Re: [Qemu-devel] [PATCH 1/2] memory: Provide separate handling of unassigned io ports accesses

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2013-08-08 17:33, Peter Maydell wrote:
> On 3 August 2013 09:31, Jan Kiszka <jan.kiszka@web.de> wrote:
>> --- a/ioport.c
>> +++ b/ioport.c
>> @@ -44,6 +44,22 @@ typedef struct MemoryRegionPortioList {
>>      MemoryRegionPortio ports[];
>>  } MemoryRegionPortioList;
>>
>> +static uint64_t unassigned_io_read(void *opaque, hwaddr addr, unsigned size)
>> +{
>> +    return -1UL;
> 
> This should probably be "-1ULL", otherwise we'll return
> different values on 32 bit and 64 bit hosts. (Actually
> managing a 64 bit read of the i/o space is pretty
> unlikely, though possibly alpha memory-mapped via the
> PCI space might let you do it.)

No problem with changing this - but wouldn't 64-bit i/o accesses be a
bug? It's not allowed according to PCI, no device can handle it
(officially), so no arch should forward such requests from mmio, rather
break them up first.

> 
> PS: something about the way these patches were submitted
> has confused Anthony's patches tool -- it reports them
> as two separate patches rather than a single series.
> (No cover letter, maybe?)

Something on my side broke the reference from the second to the first email.

Jan

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