diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index de7a747..72e267f 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -382,6 +382,7 @@ found:
 	iov->nres = nres;
 	iov->ctrl = ctrl;
 	iov->total_VFs = total;
+	atomic_set(&iov->VFs_assigned_cnt, 0);
 	iov->offset = offset;
 	iov->stride = stride;
 	iov->pgsz = pgsz;
@@ -603,45 +604,51 @@ int pci_num_vf(struct pci_dev *dev)
 EXPORT_SYMBOL_GPL(pci_num_vf);
 
 /**
- * pci_vfs_assigned - returns number of VFs are assigned to a guest
- * @dev: the PCI device
+ * pci_vfs_assigned - returns number of VFs are assigned to VM
+ * @dev: the physical PCI device that contains the VFs.
  *
- * Returns number of VFs belonging to this device that are assigned to a guest.
+ * Returns number of VFs belonging to this device that are assigned to VM.
  * If device is not a physical function returns 0.
  */
 int pci_vfs_assigned(struct pci_dev *dev)
 {
-	struct pci_dev *vfdev;
-	unsigned int vfs_assigned = 0;
-	unsigned short dev_id;
-
-	/* only search if we are a PF */
 	if (!dev->is_physfn)
 		return 0;
+	if (dev->sriov)
+		return atomic_read(&dev->sriov->VFs_assigned_cnt);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 
-	/*
-	 * determine the device ID for the VFs, the vendor ID will be the
-	 * same as the PF so there is no need to check for that one
-	 */
-	pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
-
-	/* loop through all the VFs to see if we own any that are assigned */
-	vfdev = pci_get_device(dev->vendor, dev_id, NULL);
-	while (vfdev) {
-		/*
-		 * It is considered assigned if it is a virtual function with
-		 * our dev as the physical function and the assigned bit is set
-		 */
-		if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
-		    (vfdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED))
-			vfs_assigned++;
-
-		vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
-	}
+/**
+ * pci_sriov_assign_device - assign device to VM
+ * @pdev: the device to be assigned.
+ */
+void pci_sriov_assign_device(struct pci_dev *pdev)
+{
+	pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
+	if (pdev->is_virtfn && !pdev->is_physfn)
+		if (pdev->physfn)
+			if (pdev->physfn->sriov)
+				atomic_inc(&pdev->physfn->sriov->
+						VFs_assigned_cnt);
+}
+EXPORT_SYMBOL_GPL(pci_sriov_assign_device);
 
-	return vfs_assigned;
+/**
+ * pci_sriov_deassign_device - deasign device from VM
+ * @pdev: the device to be deassigned.
+ */
+void pci_sriov_deassign_device(struct pci_dev *pdev)
+{
+	pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+	if (pdev->is_virtfn && !pdev->is_physfn)
+		if (pdev->physfn)
+			if (pdev->physfn->sriov)
+				atomic_dec(&pdev->physfn->sriov->
+						VFs_assigned_cnt);
 }
-EXPORT_SYMBOL_GPL(pci_vfs_assigned);
+EXPORT_SYMBOL_GPL(pci_sriov_deassign_device);
 
 /**
  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6bd0822..d17bda2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -235,6 +235,7 @@ struct pci_sriov {
 	u32 pgsz;		/* page size for BAR alignment */
 	u8 link;		/* Function Dependency Link */
 	u16 driver_max_VFs;	/* max num VFs driver supports */
+	atomic_t VFs_assigned_cnt; /* counter of VFs assigned to VM */
 	struct pci_dev *dev;	/* lowest numbered PF */
 	struct pci_dev *self;	/* this PF */
 	struct mutex lock;	/* lock for VF bus */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index aab57b4..5cf6833 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1601,6 +1601,8 @@ int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 void pci_disable_sriov(struct pci_dev *dev);
 int pci_num_vf(struct pci_dev *dev);
 int pci_vfs_assigned(struct pci_dev *dev);
+void pci_sriov_assign_device(struct pci_dev *dev);
+void pci_sriov_deassign_device(struct pci_dev *dev);
 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
 int pci_sriov_get_totalvfs(struct pci_dev *dev);
 #else
@@ -1610,6 +1612,8 @@ 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)
 { return 0; }
+static inline void pci_sriov_assign_device(struct pci_dev *dev) { }
+static inline void pci_sriov_deassign_device(struct pci_dev *dev) { }
 static inline int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 { return 0; }
 static inline int pci_sriov_get_totalvfs(struct pci_dev *dev)
