[PATCH v2 00/10] qemu: add option to process offloaded legacy blockjob event ealier

[Nikolay Shirokovskiy]

On 04.12.2020 18:52, Peter Krempa wrote:
> On Fri, Dec 04, 2020 at 18:44:00 +0300, Nikolay Shirokovskiy wrote:
>> On 04.12.2020 18:11, Peter Krempa wrote:
>>> On Fri, Nov 13, 2020 at 09:53:28 +0300, Nikolay Shirokovskiy wrote:
> 
> [...]
> 
>> Ok. By the way what about the issue described in 
>>
>> [PATCH v2 09/10] qemu: fix race on legacy block completion and quering stats
>>
>> Are modern blockjobs have similar?
> 
> Modern blockjobs are started with '"auto-dismiss": false' so if you get
> to the monitor before the thread completing the blockjob finishes it,
> qemu still reports the status for the job.

But from qemu docs I read that graph changes occur on finalize step and modern
blockjobs use auto-finalize = true. So at the moment of querying stats
graph in libvirt and qemu can be different I thought.


Nikolay

> 
> The completion is done inside a 'MODIFY' job lock, so other thread won't
> be able to get to the monitor in the time between the job is dismissed
> in qemu and the XML/definition is updated.
>