Re: [Qemu-devel] [PATCH v2 1/2] memory: Fix old portio word accesses

[Avi Kivity <avi@redhat.com>]

On 09/18/2011 06:43 PM, Jan Kiszka wrote:
> On 2011-09-18 17:37, Avi Kivity wrote:
> >  On 09/18/2011 03:51 PM, Jan Kiszka wrote:
> >>  From: Jan Kiszka<jan.kiszka@siemens.com>
> >>
> >>  As we register old portio regions via ioport_register, we are also
> >>  responsible for providing the word access wrapper.
> >>
> >>  Signed-off-by: Jan Kiszka<jan.kiszka@siemens.com>
> >>  ---
> >>
> >>  Oops, was lacking a shift for word reads.
> >>
> >>    memory.c |   10 ++++++++++
> >>    1 files changed, 10 insertions(+), 0 deletions(-)
> >>
> >>  diff --git a/memory.c b/memory.c
> >>  index b3ee232..aef4702 100644
> >>  --- a/memory.c
> >>  +++ b/memory.c
> >>  @@ -397,6 +397,11 @@ static void memory_region_iorange_read(IORange
> >>  *iorange,
> >>            *data = ((uint64_t)1<<   (width * 8)) - 1;
> >>            if (mrp) {
> >>                *data = mrp->read(mr->opaque, offset + mr->offset);
> >>  +        } else if (width == 2) {
> >>  +            mrp = find_portio(mr, offset, 1, false);
> >>  +            assert(mrp);
> >>  +            *data = mrp->read(mr->opaque, offset + mr->offset) |
> >>  +                    (mrp->read(mr->opaque, offset + mr->offset +
> >>  1)<<   8);
> >>            }
> >
> >  What about width 4?
>
> This is PIO, limited by the x86 address space to 16 bit. Will add a comment.

x86 PIO is not limited to 16 bits, just ISA, which memory.c knows 
nothing about.

> >   Why not use access_with_adjusted_size()?
>
> Because of different accessor prototypes.
>

Can be thunked.  There is a different issue, a_w_a_s() can use small 
accesses to emulate large ones, but not vice versa.  It needs fixing anyway.

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