Merge tag 'for-linus-5.13b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - a fix for a boot regression when running as PV guest on hardware
   without NX support

 - a small series fixing a bug in the Xen pciback driver when
   configuring a PCI card with multiple virtual functions

* tag 'for-linus-5.13b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-pciback: reconfigure also from backend watch handler
  xen-pciback: redo VF placement in the virtual topology
  x86/Xen: swap NX determination and GDT setup on BSP

arch/x86/xen/enlighten_pv.c

@@ -1273,16 +1273,16 @@ asmlinkage __visible void __init xen_start_kernel(void)
 	/* Get mfn list */
 	xen_build_dynamic_phys_to_machine();
 
+	/* Work out if we support NX */
+	get_cpu_cap(&boot_cpu_data);
+	x86_configure_nx();
+
 	/*
 	 * Set up kernel GDT and segment registers, mainly so that
 	 * -fstack-protector code can be executed.
 	 */
 	xen_setup_gdt(0);
 
-	/* Work out if we support NX */
-	get_cpu_cap(&boot_cpu_data);
-	x86_configure_nx();
-
 	/* Determine virtual and physical address sizes */
 	get_cpu_address_sizes(&boot_cpu_data);
 

drivers/xen/xen-pciback/vpci.c

@@ -70,7 +70,7 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
 				   struct pci_dev *dev, int devid,
 				   publish_pci_dev_cb publish_cb)
 {
-	int err = 0, slot, func = -1;
+	int err = 0, slot, func = PCI_FUNC(dev->devfn);
 	struct pci_dev_entry *t, *dev_entry;
 	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
 
@@ -95,22 +95,25 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
 
 	/*
 	 * Keep multi-function devices together on the virtual PCI bus, except
-	 * virtual functions.
+	 * that we want to keep virtual functions at func 0 on their own. They
+	 * aren't multi-function devices and hence their presence at func 0
+	 * may cause guests to not scan the other functions.
 	 */
-	if (!dev->is_virtfn) {
+	if (!dev->is_virtfn || func) {
 		for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
 			if (list_empty(&vpci_dev->dev_list[slot]))
 				continue;
 
 			t = list_entry(list_first(&vpci_dev->dev_list[slot]),
 				       struct pci_dev_entry, list);
+			if (t->dev->is_virtfn && !PCI_FUNC(t->dev->devfn))
+				continue;
 
 			if (match_slot(dev, t->dev)) {
 				dev_info(&dev->dev, "vpci: assign to virtual slot %d func %d\n",
-					 slot, PCI_FUNC(dev->devfn));
+					 slot, func);
 				list_add_tail(&dev_entry->list,
 					      &vpci_dev->dev_list[slot]);
-				func = PCI_FUNC(dev->devfn);
 				goto unlock;
 			}
 		}
@@ -123,7 +126,6 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
 				 slot);
 			list_add_tail(&dev_entry->list,
 				      &vpci_dev->dev_list[slot]);
-			func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
 			goto unlock;
 		}
 	}

drivers/xen/xen-pciback/xenbus.c

@@ -359,7 +359,8 @@ static int xen_pcibk_publish_pci_root(struct xen_pcibk_device *pdev,
 	return err;
 }
 
-static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
+static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev,
+				 enum xenbus_state state)
 {
 	int err = 0;
 	int num_devs;
@@ -373,9 +374,7 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
 	dev_dbg(&pdev->xdev->dev, "Reconfiguring device ...\n");
 
 	mutex_lock(&pdev->dev_lock);
-	/* Make sure we only reconfigure once */
-	if (xenbus_read_driver_state(pdev->xdev->nodename) !=
-	    XenbusStateReconfiguring)
+	if (xenbus_read_driver_state(pdev->xdev->nodename) != state)
 		goto out;
 
 	err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d",
@@ -500,6 +499,10 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
 		}
 	}
 
+	if (state != XenbusStateReconfiguring)
+		/* Make sure we only reconfigure once. */
+		goto out;
+
 	err = xenbus_switch_state(pdev->xdev, XenbusStateReconfigured);
 	if (err) {
 		xenbus_dev_fatal(pdev->xdev, err,
@@ -525,7 +528,7 @@ static void xen_pcibk_frontend_changed(struct xenbus_device *xdev,
 		break;
 
 	case XenbusStateReconfiguring:
-		xen_pcibk_reconfigure(pdev);
+		xen_pcibk_reconfigure(pdev, XenbusStateReconfiguring);
 		break;
 
 	case XenbusStateConnected:
@@ -664,6 +667,15 @@ static void xen_pcibk_be_watch(struct xenbus_watch *watch,
 		xen_pcibk_setup_backend(pdev);
 		break;
 
+	case XenbusStateInitialised:
+		/*
+		 * We typically move to Initialised when the first device was
+		 * added. Hence subsequent devices getting added may need
+		 * reconfiguring.
+		 */
+		xen_pcibk_reconfigure(pdev, XenbusStateInitialised);
+		break;
+
 	default:
 		break;
 	}