Re: [PATCH/RFC] KVM: track pid for VCPU only on KVM_RUN ioctl

David Hildenbrand
2014-08-19T12:14:08Z

> Il 19/08/2014 13:28, David Hildenbrand ha scritto:
> > Looking at the code, kvm_cpu_synchronize_state() seems to do these ioctls in
> > the vcpu thread (e.g. comming from cpu_synchronize_all_states()), any reasons
> > why kvm_cpu_synchronize_post_reset() doesn't do the same (e.g. called from
> > cpu_synchronize_all_post_reset())?
>
> No reason, feel free to post a patch for QEMU kvm-all.c.
> Documentation/virtual/kvm/api.txt clearly says:
>
> Only run vcpu ioctls from the same thread that was used to create the
> vcpu.
>
> Paolo
>

Thanks! A little more tweaking in the other parts of s390x resets
and we should be able to reduce the number of "wrong" ioctls (I think I found
most cases that are responsible for the performance degradation).

David