Re: [PATCH v7 2/2] kvm: KVM_EOIFD, an eventfd for EOIs

[Avi Kivity <avi@redhat.com>]

On 08/06/2012 01:17 PM, Avi Kivity wrote:
> 
>>  
>> +4.77 KVM_EOIFD
>> +
>> +Capability: KVM_CAP_EOIFD
>> +Architectures: x86
>> +Type: vm ioctl
>> +Parameters: struct kvm_eoifd (in)
>> +Returns: 0 on success, < 0 on error
>> +
>> +KVM_EOIFD allows userspace to receive interrupt EOI notification
>> +through an eventfd.  kvm_eoifd.fd specifies the eventfd used for
>> +notification.  KVM_EOIFD_FLAG_DEASSIGN is used to de-assign an eoifd
>> +once assigned.  KVM_EOIFD also requires additional bits set in
>> +kvm_eoifd.flags to bind to the proper interrupt line.  The
>> +KVM_EOIFD_FLAG_LEVEL_IRQFD indicates that kvm_eoifd.key is provided
>> +and is a key from a level triggered interrupt (configured from
>> +KVM_IRQFD using KVM_IRQFD_FLAG_LEVEL).  The EOI notification is bound
>> +to the same GSI and irqchip input as the irqfd.  Both kvm_eoifd.key
>> +and KVM_EOIFD_FLAG_LEVEL_IRQFD must be specified on assignment and
>> +de-assignment of KVM_EOIFD.  A level irqfd may only be bound to a
>> +single eoifd.  KVM_CAP_EOIFD_LEVEL_IRQFD indicates support of
>> +KVM_EOIFD_FLAG_LEVEL_IRQFD.
> 
> Why do we need to couple eoifd and irqfd?

Oh, it's to auto-deassert the line.

Regarding the implementation, instead of a linked list, would an array
of counters parallel to the bitmap make it simpler?

-- 
error compiling committee.c: too many arguments to function