Hello Belmiro, We ran into this issue recently, similarly upgrading a RHEL7.3 OpenStack Platform Overcloud to RHEL7.4 and in the process upgrading libvirtd.
For instances that were spawned prior to this upgrade, we see the CPU flags [1] , but for new instance workload the CPU flags [2]. Notably the CMT=disabled flag is present in [1] but absent in [2] This similarly prevents live migration of the older spawned instances, as the CMT=disabled flag is rejected. A RH bugzilla [3] was opened on the issue which attracted a lot of really good contributions from libvirt maintainers. The one sure-fire workaround we'd found is just to cold-boot the instance again, starting it under the new libvirtd. But from that BZ there is also a slightly more hack-ish workaround to hand-edit the running domain XML and clear the offending CMT flag (comment 12 on that BZ). Hope this helps some, Thanks, Paul Browne [1] https://pastebin.com/JshWi6i3 [2] https://pastebin.com/5b8cAanP [3] https://bugzilla.redhat.com/show_bug.cgi?id=1495171 On 9 October 2017 at 04:59, Belmiro Moreira < moreira.belmiro.email.li...@gmail.com> wrote: > Hi, > the CPU model that we expose to the guest VMs varies considering the > compute node use case. > We use "cpu_mode=host-passthrough" for the compute nodes that run batch > processing VMs and "cpu_mode=host-model" for the compute nodes for service > VMs. The reason to have "cpu_mode=host-model" is because we assumed that > new CPUs (in the libvirt map) will continue to support previous features > allowing for live migration when we need to move the VMs to a new CPU > generation. > > We recently upgraded from CentOS7.3 (libvirt 2.0.0) to CentOS7.4 (libvirt > 3.2.0) and noticed that now libvirt maps a slightly different CPU for the > guests. For example, still "Haswell no-TSX" but no mention to the feature > "cmt". This blocks suspended VMs to restore and live migrate. > > Has anyone experienced this same problem? > > We are thinking in few solutions but none of them are nice (downgrade > libvirt? hard reboot instances? ...) > > thanks, > Belmiro > > _______________________________________________ > OpenStack-operators mailing list > OpenStack-operators@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators > > -- ******************* Paul Browne Research Computing Platforms University Information Services Roger Needham Building JJ Thompson Avenue University of Cambridge Cambridge United Kingdom E-Mail: pf...@cam.ac.uk Tel: 0044-1223-746548 *******************
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