[PATCH 7/7] target/arm/cpu: spe: Enable spe to work with host cpu

[Haibo Xu]

Turn on the spe cpu property by default when working with host
cpu type in KVM mode, i.e. we can now do '-cpu host' to add the 
vSPE, and '-cpu host,spe=off' to remove it. 

Signed-off-by: Haibo Xu <haibo.xu@linaro.org>
---
 target/arm/cpu.c   | 4 ++++
 target/arm/kvm64.c | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 67ab0089fd..42fa99953c 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1719,6 +1719,10 @@ static void arm_cpu_realizefn(DeviceState *dev, Error 
**errp)
         cpu->pmceid1 = 0;
     }   
 
+    if (!cpu->has_spe || !kvm_enabled()) {
+        unset_feature(env, ARM_FEATURE_SPE);
+    }
+
     if (!arm_feature(env, ARM_FEATURE_EL2)) {
         /* Disable the hypervisor feature bits in the processor feature
          * registers if we don't have EL2. These are id_pfr1[15:12] and
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index be045ccc5f..4ea58afc1d 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -679,6 +679,7 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     features |= 1ULL << ARM_FEATURE_AARCH64;
     features |= 1ULL << ARM_FEATURE_PMU;
     features |= 1ULL << ARM_FEATURE_GENERIC_TIMER;
+    features |= 1ULL << ARM_FEATURE_SPE;

     ahcf->features = features;

@@ -826,6 +827,14 @@ int kvm_arch_init_vcpu(CPUState *cs)
     } else {
         env->features &= ~(1ULL << ARM_FEATURE_PMU);
     }
+    if (!kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_SPE_V1)) {
+        cpu->has_spe = false;
+    }
+    if (cpu->has_spe) {
+        cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_SPE_V1;
+    } else {
+        env->features &= ~(1ULL << ARM_FEATURE_SPE);
+    }
     if (cpu_isar_feature(aa64_sve, cpu)) {
         assert(kvm_arm_sve_supported());
         cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_SVE;
-- 
2.17.1