Re: [Qemu-devel] [PATCH] target-mips: fix CP0.BadVAddr by stopping translation on Address error

[Leon Alrae <leon.alrae@imgtec.com>]

On 28/01/2015 00:39, Maciej W. Rozycki wrote:
> On Mon, 26 Jan 2015, Leon Alrae wrote:
> 
>> BadVAddr is supposed to capture the most recent address that caused
>> the exception. Currently this is not happening as translation is not stopped
>> and BadVAddr is updated with subsequent addresses.
>>
>> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
>> ---
> 
>  I think this deserves a better description as it is about the specific 
> case of an unaligned standard MIPS instruction fetch.  Address Error 
> exceptions can also happen for other reasons: unaligned data accesses or 
> any accesses outside memory segments the current execution mode is allowed 
> to reach.

I believe that the one line change in the patch makes that clear. I
agree however that the description itself could be more precise.

>  While at it I think it may be worth double-checking if the other places 
> that trigger this exception get it right.

Other places seem to look fine. Even decode_micromips_opc handles it
correctly whereas decode_opc -– which obviously was implemented before
microMIPS -- never got fixed.

Regards,
Leon