Re: [libvirt] Modern CPU models cannot be used with libvirt

Resurrecting an old thread: I didn't see any clear conclusion in this thread (this is why I am resurrecting it), except that many were arguing that libvirt should simply copy and/or generate the CPU model definitions from Qemu. I really don't think it's reasonable to expect that. On Thu, Dec 15, 2011 at 03:54:15PM +0100, Jiri Denemark wrote: > Hi, > > Recently I realized that all modern CPU models defined in > /etc/qemu/target-x86_64.conf are useless when qemu is used through libvirt. > That's because we start qemu with -nodefconfig which results in qemu ignoring > that file with CPU model definitions. We have a very good reason for using > -nodefconfig because we need to control the ABI presented to a guest OS and we > don't want any configuration file that can contain lots of things including > device definitions to be read by qemu. However, we would really like the new > CPU models to be understood by qemu even if used through libvirt. What would > be the best way to solve this? > > I suspect this could have been already discussed in the past but obviously a > workable solution was either not found or just not implemented. So, our problem today is basically: A) libvirt uses -nodefconfig; B) -nodefconfig makes Qemu not load the config file containing the CPU model definitions; and C) libvirt expects the full CPU model list from Qemu to be available.