diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 54ec841e3e18cd53d21f7da88ca6f697cb8d68f2..4fe91d7410529e93ed1595c4e8de7d2e08eaf9d5 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -17,6 +17,8 @@
 
 #define VIRTFN_ID_LEN	17	/* "virtfn%u\0" for 2^32 - 1 */
 
+static DEFINE_MUTEX(pci_sriov_numvfs_lock);
+
 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
 {
 	if (!dev->is_physfn)
@@ -358,6 +360,16 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 	return rc;
 }
 
+int pci_iov_add_virtfn_locked(struct pci_dev *dev, int id)
+{
+	int rc;
+
+	mutex_lock(&pci_sriov_numvfs_lock);
+	rc = pci_iov_add_virtfn(dev, id);
+	mutex_unlock(&pci_sriov_numvfs_lock);
+	return rc;
+}
+
 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 {
 	char buf[VIRTFN_ID_LEN];
@@ -390,6 +402,13 @@ void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 	}
 }
 
+void pci_iov_remove_virtfn_locked(struct pci_dev *dev, int id)
+{
+	mutex_lock(&pci_sriov_numvfs_lock);
+	pci_iov_remove_virtfn(dev, id);
+	mutex_unlock(&pci_sriov_numvfs_lock);
+}
+
 static ssize_t sriov_totalvfs_show(struct device *dev,
 				   struct device_attribute *attr,
 				   char *buf)
@@ -591,14 +610,21 @@ static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
 		return 0;
 
 	for (i = 0; i < num_vfs; i++) {
-		rc = pci_iov_add_virtfn(dev, i);
+		if (dev->bus->number != pci_iov_virtfn_bus(dev, i))
+			rc = pci_iov_add_virtfn_locked(dev, i);
+		else
+			rc = pci_iov_add_virtfn(dev, i);
 		if (rc)
 			goto failed;
 	}
 	return 0;
 failed:
-	while (i--)
-		pci_iov_remove_virtfn(dev, i);
+	while (i--) {
+		if (dev->bus->number != pci_iov_virtfn_bus(dev, i))
+			pci_iov_remove_virtfn_locked(dev, i);
+		else
+			pci_iov_remove_virtfn(dev, i);
+	}
 
 	return rc;
 }
@@ -718,8 +744,12 @@ static void sriov_del_vfs(struct pci_dev *dev)
 	struct pci_sriov *iov = dev->sriov;
 	int i;
 
-	for (i = 0; i < iov->num_VFs; i++)
-		pci_iov_remove_virtfn(dev, i);
+	for (i = 0; i < iov->num_VFs; i++) {
+		if (dev->bus->number != pci_iov_virtfn_bus(dev, i))
+			pci_iov_remove_virtfn_locked(dev, i);
+		else
+			pci_iov_remove_virtfn(dev, i);
+	}
 }
 
 static void sriov_disable(struct pci_dev *dev)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9b1b2265da1f7e707c3b0c77c5c6cded6028725f..96fe2624b8cee7d753053889de4e101e497c89c8 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2376,7 +2376,9 @@ void pci_disable_sriov(struct pci_dev *dev);
 
 int pci_iov_sysfs_link(struct pci_dev *dev, struct pci_dev *virtfn, int id);
 int pci_iov_add_virtfn(struct pci_dev *dev, int id);
+int pci_iov_add_virtfn_locked(struct pci_dev *dev, int id);
 void pci_iov_remove_virtfn(struct pci_dev *dev, int id);
+void pci_iov_remove_virtfn_locked(struct pci_dev *dev, int id);
 int pci_num_vf(struct pci_dev *dev);
 int pci_vfs_assigned(struct pci_dev *dev);
 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
@@ -2422,8 +2424,14 @@ static inline int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 {
 	return -ENOSYS;
 }
+static inline int pci_iov_add_virtfn_locked(struct pci_dev *dev, int id)
+{
+	return -ENOSYS;
+}
 static inline void pci_iov_remove_virtfn(struct pci_dev *dev,
 					 int id) { }
+static inline void pci_iov_remove_virtfn_locked(struct pci_dev *dev,
+						int id) { }
 static inline void pci_disable_sriov(struct pci_dev *dev) { }
 static inline int pci_num_vf(struct pci_dev *dev) { return 0; }
 static inline int pci_vfs_assigned(struct pci_dev *dev)