Comment # 1 on bug 1092035 from Fei Li

Hi,
Sorry for the late reply. Could you help to provide your CPU flags and CPU bugs
by issuing `cat /proc/cpuinfo | grep -e flags -e bugs`? Besides, please provide
the meltdown/spectre-v1/spectre_v2 values by running `grep -H .
/sys/devices/system/cpu/vulnerabilities/*`
On the other side, would you mind providing the benchmarks you use to test CPU
performance? I mean, frequently interacting between the kernel and user space,
like open/read/write one file, indeed will downgrade the performance. Besides,
if there are lots of workloads either on the host or the guest, downgrade is
quite obvious too. If the above are the cases, I guess, stop the benchmarks &
reduce workload will make CPU performance not so bad. :)