Re: [PATCH v3 7/7] target/arm: Honor the HCR_EL2.TTLB bit

[Peter Maydell <peter.maydell@linaro.org>]

On Tue, 18 Feb 2020 at 19:10, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> This bit traps EL1 access to tlb maintenance insns.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/helper.c | 85 +++++++++++++++++++++++++++++----------------
>  1 file changed, 55 insertions(+), 30 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 21ee9cf7de..87c0cf4a96 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -563,6 +563,16 @@ static CPAccessResult access_tacr(CPUARMState *env, const ARMCPRegInfo *ri,
>      return CP_ACCESS_OK;
>  }
>
> +/* Check for traps from EL1 due to HCR_EL2.TTLB. */
> +static CPAccessResult access_ttlb(CPUARMState *env, const ARMCPRegInfo *ri,
> +                                  bool isread)
> +{
> +    if (arm_current_el(env) == 1 && (arm_hcr_el2_eff(env) & HCR_TTLB)) {
> +        return CP_ACCESS_TRAP_EL2;
> +    }
> +    return CP_ACCESS_OK;
> +}

The set of operations this traps differs when ARMv8.4-TLBI is
implemented. It looks like you've applied this access fn to
the wider with-v8.4-TLBI set? (eg TLBI_VMALLE1 is only trapped
with ARMv8.4-TLBI, not without.)

thanks
-- PMM