Re: Windows Guest on KVM running "single core" after windows update

On Tue, May 09, 2023 at 02:00:25PM -0500, Benjammin2068 wrote: Historically, if you did NOT specify topology then QEMU would defaults to sockets==nCPUs, cores==1, threads=1. Since QEMU 6.2, new machine types for x86 will prefer cores, IOW, if you don't specify topology then QEMU would give you sockets=1, cores=nCPUs, threads=1 The rationale for this is that it matches common physical hardware. It is rare to see an x86 machine with 32 sockets, and 1 core, but "commonplace" to see 1 sockets and 32 cores. Many OS have also had/have dubious licensing logic that would refuse to use > 1 sockets, but happily use > 1 cores, so defaulting to cores makes it more likely guest OS would avoid hitting licensing caps. Still none of it explains why a guest OS upgrade would suddenly cease to use all CPUs that it previously had With 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 :|