Re: [libvirt] Cannot add iothreads label in libvirt xml configuration file

On 12/21/2016 12:11 PM, Weiwei Jia wrote: > Hi, > > I cannot add iothreads > (https://libvirt.org/formatdomain.html#elementsIOThreadsAllocation) in > the libvirt xml configuration file. Once I add > "<iothreads>4</iothreads>" and other related config for IOthreads into > the libvirt xml configuration file with virsh command and save it, > these iothreads related configuration will disappear after I open > libvirt xml configuration file again for double-check. > > The current libvirt xml configuration file is like following. > If I try to just cut-n-paste the following xml into a buffer, then run virsh define kvm1.xml, I get: error: Failed to define domain from kvm1.xml error: Cannot check QEMU binary /usr/bin/kvm-spice: No such file or directory In order to support iothreads, it requires an "-object iothread"... The "shortest" command line using qemu-kvm would be "qemu-kvm -object iothread,id=xxx1", so you could try the same with that /usr/bin/kvm-spice image and see what you get. You could try to figure out from the /var/cach/libvirt/qemu/capabilities/*.xml files whether or not the "iothread" object exists... I would think though that the reason why this is failing for you is that the kvm-spice emulator doesn't have the required capability (I forget if there's a magic incantation to ask the emulator image what it supports, especially for objects).