Re: [PATCH v5 1/4] target/riscv: Add functions for common matching conditions of trigger

[Alistair Francis <alistair23@gmail.com>]

On Tue, Jun 4, 2024 at 2:42 PM Alvin Chang via <qemu-devel@nongnu.org> wrote:

The `From` address is mangled here. It shows it was sent from the list
instead of your actual email address.

Do you mind looking into your email setup and see if you can fix it?

Alistair

>
> According to RISC-V Debug specification version 0.13 [1] (also applied
> to version 1.0 [2] but it has not been ratified yet), there are several
> common matching conditions before firing a trigger, including the
> enabled privilege levels of the trigger.
>
> This commit adds trigger_common_match() to prepare the common matching
> conditions for the type 2/3/6 triggers. For now, we just implement
> trigger_priv_match() to check if the enabled privilege levels of the
> trigger match CPU's current privilege level.
>
> [1]: https://github.com/riscv/riscv-debug-spec/releases/tag/task_group_vote
> [2]: https://github.com/riscv/riscv-debug-spec/releases/tag/1.0.0-rc1-asciidoc
>
> Signed-off-by: Alvin Chang <alvinga@andestech.com>
> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/debug.c | 70 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
>
> diff --git a/target/riscv/debug.c b/target/riscv/debug.c
> index b110370ea6..05e001d041 100644
> --- a/target/riscv/debug.c
> +++ b/target/riscv/debug.c
> @@ -241,6 +241,76 @@ static void do_trigger_action(CPURISCVState *env, target_ulong trigger_index)
>      }
>  }
>
> +/*
> + * Check the privilege level of specific trigger matches CPU's current privilege
> + * level.
> + */
> +static bool trigger_priv_match(CPURISCVState *env, trigger_type_t type,
> +                               int trigger_index)
> +{
> +    target_ulong ctrl = env->tdata1[trigger_index];
> +
> +    switch (type) {
> +    case TRIGGER_TYPE_AD_MATCH:
> +        /* type 2 trigger cannot be fired in VU/VS mode */
> +        if (env->virt_enabled) {
> +            return false;
> +        }
> +        /* check U/S/M bit against current privilege level */
> +        if ((ctrl >> 3) & BIT(env->priv)) {
> +            return true;
> +        }
> +        break;
> +    case TRIGGER_TYPE_AD_MATCH6:
> +        if (env->virt_enabled) {
> +            /* check VU/VS bit against current privilege level */
> +            if ((ctrl >> 23) & BIT(env->priv)) {
> +                return true;
> +            }
> +        } else {
> +            /* check U/S/M bit against current privilege level */
> +            if ((ctrl >> 3) & BIT(env->priv)) {
> +                return true;
> +            }
> +        }
> +        break;
> +    case TRIGGER_TYPE_INST_CNT:
> +        if (env->virt_enabled) {
> +            /* check VU/VS bit against current privilege level */
> +            if ((ctrl >> 25) & BIT(env->priv)) {
> +                return true;
> +            }
> +        } else {
> +            /* check U/S/M bit against current privilege level */
> +            if ((ctrl >> 6) & BIT(env->priv)) {
> +                return true;
> +            }
> +        }
> +        break;
> +    case TRIGGER_TYPE_INT:
> +    case TRIGGER_TYPE_EXCP:
> +    case TRIGGER_TYPE_EXT_SRC:
> +        qemu_log_mask(LOG_UNIMP, "trigger type: %d is not supported\n", type);
> +        break;
> +    case TRIGGER_TYPE_NO_EXIST:
> +    case TRIGGER_TYPE_UNAVAIL:
> +        qemu_log_mask(LOG_GUEST_ERROR, "trigger type: %d does not exist\n",
> +                      type);
> +        break;
> +    default:
> +        g_assert_not_reached();
> +    }
> +
> +    return false;
> +}
> +
> +/* Common matching conditions for all types of the triggers. */
> +static bool trigger_common_match(CPURISCVState *env, trigger_type_t type,
> +                                 int trigger_index)
> +{
> +    return trigger_priv_match(env, type, trigger_index);
> +}
> +
>  /* type 2 trigger */
>
>  static uint32_t type2_breakpoint_size(CPURISCVState *env, target_ulong ctrl)
> --
> 2.34.1
>
>