Re: [Qemu-devel] [RFC v2 01/11] tcg: move tb_invalidated_flag to CPUState

[Paolo Bonzini]

On 05/04/2016 17:32, Alex Bennée wrote:
> +    cpu->tb_invalidated_flag = false;
>      tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags,
>                       max_cycles | CF_NOCACHE
>                           | (ignore_icount ? CF_IGNORE_ICOUNT : 0));
> -    tb->orig_tb = tcg_ctx.tb_ctx.tb_invalidated_flag ? NULL : orig_tb;
> +    tb->orig_tb = cpu->tb_invalidated_flag ? NULL : orig_tb;
>      cpu->current_tb = tb;

Based on discussion, it's safest to save the old value at the beginning
of the hunk, and "OR" it into cpu->tb_invalidated_flag here.

>      /* if no translated code available, then translate it now */
> +    cpu->tb_invalidated_flag = false;

Please remove this...

>      tb = tb_gen_code(cpu, pc, cs_base, flags, 0);
>  
>  #ifdef CONFIG_USER_ONLY
> @@ -509,12 +509,11 @@ int cpu_exec(CPUState *cpu)
>                  tb = tb_find_fast(cpu);
>                  /* Note: we do it here to avoid a gcc bug on Mac OS X when
>                     doing it in tb_find_slow */
> -                if (tcg_ctx.tb_ctx.tb_invalidated_flag) {
> +                if (cpu->tb_invalidated_flag) {
>                      /* as some TB could have been invalidated because
> -                       of memory exceptions while generating the code, we
> +                       of a tb_flush while generating the code, we
>                         must recompute the hash index here */
>                      next_tb = 0;
> -                    tcg_ctx.tb_ctx.tb_invalidated_flag = 0;

... and leave the zeroing here.

Paolo

>                  }