On Wed, 2 Aug 2023 at 18:02, Jean-Philippe Brucker
<jean-phili...@linaro.org> wrote:
>
> The AT instruction is UNDEFINED if the {NSE,NS} configuration is
> invalid. Add a function to check this on all AT instructions that apply
> to an EL lower than 3.
>
> Suggested-by: Peter Maydell <peter.mayd...@linaro.org>
> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
> ---
> target/arm/helper.c | 36 +++++++++++++++++++++++++-----------
> 1 file changed, 25 insertions(+), 11 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index fbb03c364b..77dd80ad28 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -3616,6 +3616,20 @@ static void ats1h_write(CPUARMState *env, const
> ARMCPRegInfo *ri,
> #endif /* CONFIG_TCG */
> }
>
> +static CPAccessResult at_e012_access(CPUARMState *env, const ARMCPRegInfo
> *ri,
> + bool isread)
> +{
> + /*
> + * R_NYXTL: instruction is UNDEFINED if it applies to an Exception level
> + * lower than EL3 and the combination SCR_EL3.{NSE,NS} is reserved.
> + */
> + if (cpu_isar_feature(aa64_rme, env_archcpu(env)) &&
> + (env->cp15.scr_el3 & (SCR_NSE | SCR_NS)) == SCR_NSE) {
> + return CP_ACCESS_TRAP;
> + }
The AArch64.AT() pseudocode and the text in the individual
AT insn descriptions ("When FEAT_RME is implemented, if the Effective
value of SCR_EL3.{NSE, NS} is a reserved value, this instruction is
UNDEFINED at EL3") say that this check needs an "arm_current_el(env) == 3"
condition too.
> + return CP_ACCESS_OK;
> +}
> +
> static CPAccessResult at_s1e2_access(CPUARMState *env, const ARMCPRegInfo
> *ri,
> bool isread)
> {
thanks
-- PMM
