Re: [PATCH 1/1] target/arm: Split out aa64_va_parameter_tbi, aa64_va_parameter_tbid

[Richard Henderson <richard.henderson@linaro.org>]

On 2/7/20 2:00 PM, Peter Maydell wrote:
>>
>> +    /* Present TBI as a composite with TBID.  */
>> +    tbi = aa64_va_parameter_tbi(tcr, mmu_idx);
>> +    if (!data) {
>> +        tbi &= ~aa64_va_parameter_tbid(tcr, mmu_idx);
>> +    }
>> +    tbi = (tbi >> select) & 1;
> 
> ...but aa64_va_parameters() always sets
>     select = extract64(va, 55, 1);
> even for the 1-range case, and then we assume in this bit
> of code that we can pull the corresponding bit out of tbi.
> 
> Don't we need to either duplicate the bit returned by
> aa64_va_parameter_tbi() in the 1-range case, or else
> only shift tbi by 'select' in the 2-range case ?

I think we need to force select = 0 in the 1-range case, since "select == 1"
makes no sense in that case.


r~