I'm not sure what "The developer have impleted differently the AMD patch but with Qemu 3.0.0/3.1 i don't need this fix." means. Does it mean the qemu developers have implemented the patch in a different way? Regardless, qemu 3.1 gives me the following warning,
"(qemu) qemu-system-x86_64: warning: This family of AMD CPU doesn't support hyperthreading(2) Please configure -smp options properly or try enabling topoext feature." I'm trying to run qemu 3.1 on my Threadripper 1950x and that CPU does indeed support hyperthreading. How do I enable topoext feature like what the warning message suggests?