[PATCH 3/7] target/arm/cpu: spe: Add an option to turn on/off vSPE support

[Haibo Xu]

Adds a spe=[on/off] option to enable/disable vSPE support in
guest vCPU. Note this option is only available for "-cpu host"
with KVM mode, and default value is on. 

Signed-off-by: Haibo Xu <haibo.xu@linaro.org>
---
 target/arm/cpu.c | 28 ++++++++++++++++++++++++++++
 target/arm/cpu.h |  3 +++ 
 2 files changed, 31 insertions(+)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 111579554f..40768b4d19 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1122,6 +1122,29 @@ static void arm_set_pmu(Object *obj, bool value, Error 
**errp)
     cpu->has_pmu = value;
 }
 
+static bool arm_get_spe(Object *obj, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+
+    return cpu->has_spe;
+}
+
+static void arm_set_spe(Object *obj, bool value, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+
+    if (value) {
+        if (kvm_enabled() && !kvm_arm_spe_supported()) {
+            error_setg(errp, "'spe' feature not supported by KVM on this 
host");
+            return;
+        }
+        set_feature(&cpu->env, ARM_FEATURE_SPE);
+    } else {
+        unset_feature(&cpu->env, ARM_FEATURE_SPE);
+    }
+    cpu->has_spe = value;
+}
+
 unsigned int gt_cntfrq_period_ns(ARMCPU *cpu)
 {
     /*
@@ -1195,6 +1218,11 @@ void arm_cpu_post_init(Object *obj)
         object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu);
     }

+    if (arm_feature(&cpu->env, ARM_FEATURE_SPE)) {
+        cpu->has_spe = true;
+        object_property_add_bool(obj, "spe", arm_get_spe, arm_set_spe);
+    }
+
     /*
      * Allow user to turn off VFP and Neon support, but only for TCG --
      * KVM does not currently allow us to lie to the guest about its
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 9e8ed423ea..fe0ac14386 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -822,6 +822,8 @@ struct ARMCPU {
     bool has_el3;
     /* CPU has PMU (Performance Monitor Unit) */
     bool has_pmu;
+    /* CPU has SPE (Statistical Profiling Extension) */
+    bool has_spe;
     /* CPU has VFP */
     bool has_vfp;
     /* CPU has Neon */
@@ -1959,6 +1961,7 @@ enum arm_features {
     ARM_FEATURE_VBAR, /* has cp15 VBAR */
     ARM_FEATURE_M_SECURITY, /* M profile Security Extension */
     ARM_FEATURE_M_MAIN, /* M profile Main Extension */
+    ARM_FEATURE_SPE, /* has SPE support */
 };

 static inline int arm_feature(CPUARMState *env, int feature)
-- 
2.17.1