peripherals: 0.891
device: 0.759
architecture: 0.727
permissions: 0.591
performance: 0.534
network: 0.531
mistranslation: 0.461
semantic: 0.425
assembly: 0.419
graphic: 0.407
user-level: 0.338
ppc: 0.269
PID: 0.262
virtual: 0.241
debug: 0.229
files: 0.163
i386: 0.120
boot: 0.118
TCG: 0.093
vnc: 0.069
register: 0.064
socket: 0.056
VMM: 0.054
hypervisor: 0.042
arm: 0.042
risc-v: 0.028
x86: 0.015
kernel: 0.014
KVM: 0.010

Cannot use usb-host on Mac OS