Re: [PATCH 2/7] accel/tcg: Set CPUState.plugin_ra before all plugin callbacks

[Pierrick Bouvier]

On 4/15/24 21:06, Richard Henderson wrote:
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   include/hw/core/cpu.h  |  1 +
>   accel/tcg/plugin-gen.c | 50 +++++++++++++++++++++++++++++++++++++-----
>   2 files changed, 46 insertions(+), 5 deletions(-)
>
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 10cd492aff..f4af37c13d 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -350,6 +350,7 @@ typedef union IcountDecr {
>   typedef struct CPUNegativeOffsetState {
>       CPUTLB tlb;
>   #ifdef CONFIG_PLUGIN
> +    uintptr_t plugin_ra;
>       GArray *plugin_mem_cbs;
>   #endif
>       IcountDecr icount_decr;
> diff --git a/accel/tcg/plugin-gen.c b/accel/tcg/plugin-gen.c
> index 36e9134a5d..f96b49cce6 100644
> --- a/accel/tcg/plugin-gen.c
> +++ b/accel/tcg/plugin-gen.c
> @@ -37,6 +37,12 @@ enum plugin_gen_from {
>       PLUGIN_GEN_AFTER_TB,
>   };
>   
> +enum plugin_gen_ra {
> +    GEN_RA_DONE,
> +    GEN_RA_FROM_TB,
> +    GEN_RA_FROM_INSN,
> +};
> +
>   /* called before finishing a TB with exit_tb, goto_tb or goto_ptr */
>   void plugin_gen_disable_mem_helpers(void)
>   {
> @@ -151,11 +157,38 @@ static void gen_mem_cb(struct qemu_plugin_dyn_cb *cb,
>       tcg_temp_free_i32(cpu_index);
>   }
>   
> -static void inject_cb(struct qemu_plugin_dyn_cb *cb)
> +static void inject_ra(enum plugin_gen_ra *gen_ra)
> +{
> +    TCGv_ptr ra;
> +
> +    switch (*gen_ra) {
> +    case GEN_RA_DONE:
> +        return;
> +    case GEN_RA_FROM_TB:
> +        ra = tcg_constant_ptr(NULL);
> +        break;
> +    case GEN_RA_FROM_INSN:
> +        ra = tcg_temp_ebb_new_ptr();
> +        tcg_gen_plugin_pc(ra);
> +        break;
> +    default:
> +        g_assert_not_reached();
> +    }
> +
> +    tcg_gen_st_ptr(ra, tcg_env,
> +                   offsetof(CPUState, neg.plugin_ra) -
> +                   offsetof(ArchCPU, env));
> +    tcg_temp_free_ptr(ra);
> +    *gen_ra = GEN_RA_DONE;
> +}
> +
> +static void inject_cb(struct qemu_plugin_dyn_cb *cb,
> +                      enum plugin_gen_ra *gen_ra)
>   
>   {
>       switch (cb->type) {
>       case PLUGIN_CB_REGULAR:
> +        inject_ra(gen_ra);
>           gen_udata_cb(cb);
>           break;
>       case PLUGIN_CB_INLINE:
> @@ -167,16 +200,18 @@ static void inject_cb(struct qemu_plugin_dyn_cb *cb)
>   }
>   
>   static void inject_mem_cb(struct qemu_plugin_dyn_cb *cb,
> +                          enum plugin_gen_ra *gen_ra,
>                             enum qemu_plugin_mem_rw rw,
>                             qemu_plugin_meminfo_t meminfo, TCGv_i64 addr)
>   {
>       if (cb->rw & rw) {
>           switch (cb->type) {
>           case PLUGIN_CB_MEM_REGULAR:
> +            inject_ra(gen_ra);
>               gen_mem_cb(cb, meminfo, addr);
>               break;
>           default:
> -            inject_cb(cb);
> +            inject_cb(cb, gen_ra);
>               break;
>           }
>       }
> @@ -186,6 +221,7 @@ static void plugin_gen_inject(struct qemu_plugin_tb 
> *plugin_tb)
>   {
>       TCGOp *op, *next;
>       int insn_idx = -1;
> +    enum plugin_gen_ra gen_ra;
>   
>       if (unlikely(qemu_loglevel_mask(LOG_TB_OP_PLUGIN)
>                    && qemu_log_in_addr_range(plugin_tb->vaddr))) {
> @@ -205,10 +241,12 @@ static void plugin_gen_inject(struct qemu_plugin_tb 
> *plugin_tb)
>        */
>       memset(tcg_ctx->free_temps, 0, sizeof(tcg_ctx->free_temps));
>   
> +    gen_ra = GEN_RA_FROM_TB;
>       QTAILQ_FOREACH_SAFE(op, &tcg_ctx->ops, link, next) {
>           switch (op->opc) {
>           case INDEX_op_insn_start:
>               insn_idx++;
> +            gen_ra = GEN_RA_FROM_INSN;
>               break;
>   
>           case INDEX_op_plugin_cb:
> @@ -244,7 +282,8 @@ static void plugin_gen_inject(struct qemu_plugin_tb 
> *plugin_tb)
>                   cbs = plugin_tb->cbs;
>                   for (i = 0, n = (cbs ? cbs->len : 0); i < n; i++) {
>                       inject_cb(
> -                        &g_array_index(cbs, struct qemu_plugin_dyn_cb, i));
> +                        &g_array_index(cbs, struct qemu_plugin_dyn_cb, i),
> +                        &gen_ra);
>                   }
>                   break;
>   
> @@ -256,7 +295,8 @@ static void plugin_gen_inject(struct qemu_plugin_tb *plugin_tb)
>                   cbs = insn->insn_cbs;
>                   for (i = 0, n = (cbs ? cbs->len : 0); i < n; i++) {
>                       inject_cb(
> -                        &g_array_index(cbs, struct qemu_plugin_dyn_cb, i));
> +                        &g_array_index(cbs, struct qemu_plugin_dyn_cb, i),
> +                        &gen_ra);
>                   }
>                   break;
>   
> @@ -288,7 +328,7 @@ static void plugin_gen_inject(struct qemu_plugin_tb *plugin_tb)
>               cbs = insn->mem_cbs;
>               for (i = 0, n = (cbs ? cbs->len : 0); i < n; i++) {
>                   inject_mem_cb(&g_array_index(cbs, struct qemu_plugin_dyn_cb, 
> i),
> -                              rw, meminfo, addr);
> +                              &gen_ra, rw, meminfo, addr);
>               }
>   
>               tcg_ctx->emit_before_op = NULL;

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>