Re: [Qemu-devel] [PATCH v3 2/2] target-i386: add migration support for Intel LMCE

[Haozhong Zhang]

On 06/08/16 13:36, Paolo Bonzini wrote:
> 
> 
> On 03/06/2016 08:09, Haozhong Zhang wrote:
> > LMCE is disabled by default, but a cpu option 'lmce=on/off' is provided
> > to enable/disable it. Migration is only allowed between VCPUs with the
> > same lmce option.
> 
> This is not needed at all if you do the change in patch 1 that Eduardo
> requested (refuse to start if the host doesn't have the required
> capabilities).
> 
> So if you do that you can just move the lmce property to patch 1.
>

But it doesn't cover the migration from lmce-enabled qemu to
lmce-disabled qemu where KVM on both hosts support LMCE. In that case,
both qemu can start without failure, but the guest OS will run in a VM
with different configurations after migration. To avoid this, I didn't
leave the lmce property in patch 1, so that users have no way to
enable LMCE without this patch 2.

Thanks,
Haozhong