Re: [PATCH v4 25/40] target/arm: Update timer access for VHE

[Alex Bennée]

Richard Henderson <address@hidden> writes:

> Signed-off-by: Richard Henderson <address@hidden>

Reviewed-by: Alex Bennée <address@hidden>

> ---
>  target/arm/helper.c | 102 +++++++++++++++++++++++++++++++++++---------
>  1 file changed, 81 insertions(+), 21 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index a4a7f82661..023b8963cf 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -2287,10 +2287,18 @@ static CPAccessResult gt_cntfrq_access(CPUARMState 
> *env, const ARMCPRegInfo *ri,
>       * Writable only at the highest implemented exception level.
>       */
>      int el = arm_current_el(env);
> +    uint64_t hcr;
> +    uint32_t cntkctl;
>  
>      switch (el) {
>      case 0:
> -        if (!extract32(env->cp15.c14_cntkctl, 0, 2)) {
> +        hcr = arm_hcr_el2_eff(env);
> +        if ((hcr & (HCR_E2H | HCR_TGE)) == (HCR_E2H | HCR_TGE)) {
> +            cntkctl = env->cp15.cnthctl_el2;
> +        } else {
> +            cntkctl = env->cp15.c14_cntkctl;
> +        }
> +        if (!extract32(cntkctl, 0, 2)) {
>              return CP_ACCESS_TRAP;
>          }
>          break;
> @@ -2318,17 +2326,47 @@ static CPAccessResult gt_counter_access(CPUARMState 
> *env, int timeridx,
>  {
>      unsigned int cur_el = arm_current_el(env);
>      bool secure = arm_is_secure(env);
> +    uint64_t hcr = arm_hcr_el2_eff(env);
>  
> -    /* CNT[PV]CT: not visible from PL0 if ELO[PV]CTEN is zero */
> -    if (cur_el == 0 &&
> -        !extract32(env->cp15.c14_cntkctl, timeridx, 1)) {
> -        return CP_ACCESS_TRAP;
> -    }
> +    switch (cur_el) {
> +    case 0:
> +        /* If HCR_EL2.<E2H,TGE> == '11': check CNTHCTL_EL2.EL0[PV]CTEN. */
> +        if ((hcr & (HCR_E2H | HCR_TGE)) == (HCR_E2H | HCR_TGE)) {
> +            return (extract32(env->cp15.cnthctl_el2, timeridx, 1)
> +                    ? CP_ACCESS_OK : CP_ACCESS_TRAP_EL2);
> +        }
>  
> -    if (arm_feature(env, ARM_FEATURE_EL2) &&
> -        timeridx == GTIMER_PHYS && !secure && cur_el < 2 &&
> -        !extract32(env->cp15.cnthctl_el2, 0, 1)) {
> -        return CP_ACCESS_TRAP_EL2;
> +        /* CNT[PV]CT: not visible from PL0 if EL0[PV]CTEN is zero */
> +        if (!extract32(env->cp15.c14_cntkctl, timeridx, 1)) {
> +            return CP_ACCESS_TRAP;
> +        }
> +
> +        /* If HCR_EL2.<E2H,TGE> == '10': check CNTHCTL_EL2.EL1PCTEN. */
> +        if (hcr & HCR_E2H) {
> +            if (timeridx == GTIMER_PHYS &&
> +                !extract32(env->cp15.cnthctl_el2, 10, 1)) {
> +                return CP_ACCESS_TRAP_EL2;
> +            }
> +        } else {
> +            /* If HCR_EL2.<E2H> == 0: check CNTHCTL_EL2.EL1PCEN. */
> +            if (arm_feature(env, ARM_FEATURE_EL2) &&
> +                timeridx == GTIMER_PHYS && !secure &&
> +                !extract32(env->cp15.cnthctl_el2, 1, 1)) {
> +                return CP_ACCESS_TRAP_EL2;
> +            }
> +        }
> +        break;
> +
> +    case 1:
> +        /* Check CNTHCTL_EL2.EL1PCTEN, which changes location based on E2H. 
> */
> +        if (arm_feature(env, ARM_FEATURE_EL2) &&
> +            timeridx == GTIMER_PHYS && !secure &&
> +            (hcr & HCR_E2H
> +             ? !extract32(env->cp15.cnthctl_el2, 10, 1)
> +             : !extract32(env->cp15.cnthctl_el2, 0, 1))) {
> +            return CP_ACCESS_TRAP_EL2;
> +        }
> +        break;
>      }
>      return CP_ACCESS_OK;
>  }
> @@ -2338,19 +2376,41 @@ static CPAccessResult gt_timer_access(CPUARMState 
> *env, int timeridx,
>  {
>      unsigned int cur_el = arm_current_el(env);
>      bool secure = arm_is_secure(env);
> +    uint64_t hcr = arm_hcr_el2_eff(env);
>  
> -    /* CNT[PV]_CVAL, CNT[PV]_CTL, CNT[PV]_TVAL: not visible from PL0 if
> -     * EL0[PV]TEN is zero.
> -     */
> -    if (cur_el == 0 &&
> -        !extract32(env->cp15.c14_cntkctl, 9 - timeridx, 1)) {
> -        return CP_ACCESS_TRAP;
> -    }
> +    switch (cur_el) {
> +    case 0:
> +        if ((hcr & (HCR_E2H | HCR_TGE)) == (HCR_E2H | HCR_TGE)) {
> +            /* If HCR_EL2.<E2H,TGE> == '11': check CNTHCTL_EL2.EL0[PV]TEN. */
> +            return (extract32(env->cp15.cnthctl_el2, 9 - timeridx, 1)
> +                    ? CP_ACCESS_OK : CP_ACCESS_TRAP_EL2);
> +        }
>  
> -    if (arm_feature(env, ARM_FEATURE_EL2) &&
> -        timeridx == GTIMER_PHYS && !secure && cur_el < 2 &&
> -        !extract32(env->cp15.cnthctl_el2, 1, 1)) {
> -        return CP_ACCESS_TRAP_EL2;
> +        /*
> +         * CNT[PV]_CVAL, CNT[PV]_CTL, CNT[PV]_TVAL: not visible from
> +         * EL0 if EL0[PV]TEN is zero.
> +         */
> +        if (!extract32(env->cp15.c14_cntkctl, 9 - timeridx, 1)) {
> +            return CP_ACCESS_TRAP;
> +        }
> +        /* fall through */
> +
> +    case 1:
> +        if (arm_feature(env, ARM_FEATURE_EL2) &&
> +            timeridx == GTIMER_PHYS && !secure) {
> +            if (hcr & HCR_E2H) {
> +                /* If HCR_EL2.<E2H,TGE> == '10': check CNTHCTL_EL2.EL1PTEN. 
> */
> +                if (!extract32(env->cp15.cnthctl_el2, 11, 1)) {
> +                    return CP_ACCESS_TRAP_EL2;
> +                }
> +            } else {
> +                /* If HCR_EL2.<E2H> == 0: check CNTHCTL_EL2.EL1PCEN. */
> +                if (!extract32(env->cp15.cnthctl_el2, 1, 1)) {
> +                    return CP_ACCESS_TRAP_EL2;
> +                }
> +            }
> +        }
> +        break;
>      }
>      return CP_ACCESS_OK;
>  }


-- 
Alex Bennée