Red Hat Bugzilla – Bug 1094820
Hot plug CPU not working with RHEL6 machine types running on RHEL7 host.
Last modified: 2014-06-10 08:35:17 EDT
This bug has been copied from bug #1094285 and has been proposed to be backported to 7.0 z-stream (EUS).
QE tested this bug with qemu-kvm-1.5.3-60.el7_0.2.x86_64 and 3.10.0-123.el7.x86_64 Tested two scenarios. S1. For RHEL6.5 & win2012 & rhel7.0 guest Boot guest with machine type rhel6.0.0 ~ rhel6.5.0 & pc on rhel7.0 host result: hotplug vcpu->works S2. For RHEL6.5 & win2012 guest. 1.Boot guest with machine type rhel6.0.0 ~ rhel6.5.0 on rhel6.6 host. 2.migration from rhel6.6 -> rhel7.0 3.hotplug vcpu on rhel7.0 result: hotplug vcpu->works so, Base on this testing result. This bug is fixed. additional. For rhel6.6 host. # uname -r 2.6.32-459.el6.x86_64 qemu-kvm-0.12.1.2-2.425.el6.x86_64
Jan, As far as QE know, we support vcpu hotplug from rhel6.3. Current, according to my testing result as comment5. vcpu can be hotpluged successfully with -M RHEL6.0~6.2 as well, It is expected?
Seems we need to needinfo paolo.
There are 3 components: host, machine type and guest OS 1. KVM supports vcpu inplug starting with RHEL 6.4 host. (6.3 was tech preview) 2. Any rhel6.y.0 machine type can be used. 3. Any guest OS that supports CPU hotplug will work. So, the RHEL7 behavior matches RHEL6. Thanks.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2014-0704.html