Merge tag 'for-linus-4.9-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from David Vrabel:
 "xen features and fixes for 4.9:

   - switch to new CPU hotplug mechanism

   - support driver_override in pciback

   - require vector callback for HVM guests (the alternate mechanism via
     the platform device has been broken for ages)"

* tag 'for-linus-4.9-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/x86: Update topology map for PV VCPUs
  xen/x86: Initialize per_cpu(xen_vcpu, 0) a little earlier
  xen/pciback: support driver_override
  xen/pciback: avoid multiple entries in slot list
  xen/pciback: simplify pcistub device handling
  xen: Remove event channel notification through Xen PCI platform device
  xen/events: Convert to hotplug state machine
  xen/x86: Convert to hotplug state machine
  x86/xen: add missing \n at end of printk warning message
  xen/grant-table: Use kmalloc_array() in arch_gnttab_valloc()
  xen: Make VPMU init message look less scary
  xen: rename xen_pmu_init() in sys-hypervisor.c
  hotplug: Prevent alloc/free of irq descriptors during cpu up/down (again)
  xen/x86: Move irq allocation from Xen smp_op.cpu_up()

arch/x86/include/asm/xen/events.h

@@ -20,15 +20,4 @@ static inline int xen_irqs_disabled(struct pt_regs *regs)
 /* No need for a barrier -- XCHG is a barrier on x86. */
 #define xchg_xen_ulong(ptr, val) xchg((ptr), (val))
 
-extern int xen_have_vector_callback;
-
-/*
- * Events delivered via platform PCI interrupts are always
- * routed to vcpu 0 and hence cannot be rebound.
- */
-static inline bool xen_support_evtchn_rebind(void)
-{
-	return (!xen_hvm_domain() || xen_have_vector_callback);
-}
-
 #endif /* _ASM_X86_XEN_EVENTS_H */

arch/x86/pci/xen.c

@@ -456,7 +456,7 @@ void __init xen_msi_init(void)
 
 int __init pci_xen_hvm_init(void)
 {
-	if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
+	if (!xen_feature(XENFEAT_hvm_pirqs))
 		return 0;
 
 #ifdef CONFIG_ACPI

arch/x86/xen/enlighten.c

@@ -137,8 +137,10 @@ struct shared_info xen_dummy_shared_info;
 void *xen_initial_gdt;
 
 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
-__read_mostly int xen_have_vector_callback;
-EXPORT_SYMBOL_GPL(xen_have_vector_callback);
+
+static int xen_cpu_up_prepare(unsigned int cpu);
+static int xen_cpu_up_online(unsigned int cpu);
+static int xen_cpu_dead(unsigned int cpu);
 
 /*
  * Point at some empty memory to start with. We map the real shared_info
@@ -1519,10 +1521,7 @@ static void __init xen_pvh_early_guest_init(void)
 	if (!xen_feature(XENFEAT_auto_translated_physmap))
 		return;
 
-	if (!xen_feature(XENFEAT_hvm_callback_vector))
-		return;
-
-	xen_have_vector_callback = 1;
+	BUG_ON(!xen_feature(XENFEAT_hvm_callback_vector));
 
 	xen_pvh_early_cpu_init(0, false);
 	xen_pvh_set_cr_flags(0);
@@ -1538,6 +1537,24 @@ static void __init xen_dom0_set_legacy_features(void)
 	x86_platform.legacy.rtc = 1;
 }
 
+static int xen_cpuhp_setup(void)
+{
+	int rc;
+
+	rc = cpuhp_setup_state_nocalls(CPUHP_XEN_PREPARE,
+				       "XEN_HVM_GUEST_PREPARE",
+				       xen_cpu_up_prepare, xen_cpu_dead);
+	if (rc >= 0) {
+		rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+					       "XEN_HVM_GUEST_ONLINE",
+					       xen_cpu_up_online, NULL);
+		if (rc < 0)
+			cpuhp_remove_state_nocalls(CPUHP_XEN_PREPARE);
+	}
+
+	return rc >= 0 ? 0 : rc;
+}
+
 /* First C function to be called on Xen boot */
 asmlinkage __visible void __init xen_start_kernel(void)
 {
@@ -1639,6 +1656,8 @@ asmlinkage __visible void __init xen_start_kernel(void)
 	   possible map and a non-dummy shared_info. */
 	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
 
