Merge tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "Xen features and fixes for 4.10

  These are some fixes, a move of some arm related headers to share them
  between arm and arm64 and a series introducing a helper to make code
  more readable.

  The most notable change is David stepping down as maintainer of the
  Xen hypervisor interface. This results in me sending you the pull
  requests for Xen related code from now on"

* tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits)
  xen/balloon: Only mark a page as managed when it is released
  xenbus: fix deadlock on writes to /proc/xen/xenbus
  xen/scsifront: don't request a slot on the ring until request is ready
  xen/x86: Increase xen_e820_map to E820_X_MAX possible entries
  x86: Make E820_X_MAX unconditionally larger than E820MAX
  xen/pci: Bubble up error and fix description.
  xen: xenbus: set error code on failure
  xen: set error code on failures
  arm/xen: Use alloc_percpu rather than __alloc_percpu
  arm/arm64: xen: Move shared architecture headers to include/xen/arm
  xen/events: use xen_vcpu_id mapping for EVTCHNOP_status
  xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing
  xen-scsifront: Add a missing call to kfree
  MAINTAINERS: update XEN HYPERVISOR INTERFACE
  xenfs: Use proc_create_mount_point() to create /proc/xen
  xen-platform: use builtin_pci_driver
  xen-netback: fix error handling output
  xen: make use of xenbus_read_unsigned() in xenbus
  xen: make use of xenbus_read_unsigned() in xen-pciback
  xen: make use of xenbus_read_unsigned() in xen-fbfront
  ...

drivers/net/xen-netback/xenbus.c

@@ -785,12 +785,9 @@ static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
 	struct xenvif *vif = container_of(watch, struct xenvif,
 					  mcast_ctrl_watch);
 	struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
-	int val;
 
-	if (xenbus_scanf(XBT_NIL, dev->otherend,
-			 "request-multicast-control", "%d", &val) < 0)
-		val = 0;
-	vif->multicast_control = !!val;
+	vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
+					"request-multicast-control", 0);
 }
 
 static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
@@ -934,14 +931,11 @@ static void connect(struct backend_info *be)
 	/* Check whether the frontend requested multiple queues
 	 * and read the number requested.
 	 */
-	err = xenbus_scanf(XBT_NIL, dev->otherend,
-			   "multi-queue-num-queues",
-			   "%u", &requested_num_queues);
-	if (err < 0) {
-		requested_num_queues = 1; /* Fall back to single queue */
-	} else if (requested_num_queues > xenvif_max_queues) {
+	requested_num_queues = xenbus_read_unsigned(dev->otherend,
+					"multi-queue-num-queues", 1);
+	if (requested_num_queues > xenvif_max_queues) {
 		/* buggy or malicious guest */
-		xenbus_dev_fatal(dev, err,
+		xenbus_dev_fatal(dev, -EINVAL,
 				 "guest requested %u queues, exceeding the maximum of %u.",
 				 requested_num_queues, xenvif_max_queues);
 		return;
@@ -1134,7 +1128,7 @@ static int read_xenbus_vif_flags(struct backend_info *be)
 	struct xenvif *vif = be->vif;
 	struct xenbus_device *dev = be->dev;
 	unsigned int rx_copy;
-	int err, val;
+	int err;
 
 	err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
 			   &rx_copy);
@@ -1150,10 +1144,7 @@ static int read_xenbus_vif_flags(struct backend_info *be)
 	if (!rx_copy)
 		return -EOPNOTSUPP;
 
-	if (xenbus_scanf(XBT_NIL, dev->otherend,
-			 "feature-rx-notify", "%d", &val) < 0)
-		val = 0;
-	if (!val) {
+	if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
 		/* - Reduce drain timeout to poll more frequently for
 		 *   Rx requests.
 		 * - Disable Rx stall detection.
@@ -1162,34 +1153,21 @@ static int read_xenbus_vif_flags(struct backend_info *be)
 		be->vif->stall_timeout = 0;
 	}
 
-	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
-			 "%d", &val) < 0)
-		val = 0;
-	vif->can_sg = !!val;
+	vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
 
 	vif->gso_mask = 0;
 
-	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
-			 "%d", &val) < 0)
-		val = 0;
-	if (val)
+	if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
 		vif->gso_mask |= GSO_BIT(TCPV4);
 
-	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
-			 "%d", &val) < 0)
-		val = 0;
-	if (val)
+	if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
 		vif->gso_mask |= GSO_BIT(TCPV6);
 
-	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
-			 "%d", &val) < 0)
-		val = 0;
-	vif->ip_csum = !val;
+	vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
+					     "feature-no-csum-offload", 0);
 
-	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-ipv6-csum-offload",
-			 "%d", &val) < 0)
-		val = 0;
-	vif->ipv6_csum = !!val;
+	vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
+						"feature-ipv6-csum-offload", 0);
 
 	return 0;
 }