UPDATE:
I created a test Windows 10 VM and discovered the problem and all my VMs are working again.
The issue was that hiding the VM no longer works with kernel 6.12, at least not the way I was doing it. I’d completely forgotten that long ago I had an NVIDIA GPU for passthrough and had to hide the hypervisor in order for it to work. And even though the basic Windows 10 VM I had that didn’t use passthrough didn’t need it, I’d configured it the same as the Windows 10 and 11 VMs that did use passthrough. Once I removed the custom inserted lines to hide the hypervisor everything worked again. They weren’t need any longer anyway, as I’d replaced the NVIDIA GPU with an AMD GPU a few years ago.
Specifically, these are the lines I’d inserted that caused the VMs to freeze:
In the features block:
<features>
…
<kvm>
<hidden state=‘on’/>
</kvm>
…
<features/>
In the cpu block:
<cpu>
…
<cache mode=‘passthrough’/>
<feature policy=‘require’ name=‘topoext’/>
<feature policy=‘disable’ name=‘svm’/>
<feature policy=“disable” name=“hypervisor” />
…
</cpu>
ORIGINAL:
I’ve generated /var/log/libvirt/qemu, dmesg, journalctl, and systemctl logs for my most basic VM, Win10-2, failing with kernel 6.12.0 and succeeding with kernel 6.6.61. However I don’t see any way to upload them. Can you please tell me how? There’s an icon above for uploading pictures but not text files.