Re: [PATCH 3/4] target/riscv: Apply modularized matching conditions for watchpoint

[Daniel Henrique Barboza]

On 2/19/24 00:25, Alvin Chang wrote:
> We have implemented trigger_common_match(), which checks if the enabled
> privilege levels of the trigger match CPU's current privilege level.
> Remove the related code in riscv_cpu_debug_check_watchpoint() and invoke
> trigger_common_match() to check the privilege levels of the type 2 and
> type 6 triggers for the watchpoints.
>
> Only load/store bits and loaded/stored address should be further checked
> in riscv_cpu_debug_check_watchpoint().
>
> Signed-off-by: Alvin Chang <alvinga@andestech.com>
> ---
>   target/riscv/debug.c | 26 ++++++--------------------
>   1 file changed, 6 insertions(+), 20 deletions(-)
>
> diff --git a/target/riscv/debug.c b/target/riscv/debug.c
> index b971ed5d7a..67ba19c966 100644
> --- a/target/riscv/debug.c
> +++ b/target/riscv/debug.c
> @@ -899,13 +899,12 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, 
> CPUWatchpoint *wp)
>       for (i = 0; i < RV_MAX_TRIGGERS; i++) {
>           trigger_type = get_trigger_type(env, i);
>   
> +        if (!trigger_common_match(env, trigger_type, i)) {
> +            continue;
> +        }
> +

The same comments I made in patch 2 also applies here. It's ok to change
how the function behaves as long as we're doing it on purpose and explaining
why in the commit message. Otherwise this if (!trigger_common_match()"
conditional should "return false" instead of keep looping to maintain
the existing behavior.

Thanks,

Daniel

>           switch (trigger_type) {
>           case TRIGGER_TYPE_AD_MATCH:
> -            /* type 2 trigger cannot be fired in VU/VS mode */
> -            if (env->virt_enabled) {
> -                return false;
> -            }
> -
>               ctrl = env->tdata1[i];
>               addr = env->tdata2[i];
>               flags = 0;
> @@ -918,10 +917,7 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, 
> CPUWatchpoint *wp)
>               }
>   
>               if ((wp->flags & flags) && (wp->vaddr == addr)) {
> -                /* check U/S/M bit against current privilege level */
> -                if ((ctrl >> 3) & BIT(env->priv)) {
> -                    return true;
> -                }
> +                return true;
>               }
>               break;
>           case TRIGGER_TYPE_AD_MATCH6:
> @@ -937,17 +933,7 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, 
> CPUWatchpoint *wp)
>               }
>   
>               if ((wp->flags & flags) && (wp->vaddr == addr)) {
> -                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;
> -                    }
> -                }
> +                return true;
>               }
>               break;
>           default: