kernel: 0.965
debug: 0.701
device: 0.698
risc-v: 0.607
vnc: 0.521
performance: 0.473
architecture: 0.462
graphic: 0.457
VMM: 0.449
TCG: 0.390
boot: 0.383
PID: 0.361
register: 0.354
files: 0.343
KVM: 0.271
virtual: 0.252
arm: 0.225
socket: 0.213
ppc: 0.197
permissions: 0.123
mistranslation: 0.078
network: 0.077
semantic: 0.074
x86: 0.047
assembly: 0.033
user-level: 0.016
hypervisor: 0.009
i386: 0.007
peripherals: 0.002

xv6 kernel problem in single step mode