Hi, With CPU core hotplug support in pseries-2.7, we will have to specify the compat type using -global only as we don't yet take care of parsing -cpu cputype,compat=.
There have been patches to support that: sPAPR specific one: https://lists.nongnu.org/archive/html/qemu-devel/2016-06/msg07564.html PPC generic one: https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg02676.html but the patch isn't upstream yet. The result is that instead of specifying -cpu host,compat=power7 for pseries-2.7, we will have to use -cpu host -global driver=host-powerpc64-cpu,property=compat,value=power7 This behaviour is specific to pseries-2.7 and for earlier machine types the original way of specifying compat with -cpu works. Will this be a concern for libvirt ? Would it be difficult for libvirt to switch to -global when generating QEMU cmdline for compat mode for pseries-2.7 machine. Or, should we just include one of the above patches so that -cpu cputype,compat= continues to work for peseries-2.7 ? Regards, Bharata.