+	WARN_ON(xen_cpuhp_setup());
+
 	local_irq_disable();
 	early_boot_irqs_disabled = true;
 
@@ -1819,31 +1838,54 @@ static void __init init_hvm_pv_info(void)
 	xen_domain_type = XEN_HVM_DOMAIN;
 }
 
-static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action,
-			      void *hcpu)
+static int xen_cpu_up_prepare(unsigned int cpu)
 {
-	int cpu = (long)hcpu;
-	switch (action) {
-	case CPU_UP_PREPARE:
+	int rc;
+
+	if (xen_hvm_domain()) {
+		/*
+		 * This can happen if CPU was offlined earlier and
+		 * offlining timed out in common_cpu_die().
+		 */
+		if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
+			xen_smp_intr_free(cpu);
+			xen_uninit_lock_cpu(cpu);
+		}
+
 		if (cpu_acpi_id(cpu) != U32_MAX)
 			per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
 		else
 			per_cpu(xen_vcpu_id, cpu) = cpu;
 		xen_vcpu_setup(cpu);
-		if (xen_have_vector_callback) {
-			if (xen_feature(XENFEAT_hvm_safe_pvclock))
-				xen_setup_timer(cpu);
-		}
-		break;
-	default:
-		break;
 	}
-	return NOTIFY_OK;
+
+	if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
+		xen_setup_timer(cpu);
+
+	rc = xen_smp_intr_init(cpu);
+	if (rc) {
+		WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
+		     cpu, rc);
+		return rc;
+	}
+	return 0;
 }
 
-static struct notifier_block xen_hvm_cpu_notifier = {
-	.notifier_call	= xen_hvm_cpu_notify,
-};
+static int xen_cpu_dead(unsigned int cpu)
+{
+	xen_smp_intr_free(cpu);
+
+	if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
+		xen_teardown_timer(cpu);
+
+	return 0;
+}
+
+static int xen_cpu_up_online(unsigned int cpu)
+{
+	xen_init_lock_cpu(cpu);
+	return 0;
+}
 
 #ifdef CONFIG_KEXEC_CORE
 static void xen_hvm_shutdown(void)
@@ -1871,10 +1913,10 @@ static void __init xen_hvm_guest_init(void)
 
 	xen_panic_handler_init();
 
-	if (xen_feature(XENFEAT_hvm_callback_vector))
-		xen_have_vector_callback = 1;
+	BUG_ON(!xen_feature(XENFEAT_hvm_callback_vector));
+
 	xen_hvm_smp_init();
-	register_cpu_notifier(&xen_hvm_cpu_notifier);
+	WARN_ON(xen_cpuhp_setup());
 	xen_unplug_emulated_devices();
 	x86_init.irqs.intr_init = xen_init_IRQ;
 	xen_hvm_init_time_ops();
@@ -1910,7 +1952,7 @@ bool xen_hvm_need_lapic(void)
 		return false;
 	if (!xen_hvm_domain())
 		return false;
-	if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
+	if (xen_feature(XENFEAT_hvm_pirqs))
 		return false;
 	return true;
 }

arch/x86/xen/grant-table.c

@@ -89,7 +89,7 @@ void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
 
 static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
 {
-	area->ptes = kmalloc(sizeof(pte_t *) * nr_frames, GFP_KERNEL);
+	area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL);
 	if (area->ptes == NULL)
 		return -ENOMEM;
 

arch/x86/xen/platform-pci-unplug.c

@@ -61,7 +61,7 @@ static int check_platform_magic(void)
 		}
 		break;
 	default:
-		printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version");
+		printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version\n");
 		return XEN_PLATFORM_ERR_PROTOCOL;
 	}
 

arch/x86/xen/pmu.c

@@ -547,8 +547,11 @@ void xen_pmu_init(int cpu)
 	return;
 
