Re: [Qemu-devel] [PATCH 0/17 v3] Localhost migration with side channel for ram

[Paolo Bonzini]

Il 26/11/2013 12:07, Lei Li ha scritto:
>> Basically, "-incoming" without "-S" is a broken option because of the
>> missing handshake at the end of migration.  With "-S" something else
>> (either a human or a program) can check that everything went well and
>> choose whether to restart the source or the destination.
> 
> I see, thanks for your explanation.  :-)
> 
> BTW, do you think we should add such handling to the current migration
> protocol?

I think it's not included by design.

> The whole procedure for page flipping migration is straight forward, and
> the cases of failure I listed are in theory, which never happened at least
> since many times I have tested (except the case you raised above). But I
> agree with you on coupling with postcopy migration to make it more
> reliable, specially for the undetected problems.

The only problem that worries me is failing to load device data (most
likely due to misconfiguration or a bug).

> For this, I am not quite sure I understand it correctly, seems the latest
> update of post copy migration was sent on last Oct, would you please give
> some insights on what else could I do for the coupling with postcopy
> migration?

I don't know the state exactly.  Orit and Andrea should know.

> If no, now page flipping is implemented as a migration capability, and it's
> a good shape already as your comments in the previous version. Although it
> still needs a little more time to get the numbers of the new vmsplice,
> I'd to ask your opinion that do you consider it could be merged as an
> experimental version for now?

Yes, that could be useful.  I will review the patch as soon as possible.

Paolo