Re: [libvirt] [PATCH] qemu_driver: fix setting vcpus for offline domain

On Tue, Jan 13, 2015 at 02:46:03PM +0100, Pavel Hrdina wrote: > Commit e3435caf fixed hot-plugging of vcpus with strict memory pinning > on NUMA hosts, but unfortunately it also broke updating number of vcpus > for offline guests using our API. > > The issue is that we try to create a cpu cgroup for non-running guest > which fails as there are no cgroups for that domain. We should create > cgroups and update cpuset.mems only if we are hot-plugging. > > Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; > --- > src/qemu/qemu_driver.c | 26 ++++++++++++++------------ > 1 file changed, 14 insertions(+), 12 deletions(-) > > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index cdf4173..3a343d0 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -4576,21 +4576,23 @@ qemuDomainSetVcpusFlags(virDomainPtr dom, unsigned int nvcpus, > > priv = vm->privateData; > > - if (virCgroupNewEmulator(priv->cgroup, false, &cgroup_temp) < 0) > - goto cleanup; > - > - if (!(all_nodes = virNumaGetHostNodeset())) > - goto cleanup; > - > - if (!(all_nodes_str = virBitmapFormat(all_nodes))) > - goto cleanup; > - > if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0) > goto cleanup; > > - if (virCgroupGetCpusetMems(cgroup_temp, &mem_mask) < 0 || > - virCgroupSetCpusetMems(cgroup_temp, all_nodes_str) < 0) > - goto endjob; > + if (flags & VIR_DOMAIN_AFFECT_LIVE) { As we are also doing the guest agent cpu config stuff in this function and the cgroup stuff isn't required for that operation please add && !(flags & VIR_DOMAIN_VCPU_GUEST) to the condition. > + if (virCgroupNewEmulator(priv->cgroup, false, &cgroup_temp) < 0) > + goto cleanup; > + > + if (!(all_nodes = virNumaGetHostNodeset())) > + goto cleanup; > + > + if (!(all_nodes_str = virBitmapFormat(all_nodes))) > + goto cleanup; > + > + if (virCgroupGetCpusetMems(cgroup_temp, &mem_mask) < 0 || > + virCgroupSetCpusetMems(cgroup_temp, all_nodes_str) < 0) > + goto endjob; > + } > > maximum = (flags & VIR_DOMAIN_VCPU_MAXIMUM) != 0; > flags &= ~VIR_DOMAIN_VCPU_MAXIMUM; ACK with the addition. Peter