Skip host to guest CPU compatibility check for emulated (QEMU "TCG" mode) guests during live migration
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
OpenStack Compute (nova) |
Fix Released
|
High
|
Kashyap Chamarthy | ||
Liberty |
Fix Released
|
Medium
|
Matt Riedemann | ||
Mitaka |
Fix Released
|
High
|
Kashyap Chamarthy |
Bug Description
The _compare_cpu() method of Nova's libvirt driver performs guest vCPU
model to destination host CPU model comparison (during live migration)
even in the case of emulated (QEMU "TCG" mode) guests, where the CPU
instructions are emulated completely in software, and no hardware
acceleration, such as KVM is involved.
From nova/virt/
[...]
5464 def _compare_cpu(self, guest_cpu, host_cpu_str, instance):
5465 """Check the host is compatible with the requested CPU
[...] [...]
5481 if CONF.libvirt.
5482 return
5483
Skip the comparison for 'qemu' part above.
Fix for master branch is here:
https:/
libvirt: Skip CPU compatibility check for emulated guests
This bug is for stable branch backports: Mitaka and Liberty.
[Thanks: Daniel P. Berrange for the pointer.]
Related context and references
-------
(a) This upstream discussion thread where using the custom CPU model
("gate64") is causing live migration CI jobs to fail.
http://
-- "[gate] [nova] live migration, libvirt 1.3, and the gate"
(b) Gate DevStack change to avoid setting the custom CPU model in
nova.conf
https:/
cpu_model
Changed in nova: | |
assignee: | nobody → Kashyap Chamarthy (kashyapc) |
importance: | Undecided → High |
Changed in nova: | |
status: | New → In Progress |
Changed in nova: | |
status: | In Progress → Invalid |
Changed in nova: | |
status: | Invalid → Fix Released |
Fix proposed to branch: stable/mitaka /review. openstack. org/324098
Review: https:/