 fail:
-	pr_info_once("Could not initialize VPMU for cpu %d, error %d\n",
-		cpu, err);
+	if (err == -EOPNOTSUPP || err == -ENOSYS)
+		pr_info_once("VPMU disabled by hypervisor.\n");
+	else
+		pr_info_once("Could not initialize VPMU for cpu %d, error %d\n",
+			cpu, err);
 	free_pages((unsigned long)xenpmu_data, 0);
 }
 

arch/x86/xen/smp.c

@@ -87,6 +87,12 @@ static void cpu_bringup(void)
 	cpu_data(cpu).x86_max_cores = 1;
 	set_cpu_sibling_map(cpu);
 
+	/*
+	 * identify_cpu() may have set logical_pkg_id to -1 due
+	 * to incorrect phys_proc_id. Let's re-comupte it.
+	 */
+	topology_update_package_map(apic->cpu_present_to_apicid(cpu), cpu);
+
 	xen_setup_cpu_clockevents();
 
 	notify_cpu_starting(cpu);
@@ -115,7 +121,7 @@ asmlinkage __visible void cpu_bringup_and_idle(int cpu)
 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 }
 
-static void xen_smp_intr_free(unsigned int cpu)
+void xen_smp_intr_free(unsigned int cpu)
 {
 	if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
 		unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
@@ -159,7 +165,7 @@ static void xen_smp_intr_free(unsigned int cpu)
 		per_cpu(xen_pmu_irq, cpu).name = NULL;
 	}
 };
-static int xen_smp_intr_init(unsigned int cpu)
+int xen_smp_intr_init(unsigned int cpu)
 {
 	int rc;
 	char *resched_name, *callfunc_name, *debug_name, *pmu_name;
@@ -475,8 +481,6 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
 	common_cpu_up(cpu, idle);
 
 	xen_setup_runstate_info(cpu);
-	xen_setup_timer(cpu);
-	xen_init_lock_cpu(cpu);
 
 	/*
 	 * PV VCPUs are always successfully taken down (see 'while' loop
@@ -495,10 +499,6 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
 
 	xen_pmu_init(cpu);
 
-	rc = xen_smp_intr_init(cpu);
-	if (rc)
-		return rc;
-
 	rc = HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL);
 	BUG_ON(rc);
 
@@ -769,47 +769,10 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
 	xen_init_lock_cpu(0);
 }
 
-static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
-{
-	int rc;
-
-	/*
-	 * This can happen if CPU was offlined earlier and
-	 * offlining timed out in common_cpu_die().
-	 */
-	if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
-		xen_smp_intr_free(cpu);
-		xen_uninit_lock_cpu(cpu);
-	}
-
-	/*
-	 * xen_smp_intr_init() needs to run before native_cpu_up()
-	 * so that IPI vectors are set up on the booting CPU before
-	 * it is marked online in native_cpu_up().
-	*/
-	rc = xen_smp_intr_init(cpu);
-	WARN_ON(rc);
-	if (!rc)
-		rc =  native_cpu_up(cpu, tidle);
-
-	/*
-	 * We must initialize the slowpath CPU kicker _after_ the native
-	 * path has executed. If we initialized it before none of the
-	 * unlocker IPI kicks would reach the booting CPU as the booting
-	 * CPU had not set itself 'online' in cpu_online_mask. That mask
-	 * is checked when IPIs are sent (on HVM at least).
-	 */
-	xen_init_lock_cpu(cpu);
-	return rc;
-}
-
 void __init xen_hvm_smp_init(void)
 {
-	if (!xen_have_vector_callback)
-		return;
 	smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
 	smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
-	smp_ops.cpu_up = xen_hvm_cpu_up;
 	smp_ops.cpu_die = xen_cpu_die;
 	smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
 	smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;

arch/x86/xen/smp.h

@@ -1,5 +1,6 @@
 #ifndef _XEN_SMP_H
 
+#ifdef CONFIG_SMP
 extern void xen_send_IPI_mask(const struct cpumask *mask,
 			      int vector);
 extern void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
@@ -8,6 +9,18 @@ extern void xen_send_IPI_allbutself(int vector);
 extern void xen_send_IPI_all(int vector);
 extern void xen_send_IPI_self(int vector);
 
