graphic: 0.875
x86: 0.722
device: 0.688
architecture: 0.409
performance: 0.327
network: 0.265
semantic: 0.249
debug: 0.216
PID: 0.186
kernel: 0.179
user-level: 0.162
mistranslation: 0.157
hypervisor: 0.156
VMM: 0.088
boot: 0.080
ppc: 0.075
socket: 0.064
arm: 0.063
files: 0.058
TCG: 0.054
vnc: 0.049
i386: 0.048
permissions: 0.043
virtual: 0.039
risc-v: 0.038
register: 0.037
peripherals: 0.034
assembly: 0.030
KVM: 0.012

qemu-x86_64 don't support unshare(CLONE_NEWUSER)
Description of problem:
Why qemu-x86_64 call unshare(CLONE_NEWUSER) fail?
```
    fuzzing@ubuntu:~/Desktop/afl/AFLplusplus$ qemu-x86_64 /bin/unshare --user /bin/bash
    unshare: unshare failed: Invalid argument
    fuzzing@ubuntu:~/Desktop/afl/AFLplusplus$ /bin/unshare --user /bin/bash
    nobody@ubuntu:~/Desktop/afl/AFLplusplus$
```
Steps to reproduce:
1.execute `qemu-x86_64 /bin/unshare --user /bin/bash` ,it will fail <br/>
2.execute `/bin/unshare --user /bin/bash` ,it will ok

How i fix that?