From 536aa9ecc3cb25c81c2df56230c690257189d4ef Mon Sep 17 00:00:00 2001
From: Peng Liang <liangpeng10@huawei.com>
Date: Thu, 6 Aug 2020 16:14:55 +0800
Subject: [PATCH] target/arm: introduce KVM_CAP_ARM_CPU_FEATURE

Introduce KVM_CAP_ARM_CPU_FEATURE to check whether KVM supports to set
CPU features in ARM.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Peng Liang <liangpeng10@huawei.com>
Signed-off-by: Dongxu Sun <sundongxu3@huawei.com>
---
 linux-headers/linux/kvm.h |  2 ++
 target/arm/cpu.c          |  5 +++++
 target/arm/kvm64.c        | 14 ++++++++++++++
 target/arm/kvm_arm.h      |  7 +++++++
 4 files changed, 28 insertions(+)

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index bcaf66cc4d..5d8e42b8f8 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -1113,6 +1113,8 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204
 #define KVM_CAP_ARM_MTE 205
 
+#define KVM_CAP_ARM_CPU_FEATURE 555
+
 #ifdef KVM_CAP_IRQ_ROUTING
 
 struct kvm_irq_routing_irqchip {
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index ee09642dae..3024f4a3f5 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1604,6 +1604,11 @@ static void arm_cpu_set_bit_prop(Object *obj, Visitor *v, const char *name,
     Error *local_err = NULL;
     bool value;
 
+    if (!kvm_arm_cpu_feature_supported()) {
+        warn_report("KVM doesn't support to set CPU feature in arm.  "
+                    "Setting to `%s` is ignored.", name);
+        return;
+    }
     if (dev->realized) {
         qdev_prop_set_after_realize(dev, name, errp);
         return;
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 4f97e516c2..b34a87fd24 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -827,6 +827,20 @@ static int kvm_arm_sve_set_vls(CPUState *cs)
     return kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 }
 
+bool kvm_arm_cpu_feature_supported(void)
+{
+    static bool cpu_feature_initialized;
+    static bool cpu_feature_supported;
+
+    if (!cpu_feature_initialized) {
+        cpu_feature_supported = kvm_check_extension(kvm_state,
+                                                    KVM_CAP_ARM_CPU_FEATURE);
+        cpu_feature_initialized = true;
+    }
+
+    return cpu_feature_supported;
+}
+
 #define ARM_CPU_ID_MPIDR       3, 0, 0, 0, 5
 
 int kvm_arch_init_vcpu(CPUState *cs)
diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index f8e0e64363..82145607ec 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -306,6 +306,13 @@ bool kvm_arm_pmu_supported(void);
  */
 bool kvm_arm_sve_supported(void);
 
+/**
+ * kvm_arm_cpu_feature_supported:
+ *
+ * Returns true if KVM can set CPU features and false otherwise.
+ */
+bool kvm_arm_cpu_feature_supported(void);
+
 /**
  * kvm_arm_get_max_vm_ipa_size:
  * @ms: Machine state handle
-- 
2.27.0