Re: [Qemu-devel] [PATCH 1/2] Type-safe ioport callbacks

[Avi Kivity <avi@redhat.com>]

  On 10/25/2010 08:38 PM, Blue Swirl wrote:
> >
> >  I don't really see why we need registration; cpu_register_io() takes
> >  function pointers, a size, and an opaque, and gives an integer handle in
> >  return.  With the IOPort object approach, you set up the IOPort with
> >  function pointers, size is implied, and the opaque is derived using
> >  container_of(); the handle is simply the address of the object.
>
> With the handle, we can separate setting up the structures at device
> level, and mapping the object using only the handle at bus or other
> higher level. Can this be done with the object approach?

I believe so.  The handle is simply an indirect pointer, no?

> The purpose of that patch series was to perform the separation for PCI
> BARs. I wasn't so happy with the series, so I never pushed.

In fact I think an IOPort is even more suitable; if we need additional 
attributes we can use a derived object:

struct PCIIOPort {
     IOPort ioport;
     /* additional fields */
};



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