+extern int xen_smp_intr_init(unsigned int cpu);
+extern void xen_smp_intr_free(unsigned int cpu);
+
+#else /* CONFIG_SMP */
+
+static inline int xen_smp_intr_init(unsigned int cpu)
+{
+	return 0;
+}
+static inline void xen_smp_intr_free(unsigned int cpu) {}
+#endif /* CONFIG_SMP */
+
 #ifdef CONFIG_XEN_PVH
 extern void xen_pvh_early_cpu_init(int cpu, bool entry);
 #else

arch/x86/xen/time.c

@@ -432,11 +432,6 @@ static void xen_hvm_setup_cpu_clockevents(void)
 
 void __init xen_hvm_init_time_ops(void)
 {
-	/* vector callback is needed otherwise we cannot receive interrupts
-	 * on cpu > 0 and at this point we don't know how many cpus are
-	 * available */
-	if (!xen_have_vector_callback)
-		return;
 	if (!xen_feature(XENFEAT_hvm_safe_pvclock)) {
 		printk(KERN_INFO "Xen doesn't support pvclock on HVM,"
 				"disable pv timer\n");

drivers/xen/events/events_base.c

@@ -1314,9 +1314,6 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
 	if (!VALID_EVTCHN(evtchn))
 		return -1;
 
-	if (!xen_support_evtchn_rebind())
-		return -1;
-
 	/* Send future instances of this interrupt to other vcpu. */
 	bind_vcpu.port = evtchn;
 	bind_vcpu.vcpu = xen_vcpu_nr(tcpu);
@@ -1650,20 +1647,15 @@ void xen_callback_vector(void)
 {
 	int rc;
 	uint64_t callback_via;
-	if (xen_have_vector_callback) {
-		callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
-		rc = xen_set_callback_via(callback_via);
-		if (rc) {
-			pr_err("Request for Xen HVM callback vector failed\n");
-			xen_have_vector_callback = 0;
-			return;
-		}
-		pr_info("Xen HVM callback vector for event delivery is enabled\n");
-		/* in the restore case the vector has already been allocated */
-		if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
-			alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
-					xen_hvm_callback_vector);
-	}
+
+	callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
+	rc = xen_set_callback_via(callback_via);
+	BUG_ON(rc);
+	pr_info("Xen HVM callback vector for event delivery is enabled\n");
+	/* in the restore case the vector has already been allocated */
+	if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
+		alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
+				xen_hvm_callback_vector);
 }
 #else
 void xen_callback_vector(void) {}

drivers/xen/events/events_fifo.c

@@ -418,30 +418,18 @@ static int evtchn_fifo_alloc_control_block(unsigned cpu)
 	return ret;
 }
 
-static int evtchn_fifo_cpu_notification(struct notifier_block *self,
-						  unsigned long action,
-						  void *hcpu)
+static int xen_evtchn_cpu_prepare(unsigned int cpu)
 {
-	int cpu = (long)hcpu;
-	int ret = 0;
-
-	switch (action) {
-	case CPU_UP_PREPARE:
-		if (!per_cpu(cpu_control_block, cpu))
-			ret = evtchn_fifo_alloc_control_block(cpu);
-		break;
-	case CPU_DEAD:
-		__evtchn_fifo_handle_events(cpu, true);
-		break;
-	default:
-		break;
-	}
-	return ret < 0 ? NOTIFY_BAD : NOTIFY_OK;
+	if (!per_cpu(cpu_control_block, cpu))
+		return evtchn_fifo_alloc_control_block(cpu);
+	return 0;
 }
 
-static struct notifier_block evtchn_fifo_cpu_notifier = {
-	.notifier_call	= evtchn_fifo_cpu_notification,
-};
+static int xen_evtchn_cpu_dead(unsigned int cpu)
+{
+	__evtchn_fifo_handle_events(cpu, true);
+	return 0;
+}
 
 int __init xen_evtchn_fifo_init(void)
 {
@@ -456,7 +444,9 @@ int __init xen_evtchn_fifo_init(void)
 
 	evtchn_ops = &evtchn_ops_fifo;
 
