[Qemu-devel] [PATCH v5] target-i386: Register QOM properties for feature flags

[Qemu-devel] [PATCH v5] target-i386: Register QOM properties for feature flags

[Eduardo Habkost]

This uses the feature name arrays to register QOM properties for feature
flags. This simply adds properties that can be configured using -global,
but doesn't change x86_cpu_parse_featurestr() to use them yet.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
Changes v1 -> v2:
* Use "cpuid-" prefix instead of "feat-"
* Register release function for property
* Convert '_' to '-' on feature name before registering property
* Add dev->realized check to property setter

Changes v2 -> v3:
* Register alias properties for feature name aliases
* Patch is based on x86 tree, at:
  https://github.com/ehabkost/qemu.git x86

Changes v3 -> v4:
* Remove "cpuid-" prefix altogether

Changes v4 -> v5:
* Coding style changes (mostly blank lines after variable declarations)
* Change feature property registration to be a generic "bit property"
  registration function
* Check for visitor errors on bit property setter
* Rename "bit" variables to "bitnr"
* Get bitnr as argument to bit property registration function, instead
  of mask
---
 target-i386/cpu.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 3305e09..9b11208 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2841,12 +2841,125 @@ out:
     }
 }
 
+typedef struct BitProperty {
+    uint32_t *ptr;
+    uint32_t mask;
+} BitProperty;
+
+static void x86_cpu_get_bit_prop(Object *obj,
+                                 struct Visitor *v,
+                                 void *opaque,
+                                 const char *name,
+                                 Error **errp)
+{
+    BitProperty *fp = opaque;
+    bool value = (*fp->ptr & fp->mask) == fp->mask;
+    visit_type_bool(v, &value, name, errp);
+}
+
+static void x86_cpu_set_bit_prop(Object *obj,
+                                 struct Visitor *v,
+                                 void *opaque,
+                                 const char *name,
+                                 Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    BitProperty *fp = opaque;
+    Error *local_err = NULL;
+    bool value;
+
+    if (dev->realized) {
+        qdev_prop_set_after_realize(dev, name, errp);
+        return;
+    }
+
+    visit_type_bool(v, &value, name, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    if (value) {
+        *fp->ptr |= fp->mask;
+    } else {
+        *fp->ptr &= ~fp->mask;
+    }
+}
+
+static void x86_cpu_release_bit_prop(Object *obj, const char *name,
+                                         void *opaque)
+{
+    BitProperty *prop = opaque;
+    g_free(prop);
+}
+
+/* Register a boolean property to get/set a single bit in a uint32_t field.
+ *
+ * The same property name can be registered multiple times to make it affect
+ * multiple bits in the same FeatureWord. In that case, the getter will return
+ * true only if all bits are set.
+ */
+static void x86_cpu_register_bit_prop(X86CPU *cpu,
+                                      const char *prop_name,
+                                      uint32_t *field,
+                                      int bitnr)
+{
+    BitProperty *fp;
+    ObjectProperty *op;
+    uint32_t mask = (1UL << bitnr);
+
+    op = object_property_find(OBJECT(cpu), prop_name, NULL);
+    if (op) {
+        fp = op->opaque;
+        assert(fp->ptr == field);
+        fp->mask |= mask;
+    } else {
+        fp = g_new0(BitProperty, 1);
+        fp->ptr = field;
+        fp->mask = mask;
+        object_property_add(OBJECT(cpu), prop_name, "bool",
+                            x86_cpu_get_bit_prop,
+                            x86_cpu_set_bit_prop,
+                            x86_cpu_release_bit_prop, fp, &error_abort);
+    }
+}
+
+static void x86_cpu_register_feature_bit_props(X86CPU *cpu,
+                                               FeatureWord w,
+                                               int bitnr)
+{
+    Object *obj = OBJECT(cpu);
+    int i;
+    char **names;
+    FeatureWordInfo *fi = &feature_word_info[w];
+
+    if (!fi->feat_names) {
+        return;
+    }
+    if (!fi->feat_names[bitnr]) {
+        return;
+    }
+
+    names = g_strsplit(fi->feat_names[bitnr], "|", 0);
+
+    feat2prop(names[0]);
+    x86_cpu_register_bit_prop(cpu, names[0], &cpu->env.features[w], bitnr);
+
+    for (i = 1; names[i]; i++) {
+        feat2prop(names[i]);
+        object_property_add_alias(obj, names[i], obj, names[0], &error_abort);
+    }
+
+    g_strfreev(names);
+}
+
 static void x86_cpu_initfn(Object *obj)
 {
     CPUState *cs = CPU(obj);
     X86CPU *cpu = X86_CPU(obj);
     X86CPUClass *xcc = X86_CPU_GET_CLASS(obj);
     CPUX86State *env = &cpu->env;
+    FeatureWord w;
     static int inited;
 
     cs->env_ptr = env;
@@ -2887,6 +3000,14 @@ static void x86_cpu_initfn(Object *obj)
     cpu->apic_id = -1;
 #endif
 
