Re: [PATCH v5 11/25] target/m68k: call plugin trap callbacks

[Richard Henderson <richard.henderson@linaro.org>]

On 5/19/25 16:19, Julian Ganz wrote:
> We recently introduced API for registering callbacks for trap related
> events as well as the corresponding hook functions. Due to differences
> between architectures, the latter need to be called from target specific
> code.
> 
> This change places hooks for Motorola 68000 targets.
> 
> Signed-off-by: Julian Ganz <neither@nut.email>
> ---
>   target/m68k/op_helper.c | 24 ++++++++++++++++++++++++
>   1 file changed, 24 insertions(+)
> 
> diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c
> index f29ae12af8..ca15af5765 100644
> --- a/target/m68k/op_helper.c
> +++ b/target/m68k/op_helper.c
> @@ -22,6 +22,7 @@
>   #include "exec/helper-proto.h"
>   #include "accel/tcg/cpu-ldst.h"
>   #include "semihosting/semihost.h"
> +#include "qemu/plugin.h"
>   
>   #if !defined(CONFIG_USER_ONLY)
>   
> @@ -183,6 +184,21 @@ static const char *m68k_exception_name(int index)
>       return "Unassigned";
>   }
>   
> +static void do_plugin_vcpu_interrupt_cb(CPUState *cs, uint64_t from)
> +{
> +    switch (cs->exception_index) {
> +    case EXCP_SPURIOUS ... EXCP_INT_LEVEL_7:
> +        qemu_plugin_vcpu_interrupt_cb(cs, from);
> +        break;
> +    case EXCP_SEMIHOSTING:
> +        qemu_plugin_vcpu_hostcall_cb(cs, from);
> +        break;
> +    default:
> +        qemu_plugin_vcpu_exception_cb(cs, from);
> +        break;
> +    }
> +}
> +
>   static void cf_interrupt_all(CPUM68KState *env, int is_hw)
>   {
>       CPUState *cs = env_cpu(env);
> @@ -200,9 +216,11 @@ static void cf_interrupt_all(CPUM68KState *env, int is_hw)
>           case EXCP_RTE:
>               /* Return from an exception.  */
>               cf_rte(env);
> +            qemu_plugin_vcpu_exception_cb(cs, retaddr);
>               return;

EXCP_RTE is not an architectural exception, it's qemu implementation detail.  Think 
"subroutine return, and also pop cpu state".  I don't think you should expose this. 
Certainly you're not instrumenting "return from exception" for other targets.

> @@ -277,12 +297,14 @@ static void m68k_interrupt_all(CPUM68KState *env, int is_hw)
>       uint32_t sp;
>       uint32_t vector;
>       uint16_t sr, oldsr;
> +    uint64_t last_pc = env->pc;
>   
>       if (!is_hw) {
>           switch (cs->exception_index) {
>           case EXCP_RTE:
>               /* Return from an exception.  */
>               m68k_rte(env);
> +            qemu_plugin_vcpu_exception_cb(cs, last_pc);
>               return;
>           }
>       }

Likewise.


r~