Re: [patch uq/master 7/8] MCE: Relay UCR MCE to guest

Dean Nelson
2010-10-08T12:02:53Z

On 10/07/2010 10:15 PM, Huang Ying wrote:
> Hi, Seto,
>
> On Thu, 2010-10-07 at 11:41 +0800, Hidetoshi Seto wrote:
>> (2010/10/07 3:10), Dean Nelson wrote:
<snip>
>>> When I applied a patch to the guest's kernel which forces mce_ser to be
>>> set, as if MCG_SER_P was set (see __mcheck_cpu_cap_init()), I found
>>> that when the memory page was 'owned' by a guest process, the process
>>> would be killed (if the page was dirty), and the guest would stay
>>> running. The HWPoisoned page would be sidelined and not cause any more
>>> issues.
>>
>> Excellent.
>> So while guest kernel knows which page is poisoned, guest processes
>> are controlled not to touch the page.
>>
>> ... Therefore rebooting the vm and renewing kernel will lost the
>> information where is poisoned.
>
> Yes. That is an issue. Dean suggests that make qemu-kvm to refuse reboot
> the guest if there is poisoned page and ask for user to intervention. I
> have another idea to replace the poison pages with good pages when
> reboot, that is, recover without user intervention.

Hi, Huang, I much prefer the replacing of the poisoned pages with good
pages on reboot, over the refusing to reboot. So definitely go with
your idea.

Thanks,
Dean