-	register_cpu_notifier(&evtchn_fifo_cpu_notifier);
+	cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
+				  "CPUHP_XEN_EVTCHN_PREPARE",
+				  xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
 out:
 	put_cpu();
 	return ret;

drivers/xen/platform-pci.c

@@ -42,7 +42,6 @@
 static unsigned long platform_mmio;
 static unsigned long platform_mmio_alloc;
 static unsigned long platform_mmiolen;
-static uint64_t callback_via;
 
 static unsigned long alloc_xen_mmio(unsigned long len)
 {
@@ -55,51 +54,6 @@ static unsigned long alloc_xen_mmio(unsigned long len)
 	return addr;
 }
 
-static uint64_t get_callback_via(struct pci_dev *pdev)
-{
-	u8 pin;
-	int irq;
-
-	irq = pdev->irq;
-	if (irq < 16)
-		return irq; /* ISA IRQ */
-
-	pin = pdev->pin;
-
-	/* We don't know the GSI. Specify the PCI INTx line instead. */
-	return ((uint64_t)0x01 << 56) | /* PCI INTx identifier */
-		((uint64_t)pci_domain_nr(pdev->bus) << 32) |
-		((uint64_t)pdev->bus->number << 16) |
-		((uint64_t)(pdev->devfn & 0xff) << 8) |
-		((uint64_t)(pin - 1) & 3);
-}
-
-static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
-{
-	xen_hvm_evtchn_do_upcall();
-	return IRQ_HANDLED;
-}
-
-static int xen_allocate_irq(struct pci_dev *pdev)
-{
-	return request_irq(pdev->irq, do_hvm_evtchn_intr,
-			IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
-			"xen-platform-pci", pdev);
-}
-
-static int platform_pci_resume(struct pci_dev *pdev)
-{
-	int err;
-	if (xen_have_vector_callback)
-		return 0;
-	err = xen_set_callback_via(callback_via);
-	if (err) {
-		dev_err(&pdev->dev, "platform_pci_resume failure!\n");
-		return err;
-	}
-	return 0;
-}
-
 static int platform_pci_probe(struct pci_dev *pdev,
 			      const struct pci_device_id *ent)
 {
@@ -138,21 +92,6 @@ static int platform_pci_probe(struct pci_dev *pdev,
 	platform_mmio = mmio_addr;
 	platform_mmiolen = mmio_len;
 
-	if (!xen_have_vector_callback) {
-		ret = xen_allocate_irq(pdev);
-		if (ret) {
-			dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
-			goto out;
-		}
-		callback_via = get_callback_via(pdev);
-		ret = xen_set_callback_via(callback_via);
-		if (ret) {
-			dev_warn(&pdev->dev, "Unable to set the evtchn callback "
-					 "err=%d\n", ret);
-			goto out;
-		}
-	}
-
 	max_nr_gframes = gnttab_max_grant_frames();
 	grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
 	ret = gnttab_setup_auto_xlat_frames(grant_frames);
@@ -184,9 +123,6 @@ static struct pci_driver platform_driver = {
 	.name =           DRV_NAME,
 	.probe =          platform_pci_probe,
 	.id_table =       platform_pci_tbl,
-#ifdef CONFIG_PM
-	.resume_early =   platform_pci_resume,
-#endif
 };
 
 static int __init platform_pci_init(void)

drivers/xen/sys-hypervisor.c

@@ -215,7 +215,7 @@ static const struct attribute_group xen_compilation_group = {
 	.attrs = xen_compile_attrs,
 };
 
-static int __init xen_compilation_init(void)
+static int __init xen_sysfs_compilation_init(void)
 {
 	return sysfs_create_group(hypervisor_kobj, &xen_compilation_group);
 }
@@ -341,7 +341,7 @@ static const struct attribute_group xen_properties_group = {
 	.attrs = xen_properties_attrs,
 };
 
