Re: [Qemu-devel] [RFC PATCH] spapr: support time base offset migration

[Alexander Graf]

On 09.09.2013, at 11:29, Benjamin Herrenschmidt wrote:

> On Mon, 2013-09-09 at 08:06 +0200, Alexander Graf wrote:
>> I think it's ok to restrict live migration to machines with the same
>> tb frequency when kvm is enabled. Whether you implement it through a
>> hardcoded 512Mhz or through a timebase value that gets live migrated
>> and then compared is up to you - both ways work for me :).
> 
> The latter might be handy if we want to support migration on 970, though
> we don't have the TBU40 stuff there so adjusting the TB in the host
> kernel would be ... problematic.

Well, we could save/restore TB when we enter/exit the guest, no? But I really 
only want to have something that doesn't block the door for someone who wants 
to enable things.


Alex