Re: [Qemu-devel] [PATCH v3 2/2] vhost user: Add RARP injection for legacy guest

[Michael S. Tsirkin]

On Wed, Jun 17, 2015 at 12:16:09PM +0800, Jason Wang wrote:
> 
> 
> On 06/16/2015 04:16 PM, Thibaut Collet wrote:
> > For a live migration my understanding is there are a suspend resume 
> > operation:
> > - The VM image is regularly copied from the old host to the new one
> > (modified pages due to VM operation can be copied several time)
> > - As soon as there are only few pages to copy the VM is suspended on
> > the old host, the last pages are copied, and the VM is resumed on the
> > new host. Migration is not totally transparent  to guest that has a
> > small period of unavailability.
> 
> But guest is not involved in the any of the migration process. Unless
> the performance drop, guest should not notice the migration at all.

It is easy for backend to detect that guest started using the device,
e.g. detect DRIVER_OK status set.
I think that's enough to send RARPs.

> Btw, please use bottom-posting which is easier for reader to understand
> the context.
> 
> Thanks

I agree, please don't top-post.

-- 
MST