Re: [Qemu-devel] [Qemu-arm] [PATCH 1/2] target/arm: Set S and PTW in 64-bit PAR format

["Alex Bennée" <alex.bennee@linaro.org>]

Peter Maydell <peter.maydell@linaro.org> writes:

> In do_ats_write() we construct a PAR value based on the result
> of the translation.  A comment says "S2WLK and FSTAGE are always
> zero, because we don't implement virtualization".
> Since we do in fact now implement virtualization, add the missing
> code that sets these bits based on the reported ARMMMUFaultInfo.
>
> (These bits are named PTW and S in ARMv8, so we follow that
> convention in the new comments in this patch.)
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target/arm/helper.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 43afdd082e1..dc849b09893 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -2344,10 +2344,12 @@ static uint64_t do_ats_write(CPUARMState *env, uint64_t value,
>
>              par64 |= 1; /* F */

To aid readability, mainly for those not familiar like me, maybe:

  par64 |= 1; /* PAR_EL1.F == 1, failed translation */

>              par64 |= (fsr & 0x3f) << 1; /* FS */
> -            /* Note that S2WLK and FSTAGE are always zero, because we don't
> -             * implement virtualization and therefore there can't be a stage 2
> -             * fault.
> -             */
> +            if (fi.stage2) {
> +                par64 |= (1 << 9); /* S */
> +            }
> +            if (fi.s1ptw) {
> +                par64 |= (1 << 8); /* PTW */
> +            }
>          }
>      } else {
>          /* fsr is a DFSR/IFSR value for the short descriptor

Anyway:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>


--
Alex Bennée