Ok, I was about to prepare a bug report to Pop OS, but then I managed to narrow down the issue a bit more, prompting me to check back here again - It turns out that libvirt’s cache mode setting matters. I always used cache mode = none, as this were usually recommended, but this turned out to be the culprit.
- Cache modes that fail:
none,directsync - Cache modes that work:
writeback,writethrough,unsafe(and “Hypervisor default”, which I assume is an alias for one of these)
Disk model (SATA, virtio-blk, virtio-scsi) does not seem to matter, nor does EFI vs. Seabios. All cache modes worked with kernels < 6. Did I miss some major change in features/practices that makes this behavior expected, or is it still simply wrong?
Anyone here who can test out the two failing cache modes for a KVM/libvirt guest and kernel 6.0.x on the host?