Public bug reported: A recent security update broke booting of some images, particularly CirrOS [3]:
$ wget 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 qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.80000001H:ECX.svm [bit 2] And then nothing happens at all any more, other than QEMU using 100% CPU. This also affects version 0.4.0 and x86_64, so it's not particularly sensitive to guest changes. I'm testing this with (nested) KVM inside an Ubuntu 18.04 LTS VM. When going back to an older image that was built 5 days ago [4], it works: # qemu-system-x86_64 -enable-kvm -nographic cirros-0.3.5-i386-disk.img -snapshot qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.80000001H:ECX.svm [bit 2] [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Linux version 3.2.0-80-virtual (buildd@komainu) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #116-Ubuntu SMP Mon Mar 23 17:48:17 UTC 2015 (Ubuntu 3.2.0-80.116-virtual 3.2.68) [...] This shows that the "ECX.svm" warning already happened before and seems to be unrelated. The most recent security update of Qemu 2.11+dfsg-1ubuntu7.2 [1] and Linux 4.15.0-22.24 [2] are already on that previous image, so it seems this is some dependency update in between these stacks. I. e. this is *not* a regression in QEMU itself or Linux. I file it against qemu for now, but I will bisect which particular update was responsible. [1] https://launchpad.net/ubuntu/+source/qemu/1:2.11+dfsg-1ubuntu7.2 [2] https://launchpad.net/ubuntu/+source/linux/4.15.0-22.24 [3] https://download.cirros-cloud.net/ [4] https://github.com/cockpit-project/cockpit/pull/9221 ** Affects: qemu (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1774000 Title: Regression: Fails to boot cirros image To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1774000/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
