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Re: [Qemu-devel] [PATCH v3 04/32] target-arm: add arm_is_secure() functi


From: Sergey Fedorov
Subject: Re: [Qemu-devel] [PATCH v3 04/32] target-arm: add arm_is_secure() function
Date: Thu, 12 Jun 2014 21:26:47 +0400
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0

Hi Greg,

I'm sorry, I wasn't thoughtful enough and missed that.
I would just suggest to combine that functions since they have a common part, i.e.:

    if (arm_feature(env, ARM_FEATURE_EL3)) {
        ...

What do you think?

// Sergey

12.06.2014 20:26, Greg Bellows пишет:
Hi Sergey,

I think I am missing your point.  In patch 6 arm_current_pl calls arm_is_secure.  Can you elaborate?

Greg


On 11 June 2014 07:17, Sergey Fedorov <address@hidden> wrote:
On 11.06.2014 03:54, Fabian Aggeler wrote:
> arm_is_secure() function allows to determine CPU security state
> if the CPU implements Security Extensions/EL3.
> arm_is_secure_below_el3() returns true if CPU is in secure state
> below EL3.
>
> Signed-off-by: Sergey Fedorov <address@hidden>
> Signed-off-by: Fabian Aggeler <address@hidden>
> ---
>  target-arm/cpu.h | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
>
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 903aa01..cb0da6b 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -710,6 +710,44 @@ static inline int arm_feature(CPUARMState *env, int feature)
>      return (env->features & (1ULL << feature)) != 0;
>  }
>
> +
> +/* Return true if exception level below EL3 is in secure state */
> +static inline bool arm_is_secure_below_el3(CPUARMState *env)
> +{
> +#if !defined(CONFIG_USER_ONLY)
> +    if (arm_feature(env, ARM_FEATURE_EL3)) {
> +        return !(env->cp15.scr_el3 & SCR_NS);
> +    } else if (arm_feature(env, ARM_FEATURE_EL2)) {
> +        return false;
> +    } else {
> +        /* IMPDEF: QEMU defaults to non-secure */
> +        return false;
> +    }
> +#else
> +    return false;
> +#endif
> +}
> +
> +/* Return true if the processor is in secure state */
> +static inline bool arm_is_secure(CPUARMState *env)
> +{
> +#if !defined(CONFIG_USER_ONLY)
> +    if (arm_feature(env, ARM_FEATURE_EL3)) {
> +        if (env->aarch64 && extract32(env->pstate, 2, 2) == 3) {
> +            /* CPU currently in Aarch64 state and EL3 */
> +            return true;
> +        } else if (!env->aarch64 &&
> +                (env->uncached_cpsr & CPSR_M) == ARM_CPU_MODE_MON) {
> +            /* CPU currently in Aarch32 state and monitor mode */
> +            return true;
> +        }

Hi Fabian,

Why don't use arm_current_pl() from patch 6 to determine EL here?

Best regards,
Sergey

> +    }
> +    return arm_is_secure_below_el3(env);
> +#else
> +    return false;
> +#endif
> +}
> +
>  /* Return true if the specified exception level is running in AArch64 state. */
>  static inline bool arm_el_is_aa64(CPUARMState *env, int el)
>  {




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