tracking easier.

quoted

Also, assuming you just want to do ifdown/ifup for some reason, it's
easy enough to do using a guest agent, in a completely generic way.

Just ifdown/ifup is not enough for migration. It needs to restore some PCI
settings before doing ifup on the target machine

I'd focus on just restoring then.

-- 
MST