Re: [PATCH] ioeventfd: Introduce KVM_IOEVENTFD_FLAG_PIPE

[Avi Kivity <avi@redhat.com>]

On 07/04/2011 05:38 PM, Sasha Levin wrote:
> >
> >  In general incremental development is great, but I don't want to
> >  fragment the ABI.  I'd like to be able to forward an entire PCI BAR over
> >  a pipe.  That means sending the address/data/length tuple, and both read
> >  and write support.
>
> Would this mean that for sockets we want to remove the 8 byte limit?

Yes.  Register a range and support all sizes.

Perhaps it merits a separate ioctl.

> What about eventfds? We can remove the limit there and assume that if
> the user asked for more than 8 bytes he knows what he's doing?

I can't really see that as useful.  eventfds destroy information; 
without datamatch, you have no idea what value was written.  Even with 
datamatch, you have no idea how many times it was written.  With a 
range, you also have no idea which address was written.  It's pretty 
meaningless.

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