1 files changed, 33 insertions, 1 deletions

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 6dd802c6d780..713f1b3bad52 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -500,6 +500,38 @@ void __init kvm_guest_init(void)
 #endif
 }
 
+static noinline uint32_t __kvm_cpuid_base(void)
+{
+        if (boot_cpu_data.cpuid_level < 0)
+                return 0;       /* So we don't blow up on old processors */
+
+        if (cpu_has_hypervisor)
+                return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0);
+
+        return 0;
+}
+
+static inline uint32_t kvm_cpuid_base(void)
+{
+        static int kvm_cpuid_base = -1;
+
+        if (kvm_cpuid_base == -1)
+                kvm_cpuid_base = __kvm_cpuid_base();
+
+        return kvm_cpuid_base;
+}
+
+bool kvm_para_available(void)
+{
+        return kvm_cpuid_base() != 0;
+}
+EXPORT_SYMBOL_GPL(kvm_para_available);
+
+unsigned int kvm_arch_para_features(void)
+{
+        return cpuid_eax(kvm_cpuid_base() | KVM_CPUID_FEATURES);
+}
+
 static uint32_t __init kvm_detect(void)
 {
         return kvm_cpuid_base();
@@ -673,7 +705,7 @@ static cpumask_t waiting_cpus;
 /* Track spinlock on which a cpu is waiting */
 static DEFINE_PER_CPU(struct kvm_lock_waiting, klock_waiting);
 
-static void kvm_lock_spinning(struct arch_spinlock *lock, __ticket_t want)
+__visible void kvm_lock_spinning(struct arch_spinlock *lock, __ticket_t want)
 {
         struct kvm_lock_waiting *w;
         int cpu;