[libvirt] [PATCH 1/1] qemu: Tidy up job handling during live migration

[Ján Tomko]

On 07/29/2014 02:41 AM, Sam Bobroff wrote:
> During a QEMU live migration several warning messages about job
> handling could be written to syslog on the destination host:
> 
> "entering monitor without asking for a nested job is dangerous"
> 
> The messages are written because the job handling during migration
> uses hard coded asyncJob values in several places that are incorrect.
> 
> This patch passes the required asyncJob value around and prevents
> the warnings as well as any issues that the warnings may be referring
> to.
> 
> Signed-off-by: Sam Bobroff <sam.bobroff at au1.ibm.com>
> --

This patch seems to fix the deadlock that can happen if the migrated domain is
destroyed at the destination reported here:
https://www.redhat.com/archives/libvir-list/2014-May/msg00236.html

It looks good to me, but it seems there are more functions calling
qemuDomainObjEnterMonitor that can be called from qemuProcessStart,
for example qemuDomainChangeGraphicsPasswords.


> @@ -2505,7 +2506,7 @@ qemuDomainUpdateDeviceList(virQEMUDriverPtr driver,
>      if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE_DEL_EVENT))
>          return 0;
>  
> -    qemuDomainObjEnterMonitor(driver, vm);
> +    ignore_value(qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob));

Also, the return value of this call could be dangerous to ignore if asyncJob
!= NONE.

Jan

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