[PATCH] qemu: save status xml after generating taint message

[Daniel P. Berrangé]

On Wed, Jul 21, 2021 at 02:29:34PM +0200, Peter Krempa wrote:
> On Wed, Jul 21, 2021 at 14:05:05 +0200, Kristina Hanicova wrote:
> > We didn't always save status xml after generating new taint
> > message, which resulted in it being deleted in case of a libvirtd
> > restart.  Some taint messages were preserved thanks to saving
> > status xml separately at the end of the calling functions (which
> > makes sense, because qemuDomainObjTaint was usually called there
> > multiple times).  But for special cases (e.g. When only few taint
> > messages are generated) we need a separate function for
> > generating them and saving status xml explicitly.
> 
> Saving the status XML is a very common operation which we in some cases
> repeat a few times when doing an multi-step operation, thus we can
> reasonably assume that saving the status XML in all cases when we are
> adding a taint on a VM object is okay without the need to special case
> operations which don't save the status XML as part of their code.

The bug quoted shows a few examples where we fail to save status.

I'm very surprised we don't save status when hotplugging a NIC or a
disk, as the BZ suggests.

Missing status save in QMP monitor command passthrough is less
surprising though since we're not actually changing the VM state
when doing that, so would not have reason to save state except
for the taint message.

Regards,
Daniel
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