Re: [Qemu-devel] [PATCH] usb-ohci: add vmstate descriptor

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 03/23/2014 08:23 AM, Peter Maydell wrote:
> On 22 March 2014 21:04, Andreas Färber <afaerber@suse.de> wrote:
>> Am 22.03.2014 21:54, schrieb Peter Maydell:
>>> On 22 March 2014 20:18, Andreas Färber <afaerber@suse.de> wrote:
>>>> Because AFAIU
>>>> migration is possible without VMSD, just not with VMSD that sets
>>>> .unmigratable = 1.
>>>
>>> Well, the migration won't fail with an error, but on the destination
>>> end you'll end up with a device in its reset state but a guest which
>>> may think the device is in some other state. If the device was
>>> quiescent and doesn't need complex setup it might cope, but
>>> more likely is that that guest driver will fall over in a heap next
>>> time you try to use it...
>>
>> Well, there is no OHCI state being added, only PCI state. So I'd be
>> curious to know what in there is the problem because a general review of
>> PCI devices might be due then - and ideally before we do the release.
> 
> Oops, I hadn't noticed that; this patch is incorrect, then, because
> vmstate_ohci needs to include a line for the OHCIState, and we
> need a second vmstate struct for the OHCIState.


Sorry but what is incorrect in the patch? I can understand that it is
incomplete as it is missing OHCI-specific bits from the OHCIState state and
I can do that but I need some hints what is really necessary. So far the
USB device was able to recover, only PCI bits were really needed. Thanks.




-- 
Alexey