Re: [RFC v5 11/12] i386: centralize initialization of cpu accel interfaces

[Eduardo Habkost]

On Tue, Nov 24, 2020 at 05:22:09PM +0100, Claudio Fontana wrote:
> Signed-off-by: Claudio Fontana <cfontana@suse.de>

Probably this can be squashed into patch 10/12.

> ---
>  target/i386/cpu-qom.h |  2 --
>  target/i386/cpu.c     | 27 ++++++++++++++++++++-------
>  target/i386/hvf/cpu.c |  9 ---------
>  target/i386/kvm/cpu.c |  8 --------
>  target/i386/tcg/cpu.c |  9 ---------
>  5 files changed, 20 insertions(+), 35 deletions(-)
> 
> diff --git a/target/i386/cpu-qom.h b/target/i386/cpu-qom.h
> index 9316e78e71..2cea5394c6 100644
> --- a/target/i386/cpu-qom.h
> +++ b/target/i386/cpu-qom.h
> @@ -98,6 +98,4 @@ struct X86CPUAccelClass {
>      void (*cpu_realizefn)(X86CPU *cpu, Error **errp);
>  };
>  
> -void x86_cpu_accel_init(const char *accel_name);
> -
>  #endif
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index b799723e53..f6fd055046 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -7066,18 +7066,31 @@ type_init(x86_cpu_register_types)
>  static void x86_cpu_accel_init_aux(ObjectClass *klass, void *opaque)
>  {
>      X86CPUClass *xcc = X86_CPU_CLASS(klass);
> -    const X86CPUAccelClass **accel = opaque;
> +    X86CPUAccelClass *accel = opaque;
>  
> -    xcc->accel = *accel;
> +    xcc->accel = accel;
>      xcc->accel->cpu_common_class_init(xcc);
>  }
>  
> -void x86_cpu_accel_init(const char *accel_name)
> +static void x86_cpu_accel_init(void)
>  {
> -    X86CPUAccelClass *acc;
> +    const char *ac_name;
> +    ObjectClass *ac;
> +    char *xac_name;
> +    ObjectClass *xac;
>  
> -    acc = X86_CPU_ACCEL_CLASS(object_class_by_name(accel_name));
> -    g_assert(acc != NULL);
> +    ac = object_get_class(OBJECT(current_accel()));
> +    g_assert(ac != NULL);
> +    ac_name = object_class_get_name(ac);
> +    g_assert(ac_name != NULL);
>  
> -    object_class_foreach(x86_cpu_accel_init_aux, TYPE_X86_CPU, false, &acc);
> +    xac_name = g_strdup_printf("%s-%s", ac_name, TYPE_X86_CPU);
> +    xac = object_class_by_name(xac_name);
> +    g_free(xac_name);
> +
> +    if (xac) {
> +        object_class_foreach(x86_cpu_accel_init_aux, TYPE_X86_CPU, false, 
> xac);
> +    }
>  }
> +
> +accel_cpu_init(x86_cpu_accel_init);

This keeps the hidden initialization ordering dependency between
MODULE_INIT_ACCEL_CPU and current_accel().  I thought we were
going to get rid of module init functions that depend on runtime
state.

This is an improvement to the code in patch 10/12, though.  If
others believe it is an acceptable (temporary) solution, I won't
block it.

I would still prefer to have a
  void arch_accel_cpu_init(AccelState*)
function which would call a
  void x86_cpu_accel_init(AccelState*)
function.  That would make the dependency between
x86_cpu_accel_init() and accelerator creation explicit.


> diff --git a/target/i386/hvf/cpu.c b/target/i386/hvf/cpu.c
> index 7e7dc044d3..70b6dbfc10 100644
> --- a/target/i386/hvf/cpu.c
> +++ b/target/i386/hvf/cpu.c
> @@ -65,12 +65,3 @@ static void hvf_cpu_accel_register_types(void)
>      type_register_static(&hvf_cpu_accel_type_info);
>  }
>  type_init(hvf_cpu_accel_register_types);
> -
> -static void hvf_cpu_accel_init(void)
> -{
> -    if (hvf_enabled()) {
> -        x86_cpu_accel_init(X86_CPU_ACCEL_TYPE_NAME("hvf"));
> -    }
> -}
> -
> -accel_cpu_init(hvf_cpu_accel_init);
> diff --git a/target/i386/kvm/cpu.c b/target/i386/kvm/cpu.c
> index bc5f519479..c17ed5a3f2 100644
> --- a/target/i386/kvm/cpu.c
> +++ b/target/i386/kvm/cpu.c
> @@ -147,11 +147,3 @@ static void kvm_cpu_accel_register_types(void)
>      type_register_static(&kvm_cpu_accel_type_info);
>  }
>  type_init(kvm_cpu_accel_register_types);
> -
> -static void kvm_cpu_accel_init(void)
> -{
> -    if (kvm_enabled()) {
> -        x86_cpu_accel_init(X86_CPU_ACCEL_TYPE_NAME("kvm"));
> -    }
> -}
> -accel_cpu_init(kvm_cpu_accel_init);
> diff --git a/target/i386/tcg/cpu.c b/target/i386/tcg/cpu.c
> index e7d4effdd0..00166c36e9 100644
> --- a/target/i386/tcg/cpu.c
> +++ b/target/i386/tcg/cpu.c
> @@ -170,12 +170,3 @@ static void tcg_cpu_accel_register_types(void)
>      type_register_static(&tcg_cpu_accel_type_info);
>  }
>  type_init(tcg_cpu_accel_register_types);
> -
> -static void tcg_cpu_accel_init(void)
> -{
> -    if (tcg_enabled()) {
> -        x86_cpu_accel_init(X86_CPU_ACCEL_TYPE_NAME("tcg"));
> -    }
> -}
> -
> -accel_cpu_init(tcg_cpu_accel_init);
> -- 
> 2.26.2
> 

-- 
Eduardo