Re: [Qemu-devel] [Qemu-ppc] [PATCH 4/4] spapr: Add support for time base offset migration

[Alexander Graf]

> Am 12.04.2014 um 00:59 schrieb Alexander Graf <address@hidden>:
> 
> 
> 
>> Am 11.04.2014 um 23:55 schrieb Benjamin Herrenschmidt <address@hidden>:
>> 
>> On Fri, 2014-04-11 at 11:40 +0200, Alexander Graf wrote:
>>>> And G5 uses 33333333. I really do not understand why it is bad to
>>>> send-and-check timer frequency. Why?
>>> 
>>> Because the guest will continue to run at a different TB frequency on 
>>> the new host and break.
>> 
>> Right, which is why we should send it accross so it can be checked and
>> we can barf accordingly rather than having random odd things happen :-)
> 
> Would the TB frequency ever be different inside the same generation? We can't 
> properly support cross-family migration, so we need to bail out on that 
> anyway. No need for an additional check here, no?

Unless we're trying to do PR migration.

Ok, an assert() would make a lot of sense. Or is there a better way to fail 
migration?


Alex

> 
> Alex
> 
>> 
>> Ben.
>