-static int __init xen_properties_init(void)
+static int __init xen_sysfs_properties_init(void)
 {
 	return sysfs_create_group(hypervisor_kobj, &xen_properties_group);
 }
@@ -455,7 +455,7 @@ static const struct attribute_group xen_pmu_group = {
 	.attrs = xen_pmu_attrs,
 };
 
-static int __init xen_pmu_init(void)
+static int __init xen_sysfs_pmu_init(void)
 {
 	return sysfs_create_group(hypervisor_kobj, &xen_pmu_group);
 }
@@ -474,18 +474,18 @@ static int __init hyper_sysfs_init(void)
 	ret = xen_sysfs_version_init();
 	if (ret)
 		goto version_out;
-	ret = xen_compilation_init();
+	ret = xen_sysfs_compilation_init();
 	if (ret)
 		goto comp_out;
 	ret = xen_sysfs_uuid_init();
 	if (ret)
 		goto uuid_out;
-	ret = xen_properties_init();
+	ret = xen_sysfs_properties_init();
 	if (ret)
 		goto prop_out;
 #ifdef CONFIG_XEN_HAVE_VPMU
 	if (xen_initial_domain()) {
-		ret = xen_pmu_init();
+		ret = xen_sysfs_pmu_init();
 		if (ret) {
 			sysfs_remove_group(hypervisor_kobj,
 					   &xen_properties_group);

drivers/xen/xen-pciback/pci_stub.c

@@ -25,6 +25,8 @@
 #include "conf_space.h"
 #include "conf_space_quirks.h"
 
+#define PCISTUB_DRIVER_NAME "pciback"
+
 static char *pci_devs_to_hide;
 wait_queue_head_t xen_pcibk_aer_wait_queue;
 /*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops,
@@ -149,13 +151,10 @@ static inline void pcistub_device_put(struct pcistub_device *psdev)
 	kref_put(&psdev->kref, pcistub_device_release);
 }
 
-static struct pcistub_device *pcistub_device_find(int domain, int bus,
-						  int slot, int func)
+static struct pcistub_device *pcistub_device_find_locked(int domain, int bus,
+							 int slot, int func)
 {
-	struct pcistub_device *psdev = NULL;
-	unsigned long flags;
-
-	spin_lock_irqsave(&pcistub_devices_lock, flags);
+	struct pcistub_device *psdev;
 
 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 		if (psdev->dev != NULL
@@ -163,15 +162,25 @@ static struct pcistub_device *pcistub_device_find(int domain, int bus,
 		    && bus == psdev->dev->bus->number
 		    && slot == PCI_SLOT(psdev->dev->devfn)
 		    && func == PCI_FUNC(psdev->dev->devfn)) {
-			pcistub_device_get(psdev);
-			goto out;
+			return psdev;
 		}
 	}
 
-	/* didn't find it */
-	psdev = NULL;
+	return NULL;
+}
+
+static struct pcistub_device *pcistub_device_find(int domain, int bus,
+						  int slot, int func)
+{
+	struct pcistub_device *psdev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pcistub_devices_lock, flags);
+
+	psdev = pcistub_device_find_locked(domain, bus, slot, func);
+	if (psdev)
+		pcistub_device_get(psdev);
 
-out:
 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 	return psdev;
 }
@@ -207,16 +216,9 @@ struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 
 	spin_lock_irqsave(&pcistub_devices_lock, flags);
 
-	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
-		if (psdev->dev != NULL
-		    && domain == pci_domain_nr(psdev->dev->bus)
-		    && bus == psdev->dev->bus->number
-		    && slot == PCI_SLOT(psdev->dev->devfn)
-		    && func == PCI_FUNC(psdev->dev->devfn)) {
-			found_dev = pcistub_device_get_pci_dev(pdev, psdev);
-			break;
-		}
-	}
+	psdev = pcistub_device_find_locked(domain, bus, slot, func);
+	if (psdev)
+		found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 
 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 	return found_dev;
@@ -478,15 +480,48 @@ static int __init pcistub_init_devices_late(void)
 	return 0;
 }
 
