On 5/31/19 11:22 AM, Andrea Bolognani wrote: > Commit f136b83139c6 made some changes in the way we set CPU > affinity for QEMU processes, and while doing so unfortunately > also introduced a logic bug in that it tried to use a NUMA node > map where a CPU map was expected. > > Because of that, guests using <numatune> would suddenly fail to > start: > > # virsh start guest > error: Failed to start domain guest > error: cannot set CPU affinity on process 40055: Invalid argument > > This was particularly easy to trigger on POWER 8 machines, > where secondary threads always show up as offline in the host: > having > > <numatune> > <memory mode='strict' placement='static' nodeset='1'/> > </numatune> > > in the guest configuration, for example, would result in libvirt > trying to set the process affinity so that it would prefer > running on CPU 1, but since that's a secondary thread and thus > shows up as offline, the operation would fail, and so would > starting the guest. > > Use the newly introduced virNumaNodesetToCPUset() to convert > the NUMA node map to a CPU map, which in the example above would > be 8-15 with CPU 8 showing up as online in the guest. > > https://bugzilla.redhat.com/show_bug.cgi?id=1703661 > > Signed-off-by: Andrea Bolognani <abologna@xxxxxxxxxx> > --- > src/qemu/qemu_process.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c > index fa5909e9be..295ad2e1ff 100644 > --- a/src/qemu/qemu_process.c > +++ b/src/qemu/qemu_process.c > @@ -2489,11 +2489,16 @@ qemuProcessInitCpuAffinity(virDomainObjPtr vm) > if (virDomainNumaGetNodeCount(vm->def->numa) <= 1 && > virDomainNumatuneGetMode(vm->def->numa, -1, &mem_mode) == 0 && > mem_mode == VIR_DOMAIN_NUMATUNE_MEM_STRICT) { > + virBitmapPtr nodeset = NULL; > + > if (virDomainNumatuneMaybeGetNodeset(vm->def->numa, > priv->autoNodeset, > - &cpumapToSet, > + &nodeset, > -1) < 0) > goto cleanup; > + > + if (virNumaNodesetToCPUset(nodeset, &cpumapToSet) < 0) > + goto cleanup; Coverity complained this morning because virNumaNodesetToCPUset will allocate something into @cpumapToSet which isn't free'd when this code jumps to cleanup. John > } else if (vm->def->cputune.emulatorpin) { > cpumapToSet = vm->def->cputune.emulatorpin; > } else { > -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
