Audio Output from VM causes hangs and instability

[conath]

This has happened with multiple different guest OSes and guest audio cards. Here's what happens in the log when the VM tries to play audio, causing it to freeze for >10 seconds. (between the second and third messages)
Sometimes this freeze causes the VM to lock up completely.

2021-03-04 12:02:19.021067+0100 UTM[4760:1778910] [aurioc] AURemoteIO.cpp:1598:Start: AUIOClient_StartIO failed (268451843)
2021-03-04 12:02:19.021365+0100 UTM[4760:1778948] [aurioc] AURemoteIO.cpp:1936:Run: AURemoteIO@0x1383dfc40: IOThread exiting with error 0x10004006
2021-03-04 12:02:49.089931+0100 UTM[4760:1778939] [aurioc] AURemoteIO.cpp:1639:Stop: AURemoteIO::Stop: error 268451843 calling TerminateOwnIOThread (port 94231)

Configuration (required)

• UTM Version: 2.0.23
• OS Version: iPadOS 14.4
• Device Model: iPad Pro 11"
• Is it jailbroken (name jailbreak used)? No
• How did you install UTM? Xcode

VM (for example): pc 1996, sb16 audio card.

I'm not entirely sure how to reproduce this yet. It might be related to iOS looking for bluetooth headphones to play the audio on.

If you, the reader, are experiencing this as well, please add a comment with your configuration and whether you have any Bluetooth headphones connected to your device.

[conath]

While testing UTM SE, I've experienced another complete freeze of the VM while playing audio. This time the VM was once again the pc system with the sb16 sound card.

I was able to attach a debugger and noticed what seems like a stuck thread related to audio rendering in the GST framework used within QEMU:

I believe that the thread is stuck because, when I resume the application and then pause it again with the debugger, this thread remains at the same spot in the code.