Re: [Qemu-devel] [PULL 08/41] intel_iommu: support device iotlb descriptor

[Paolo Bonzini]

On 19/01/2017 04:32, Jason Wang wrote:
>>
>>>
>>>> +        addr &= ~(sz - 1);
>>>> +    } else {
>>>> +        sz = VTD_PAGE_SIZE;
>>>> +    }
>>>>   +    entry.target_as = &vtd_dev_as->as;
>>>> +    entry.addr_mask = sz - 1;
>>>> +    entry.iova = addr;
>>> If S=1, entry.iova must mask away the 1 bits that specified the size.
>>> For example,
>>>
>>>       addr = 0xabcd1000
>>>
>>> has cto64(0xabcd1) == 1, so it indicates a 16K invalidation from
>>> 0xabcd0000 to 0xabcd3fff.  The "1" must be masked away with "addr & -sz"
>>> or "addr & ~entry.addr_mask".
>>>
>>> Thanks,
>>>
>>> Paolo
>>
>> Good catch.
> 
> It should be addr & ~(sz - 1) I think? And it has been done above :)

Oh, of course!

Paolo