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

[Peter Krempa]

On Fri, Dec 04, 2020 at 19:00:57 +0300, Nikolay Shirokovskiy wrote:
> 
> 
> 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.

That doesn't matter for the purposte of data returned from
'qemuDomainGetBlockJobInfo'. QEMU still reports the job, so you will
still see it as running and the XML will look the same as while it was
running.

In fact the images are still in use by qemu at that point as they were
not blockdev-del-ed. The graph will change though.