[Lguest] lguest stop/restart and guest (live?) migration

[Matias Zabaljauregui]

Hi, everybody seem to be working this weekend...

> I'd start with save and restore.  All we really need is a method of setting 
> and restoring guest state, which should then also be used to boot the guest 
> (with sanity checks).
> 
> Something like:
> LHREQ_GETREGS /* + addr */
> LHREQ_SETREGS /* + addr */

ok, I've started to write some code. 

Still can't imagine how to save guest memory contents 
in some efficient way. 

Am I supposed to write every "guest frame" down to a file ?  
(i.e. if my guest's memory is 1GB , the guest-memory-contents file will
be 1 GB ? 


Thanks,
Matias

> 
> Live migration is harder.  One idea would be to hand unservicable page faults 
> back to the Launcher: then it can unmap pages as it sends them and remap them 
> if they're needed again.   The problem is that the latest lguest uses threads 
> for all the devices, and those device accesses will need to be aware of the 
> unmapped pages too.  I'm sure there is a neat solution somewhere though 
> (perhaps when we're migrating all I/O goes via the main Launcher process 
> again).
> 
> Thanks!
> Rusty.
>