On Mon, Jul 16, 2012 at 02:33:38PM -0600, Alex Williamson wrote: > v5: > - irqfds now have a one-to-one mapping with eoifds to prevent users > from consuming all of kernel memory by repeatedly creating eoifds > from a single irqfd. > - implement a kvm_clear_irq() which does a test_and_clear_bit of > the irq_state, only updating the pic/ioapic if changes and allowing > the caller to know if anything was done. I added this onto the end > as it's essentially an optimization on the previous design. It's > hard to tell if there's an actual performance benefit to this. > - dropped eoifd gsi support patch as it was only an FYI. > > Thanks, > > Alex
So 3/4, 4/4 are racy and I think you convinced me it's best to drop it for now. I hope that fact that we already scan all vcpus under spinlock for level interrupts is enough to justify adding a lock here. To summarize issues still outstanding with 1/2, 2/2: - source id lingering after irqfd was destroyed/deassigned prevents assigning a new irqfd - if same irqfd is deassigned and re-assigned, this seems to succeed but does not give any more EOIs - document that user needs to re-inject interrupts injected by level IRQFD after migration as they are cleared Hope this helps! > --- > > Alex Williamson (4): > kvm: Convert eoifd to use kvm_clear_irq > kvm: Create kvm_clear_irq() > kvm: KVM_EOIFD, an eventfd for EOIs > kvm: Extend irqfd to support level interrupts > > > Documentation/virtual/kvm/api.txt | 28 +++ > arch/x86/kvm/x86.c | 3 > include/linux/kvm.h | 18 ++ > include/linux/kvm_host.h | 16 ++ > virt/kvm/eventfd.c | 333 > +++++++++++++++++++++++++++++++++++++ > virt/kvm/irq_comm.c | 78 +++++++++ > virt/kvm/kvm_main.c | 11 + > 7 files changed, 483 insertions(+), 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
