Description of problem: Magny-cours processors with 12 cores per physical socket should be detected as either having one socket and 12 cores, or possibly two sockets with 6 cores each. Instead they are detected as one socket and six cores, so only half the cores are usable by libvirt. Version-Release number of selected component (if applicable): 0.9.11, 0.9.10, and possibly more after 0.9.4. How reproducible: Always. Steps to Reproduce: 1. Run virsh capabilities on a host with an AMD Opteron 6174 or similar processor 2. Examine the topology entry 3. Actual results: <capabilities> <host> <uuid>48385147-3600-0030-48fe-003048fe7e7e</uuid> <cpu> <arch>x86_64</arch> <model>Opteron_G3</model> <vendor>AMD</vendor> <topology sockets='4' cores='6' threads='1'/> ... Expected results: <capabilities> <host> <uuid>48385147-3600-0030-48fe-003048fe7e7e</uuid> <cpu> <arch>x86_64</arch> <model>Opteron_G3</model> <vendor>AMD</vendor> <topology sockets='4' cores='12' threads='1'/> ... Additional info: There seems to be confusion between the topology reported by numa and the physical topology that's causing the problem. Numa detects 8 sockets with 6 cores each, yet there are four physical sockets with 12 cores. The issue did not exist in libvirt 0.9.4.
Sorry this never received a response. I'm not sure if this was ever fixed since I don't have that system. If you can still reproduce with newer libvirt please reopen this bug and provide /proc/cpuinfo