puppet-nova/releasenotes/notes/cpu_mode-for-virt_type=qemu-is-now-none-da2f1ada88d6d2c0.yaml
Javier Pena 313eb84b26 Set cpu_mode to "none" when virt_type is qemu
The Nova code states that the default value for cpu_mode when using
qemu as virt_type should be host-model [1]. However, this is not
actually tested in the gate due to [2], and with QEMU 2.6.0 it is
known to cause issues [3], because there is a chance a new CPU
flag is used, but not emulated by QEMU TCG code.

Setting cpu_mode to "none" in this case as default would prevent us
from hitting issues when this code is most exercised, i.e. CI
environments.

[1] f419825c21/nova/conf/libvirt.py (L442-L448)
[2] https://github.com/openstack-dev/devstack/blob/master/lib/nova_plugins/hypervisor-libvirt#L42
[3] https://bugzilla.redhat.com/show_bug.cgi?id=1404627

Change-Id: Ic95755a927eef0580433cd5c8eca1c4c7cad2f69
2016-12-15 14:48:39 +01:00

11 lines
436 B
YAML

---
upgrade:
- The default value for nova::compute::libvirt::libvirt_cpu_mode
when nova::compute::libvirt::libvirt_virt_type is set to 'qemu'
has been changed from 'host-model' to 'none'. The Nova gate
does not really test the 'host-model' option in their CI, but
'none' due to Devstack configuration, and it is known to create
issues with QEMU 2.6 (see
https://bugzilla.redhat.com/show_bug.cgi?id=1404627).