[PATCH RFC 0/2] kvm: set irq affinity for assigned devices

[Michael S. Tsirkin]

To forward an interrupt to a vcpu that runs on
a host cpu different from the current one,
we need an ipi which likely will cost us as much
as delivering the interrupt directly to that cpu would.
    
So it seems to make sense to set irq affinity hint to point there, irq
balancer can then take this into accound and balance interrupts
accordingly.

This is what this patchset does.
Note: it might make sense to optimize the gsi lookups
here for the msi case, using rcu, the way we did for eventfd.
But that's a subject for another patch.

Warning: compiled only.

Any early comments / flames?

Thanks,

-- 
MST


Michael S. Tsirkin (2):
  kvm: pass host irq number to set irq calls
  kvm: set affinity hint for assigned device msi

 arch/x86/kvm/i8254.c     |    4 ++--
 arch/x86/kvm/lapic.c     |    2 +-
 arch/x86/kvm/x86.c       |    2 +-
 include/linux/kvm_host.h |    7 ++++---
 virt/kvm/assigned-dev.c  |   17 ++++++++++-------
 virt/kvm/eventfd.c       |    7 ++++---
 virt/kvm/ioapic.c        |    2 +-
 virt/kvm/ioapic.h        |    2 +-
 virt/kvm/irq_comm.c      |   35 +++++++++++++++++++++++++++--------
 9 files changed, 51 insertions(+), 27 deletions(-)

-- 
1.7.5.53.gc233e
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