Re: [Qemu-devel] [PATCH 04/10] target-i386: convert 'hv_spinlocks' to static property

[Eduardo Habkost]

On Mon, Feb 25, 2013 at 02:03:03AM +0100, Igor Mammedov wrote:
> Signed-off-by: Igor Mammedov <address@hidden>
> ---
>  target-i386/cpu.c |   50 ++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 files changed, 48 insertions(+), 2 deletions(-)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 35fc303..443c15e 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -1295,6 +1295,50 @@ static PropertyInfo qdev_prop_tsc_freq = {
>  #define DEFINE_PROP_TSC_FREQ(_n)                                             
>   \
>      DEFINE_PROP(_n, X86CPU, env.tsc_khz, qdev_prop_tsc_freq, int32_t)
>  
> +static void x86_get_hv_spinlocks(Object *obj, Visitor *v, void *opaque,
> +                                 const char *name, Error **errp)
> +{
> +    X86CPU *cpu = X86_CPU(obj);
> +    int64_t value = cpu->env.hyperv_spinlock_attempts;
> +
> +    visit_type_int(v, &value, name, errp);
> +}
> +
> +static void x86_set_hv_spinlocks(Object *obj, Visitor *v, void *opaque,
> +                                 const char *name, Error **errp)
> +{
> +    const int64_t min = 0xFFF;
> +    const int64_t max = UINT_MAX;
> +    X86CPU *cpu = X86_CPU(obj);
> +    int64_t value;
> +
> +    visit_type_int(v, &value, name, errp);
> +    if (error_is_set(errp)) {
> +        return;
> +    }
> +
> +    if (value < min || value > max) {
> +        error_setg(errp, "Property %s.%s doesn't take value %" PRId64
> +                  " (minimum: %" PRId64 ", maximum: %" PRId64 ")",
> +                  object_get_typename(obj), name ? name : "null",
> +                  value, min, max);
> +        return;
> +    }
> +    cpu->env.hyperv_spinlock_attempts = value;
> +}
> +
> +static PropertyInfo qdev_prop_spinlocks = {
> +    .name  = "int",
> +    .get   = x86_get_hv_spinlocks,
> +    .set   = x86_set_hv_spinlocks,
> +};
> +#define DEFINE_PROP_HV_SPINLOCKS(_n, _defval) {                              
>   \
> +    .name  = _n,                                                             
>   \
> +    .info  = &qdev_prop_spinlocks,                                           
>   \
> +    .qtype = QTYPE_QINT,                                                     
>   \
> +    .defval = _defval                                                        
>   \
> +}
> +
>  static Property cpu_x86_properties[] = {
>      DEFINE_PROP_FAMILY("family"),
>      DEFINE_PROP_MODEL("model"),
> @@ -1304,6 +1348,7 @@ static Property cpu_x86_properties[] = {
>      DEFINE_PROP_VENDOR("vendor"),
>      DEFINE_PROP_MODEL_ID("model-id"),
>      DEFINE_PROP_TSC_FREQ("tsc-frequency"),
> +    DEFINE_PROP_HV_SPINLOCKS("hv-spinlocks", HYPERV_SPINLOCK_NEVER_RETRY),

I'm still bothered by how complicated it is to define a simple property
that has a custom setter/getter.

Registering a property with a getter/setter on instance_init require
only one line of code, why doing the same with a static property
requires _twelve_ lines?

Are we using the static property API in a wrong or unexpected way, or
this is really how things are supposed to work?


>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> @@ -1421,6 +1466,7 @@ static void cpu_x86_parse_featurestr(X86CPU *cpu, char 
> *features, Error **errp)
>              } else if (!strcmp(featurestr, "hv-spinlocks")) {
>                  char *err;
>                  const int min = 0xFFF;
> +                char num[32];
>                  numvalue = strtoul(val, &err, 0);
>                  if (!*val || *err) {
>                      error_setg(errp, "bad numerical value %s", val);
> @@ -1432,7 +1478,8 @@ static void cpu_x86_parse_featurestr(X86CPU *cpu, char 
> *features, Error **errp)
>                              min);
>                      numvalue = min;
>                  }
> -                env->hyperv_spinlock_attempts = numvalue;
> +                snprintf(num, sizeof(num), "%" PRId32, numvalue);
> +                object_property_parse(OBJECT(cpu), num, featurestr, errp);
>              } else {
>                  error_setg(errp, "unrecognized feature %s", featurestr);
>                  goto out;
> @@ -1597,7 +1644,6 @@ static void cpu_x86_register(X86CPU *cpu, const char 
> *name, Error **errp)
>          def->kvm_features |= kvm_default_features;
>      }
>      def->ext_features |= CPUID_EXT_HYPERVISOR;
> -    env->hyperv_spinlock_attempts = HYPERV_SPINLOCK_NEVER_RETRY;
>  
>      object_property_set_str(OBJECT(cpu), def->vendor, "vendor", errp);
>      object_property_set_int(OBJECT(cpu), def->level, "level", errp);
> -- 
> 1.7.1
> 

-- 
Eduardo