Re: [libvirt] [PATCH 4/4] qemu: Fix qemuProcessInitCpuAffinity()

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(a)redhat.com&gt; --- src/qemu/qemu_process.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)