On 2011-09-18 17:45, Avi Kivity wrote:
> 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.kis...@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.kis...@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.Confused address and data, the former is limited 16, the latter can be 32 as well. But I guess only ISA models made use of the core's split up service, and that's why QEMU limited itself accordingly. > >> > 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. > IIRC, that's a feature: Devices not implementing small accesses tend to refuse them in reality. Jan
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