Hi Alex, On 08/07/2015 10:09 PM, Alex Williamson wrote: > On Mon, 2015-08-03 at 19:20 +0200, Eric Auger wrote: >> This patch adds the registration/unregistration of an >> irq_bypass_consumer on irqfd assignment/deassignment. >> >> Signed-off-by: Eric Auger <[email protected]> >> Signed-off-by: Feng Wu <[email protected]> >> >> --- >> >> v2 -> v3 (Feng Wu): >> - Use kvm_arch_irq_bypass_start >> - Remove kvm_arch_irq_bypass_update >> - Add member 'struct irq_bypass_producer *producer' in >> 'struct kvm_kernel_irqfd', it is needed by posted interrupt. >> - Remove 'irq_bypass_unregister_consumer' in kvm_irqfd_deassign() >> >> v1 -> v2: >> - populate of kvm and gsi removed >> - unregister the consumer on irqfd_shutdown >> --- >> include/linux/kvm_irqfd.h | 2 ++ >> virt/kvm/eventfd.c | 10 ++++++++++ >> 2 files changed, 12 insertions(+) >> >> diff --git a/include/linux/kvm_irqfd.h b/include/linux/kvm_irqfd.h >> index f926b39..0c1de05 100644 >> --- a/include/linux/kvm_irqfd.h >> +++ b/include/linux/kvm_irqfd.h >> @@ -64,6 +64,8 @@ struct kvm_kernel_irqfd { >> struct list_head list; >> poll_table pt; >> struct work_struct shutdown; >> + struct irq_bypass_consumer consumer; >> + struct irq_bypass_producer *producer; >> }; >> >> #endif /* __LINUX_KVM_IRQFD_H */ >> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c >> index 647ffb8..08855de 100644 >> --- a/virt/kvm/eventfd.c >> +++ b/virt/kvm/eventfd.c >> @@ -35,6 +35,7 @@ >> #include <linux/srcu.h> >> #include <linux/slab.h> >> #include <linux/seqlock.h> >> +#include <linux/irqbypass.h> >> #include <trace/events/kvm.h> >> >> #include <kvm/iodev.h> >> @@ -140,6 +141,7 @@ irqfd_shutdown(struct work_struct *work) >> /* >> * It is now safe to release the object's resources >> */ >> + irq_bypass_unregister_consumer(&irqfd->consumer); >> eventfd_ctx_put(irqfd->eventfd); >> kfree(irqfd); >> } >> @@ -380,6 +382,14 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd >> *args) >> */ >> fdput(f); >> >> + irqfd->consumer.token = (void *)irqfd->eventfd; >> + irqfd->consumer.add_producer = kvm_arch_irq_bypass_add_producer; >> + irqfd->consumer.del_producer = kvm_arch_irq_bypass_del_producer; >> + irqfd->consumer.stop = kvm_arch_irq_bypass_stop; >> + irqfd->consumer.start = kvm_arch_irq_bypass_start; >> + ret = irq_bypass_register_consumer(&irqfd->consumer); >> + WARN_ON(ret); > > This seems like a lazy way to handle this error. What is the stack > trace from this WARN_ON going to tell us that we didn't already know? > If we get the WARN_ON, it's probably means that an incompatible producer > registered the token first. It means we can't do bypass, but it doesn't > tell us anything about whether bypass is or is not enabled. Wouldn't a > pr_info/debug() suffice for that? Thanks,
Sure I will output some more relevant traces. Thanks Eric > > Alex > >> + >> return 0; >> >> fail: > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
