Re: [Qemu-devel] [RFC PATCH V2 3/3] Ixgbevf: Add migration support for ixgbevf driver

[Michael S. Tsirkin]

On Thu, Nov 26, 2015 at 12:02:33AM +0800, Lan, Tianyu wrote:
> On 11/25/2015 8:28 PM, Michael S. Tsirkin wrote:
> >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.
> 
> 
> >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