Re: [KVM PATCH v2 2/2] kvm: add support for irqfd via eventfd-notification interface

[Avi Kivity <avi@redhat.com>]

Gregory Haskins wrote:
>>>> But eventfd_signal basically marries us to eventfd.
>>>>     
>>>>         
>>> Well, only if we expect the fd to have eventfd semantics.  There are
>>> advantages to doing so, as we have discussed, because things like AIO
>>> can polymorhpically signal an interrupt without even knowing whats
>>> behind the eventfd.  But this isn't a strict requirement to support
>>> AIO.  Really all we need is a way for both kernel and userspace to
>>> signal.  Perhaps I should export an "irqfd_signal()" function from kvm,
>>> which today will map to eventfd_signal(), and tomorrow to ??.  I don't
>>> think using f_ops->write() is an option for in-kernel signaling, so we
>>> need some kind of interface here.
>>>
>>> Does that sound reasonable?
>>>   
>>>       
>> irqfd_signal() ties the user of irqfd to kvm.  I want this user to be
>> independent of kvm; it should work with eventfd, kvm's eventfd
>> lookalike (if we move away from eventfd) or pipes.
>>     
>
> So what is your proposal for such interface?
>
>   

->write().

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.