[PATCH v5 5/5] KVM: eventfd: add irq bypass consumer management

[Alex Williamson]

On Mon, 2015-08-10 at 15:31 +0200, Eric Auger wrote:
> This patch adds the registration/unregistration of an
> irq_bypass_consumer on irqfd assignment/deassignment.
> 
> Signed-off-by: Eric Auger <eric.auger at linaro.org>
> Signed-off-by: Feng Wu <feng.wu at intel.com>
> 
> ---
> 
> v4 -> v5:
> - due to removal of static inline stubs, add
>   #ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
>   around consumer registration/unregistration
> - add pr_info when registration fails
> 
> 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        | 15 +++++++++++++++
>  2 files changed, 17 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..d7a230f 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 +141,9 @@ irqfd_shutdown(struct work_struct *work)
>  	/*
>  	 * It is now safe to release the object's resources
>  	 */
> +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
> +	irq_bypass_unregister_consumer(&irqfd->consumer);
> +#endif
>  	eventfd_ctx_put(irqfd->eventfd);
>  	kfree(irqfd);
>  }
> @@ -379,6 +383,17 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
>  	 * we might race against the POLLHUP
>  	 */
>  	fdput(f);
> +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
> +	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);
> +	if (ret)
> +		pr_info("irq bypass consumer (token %p) registration fails: %d\n",
> +				irqfd->consumer.token, ret);
> +#endif

Does this series compile on its own?  Aren't all these arch function
unresolved?

>  
>  	return 0;
>