Re: [Qemu-arm] [PATCH] target-arm: Fix descriptor address masking in ARM address translation

[Peter Maydell]

On 17 March 2016 at 15:21, Sergey Sorokin <address@hidden> wrote:
> 17.03.2016, 14:40, "Peter Maydell" <address@hidden>:
>> On 13 March 2016 at 18:28, Sergey Sorokin <address@hidden> wrote:
>>>> If you want to implement the AddressSize checks that's fine,
>>>> but otherwise please leave this bit of the code alone.
>>>
>>>  You said me that my code is not correct, I have proved that it conforms
>>>  to the documentation.
>>>  It's a bit obfuscating when the doc explicitly says to take bits up to 39
>>>  from the descriptor, but in QEMU we take bits up to 47 relying on the 
>>> check in
>>>  another part of the code, even if both ways are correct.
>>
>> The way the code in QEMU is structured is that we extract the
>> descriptor field in one go and then will operate on it
>> (checking for need to AddressSize fault, etc) as a second
>> action. The field descriptors themselves are the sizes I said.
>
> Well, may be it's enough just to change this comment as you intend:
>
>>> -    /* The address field in the descriptor goes up to bit 39 for ARMv7
>>> -     * but up to bit 47 for ARMv8.
>>> +    /* The address field in the descriptor goes up to bit 39 for AArch32
>>> +     * but up to bit 47 for AArch64.
>>>       */

The comment is correct as it stands.

thanks
-- PMM