Comment 10 for bug 367137

Confirmed, libvirtd stack trace looks like:

#0 0x00774416 in __kernel_vsyscall ()
#1 0x002dad99 in __lll_lock_wait () from /lib/libpthread.so.0
#2 0x002d6149 in _L_lock_89 () from /lib/libpthread.so.0
#3 0x002d5a52 in pthread_mutex_lock () from /lib/libpthread.so.0
#4 0x04a12bfd in virMutexLock (m=0x85087a8) at threads-pthread.c:51
#5 0x04a28fdd in virDomainObjLock (obj=0x85087a8) at domain_conf.c:3731
#6 0x04a2b065 in virDomainFindByUUID (doms=0x85042f8, uuid=0x8506a64 "�\005�\024�E��B�Z>\234�h��") at domain_conf.c:192
#7 0x08070b12 in qemudDomainGetMaxVcpus (dom=0x8506a50) at qemu_driver.c:2697
#8 0x08070cd6 in qemudDomainSetVcpus (dom=0x8506a50, nvcpus=2) at qemu_driver.c:2527
#9 0x04a22155 in virDomainSetVcpus (domain=0x8506a50, nvcpus=2) at libvirt.c:3981
#10 0x0805ce62 in remoteDispatchDomainSetVcpus (server=0x84fb5a0, client=0x8519980, conn=0x8506d08, rerr=0xb6b70218,
    args=0xb6b702d0, ret=0xb6b70290) at remote.c:1984
#11 0x08060664 in remoteDispatchClientRequest (server=0x84fb5a0, client=0x8519980, msg=0x855abe8) at remote.c:322
#12 0x0805537f in qemudWorker (data=0x8506a90) at qemud.c:1406
#13 0x002d451f in start_thread () from /lib/libpthread.so.0
#14 0x0020a04e in clone () from /lib/libc.so.6