KVM: VMX: use cmpxchg64

BugLink: http://bugs.launchpad.net/bugs/1721550

commit c0a1666b upstream.

This fixes a compilation failure on 32-bit systems.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

arch/x86/kvm/vmx.c

@@ -2028,8 +2028,8 @@ static void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu)
 
 		/* Allow posting non-urgent interrupts */
 		new.sn = 0;
-	} while (cmpxchg(&pi_desc->control, old.control,
-			new.control) != old.control);
+	} while (cmpxchg64(&pi_desc->control, old.control,
+			   new.control) != old.control);
 }
 /*
  * Switches to specified vcpu, until a matching vcpu_put(), but assumes
@@ -10708,8 +10708,8 @@ static int vmx_pre_block(struct kvm_vcpu *vcpu)
 
 		/* set 'NV' to 'wakeup vector' */
 		new.nv = POSTED_INTR_WAKEUP_VECTOR;
-	} while (cmpxchg(&pi_desc->control, old.control,
-			new.control) != old.control);
+	} while (cmpxchg64(&pi_desc->control, old.control,
+			   new.control) != old.control);
 
 	return 0;
 }
@@ -10740,8 +10740,8 @@ static void vmx_post_block(struct kvm_vcpu *vcpu)
 
 		/* set 'NV' to 'notification vector' */
 		new.nv = POSTED_INTR_VECTOR;
-	} while (cmpxchg(&pi_desc->control, old.control,
-			new.control) != old.control);
+	} while (cmpxchg64(&pi_desc->control, old.control,
+			   new.control) != old.control);
 
 	if(vcpu->pre_pcpu != -1) {
 		spin_lock_irqsave(