On Fri, 2012-07-20 at 10:33 -0600, Alex Williamson wrote: > v6: > > So we're back to just the first two patches, unfortunately the > diffstat got bigger though. The reason for that is that I discovered > we don't do anything on release of an eoifd. We cleanup if the kvm > vm is released, but we're dealing with a constrained resource of irq > source IDs, so I think it's best that we cleanup to make sure those > are returned. To do that we need nearly the same infrastructure as > irqfd, we just only watch for POLLHUP. So while there's more code > here, the structure and function names line up identically to irqfd. > > The other big change here is that KVM_IRQFD returns a token when > setting up a level irqfd. We use this token to associate the eoifd > with the right source. This means we have to put the struct > _source_ids on a list so we can find them. This removes the weird > interaction we were headed to where the eoifd is associated with > the eventfd of the irqfd. There's potentially more flexibility for > the future here too as we might come up with other interfaces that > can return a source ID "key". Perhaps some future KVM_IRQFD will > allow specifying a key for re-attaching. Anyway, the sequence > Michael pointed out where an irqfd is de-assigned then re-assigned > now results in a new key instead of leaving the user wondering if > it re-associates back to the eoifd. > > Also added workqueue flushes on assign since releasing either > object now results in a lazy release via workqueue. This ensures > we re-claim any source IDs we can. Thanks, FYI, I seem to have found a new locking issue in this version. I'll send an update when I find it. Thanks, Alex > --- > > Alex Williamson (2): > kvm: KVM_EOIFD, an eventfd for EOIs > kvm: Extend irqfd to support level interrupts > > > Documentation/virtual/kvm/api.txt | 32 ++- > arch/x86/kvm/x86.c | 3 > include/linux/kvm.h | 18 + > include/linux/kvm_host.h | 17 + > virt/kvm/eventfd.c | 463 ++++++++++++++++++++++++++++++++++++- > virt/kvm/kvm_main.c | 11 + > 6 files changed, 536 insertions(+), 8 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
