Merge tag 'stable/for-linus-3.10-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen fixes from Konrad Rzeszutek Wilk:
 - Use proper error paths
 - Clean up APIC IPI usage (incorrect arguments)
 - Delay XenBus frontend resume is backend (xenstored) is not running
 - Fix build error with various combinations of CONFIG_

* tag 'stable/for-linus-3.10-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xenbus_client.c: correct exit path for xenbus_map_ring_valloc_hvm
  xen-pciback: more uses of cached MSI-X capability offset
  xen: Clean up apic ipi interface
  xenbus: save xenstore local status for later use
  xenbus: delay xenbus frontend resume if xenstored is not running
  xmem/tmem: fix 'undefined variable' build error.

arch/x86/xen/smp.c

@@ -576,24 +576,22 @@ void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
 {
 	unsigned cpu;
 	unsigned int this_cpu = smp_processor_id();
+	int xen_vector = xen_map_vector(vector);
 
-	if (!(num_online_cpus() > 1))
+	if (!(num_online_cpus() > 1) || (xen_vector < 0))
 		return;
 
 	for_each_cpu_and(cpu, mask, cpu_online_mask) {
 		if (this_cpu == cpu)
 			continue;
 
-		xen_smp_send_call_function_single_ipi(cpu);
+		xen_send_IPI_one(cpu, xen_vector);
 	}
 }
 
 void xen_send_IPI_allbutself(int vector)
 {
-	int xen_vector = xen_map_vector(vector);
-
-	if (xen_vector >= 0)
-		xen_send_IPI_mask_allbutself(cpu_online_mask, xen_vector);
+	xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
 }
 
 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)

arch/x86/xen/smp.h

@@ -5,7 +5,6 @@ extern void xen_send_IPI_mask(const struct cpumask *mask,
 extern void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
 				int vector);
 extern void xen_send_IPI_allbutself(int vector);
-extern void physflat_send_IPI_allbutself(int vector);
 extern void xen_send_IPI_all(int vector);
 extern void xen_send_IPI_self(int vector);
 

drivers/xen/tmem.c

@@ -41,6 +41,8 @@ module_param(selfballooning, bool, S_IRUGO);
 #ifdef CONFIG_FRONTSWAP
 static bool frontswap __read_mostly = true;
 module_param(frontswap, bool, S_IRUGO);
+#else /* CONFIG_FRONTSWAP */
+#define frontswap (0)
 #endif /* CONFIG_FRONTSWAP */
 
 #ifdef CONFIG_XEN_SELFBALLOONING

drivers/xen/xen-pciback/pci_stub.c

@@ -106,7 +106,7 @@ static void pcistub_device_release(struct kref *kref)
 	else
 		pci_restore_state(dev);
 
-	if (pci_find_capability(dev, PCI_CAP_ID_MSIX)) {
+	if (dev->msix_cap) {
 		struct physdev_pci_device ppdev = {
 			.seg = pci_domain_nr(dev->bus),
 			.bus = dev->bus->number,
@@ -371,7 +371,7 @@ static int pcistub_init_device(struct pci_dev *dev)
 	if (err)
 		goto config_release;
 
-	if (pci_find_capability(dev, PCI_CAP_ID_MSIX)) {
+	if (dev->msix_cap) {
 		struct physdev_pci_device ppdev = {
 			.seg = pci_domain_nr(dev->bus),
 			.bus = dev->bus->number,

drivers/xen/xenbus/xenbus_client.c

@@ -534,7 +534,7 @@ static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
 
 	err = xenbus_map_ring(dev, gnt_ref, &node->handle, addr);
 	if (err)
-		goto out_err;
+		goto out_err_free_ballooned_pages;
 
 	spin_lock(&xenbus_valloc_lock);
 	list_add(&node->next, &xenbus_valloc_pages);
@@ -543,8 +543,9 @@ static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
 	*vaddr = addr;
 	return 0;
 
- out_err:
+ out_err_free_ballooned_pages:
 	free_xenballooned_pages(1, &node->page);
+ out_err:
 	kfree(node);
 	return err;
 }

drivers/xen/xenbus/xenbus_comms.h

@@ -45,6 +45,7 @@ int xb_wait_for_data_to_read(void);
 int xs_input_avail(void);
 extern struct xenstore_domain_interface *xen_store_interface;
 extern int xen_store_evtchn;
+extern enum xenstore_init xen_store_domain_type;
 
 extern const struct file_operations xen_xenbus_fops;
 

drivers/xen/xenbus/xenbus_probe.c

@@ -69,6 +69,9 @@ EXPORT_SYMBOL_GPL(xen_store_evtchn);
 struct xenstore_domain_interface *xen_store_interface;
 EXPORT_SYMBOL_GPL(xen_store_interface);
 
+enum xenstore_init xen_store_domain_type;
+EXPORT_SYMBOL_GPL(xen_store_domain_type);
+
 static unsigned long xen_store_mfn;
 
 static BLOCKING_NOTIFIER_HEAD(xenstore_chain);
@@ -719,17 +722,11 @@ static int __init xenstored_local_init(void)
 	return err;
 }
 
