Re: [PATCH -v3] QEMU-KVM: MCE: Relay UCR MCE to guest

[Huang Ying <ying.huang@intel.com>]

On Sat, 2009-09-19 at 01:05 +0800, Marcelo Tosatti wrote: 
> On Fri, Sep 18, 2009 at 03:58:59PM +0800, Huang Ying wrote:
> > UCR (uncorrected recovery) MCE is supported in recent Intel CPUs,
> > where some hardware error such as some memory error can be reported
> > without PCC (processor context corrupted). To recover from such MCE,
> > the corresponding memory will be unmapped, and all processes accessing
> > the memory will be killed via SIGBUS.
> >
> > For KVM, if QEMU/KVM is killed, all guest processes will be killed
> > too. So we relay SIGBUS from host OS to guest system via a UCR MCE
> > injection. Then guest OS can isolate corresponding memory and kill
> > necessary guest processes only. SIGBUS sent to main thread (not VCPU
> > threads) will be broadcast to all VCPU threads as UCR MCE.
> >
> > v3:
> >
> > - Re-raise SIGBUS for SIGBUS not from MCE
> > - Kill itself for error in kvm_inject_x86_mce
> 
> This is broken, non-MCE SIGBUS causes qemu-kvm to call the sigbus
> handler in a loop.

Sorry. I tested the wrong branch in previous development. I will fix
this.

> BTW, how are you testing this and what guests have been tested?

I use a self-made kernel module to simulate SIGBUS from MCE handler to
qemu. Until now, only Linux guest has been tested.

Best Regards,
Huang Ying