What were you trying to do that didn't work?
Boot up win2019 guest with balloon device and try to get memory statistics by balloon service, qemu-kvm quit with "[qemu output] qemu-kvm: ../qapi/qobject-output-visitor.c:95: void qobject_output_add_obj(QObjectOutputVisitor *, const char *, QObject *): Assertion `name' failed."

The automation logs:
http://virtqetools.lab.eng.pek2.redhat.com/autotest_static_job_log/10465134/test-results/066-Host_RHEL.m10.u0.ovmf.qcow2.virtio_scsi.up.virtio_net.Guest.Win2019.x86_64.io-github-autotest-qemu.balloon_service.small_polling_interval.q35/debug.log

Please provide the package NVR for which bug is seen:
qemu-kvm-9.1.0-9.el10.x86_64
edk2-ovmf-20241117-1.el10.noarch
seabios-bin-1.16.3-7.el10.noarch
kernel-6.12.0-39.el10.x86_64
swtpm-0.9.0-4.el10.x86_64
virtio-win-prewhql-0.1-271

How reproducible:
Always

Steps to reproduce
1.boot up VM and enable balloon polling
[stdlog] 2025-01-14 13:37:25,865 avocado.test error_context L0084 INFO | Context: Enable polling
[stdlog] 2025-01-14 13:37:25,865 avocado.virttest.qemu_monitor qemu_monitor L0449 DEBUG| (monitor avocado-vt-vm1.qmp1) Sending command 'qom-set'
[stdlog] 2025-01-14 13:37:25,865 avocado.virttest.qemu_monitor qemu_monitor L2075 DEBUG| Send command: {"execute": "qom-set", "arguments":

{"path": "/machine/peripheral/balloon0", "property": "guest-stats-polling-interval", "value": 2}

, "id": "ENOwBqRF"}
[stdlog] 2025-01-14 13:37:45,867 avocado.virttest.qemu_monitor qemu_monitor L0449 DEBUG| (monitor avocado-vt-vm1.qmp1) Sending command 'qom-get'
[stdlog] 2025-01-14 13:37:45,868 avocado.virttest.qemu_monitor qemu_monitor L2075 DEBUG| Send command: {"execute": "qom-get", "arguments":

{"path": "/machine/peripheral/balloon0", "property": "guest-stats"}

, "id": "oOrK4pNk"}
[stdlog] 2025-01-14 13:37:45,870 avocado.virttest.qemu_vm client L0652 INFO | [qemu output] qemu-kvm: ../qapi/qobject-output-visitor.c:95: void qobject_output_add_obj(QObjectOutputVisitor *, const char *, QObject *): Assertion `name' failed.
2.
3.

Expected results
qemu-kvm process quit

Actual results
Could get the memory info via balloon service.

 

Others info:

Run a RHEL10.0 guest, 

Passed with qemu-kvm-9.1.0-8.el10.x86_64

Failed with qemu-kvm-9.1.0-9.el10.x86_64