Re: [Qemu-devel] [PATCH 1/7] trace: Add event "guest_bbl_before"

[Richard Henderson]

On 09/10/2017 09:15 AM, Lluís Vilanova wrote:
> Signed-off-by: Lluís Vilanova <address@hidden>
> ---
>  accel/tcg/translator.c |    6 ++++++
>  trace-events           |   11 +++++++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
> index afa3af478a..91b3b0da32 100644
> --- a/accel/tcg/translator.c
> +++ b/accel/tcg/translator.c
> @@ -13,6 +13,7 @@
>  #include "cpu.h"
>  #include "tcg/tcg.h"
>  #include "tcg/tcg-op.h"
> +#include "trace-tcg.h"
>  #include "exec/exec-all.h"
>  #include "exec/gen-icount.h"
>  #include "exec/log.h"
> @@ -91,6 +92,11 @@ void translator_loop(const TranslatorOps *ops, 
> DisasContextBase *db,
>              }
>          }
>  
> +        /* Tracing before */
> +        if (db->num_insns == 1) {
> +            trace_guest_bbl_before_tcg(cpu, tcg_ctx.tcg_env, db->pc_first);
> +        }

Why not place this before the loop, so that you don't
have to check num_insns == 1?

> +vcpu tcg guest_bbl_before(uint64_t vaddr) "vaddr=0x%016"PRIx64, 
> "vaddr=0x%016"PRIx64

You're really going to print both ENV and PC tagged with "vaddr"?
That just seems confusing.

Also, terminology.  A "basic block" ("bb" by preference, not "bbl"), has a
specific meaning (https://en.wikipedia.org/wiki/Basic_block).  What we're
generating here is a TranslationBlock (which may consist of many basic blocks),
and oft contracted within the source as "tb".


r~