Re: [Qemu-devel] [PATCH v3 4/6] target/s390x: Implement LOAD PAIR DISJOINT

[Aurelien Jarno <aurelien@aurel32.net>]

On 2017-05-09 11:07, Richard Henderson wrote:
> From: Eric Bischoff <ebischoff@nerim.net>
> 
> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
> Signed-off-by: Eric Bischoff <ebischoff@nerim.net>
> Message-Id: <20170228120134.7921-1-ebischoff@suse.com>
> [rth: Combine the two via insn->data; free the address temps.]
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  target/s390x/insn-data.def |  4 +++-
>  target/s390x/translate.c   | 42 ++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 45 insertions(+), 1 deletion(-)

[snip]

> diff --git a/target/s390x/translate.c b/target/s390x/translate.c
> index 2b66a4e..8de0177 100644
> --- a/target/s390x/translate.c
> +++ b/target/s390x/translate.c
> @@ -2559,6 +2559,7 @@ static ExitStatus op_lctlg(DisasContext *s, DisasOps *o)
>      tcg_temp_free_i32(r3);
>      return NO_EXIT;
>  }
> +
>  static ExitStatus op_lra(DisasContext *s, DisasOps *o)
>  {
>      check_privileged(s);
> @@ -2759,6 +2760,31 @@ static ExitStatus op_lm64(DisasContext *s, DisasOps *o)
>      return NO_EXIT;
>  }
>  
> +static ExitStatus op_lpd(DisasContext *s, DisasOps *o)
> +{
> +    TCGv_i64 a1, a2;
> +    TCGMemOp mop = s->insn->data;
> +
> +    /* In a parallel context, stop the world and single step.  */
> +    if (parallel_cpus) {
> +        potential_page_fault(s);
> +        gen_helper_exit_atomic(cpu_env);
> +        return EXIT_NORETURN;
> +    }

One small additional comment about this patch I haven't spotted at the
first review. The exit_atomic helper is properly restoring the CPU state
passing the return address to cpu_loop_exit_atomic, so I believe the
potential_page_fault call is not necessary. That said, it doesn't hurt
either.

Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net