[Qemu-devel] [PATCH v4 27/33] target-i386: Register X86CPU "feat-kvmclock" feature

[Eduardo Habkost]

The "kvmclock" feature is special because it affects two bits in the KVM
CPUID leaf, so it has to be handled differently from the other feature
properties that will be added.

Signed-off-by: Eduardo Habkost <address@hidden>
---
 target-i386/cpu.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index b005b0d..0eb401b 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2774,6 +2774,61 @@ uint32_t x86_cpu_apic_id_from_index(unsigned int 
cpu_index)
     }
 }
 
+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.
+ */
+static void x86_cpu_register_feature_prop(X86CPU *cpu,
+                                          const char *prop_name,
+                                          FeatureWord w,
+                                          uint32_t mask)
+{
+    FeatureProperty *fp;
+    fp = g_new0(FeatureProperty, 1);
+    fp->word = w;
+    fp->mask = mask;
+    object_property_add(OBJECT(cpu), prop_name, "bool",
+                        x86_cpu_set_feature_prop,
+                        x86_cpu_get_feature_prop,
+                        NULL, fp, &error_abort);
+}
+
 static void x86_cpu_initfn(Object *obj)
 {
     CPUState *cs = CPU(obj);
@@ -2819,6 +2874,12 @@ static void x86_cpu_initfn(Object *obj)
                         x86_cpu_get_feature_words,
                         NULL, NULL, (void *)cpu->filtered_features, NULL);
 
+    /* "feat-kvmclock" will affect both kvmclock feature bits */
+    x86_cpu_register_feature_prop(cpu, "feat-kvmclock", FEAT_KVM,
+                                  (1UL << KVM_FEATURE_CLOCKSOURCE) |
+                                  (1UL << KVM_FEATURE_CLOCKSOURCE2));
+
+
     cpu->hyperv_spinlock_attempts = HYPERV_SPINLOCK_NEVER_RETRY;
     env->cpuid_apic_id = x86_cpu_apic_id_from_index(cs->cpu_index);
 
-- 
1.9.3