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

[Dean Nelson]

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