Re: [Qemu-devel] [PATCH 6/6] use uint32_t for ioport port and value instead of int.

[Tristan Gingold]

On Jul 10, 2009, at 2:59 PM, Anthony Liguori wrote:

> Tristan Gingold wrote:
> > On Jul 10, 2009, at 10:54 AM, Samuel Thibault wrote:
> >
> > > Isaku Yamahata, le Fri 10 Jul 2009 17:45:08 +0900, a écrit :
> > > > void cpu_out[bwl](CPUState *env, int64_t addr, int{8, 16, 32}_t  
> > > > val);
> > >
> > > uint16_t addr, and uint* for val
> > >
> > > > uint{8, 16, 32}_t cpu_inw(CPUState *env, int16_t addr);
> > >
> > > uint16_t addr
> >
> > Some machines allow more than 2**16 ports (guess which :-)
>
> But I thought that PIO on ia64 ended up being MMIO or something  
> funky like that?  Would it really end up using this code path?

Yes.

Port IO is done through usual memory access, but either the processor  
or the north-bridge can recognize this
address and convert the memory access to a port access.  After all PCI  
cards knows about IO vs Memory.