Re: [PATCH v2 2/2] s390x/pci: Fix memory_region_access_valid call

[Pierre Morel <pmorel@linux.ibm.com>]

On 12/18/20 6:05 PM, Pierre Morel wrote:
> 
> 
> On 12/18/20 5:51 PM, Cornelia Huck wrote:
>> On Fri, 18 Dec 2020 17:40:50 +0100
>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>>
>>> On 12/18/20 4:32 PM, Cornelia Huck wrote:
>>>> On Fri, 18 Dec 2020 15:32:08 +0100
>>>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>>>>> On 12/18/20 12:04 PM, Cornelia Huck wrote:
>>>>>> On Fri, 18 Dec 2020 10:37:38 +0100
>>>>>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>>>>>>> On 12/17/20 11:16 PM, Matthew Rosato wrote:
>>>>>>>> In pcistb_service_handler, a call is made to validate that the 
>>>>>>>> memory
>>>>>>>> region can be accessed.  However, the call is made using the 
>>>>>>>> entire length
>>>>>>>> of the pcistb operation, which can be larger than the allowed 
>>>>>>>> memory
>>>>>>>> access size (8).  Since we already know that the provided buffer 
>>>>>>>> is a
>>>>>>>> multiple of 8, fix the call to memory_region_access_valid to 
>>>>>>>> iterate
>>>>>>>> over the memory region in the same way as the subsequent call to
>>>>>>>> memory_region_dispatch_write.
>>>>>>>>
>>>>>>>> Fixes: 863f6f52b7 ("s390: implement pci instructions")
>>>>>>>> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
>>>>>>>> ---

...snip...

>>>>
>>>
>>> The ops already exist, I thought adding a dedicated callback for s390 on
>>> every regions used by vfio_pci instead of the default.
>>> But it does not add a lot, just looks cleaner to me.
>>
>> But we end up here for every pci device, not just for vfio devices,
>> don't we?
>>
>>
> 
> Yes, but isn't what is done here?
> 

It was not my intention to slow the integration process.
We can start with this fix and eventually move the code to the callback 
in another series when/if we all agree.

Acked-by: Pierre Morel <pmorel@linux.ibm.com>



-- 
Pierre Morel
IBM Lab Boeblingen