Problem starting Whonix 14 after upgrade? Unable to write to /sys/fs/cgroup/blkio/machine.slice/machine-qemu ...

I had the exact same problem on Debian 9 with custom Linux 5 kernels that I compiled myself.

I recompiled the latest stable 5.0.6 kernel following instructions here (although I was also unable to find all exact options).

http://forums.dds6qkxpwdeubwucdiaord2xgbbeyds25rbsgr73tbfpqpt4a6vjwsyd.onion/t/solved-cant-start-the-new-14-whonix-vms-libvirterror-unsupported-configuration-block-i-o-tuning-is-not-available-on-this-host/5664/7

Still doesn’t work.

Following @HulaHoop’s instructions I edited out the

 <blkiotune>
    <weight>250</weight>
</blkiotune>

In the VM settings. Works fine now.

So probably a bug/regression in the new kernel?