accel/kvm: Introduce kvm_create_and_park_vcpu() helper

There are distinct helpers for creating and parking a KVM vCPU.
However, there can be cases where a platform needs to create and
immediately park the vCPU during early stages of vcpu init which
can later be reused when vcpu thread gets initialized. This would
help detect failures with kvm_create_vcpu at an early stage.

Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

accel/kvm/kvm-all.c

@@ -398,6 +398,18 @@ int kvm_create_vcpu(CPUState *cpu)
     return 0;
 }
 
+int kvm_create_and_park_vcpu(CPUState *cpu)
+{
+    int ret = 0;
+
+    ret = kvm_create_vcpu(cpu);
+    if (!ret) {
+        kvm_park_vcpu(cpu);
+    }
+
+    return ret;
+}
+
 static int do_kvm_destroy_vcpu(CPUState *cpu)
 {
     KVMState *s = kvm_state;

include/sysemu/kvm.h

@@ -338,6 +338,14 @@ void kvm_park_vcpu(CPUState *cpu);
  */
 int kvm_unpark_vcpu(KVMState *s, unsigned long vcpu_id);
 
+/**
+ * kvm_create_and_park_vcpu - Create and park a KVM vCPU
+ * @cpu: QOM CPUState object for which KVM vCPU has to be created and parked.
+ *
+ * @returns: 0 when success, errno (<0) when failed.
+ */
+int kvm_create_and_park_vcpu(CPUState *cpu);
+
 /* Arch specific hooks */
 
 extern const KVMCapabilityInfo kvm_arch_required_capabilities[];