Hello Evgeni, as this bug report is quite old, I first re-checked this with the versions in testing from a few days ago:
qemu-system-x86 1:5.1+dfsg-4+b2 tuned 2.10.0-1 linux-image-5.9.0-4-cloud-amd64 5.9.11-1 Without tuned, cirros boots, and gets stuck after a while trying to find a cloud-init source: checking http://169.254.169.254/2009-04-04/instance-id failed 1/20: up 9.66. request failed [... But that's fine. With tuned, the symptoms are a bit different now: QEMU does not show "warning: host doesn't support requested feature: CPUID" any more; but we already established that this was just a red herring. I see the "GRUB loading, please wait..." for several seconds, then the screen gets cleared, and nothing happens any more. QEMU is spinning at 100% CPU. So aside from the warning, it's still the same. I then dist-upgraded this VM to current sid: qemu-system-x86 1:5.2+dfsg-2 tuned 2.14.0-1 linux-image-5.9.0-5-cloud-amd64 5.9.15-1 The behaviour is still the same. This is in our cockpit test VMs, which are based on the official testing cloud images, but they install some additional packages. I re-tested this straight from the current official cloud images: curl -o sid.qcow2 https://cloud.debian.org/images/cloud/sid/daily/20201220-490/debian-sid-nocloud-amd64-daily-20201220-490.qcow2 qemu-system-x86_64 -cpu host -nographic -m 2048 -device virtio-rng-pci -drive file=sid.qcow2,if=virtio -snapshot The `-cpu host` option is necessary to provide /dev/kvm inside the VM (the default "QEMU Virtual CPU" does not). Log in as "root" (no password), then run apt update apt install -y --no-install-recommends qemu-system-x86 tuned curl -L -O https://download.cirros-cloud.net/0.3.5/cirros-0.3.5-i386-disk.img qemu-system-x86_64 -enable-kvm -nographic cirros-0.3.5-i386-disk.img -snapshot The boot hangs as above. Again, when not installing or stopping tuned, it works. Thanks, Martin
