Re: [Qemu-devel] [PATCH] ohci: Stop OHCI bus when PCI bus master is disabled

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 09/11/2014 09:02 PM, Alexey Kardashevskiy wrote:
> On 09/11/2014 08:38 PM, Gerd Hoffmann wrote:
>>   Hi,
>>
>>> Another question - I noticed that XHCI migration is broken in quite recent
>>> upstream QEMU, smells like memory corruption. Is it just me or just PPC or
>>> is it known issue?
>>
>> 2.0 -> 2.1 migration being broken is a known issue (patch for that one
>> was on the list earlier this week, unfortunately missed 2.1.1).
>>
>> Other that that I'm not aware of any issues.
> 
> My bad, it was me.
> 
> I enabled 64bit DMA on pseries (the guest ram is mapped at
> 8000.0000.0000.0000 on the pci bus) and somehow this causes migration
> errors. I thought there is no 64bit DMA-capable device in QEMU, and I was
> wrong :)
> 
> /me is debugging


After all, my issue has nothing to do with XHCI itself. I am implementing
another DMA window (64bit, maps entire guest) which is yet another child
object on the PHB device but it is dynamic - it is created by request from
the guest. And XHCI driver does it so I end up with source QEMU which has
this object and destination QEMU which does not and when I try creating
this object during migration (and this adds yet another SaveStateEntry),
something goes very wrong. QOM puzzle.



-- 
Alexey