Re: [PATCHv0 RFC] kvm: irqfd support for level interrupts

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Aug 19, 2009 at 03:20:21PM +0300, Avi Kivity wrote:
> On 07/26/2009 07:22 PM, Michael S. Tsirkin wrote:
>> Here's an untested patch with partial support for level triggered
>> interrupts in irqfd. What this patch has: support for clearing interrupt
>> on ack. What this patch does not have: support signalling eventfd on ack
>> so that userspace can take action and e.g. reenable interrupt.
>>
>> Gleb, Marcelo, I'd like your input on the approach taken wrt locking.
>> Does it look sane?
>>
>> Avi, how's the interface? I intend to also add an eventfd probably in
>> the padding in the irqfd struct.
>>    
>
> What about the state-capable eventfd?

This patch precedes that effort.

>  Seems much more natural for this.

Good. Could you please review and ack the state-capable eventfd patch
then, so I can try pushing it upstream?


>>
>>   static struct workqueue_struct *irqfd_cleanup_wq;
>> @@ -63,10 +65,15 @@ irqfd_inject(struct work_struct *work)
>>
>>   	mutex_lock(&kvm->irq_lock);
>>   	kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 1);
>> -	kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 0);
>> +	if (!irqfd->is_level)
>> +		kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 0);
>>    
>
> e.g. inject the eventfd->state as the irq level.
>
> -- 
> error compiling committee.c: too many arguments to function