+    for (w = 0; w < FEATURE_WORDS; w++) {
+        int bitnr;
+
+        for (bitnr = 0; bitnr < 32; bitnr++) {
+            x86_cpu_register_feature_bit_props(cpu, w, bitnr);
+        }
+    }
+
     x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
 
     /* init various static tables used in TCG mode */
-- 
2.1.0

Re: [Qemu-devel] [PATCH v5] target-i386: Register QOM properties for feature flags

[Igor Mammedov]

On Tue, 14 Apr 2015 12:28:24 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> This uses the feature name arrays to register QOM properties for feature
> flags. This simply adds properties that can be configured using -global,
> but doesn't change x86_cpu_parse_featurestr() to use them yet.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v1 -> v2:
> * Use "cpuid-" prefix instead of "feat-"
> * Register release function for property
> * Convert '_' to '-' on feature name before registering property
> * Add dev->realized check to property setter
> 
> Changes v2 -> v3:
> * Register alias properties for feature name aliases
> * Patch is based on x86 tree, at:
>   https://github.com/ehabkost/qemu.git x86
> 
> Changes v3 -> v4:
> * Remove "cpuid-" prefix altogether
> 
> Changes v4 -> v5:
> * Coding style changes (mostly blank lines after variable declarations)
> * Change feature property registration to be a generic "bit property"
>   registration function
> * Check for visitor errors on bit property setter
> * Rename "bit" variables to "bitnr"
> * Get bitnr as argument to bit property registration function, instead
>   of mask
> ---
>  target-i386/cpu.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 121 insertions(+)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 3305e09..9b11208 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -2841,12 +2841,125 @@ out:
>      }
>  }
>  
> +typedef struct BitProperty {
> +    uint32_t *ptr;
> +    uint32_t mask;
> +} BitProperty;
> +
> +static void x86_cpu_get_bit_prop(Object *obj,
> +                                 struct Visitor *v,
> +                                 void *opaque,
> +                                 const char *name,
> +                                 Error **errp)
> +{
> +    BitProperty *fp = opaque;
> +    bool value = (*fp->ptr & fp->mask) == fp->mask;
> +    visit_type_bool(v, &value, name, errp);
> +}
> +
> +static void x86_cpu_set_bit_prop(Object *obj,
> +                                 struct Visitor *v,
> +                                 void *opaque,
> +                                 const char *name,
> +                                 Error **errp)
> +{
> +    DeviceState *dev = DEVICE(obj);
> +    BitProperty *fp = opaque;
> +    Error *local_err = NULL;
> +    bool value;
> +
> +    if (dev->realized) {
> +        qdev_prop_set_after_realize(dev, name, errp);
> +        return;
> +    }
> +
> +    visit_type_bool(v, &value, name, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    if (value) {
> +        *fp->ptr |= fp->mask;
> +    } else {
> +        *fp->ptr &= ~fp->mask;
> +    }
> +}
> +
> +static void x86_cpu_release_bit_prop(Object *obj, const char *name,
> +                                         void *opaque)
indent went astray ^^^

