Re: [Qemu-trivial] [PATCH] ioport/memory: check that both .read and .write callbacks are defined

[Peter Crosthwaite]

Hi,

On Mon, Jun 10, 2013 at 3:27 PM, Gerd Hoffmann <address@hidden> wrote:
>   Hi,
>
>> Maybe instead (or in addition to), we should provide a dummy
>> read or write functions -- instead of fixing each such occurence
>> to use its own dummy function
>
> Makes sense, especially for write where we can just ignore what the
> guest attempts to write.  Not sure we can have a generic handler for
> reads.  Maybe two, one which returns 0xff and one which returns 0x00.
>

FWIW, I have one in my tree that qemu_log(LOG_GUEST_ERROR's such
accesses that I use for unimplemented devices. It's worthwhile to trap
such accesses and speaking for the Xilinx LQSPI case, my preference is
for some form of failure rather than silent write-ignore. And can we
have an option where a invalid writes have consistent behavior with
unassigned accesses?

Regards,
Peter

> cheers,
>   Gerd
>
>