Pausing a VM is broken: QEMULauncher uses 100% CPU after pausing VM

[LostInCompilation]

Describe the issue
If I pause a VM (Windows 11 ARM or Linux ARM, virtualization), pausing only works for the first 30 seconds After this time QEMULauncher suddenly uses 100% CPU time, even though the VM is still showing a paused state. Resuming works normally and the CPU usage suddenly drops down to normal levels after resuming.
I never used the pause feature before, but would expect the VM to use absolutely no resources at all. This issue even prevents my Mac from sleeping. When I took it out of my bag it was meltingly hot and running.
A fix for this would be really good, since my current workflow relies on the ability to pause a VM.

Configuration

• UTM Version: 4.0.9
• macOS Version: 13.0.1
• Mac Chip: M1 Pro

[osy]

I am unable to reproduce this. Next time it happens, can you get a spindump? You can either do it from the command line or by opening Activity Monitor, double clicking the process, and clicking Sample. Then attach the dump log.

[LostInCompilation]

Sure here you go: https://drive.google.com/file/d/14BGAcVFAldiNcORvXLnvxPuDFXOxUeet/view?usp=sharing
About 1 min after pausing. Load stays constant.

[osy]

Does Activity Monitor also report 200% usage?

[LostInCompilation]

This is the VM: https://drive.google.com/file/d/1aQHrr4hDa1pihlAZpmkrPKueEMaR50P4/view?usp=sharing

[LostInCompilation]

Does Activity Monitor also report 200% usage?

Yes, constantly.

[LostInCompilation]

Just tested it with a Debian ARM VM, same issue. Here is its dump: https://drive.google.com/file/d/1uPHL8aaZgvqQNMKam6xeqp74NiP-1pqD/view?usp=sharing

[osy]

Can you disable shared networking and try emulated networking?

[LostInCompilation]

Seems to work. QEMULauncher stays at about 2% load. Is this little bit of load expected?

[osy]

Yeah I think 2% is expected. I'm pretty sure I found the issue. It's in QEMU, I am working on a fix now.