On Wed, Apr 08, 2015 at 01:36:29PM +0200, Igor Mammedov wrote:
> On Tue, 7 Apr 2015 17:46:40 -0300
> Eduardo Habkost <ehabk...@redhat.com> wrote:
>
> > This uses the feature name arrays to register "feat-*" QOM properties
> > for feature flags. This simply adds the properties so they can be
> > configured using -global, but doesn't change x86_cpu_parse_featurestr()
> > to use them yet.
> >
> > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> > ---
> > target-i386/cpu.c | 98
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 98 insertions(+)
> >
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index 099ed03..f29e55e 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -2883,12 +2883,103 @@ out:
> > }
> > }
> >
> > +typedef struct FeatureProperty {
> > + FeatureWord word;
> > + uint32_t mask;
> > +} FeatureProperty;
> > +
> > +
> > +static void x86_cpu_get_feature_prop(Object *obj,
> > + struct Visitor *v,
> > + void *opaque,
> > + const char *name,
> > + Error **errp)
> > +{
> > + X86CPU *cpu = X86_CPU(obj);
> > + CPUX86State *env = &cpu->env;
> > + FeatureProperty *fp = opaque;
> > + bool value = (env->features[fp->word] & fp->mask) == fp->mask;
> > + visit_type_bool(v, &value, name, errp);
> > +}
> > +
> > +static void x86_cpu_set_feature_prop(Object *obj,
> > + struct Visitor *v,
> > + void *opaque,
> > + const char *name,
> > + Error **errp)
> > +{
> > + X86CPU *cpu = X86_CPU(obj);
> > + CPUX86State *env = &cpu->env;
> > + FeatureProperty *fp = opaque;
> > + bool value;
> > + visit_type_bool(v, &value, name, errp);
> > + if (value) {
> > + env->features[fp->word] |= fp->mask;
> > + } else {
> > + env->features[fp->word] &= ~fp->mask;
> > + }
> > +}
> > +
> > +/* Register a boolean feature-bits property.
> > + * If mask has multiple bits, all must be set for the property to return
> > true.
> > + * The same property name can be registered multiple times to make it
> > affect
> > + * multiple bits in the same FeatureWord.
> > + */
> > +static void x86_cpu_register_feature_prop(X86CPU *cpu,
> > + const char *prop_name,
> > + FeatureWord w,
> > + uint32_t mask)
> > +{
> > + FeatureProperty *fp;
> > + ObjectProperty *op;
> > + op = object_property_find(OBJECT(cpu), prop_name, NULL);
> > + if (op) {
> > + fp = op->opaque;
> > + assert(fp->word == w);
> > + fp->mask |= mask;
> > + } else {
> > + fp = g_new0(FeatureProperty, 1);
> > + fp->word = w;
> > + fp->mask = mask;
> > + object_property_add(OBJECT(cpu), prop_name, "bool",
> > + x86_cpu_get_feature_prop,
> > + x86_cpu_set_feature_prop,
> > + NULL, fp, &error_abort);
> > + }
> > +}
> it would be better to create generic bit property and replace above code with
> it
> something similar to object_property_add_uint32_ptr()
object_property_add_*_ptr() adds read-only properties, and I didn't want
to make object_property_add_bit_ptr() inconsistent with the other
functions. But maybe it is better to have an inconsistent but reusable
API than making the new code non-reusable by keeping it inside
target-i386/cpu.c. I will give it a try.
BTW, it is on my wishlist to remove the existing duplication in
DEFINE_PROP_*(), QAPI, and object_property_add_*(), that are supposed to
support the same data types without duplicating code, but this may take
a while.
>
>
> > +
> > +static void x86_cpu_register_feature_bit_props(X86CPU *cpu,
> > + FeatureWord w,
> > + int bit)
> > +{
> > + int i;
> > + char **names;
> > + FeatureWordInfo *fi = &feature_word_info[w];
> > +
> > + if (!fi->feat_names) {
> > + return;
> > + }
> > + if (!fi->feat_names[bit]) {
> > + return;
> > + }
> > +
> > + names = g_strsplit(fi->feat_names[bit], "|", 0);
> > + for (i = 0; names[i]; i++) {
> > + char *feat_name = names[i];
> > + char *prop_name = g_strdup_printf("feat-%s", feat_name);
> > + x86_cpu_register_feature_prop(cpu, prop_name, w, (1UL << bit));
> it might be better instead of creating duplicate property to make an alias
I wasn't aware of property aliases. I will take a look. Thanks!
--
Eduardo
