KVM: Add x86_hyper_kvm to complete detect_hypervisor_platform check

While debugging I noticed that unlike all the other hypervisor code in the
kernel, kvm does not have an entry for x86_hyper which is used in
detect_hypervisor_platform() which results in a nice printk in the
syslog.  This is only really a stub function but it
does make kvm more consistent with the other hypervisors.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marcelo Tostatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/include/asm/hypervisor.h

@@ -49,6 +49,7 @@ extern const struct hypervisor_x86 *x86_hyper;
 extern const struct hypervisor_x86 x86_hyper_vmware;
 extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
 extern const struct hypervisor_x86 x86_hyper_xen_hvm;
+extern const struct hypervisor_x86 x86_hyper_kvm;
 
 static inline bool hypervisor_x2apic_available(void)
 {

arch/x86/kernel/cpu/hypervisor.c

@@ -37,6 +37,7 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] =
 #endif
 	&x86_hyper_vmware,
 	&x86_hyper_ms_hyperv,
+	&x86_hyper_kvm,
 };
 
 const struct hypervisor_x86 *x86_hyper;

arch/x86/kernel/kvm.c

@@ -41,6 +41,7 @@
 #include <asm/idle.h>
 #include <asm/apic.h>
 #include <asm/apicdef.h>
+#include <asm/hypervisor.h>
 
 static int kvmapf = 1;
 
@@ -483,6 +484,19 @@ void __init kvm_guest_init(void)
 #endif
 }
 
+static bool __init kvm_detect(void)
+{
+	if (!kvm_para_available())
+		return false;
+	return true;
+}
+
+const struct hypervisor_x86 x86_hyper_kvm __refconst = {
+	.name			= "KVM",
+	.detect			= kvm_detect,
+};
+EXPORT_SYMBOL_GPL(x86_hyper_kvm);
+
 static __init int activate_jump_labels(void)
 {
 	if (has_steal_clock) {