[PATCH RFC 0/2] assign each vcpu an owning thread and improve yielding

[David Hildenbrand <dahi@linux.vnet.ibm.com>]

This series improves yielding on architectures that cannot disable preemption
while entering the guest and makes the creating thread of a VCPU the owning
thread and therefore the yield target when yielding to that VCPU.

We should focus on the case creating thread == executing thread and therefore
remove the complicated handling of PIDs involving synchronize_rcus.

This way we can speed up the creation of VCPUs and directly yield to the
executing vcpu threads.

Please note that - in theory - all VCPU ioctls should be triggered from the same
VCPU thread, so changing threads is not a scenario we should optimize.


David Hildenbrand (2):
  KVM: don't check for PF_VCPU when yielding
  KVM: thread creating a vcpu is the owner of that vcpu

 include/linux/kvm_host.h |  1 +
 virt/kvm/kvm_main.c      | 22 ++--------------------
 2 files changed, 3 insertions(+), 20 deletions(-)

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1.8.5.5