[Qemu-devel] [PATCH RFC v4 18/20] target-arm: Add cpuid-{variant, revision} properties to CPU

[Andreas Färber]

Allow to inspect and manipulate MIDR variant and revision fields.

Signed-off-by: Andreas Färber <address@hidden>
Cc: Peter Maydell <address@hidden>
---
 target-arm/cpu.c |   48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 48 insertions(+), 0 deletions(-)

diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 8917a20..ad33742 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -20,6 +20,7 @@
 
 #include "cpu-qom.h"
 #include "qemu-common.h"
+#include "qapi/qapi-visit-core.h"
 #if !defined(CONFIG_USER_ONLY)
 #include "hw/loader.h"
 #endif
@@ -173,6 +174,46 @@ static inline void unset_class_feature(ARMCPUClass *klass, 
int feature)
     klass->features &= ~(1u << feature);
 }
 
+static void arm_cpuid_variant_get(Object *obj, Visitor *v, void *opaque,
+                                  const char *name, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    int64_t value = (cpu->env.cp15.c0_cpuid >> 20) & 0xf;
+
+    visit_type_int(v, &value, name, errp);
+}
+
+static void arm_cpuid_variant_set(Object *obj, Visitor *v, void *opaque,
+                                  const char *name, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    int64_t value;
+
+    visit_type_int(v, &value, name, errp);
+    cpu->env.cp15.c0_cpuid &= ~(0xf << 20);
+    cpu->env.cp15.c0_cpuid |= (value << 20) & 0xf;
+}
+
+static void arm_cpuid_revision_get(Object *obj, Visitor *v, void *opaque,
+                                   const char *name, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    int64_t value = cpu->env.cp15.c0_cpuid & 0xf;
+
+    visit_type_int(v, &value, name, errp);
+}
+
+static void arm_cpuid_revision_set(Object *obj, Visitor *v, void *opaque,
+                                   const char *name, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    int64_t value;
+
+    visit_type_int(v, &value, name, errp);
+    cpu->env.cp15.c0_cpuid &= ~0xf;
+    cpu->env.cp15.c0_cpuid |= value & 0xf;
+}
+
 /* CPU models */
 
 typedef struct ARMCPUInfo {
@@ -554,6 +595,13 @@ static void arm_cpu_initfn(Object *obj)
     cpu->env.cp15.c0_cpuid = cpu_class->cp15.c0_cpuid;
 
     cpu_reset(CPU(cpu));
+
+    object_property_add(obj, "cpuid-variant", "uint4",
+                        arm_cpuid_variant_get,
+                        arm_cpuid_variant_set, NULL, NULL, NULL);
+    object_property_add(obj, "cpuid-revision", "uint4",
+                        arm_cpuid_revision_get,
+                        arm_cpuid_revision_set, NULL, NULL, NULL);
 }
 
 static void arm_cpu_class_init(ObjectClass *klass, void *data)
-- 
1.7.7