Re: [Qemu-devel] hotplug: VM got stuck when attaching a pass-through device to the non-pass-through VM for the first time

[Paolo Bonzini]

Il 18/02/2014 11:51, Michael S. Tsirkin ha scritto:
> I agree it's either COW breaking or (similarly) locking pages that
> the guest hasn't touched yet.
>
> You can use prealloc or "-rt mlock=on" to avoid this problem.
>
> Paolo
Or the new shared flag - IIRC shared VMAs don't do COW either.

Only if the problem isn't locking and zeroing of untouched pages (also, 
it is not upstream is it?).

Can you make a profile with perf?

Paolo