Re: [PATCH RFC 0/4] arm: regarding live migration

[Jaeyong Yoo <jaeyong.yoo@samsung.com>]

Hello Ian,
I got some more questions while implementing live migration in arm.

> > (3) Regarding split drivers, come to think of it, we have to store 
> >    both side (front/back) states, in-flight event channels, IRQs, etc.
> >    And those look like quite a work (although evtchn is migrated within vcpu)
> >    I appreciate  if you guys could share any hints from the experience of 
> >    migrating split drivers in x86.
> 
> There is no need to save any of this state, the devices are effectively
> reconnected from scratch on the destination and the frontend devices are
> responsible for replaying any inflight state on resume.
> 

I'm trying to find the suspending part of PV driver, but can not locate it.
(And, looks like there is no function like suspend in xen-blkfront.c)
One guess is by deleting vbd in xenstore, maybe hot-plug-out can suspend.
Could you give me some advice?

And, about grant table, if we effectively suspend and resume PV driver, I 
think we don't need to migrate grant table entires. Is this right?

Thanks,
Jaeyong