Comment 2 for bug 2059272

Steps with test packages on Jammy
---

Test packages built successfully in all architectures
with -proposed enabled in Launchpad PPA mfo/lp2059272.

https://launchpad.net/~mfo/+archive/ubuntu/lp2059272

Upgrade the libvirt packages and install debug symbols

 $ sudo add-apt-repository -y -c 'main' -c 'main/debug' ppa:mfo/lp2059272
 $ sudo apt install --yes libvirt{0,-daemon{,-driver-qemu}}{,-dbgsym}

 $ dpkg -l | grep libvirt
 ii libvirt-clients 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon-config-network 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon-config-nwfilter 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon-dbgsym 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon-driver-qemu 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon-driver-qemu-dbgsym 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon-system 8.0.0-1ubuntu7.9 ...
 ii libvirt-daemon-system-systemd 8.0.0-1ubuntu7.9 ...
 ii libvirt0:amd64 8.0.0-1ubuntu7.9 ...
 ii libvirt0-dbgsym:amd64 8.0.0-1ubuntu7.9 ...

...

Repeat the 'Steps to reproduce' in comment #1, until this point,
and notice the differences from here.

...

Check there are 2 threads: cleanup and domain status XML save

 (gdb) i th
   Id Target Id Frame
   1 Thread 0x7f1e79642ac0 (LWP 4404) "libvirtd" qemuStateCleanup () at ../../src/qemu/qemu_driver.c:1070
   18 Thread 0x7f1e507f8640 (LWP 4424) "gmain" (running)
   19 Thread 0x7f1e4fff7640 (LWP 4425) "gdbus" (running)
   20 Thread 0x7f1e4f7f6640 (LWP 4426) "udev-event" (running)
   26 Thread 0x7f1e50ff9640 (LWP 4496) "vm-test-vm" (running)
   27 Thread 0x7f1e4e7f4640 (LWP 4506) "qemu-event" virDomainObjSave (obj=0x7f1e6c074040, xmlopt=0x7f1e6c028010, statusDir=0x7f1e6c03b3d0 "/run/libvirt/qemu") at ../../src/conf/domain_conf.c:28879

Confirm the qemu driver's domain xml formatter/options is set/referenced:

 t 27

 (gdb) p xmlopt.privateData.format
 $1 = (virDomainXMLPrivateDataFormatFunc) 0x7f1e7054ada0 <qemuDomainObjPrivateXMLFormat>

 (gdb) p xmlopt.parent.parent_instance
 $2 = {g_type_instance = {g_class = 0x7f1e6c052000}, ref_count = 1, qdata = 0x0}

Let the cleanup function and shutdown path finish

 t 1
 c &

Check the formatter/options again; it is *STILL* referenced:

 (gdb) p xmlopt.privateData.format
 $3 = (virDomainXMLPrivateDataFormatFunc) 0x7f1e7054ada0 <qemuDomainObjPrivateXMLFormat>

 (gdb) p xmlopt.parent.parent_instance
 $4 = {g_type_instance = {g_class = 0x7f1e6c052000}, ref_count = 1, qdata = 0x0}

So, we keep `xmlopt.privateData.format` as it is
(and NOT set it to `0` as in Steps to Reproduce).

Check the VM status XML *before* the save function finishes:

 $ sudo grep -e '<domstatus' -e '<domain' -e 'monitor path' /run/libvirt/qemu/test-vm.xml
 <domstatus state='running' reason='booted' pid='4493'>
   <monitor path='/var/lib/libvirt/qemu/domain-4-test-vm/monitor.sock' type='unix'/>
   <domain type='qemu' id='4'>

Let the save function continue, and libvirt finishes shutting down:

 (gdb) c
 Continuing.
 ...
 [Inferior 1 (process 4404) exited normally]

Check the VM status XML *after*:

 $ sudo grep -e '<domstatus' -e '<domain' -e 'monitor path' /run/libvirt/qemu/test-vm.xml
 <domstatus state='running' reason='booted' pid='4493'>
   <monitor path='/var/lib/libvirt/qemu/domain-4-test-vm/monitor.sock' type='unix'/>
   <domain type='qemu' id='4'>

It *CONTINUES* to have the 'monitor path' tag/field.

Now, the next time libvirtd starts, it *CORRECTLY* parses that XML:

 $ sudo systemctl start libvirtd.service

 $ journalctl -b -u libvirtd.service | tail
 < no errors >

And libvirt is now aware of the domain, and can manage it:

 $ virsh list
  Id Name State
 -------------------------
  4 test-vm running

 $ virsh destroy test-vm
 Domain 'test-vm' destroyed