Re: [Qemu-devel] [PATCH 11/28] s390x: replace cpu_s390x_init() with cpu_generic_init()

[Cornelia Huck <cohuck@redhat.com>]

On Fri, 14 Jul 2017 15:52:02 +0200
Igor Mammedov <imammedo@redhat.com> wrote:

> cpu_s390x_init() is used only *-user targets indirectly
> via cpu_init() macro and has a hack to assign ids to created
> cpus (I'm not sure if 'id' really matters to *-user emulation).
> 
> So to on safe side, instead of having custom wrapper to do numbering
> replace it with cpu_generic_init() and use S390CPUClass::next_cpu_id
> which could serve the same purpose as static variable and move cpu->id
> initialization to s390_cpu_initfn for CONFIG_USER_ONLY use-case.
> 
> PS:
> ifdef is ugly but it allows us to hide s390x detail that isn't
> set by *-user targets and reuse generic cpu creation utility
> for btoh machine and user emulation.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> perhaps cpu->id isn't need by CONFIG_USER_ONLY but I'd leave to it
> s390x maintainers to deal with it.
> 
> CC: Richard Henderson <rth@twiddle.net>
> CC: Alexander Graf <agraf@suse.de>
> CC: Cornelia Huck <cohuck@redhat.com>
> CC: Thomas Huth <thuth@redhat.com>
> ---
>  target/s390x/cpu.h    |  3 +--
>  target/s390x/cpu.c    |  7 +++++++
>  target/s390x/helper.c | 14 --------------
>  3 files changed, 8 insertions(+), 16 deletions(-)
> 
> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> index bdb9bdb..b6d25c6 100644
> --- a/target/s390x/cpu.h
> +++ b/target/s390x/cpu.h
> @@ -477,7 +477,6 @@ static inline bool get_per_in_range(CPUS390XState *env, uint64_t addr)
>  void trigger_pgm_exception(CPUS390XState *env, uint32_t code, uint32_t ilen);
>  #endif
>  
> -S390CPU *cpu_s390x_init(const char *cpu_model);
>  S390CPU *s390x_new_cpu(const char *cpu_model, int64_t id, Error **errp);
>  S390CPU *cpu_s390x_create(const char *cpu_model, Error **errp);
>  void s390x_translate_init(void);
> @@ -641,7 +640,7 @@ static inline unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu)
>  
>  extern void subsystem_reset(void);
>  
> -#define cpu_init(model) CPU(cpu_s390x_init(model))
> +#define cpu_init(cpu_model) cpu_generic_init(TYPE_S390_CPU, cpu_model)
>  #define cpu_signal_handler cpu_s390x_signal_handler
>  
>  void s390_cpu_list(FILE *f, fprintf_function cpu_fprintf);
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index accef03..e40a26f 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -303,6 +303,13 @@ static void s390_cpu_initfn(Object *obj)
>          inited = true;
>          s390x_translate_init();
>      }
> +
> +#if defined(CONFIG_USER_ONLY)
> +    {
> +        S390CPUClass *scc = S390_CPU_GET_CLASS(obj);
> +        cpu->id = scc->next_cpu_id;
> +    }
> +#endif

What about the null machine, which calls cpu_init() as well? Am I
missing something?

>  }
>  
>  static void s390_cpu_finalize(Object *obj)
> diff --git a/target/s390x/helper.c b/target/s390x/helper.c
> index aef09e1..632b030 100644
> --- a/target/s390x/helper.c
> +++ b/target/s390x/helper.c
> @@ -129,20 +129,6 @@ out:
>      return cpu;
>  }
>  
> -S390CPU *cpu_s390x_init(const char *cpu_model)
> -{
> -    Error *err = NULL;
> -    S390CPU *cpu;
> -    /* Use to track CPU ID for linux-user only */
> -    static int64_t next_cpu_id;
> -
> -    cpu = s390x_new_cpu(cpu_model, next_cpu_id++, &err);
> -    if (err) {
> -        error_report_err(err);
> -    }
> -    return cpu;
> -}
> -
>  #if defined(CONFIG_USER_ONLY)
>  
>  void s390_cpu_do_interrupt(CPUState *cs)