[Qemu-devel] An issue for ARM VM panic after resume from suspend

[Daifulai]

Hi all,

I have an issue, the VM kernel panic when i resume ARM VM(kernel-4.19) from 
suspend.
Comparing x86 and ARM servers, i found it is normal on x86 when resume SUSE_12 
VM.
After analysis, i found the cause of the problem is that the clock source is 
different.
On x86, the clock source of the VM is kvm-clock. On ARM, the clock source of 
the VM is arch_sys_counter.
On x86, when the virtual machine resume, clock skew will not happen.
However, the ARM virtual machine will have a clock offset.

For example, i suspend virtual machine at 1:00:00 and resume it after two 
minutes.
On x86, the virtual machine time after resume is still 1:00:00.
However, the time of the virtual machine becomes 1:02:00 on ARM.
When the watchdog detects a clock transition, it triggers a softlockup,so the 
kernel will panic.

I hope somebody can help to resolve it.

xml:
  <clock offset='utc'>
    <timer name='rtc' tickpolicy='catchup' track='guest'/>
  </clock>

the kernel panic stack:
[cid:image001.png@01D4D27A.5832BBF0]

Thanks.