Re: [Qemu-arm] [Qemu-devel] [PATCH 06/13] arm: Don't let no-MPU PMSA cores write to SCTLR.M

[Alistair Francis]

On Tue, Apr 25, 2017 at 5:07 AM, Peter Maydell <address@hidden> wrote:
> If the CPU is a PMSA config with no MPU implemented, then the
> SCTLR.M bit should be RAZ/WI, so that the guest can never
> turn on the non-existent MPU.
>
> Signed-off-by: Peter Maydell <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Thanks,

Alistair

> ---
>  target/arm/helper.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 404bfdb..f0f25c8 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -3258,6 +3258,11 @@ static void sctlr_write(CPUARMState *env, const 
> ARMCPRegInfo *ri,
>          return;
>      }
>
> +    if (arm_feature(env, ARM_FEATURE_PMSA) && !cpu->has_mpu) {
> +        /* M bit is RAZ/WI for PMSA with no MPU implemented */
> +        value &= ~SCTLR_M;
> +    }
> +
>      raw_write(env, ri, value);
>      /* ??? Lots of these bits are not implemented.  */
>      /* This may enable/disable the MMU, so do a TLB flush.  */
> --
> 2.7.4
>
>