Re: [Qemu-devel] [PATCH v9 06/10] replay: fix save/load vm for non-empty queue

[Paolo Bonzini]

On 04/05/2017 13:54, Pavel Dovgalyuk wrote:
>> From: Paolo Bonzini [mailto:address@hidden
>> On 04/05/2017 13:13, Pavel Dovgalyuk wrote:
>>>>> This patch does not allows saving/loading vmstate when
>>>>> replay events queue is not empty. There is no reliable
>>>>> way to save events queue, because it describes internal
>>>>> coroutine state. Therefore saving and loading operations
>>>>> should be deferred to another record/replay step.
>>>>
>>>> Can it actually be non-empty after bdrv_drain_all?
>>>
>>> drain/flush cannot succeed, because started requests are
>>> prisoned in the replay events queue.
>>
>> But that would apply to loading only.  Saving should still be always
>> possible.
> 
> We can save it. But it wouldn't load correctly - replay queue will be empty 
> after loading.

When saving you can drain, and then the events queue should be empty.
Or I am misunderstanding how it works, which is possible too.

Paolo