diff --git a/drivers/xen/core/pci.c b/drivers/xen/core/pci.c
index 2710c18..3fd5167 100644
--- a/drivers/xen/core/pci.c
+++ b/drivers/xen/core/pci.c
@@ -12,7 +12,7 @@ static int (*pci_bus_remove)(struct device *dev);
 
 static int pci_bus_probe_wrapper(struct device *dev)
 {
-	int r;
+	int r, r1;
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	struct physdev_manage_pci manage_pci;
 	manage_pci.bus = pci_dev->bus->number;
@@ -23,16 +23,19 @@ static int pci_bus_probe_wrapper(struct device *dev)
 		return r;
 
 	r = pci_bus_probe(dev);
-	if (r)
-		WARN_ON(HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
-					      &manage_pci));
+	if (r) {
+		r1 = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
+					      &manage_pci);
+		if (r1 && r1 != -ENOSYS)
+			WARN_ON(1);
+	}
 
 	return r;
 }
 
 static int pci_bus_remove_wrapper(struct device *dev)
 {
-	int r;
+	int r, r1;
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	struct physdev_manage_pci manage_pci;
 	manage_pci.bus = pci_dev->bus->number;
@@ -41,8 +44,11 @@ static int pci_bus_remove_wrapper(struct device *dev)
 	r = pci_bus_remove(dev);
 	/* dev and pci_dev are no longer valid!! */
 
-	WARN_ON(HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
-		&manage_pci));
+	r1 = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
+		&manage_pci);
+	if (r1 && r1 != -ENOSYS)
+		WARN_ON(1);
+
 	return r;
 }