On Mon, Aug 03, 2020 at 03:35:49PM +0100, Daniel P. Berrangé wrote: > On Mon, Aug 03, 2020 at 01:45:45PM +0000, Kim-Norman Sahm wrote: > > hi, > > > > i’m running Debian 10 on POWER9 and would like to spawn x86_64 emulated VMs. > > The virtual machine is configured to run with 8 vpus but it’s very slow. > > On the host you can see that the qemu-system-x86_64 process is using just one core! > > > > Ppc64le guests are using multi cores, so its looks like an config problem or software bug with the x86 emulator. > > snip > > > Does anybody knows this problem? > > You've not mentioned what QMEU version or what libvirt version you have. Actually this doens't matter. > > Historically though emulation was single threaded. Only with MTTCG has > it become multi-threaded and thus able to use all cores for vCPUs. THat > is a few years old now though, so most distros should have MTTCG in some > form or another if reasonably up2date. x86_64 guest on ppc64 host simply cannot use MTTCG at all, so will always be restricted to 1 thread. If you want concurrency you'll need to run on a real x86_64 host. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|