> +{
> +    BitProperty *prop = opaque;
> +    g_free(prop);
> +}
> +
> +/* Register a boolean property to get/set a single bit in a uint32_t field.
> + *
> + * The same property name can be registered multiple times to make it affect
> + * multiple bits in the same FeatureWord. In that case, the getter will return
> + * true only if all bits are set.
> + */
> +static void x86_cpu_register_bit_prop(X86CPU *cpu,
> +                                      const char *prop_name,
> +                                      uint32_t *field,
> +                                      int bitnr)
> +{
> +    BitProperty *fp;
> +    ObjectProperty *op;
> +    uint32_t mask = (1UL << bitnr);
> +
> +    op = object_property_find(OBJECT(cpu), prop_name, NULL);
> +    if (op) {
> +        fp = op->opaque;
> +        assert(fp->ptr == field);
> +        fp->mask |= mask;
> +    } else {
> +        fp = g_new0(BitProperty, 1);
> +        fp->ptr = field;
> +        fp->mask = mask;
> +        object_property_add(OBJECT(cpu), prop_name, "bool",
> +                            x86_cpu_get_bit_prop,
> +                            x86_cpu_set_bit_prop,
> +                            x86_cpu_release_bit_prop, fp, &error_abort);
> +    }
> +}
> +
> +static void x86_cpu_register_feature_bit_props(X86CPU *cpu,
> +                                               FeatureWord w,
> +                                               int bitnr)
> +{
> +    Object *obj = OBJECT(cpu);
> +    int i;
> +    char **names;
> +    FeatureWordInfo *fi = &feature_word_info[w];
> +
> +    if (!fi->feat_names) {
> +        return;
> +    }
> +    if (!fi->feat_names[bitnr]) {
> +        return;
> +    }
> +
> +    names = g_strsplit(fi->feat_names[bitnr], "|", 0);
> +
> +    feat2prop(names[0]);
> +    x86_cpu_register_bit_prop(cpu, names[0], &cpu->env.features[w], bitnr);
> +
> +    for (i = 1; names[i]; i++) {
> +        feat2prop(names[i]);
> +        object_property_add_alias(obj, names[i], obj, names[0], &error_abort);
> +    }
> +
> +    g_strfreev(names);
> +}
> +
>  static void x86_cpu_initfn(Object *obj)
>  {
>      CPUState *cs = CPU(obj);
>      X86CPU *cpu = X86_CPU(obj);
>      X86CPUClass *xcc = X86_CPU_GET_CLASS(obj);
>      CPUX86State *env = &cpu->env;
> +    FeatureWord w;
>      static int inited;
>  
>      cs->env_ptr = env;
> @@ -2887,6 +3000,14 @@ static void x86_cpu_initfn(Object *obj)
>      cpu->apic_id = -1;
>  #endif
>  
> +    for (w = 0; w < FEATURE_WORDS; w++) {
> +        int bitnr;
> +
> +        for (bitnr = 0; bitnr < 32; bitnr++) {
> +            x86_cpu_register_feature_bit_props(cpu, w, bitnr);
> +        }
> +    }
> +
>      x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
>  
>      /* init various static tables used in TCG mode */

With comment above fixed,
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

Re: [Qemu-devel] [PATCH v5] target-i386: Register QOM properties for feature flags

[Eduardo Habkost]

On Tue, Apr 14, 2015 at 12:28:24PM -0300, Eduardo Habkost wrote:
> This uses the feature name arrays to register QOM properties for feature
> flags. This simply adds properties that can be configured using -global,
> but doesn't change x86_cpu_parse_featurestr() to use them yet.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

This is being applied to x86 tree with the following change, because the
object_property_add_alias() strdup() fix wasn't merged yet.

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index b2cf128..7042117 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2947,7 +2947,8 @@ static void x86_cpu_register_feature_bit_props(X86CPU *cpu,
 
     for (i = 1; names[i]; i++) {
         feat2prop(names[i]);
-        object_property_add_alias(obj, names[i], obj, names[0], &error_abort);
+        object_property_add_alias(obj, names[i], obj, g_strdup(names[0]),
+                                  &error_abort);
     }
 
     g_strfreev(names);

The g_strdup() call will be removed after the
object_property_add_alias() fix is applied.

-- 
Eduardo

Re: [Qemu-devel] [PATCH v5] target-i386: Register QOM properties for feature flags

[Paolo Bonzini]

On 14/04/2015 17:28, Eduardo Habkost wrote:
> +    for (i = 1; names[i]; i++) {
> +        feat2prop(names[i]);
> +        object_property_add_alias(obj, names[i], obj, names[0], &error_abort);

The version you committed has a strdup(names[0]) here, but
object_property_add_alias already does a strdup.

Paolo

> +    }

Re: [Qemu-devel] [PATCH v5] target-i386: Register QOM properties for feature flags

[Eduardo Habkost]

On Thu, Jul 09, 2015 at 04:15:19PM +0200, Paolo Bonzini wrote:
> 
> 
> On 14/04/2015 17:28, Eduardo Habkost wrote:
> > +    for (i = 1; names[i]; i++) {
> > +        feat2prop(names[i]);
> > +        object_property_add_alias(obj, names[i], obj, names[0], &error_abort);
> 
> The version you committed has a strdup(names[0]) here, but
> object_property_add_alias already does a strdup.

object_property_add_alias() didn't have a strdup() on June 2. I sent a
note about it at:

  Date: Fri, 22 May 2015 16:13:55 -0300
  From: Eduardo Habkost <ehabkost@redhat.com>
  To: qemu-devel@nongnu.org
  Message-ID: <20150522191355.GG28075@thinpad.lan.raisama.net>
  Subject: Re: [Qemu-devel] [PATCH v5] target-i386: Register QOM properties for feature flags

Now that the object_property_add_alias() patch was merged, we can remove
hte g_strdup() call.

-- 
Eduardo