加载使用由ptxdist通过i586_qemu config生成的映像的vm的快照时，内核崩溃

Question

I build the i586_qemu(with some changes of package selection) using ptxdist 2012.12.0. Everything works fine on my laptop(Ubuntu 12.04.2, Linux 3.5.0-23-generic in virtualbox run on MPB). However, when I copied images to a server(run Ubuntu 12.04.4, Linux 3.11.0-19-generic), and try to use savevm and loadvm command, I got a kernel panic. here's the output:

(qemu) savevm vm0  
(qemu) Clocksource tsc unstable (delta = 5441725078 ns)  
Switching to clocksource jiffies  
(qemu) info snapshots  
ID        TAG                 VM SIZE                DATE       VM CLOCK  
1         vm0                     16M 2014-04-19 00:36:32   00:04:12.923 

It seems savevm run a little longer than it runs on my laptop. But when I restart the vm, the problem comes:

sudo kvm -nographic -m 256 -M pc -no-reboot -kernel ./images/linuximage  -hda ./images/hd.img.qcow2 -device e1000,netdev=net0,mac='DE:AD:BE:EF:12:03' -netdev tap,id=net0,script=qemu-ifup.sh -append "root=/dev/sda1 rw console=ttyS0,115200 debug" -loadvm vm0
+ switch=br0
+ ovs-vsctl del-port br0 tap0
+ [ -n tap0 ]
+ whoami
+ /usr/bin/sudo /usr/sbin/tunctl -u root -t tap0
sudo: /usr/sbin/tunctl: command not found
+ /usr/bin/sudo /sbin/ip link set tap0 up
+ sleep 0.1s
+ /usr/bin/sudo ovs-vsctl add-port br0 tap0
+ exit 0
divide error: 0000 [#1] PREEMPT 
Modules linked in:

Pid: 0, comm: swapper Not tainted 3.0.0-pengutronix #1 Bochs Bochs
EIP: 0060:[<c01067e8>] EFLAGS: 00000246 CPU: 0
EAX: 00000000 EBX: c02e6a74 ECX: 00000096 EDX: 00000003
ESI: 00020800 EDI: c02b4000 EBP: c02b3ff8 ESP: c02b3fe8
 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
Process swapper (pid: 0, ti=c02b2000 task=c02ba480 task.ti=c02b2000)
Stack:
 c0101448 c02cc5a3 c02e6a74 00000800 0052b003 00000000
Call Trace:
 [<c0101448>] ? 0xc0101448
 [<c02cc5a3>] ? 0xc02cc5a3
Code: 0f 01 c8 e8 41 ff ff ff 85 c0 75 07 89 c1 fb 0f 01 c9 c3 fb c3 83 3d 98 c6 2f c0 00 75 1c 80 3d c5 9c 2c c0 00 74 13 eb 15 fb f4 <eb> 01 fb 89 e0 25 00 e0 ff ff 83 48 0c 04 c3 fb f3 90 c3 89 e0 
EIP: [<c01067e8>]  SS:ESP 0068:c02b3fe8
---[ end trace 6fe899157eb8f58b ]---
Kernel panic - not syncing: Attempted to kill the idle task!
Clocksource tsc unstable (delta = 5233522621 ns)

The most obvious thing to me is the clocksource unstable warning. According to What does “clocksource tsc unstable” mean? , the problem could be the difference of tsc between cores(the server I am using have 48). So, what should be done to stop the kernel panic? or are there any other causes?

Answer 1

The problem goes away when I use the tcg accelerator(which is the default accelerator in my laptop) instead of KVM kernel module. The clocksource problem still occurs, but seems have no influence on the VM.