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 11:38, Michael S. Tsirkin ha scritto:
> What if you detach and re-attach?
> Is it fast then?
> If yes this means the issue is COW breaking that occurs
> with get_user_pages, not translation as such.
> Try hugepages with prealloc - does it help?

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