pciback: Make PV PCI Hotplug Work with BACKEND_PASS Option

diff -r 14b987774233 -r 37f041c10fcb drivers/xen/pciback/passthrough.c
@@ -47,6 +47,8 @@ int pciback_add_pci_dev(struct pciback_d
 	struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
 	struct pci_dev_entry *dev_entry;
 	unsigned long flags;
+	unsigned int domain, bus, devfn;
+	int err;
 
 	dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
 	if (!dev_entry)

@@ -57,9 +59,13 @@ int pciback_add_pci_dev(struct pciback_d
 	list_add_tail(&dev_entry->list, &dev_data->dev_list);
 	spin_unlock_irqrestore(&dev_data->lock, flags);
 
-	/* TODO: Publish virtual domain:bus:slot.func here. */
+	/* Publish this device. */
+	domain = (unsigned int)pci_domain_nr(dev->bus);
+	bus = (unsigned int)dev->bus->number;
+	devfn = dev->devfn;
+	err = publish_cb(pdev, domain, bus, devfn, devid);
 
-	return 0;
+	return err;
 }
 
 void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev)

diff -r 14b987774233 -r 37f041c10fcb drivers/xen/pciback/xenbus.c
@@ -348,7 +348,6 @@ static int pciback_reconfigure(struct pc
 			substate = XenbusStateUnknown;
 
 		switch (substate) {
-		/* case XenbusStateUnknown: */
 		case XenbusStateInitialising:
 			dev_dbg(&pdev->xdev->dev, "Attaching dev-%d ...\n", i);
 

@@ -382,10 +381,14 @@ static int pciback_reconfigure(struct pc
 			if (err)
 				goto out;
 
-			/* TODO: if we are to support multiple pci roots
-			 * (CONFIG_XEN_PCIDEV_BACKEND_PASS), publish newly
-			 * added root here.
-			 */
+			/* Publish pci roots. */
+			err = pciback_publish_pci_roots(pdev, pciback_publish_pci_root);
+			if (err) {
+				xenbus_dev_fatal(pdev->xdev, err,
+						 "Error while publish PCI root"
+						 "buses for frontend");
+				goto out;
+			}
 
 			err = xenbus_printf(XBT_NIL, pdev->xdev->nodename,
 					    state_str, "%d",

@@ -431,10 +434,11 @@ static int pciback_reconfigure(struct pc
 			if(err)
 				goto out;
 
-			/* TODO: if we are to support multiple pci roots
-			 * (CONFIG_XEN_PCIDEV_BACKEND_PASS), remove unnecessary
-			 * root here.
+			/* TODO: If at some point we implement support for pci
+			 * root hot-remove on pcifront side, we'll need to
+			 * remove unnecessary xenstore nodes of pci roots here.
 			 */
+
 			break;
 
 		default: