Re: [Qemu-devel] [PATCH 01/23] qom: Add cpu_exec_enter and cpu_exec_exit hooks

["Andreas Färber" <afaerber@suse.de>]

Am 13.09.2014 um 18:45 schrieb Richard Henderson:
> In preparation for removing a bunch of ifdefs from cpu_exec.
> 
> Cc: Andreas Färber <afaerber@suse.de>
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  cpu-exec.c        | 9 ++-------
>  include/qom/cpu.h | 5 +++++
>  qom/cpu.c         | 6 ++++--
>  3 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/cpu-exec.c b/cpu-exec.c
> index bd93165..d5b86d0 100644
> --- a/cpu-exec.c
> +++ b/cpu-exec.c
> @@ -317,10 +317,7 @@ volatile sig_atomic_t exit_request;
>  int cpu_exec(CPUArchState *env)
>  {
>      CPUState *cpu = ENV_GET_CPU(env);
> -#if !(defined(CONFIG_USER_ONLY) && \
> -      (defined(TARGET_M68K) || defined(TARGET_PPC) || defined(TARGET_S390X)))
>      CPUClass *cc = CPU_GET_CLASS(cpu);
> -#endif
>  #ifdef TARGET_I386
>      X86CPU *x86_cpu = X86_CPU(cpu);
>  #endif
> @@ -382,9 +379,8 @@ int cpu_exec(CPUArchState *env)
>  #elif defined(TARGET_XTENSA)
>  #elif defined(TARGET_TRICORE)
>      /* XXXXX */
> -#else
> -#error unsupported target CPU
>  #endif
> +    cc->cpu_exec_enter(cpu);
>      cpu->exception_index = -1;
>  
>      /* Calculate difference between guest clock and host clock.
> @@ -856,9 +852,8 @@ int cpu_exec(CPUArchState *env)
>  #elif defined(TARGET_S390X)
>  #elif defined(TARGET_XTENSA)
>      /* XXXXX */
> -#else
> -#error unsupported target CPU
>  #endif
> +    cc->cpu_exec_exit(cpu);
>  
>      /* fail safe : never use current_cpu outside cpu_exec() */
>      current_cpu = NULL;
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index 370b3eb..0340cf4 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -99,6 +99,8 @@ struct TranslationBlock;
>   * @vmsd: State description for migration.
>   * @gdb_num_core_regs: Number of core registers accessible to GDB.
>   * @gdb_core_xml_file: File name for core registers GDB XML description.
> + * @cpu_exec_enter: Callback for cpu_exec preparation.
> + * @cpu_exec_exit: Callback for cpu_exec cleanup.
>   *
>   * Represents a CPU family or model.
>   */
> @@ -149,6 +151,9 @@ typedef struct CPUClass {
>      const struct VMStateDescription *vmsd;
>      int gdb_num_core_regs;
>      const char *gdb_core_xml_file;
> +
> +    void (*cpu_exec_enter)(CPUState *cpu);
> +    void (*cpu_exec_exit)(CPUState *cpu);

I am fine with adding such hooks, but please let's use a better, active
name. CPUClass is the struct name and cpu-exec is a file name; the hook
should say what it's doing, not where the code (used to) live(s). Just
exec_enter/exec_exit possibly?

Thanks,
Andreas

>  } CPUClass;
>  
>  #ifdef HOST_WORDS_BIGENDIAN
> diff --git a/qom/cpu.c b/qom/cpu.c
> index ba8b402..6a9d02e 100644
> --- a/qom/cpu.c
> +++ b/qom/cpu.c
> @@ -202,7 +202,7 @@ static bool cpu_common_virtio_is_big_endian(CPUState *cpu)
>      return target_words_bigendian();
>  }
>  
> -static void cpu_common_debug_excp_handler(CPUState *cpu)
> +static void cpu_common_noop(CPUState *cpu)
>  {
>  }
>  
> @@ -344,7 +344,9 @@ static void cpu_class_init(ObjectClass *klass, void *data)
>      k->gdb_read_register = cpu_common_gdb_read_register;
>      k->gdb_write_register = cpu_common_gdb_write_register;
>      k->virtio_is_big_endian = cpu_common_virtio_is_big_endian;
> -    k->debug_excp_handler = cpu_common_debug_excp_handler;
> +    k->debug_excp_handler = cpu_common_noop;
> +    k->cpu_exec_enter = cpu_common_noop;
> +    k->cpu_exec_exit = cpu_common_noop;
>      dc->realize = cpu_common_realizefn;
>      /*
>       * Reason: CPUs still need special care by board code: wiring up
> 


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