top发现cpu %s高居不下，cpu占用99%， %s : Steal time is the percentage of time a virtual CPU waits for a real CPU while the hypervisor is servicing another virtual processor.
dom0 cpu 完全100%占用，所有命令基本上都无法执行，同时伴随大量cpu死锁的类似错误：
kernel:BUG: soft lockup - CPU#3 stuck for 22s! [miniserv.pl:2240]
kernel:BUG: soft lockup - CPU#15 stuck for 22s! [miniserv.pl:7037]
xm shutdown vm1765 &
xm shutdown vm1761 &
When you run the Linux top command, you'll see a realtime view of key performance metrics. One of the lines is for the CPU:
Two metrics you might have some experience with already are %id (percent idle) and %wa (percent I/O wait). If %id is low, the CPU is working hard and doesn't have much excess capacity. If %wa is high, the CPU is ready to run, but is waiting on I/O access to complete (like fetching rows from a database table stored on the disk).
%st, or percent steal time is the last CPU metric displayed.