-enum xenstore_init {
-	UNKNOWN,
-	PV,
-	HVM,
-	LOCAL,
-};
 static int __init xenbus_init(void)
 {
 	int err = 0;
-	enum xenstore_init usage = UNKNOWN;
 	uint64_t v = 0;
+	xen_store_domain_type = XS_UNKNOWN;
 
 	if (!xen_domain())
 		return -ENODEV;
@@ -737,29 +734,29 @@ static int __init xenbus_init(void)
 	xenbus_ring_ops_init();
 
 	if (xen_pv_domain())
-		usage = PV;
+		xen_store_domain_type = XS_PV;
 	if (xen_hvm_domain())
-		usage = HVM;
+		xen_store_domain_type = XS_HVM;
 	if (xen_hvm_domain() && xen_initial_domain())
-		usage = LOCAL;
+		xen_store_domain_type = XS_LOCAL;
 	if (xen_pv_domain() && !xen_start_info->store_evtchn)
-		usage = LOCAL;
+		xen_store_domain_type = XS_LOCAL;
 	if (xen_pv_domain() && xen_start_info->store_evtchn)
 		xenstored_ready = 1;
 
-	switch (usage) {
-	case LOCAL:
+	switch (xen_store_domain_type) {
+	case XS_LOCAL:
 		err = xenstored_local_init();
 		if (err)
 			goto out_error;
 		xen_store_interface = mfn_to_virt(xen_store_mfn);
 		break;
-	case PV:
+	case XS_PV:
 		xen_store_evtchn = xen_start_info->store_evtchn;
 		xen_store_mfn = xen_start_info->store_mfn;
 		xen_store_interface = mfn_to_virt(xen_store_mfn);
 		break;
-	case HVM:
+	case XS_HVM:
 		err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
 		if (err)
 			goto out_error;

drivers/xen/xenbus/xenbus_probe.h

@@ -47,6 +47,13 @@ struct xen_bus_type {
 	struct bus_type bus;
 };
 
+enum xenstore_init {
+	XS_UNKNOWN,
+	XS_PV,
+	XS_HVM,
+	XS_LOCAL,
+};
+
 extern struct device_attribute xenbus_dev_attrs[];
 
 extern int xenbus_match(struct device *_dev, struct device_driver *_drv);

drivers/xen/xenbus/xenbus_probe_frontend.c

@@ -29,6 +29,8 @@
 #include "xenbus_probe.h"
 
 
+static struct workqueue_struct *xenbus_frontend_wq;
+
 /* device/<type>/<id> => <type>-<id> */
 static int frontend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename)
 {
@@ -89,9 +91,40 @@ static void backend_changed(struct xenbus_watch *watch,
 	xenbus_otherend_changed(watch, vec, len, 1);
 }
 
+static void xenbus_frontend_delayed_resume(struct work_struct *w)
+{
+	struct xenbus_device *xdev = container_of(w, struct xenbus_device, work);
+
+	xenbus_dev_resume(&xdev->dev);
+}
+
+static int xenbus_frontend_dev_resume(struct device *dev)
+{
+	/*
+	 * If xenstored is running in this domain, we cannot access the backend
+	 * state at the moment, so we need to defer xenbus_dev_resume
+	 */
+	if (xen_store_domain_type == XS_LOCAL) {
+		struct xenbus_device *xdev = to_xenbus_device(dev);
+
+		if (!xenbus_frontend_wq) {
+			pr_err("%s: no workqueue to process delayed resume\n",
+			       xdev->nodename);
+			return -EFAULT;
+		}
+
+		INIT_WORK(&xdev->work, xenbus_frontend_delayed_resume);
+		queue_work(xenbus_frontend_wq, &xdev->work);
+
+		return 0;
+	}
+
+	return xenbus_dev_resume(dev);
+}
+
 static const struct dev_pm_ops xenbus_pm_ops = {
 	.suspend	= xenbus_dev_suspend,
-	.resume		= xenbus_dev_resume,
+	.resume		= xenbus_frontend_dev_resume,
 	.freeze		= xenbus_dev_suspend,
 	.thaw		= xenbus_dev_cancel,
 	.restore	= xenbus_dev_resume,
@@ -440,6 +473,8 @@ static int __init xenbus_probe_frontend_init(void)
 
 	register_xenstore_notifier(&xenstore_notifier);
 
+	xenbus_frontend_wq = create_workqueue("xenbus_frontend");
+
 	return 0;
 }
 subsys_initcall(xenbus_probe_frontend_init);

include/xen/xenbus.h

@@ -70,6 +70,7 @@ struct xenbus_device {
 	struct device dev;
 	enum xenbus_state state;
 	struct completion down;
+	struct work_struct work;
 };
 
 static inline struct xenbus_device *to_xenbus_device(struct device *dev)