-static int pcistub_seize(struct pci_dev *dev)
+static void pcistub_device_id_add_list(struct pcistub_device_id *new,
+				       int domain, int bus, unsigned int devfn)
+{
+	struct pcistub_device_id *pci_dev_id;
+	unsigned long flags;
+	int found = 0;
+
+	spin_lock_irqsave(&device_ids_lock, flags);
+
+	list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
+		if (pci_dev_id->domain == domain && pci_dev_id->bus == bus &&
+		    pci_dev_id->devfn == devfn) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		new->domain = domain;
+		new->bus = bus;
+		new->devfn = devfn;
+		list_add_tail(&new->slot_list, &pcistub_device_ids);
+	}
+
+	spin_unlock_irqrestore(&device_ids_lock, flags);
+
+	if (found)
+		kfree(new);
+}
+
+static int pcistub_seize(struct pci_dev *dev,
+			 struct pcistub_device_id *pci_dev_id)
 {
 	struct pcistub_device *psdev;
 	unsigned long flags;
 	int err = 0;
 
 	psdev = pcistub_device_alloc(dev);
-	if (!psdev)
+	if (!psdev) {
+		kfree(pci_dev_id);
 		return -ENOMEM;
+	}
 
 	spin_lock_irqsave(&pcistub_devices_lock, flags);
 
@@ -507,8 +542,12 @@ static int pcistub_seize(struct pci_dev *dev)
 
 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 
-	if (err)
+	if (err) {
+		kfree(pci_dev_id);
 		pcistub_device_put(psdev);
+	} else if (pci_dev_id)
+		pcistub_device_id_add_list(pci_dev_id, pci_domain_nr(dev->bus),
+					   dev->bus->number, dev->devfn);
 
 	return err;
 }
@@ -517,11 +556,16 @@ static int pcistub_seize(struct pci_dev *dev)
  * other functions that take the sysfs lock. */
 static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
-	int err = 0;
+	int err = 0, match;
+	struct pcistub_device_id *pci_dev_id = NULL;
 
 	dev_dbg(&dev->dev, "probing...\n");
 
-	if (pcistub_match(dev)) {
+	match = pcistub_match(dev);
+
+	if ((dev->driver_override &&
+	     !strcmp(dev->driver_override, PCISTUB_DRIVER_NAME)) ||
+	    match) {
 
 		if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
 		    && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
@@ -532,8 +576,16 @@ static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
 			goto out;
 		}
 
+		if (!match) {
+			pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_ATOMIC);
+			if (!pci_dev_id) {
+				err = -ENOMEM;
+				goto out;
+			}
+		}
+
 		dev_info(&dev->dev, "seizing device\n");
-		err = pcistub_seize(dev);
+		err = pcistub_seize(dev, pci_dev_id);
 	} else
 		/* Didn't find the device */
 		err = -ENODEV;
@@ -945,7 +997,7 @@ static const struct pci_error_handlers xen_pcibk_error_handler = {
 static struct pci_driver xen_pcibk_pci_driver = {
 	/* The name should be xen_pciback, but until the tools are updated
 	 * we will keep it as pciback. */
-	.name = "pciback",
+	.name = PCISTUB_DRIVER_NAME,
 	.id_table = pcistub_ids,
 	.probe = pcistub_probe,
 	.remove = pcistub_remove,
@@ -1012,7 +1064,6 @@ static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
 static int pcistub_device_id_add(int domain, int bus, int slot, int func)
 {
 	struct pcistub_device_id *pci_dev_id;
-	unsigned long flags;
 	int rc = 0, devfn = PCI_DEVFN(slot, func);
 
 	if (slot < 0) {
@@ -1042,16 +1093,10 @@ static int pcistub_device_id_add(int domain, int bus, int slot, int func)
 	if (!pci_dev_id)
 		return -ENOMEM;
 
-	pci_dev_id->domain = domain;
-	pci_dev_id->bus = bus;
-	pci_dev_id->devfn = devfn;
-
 	pr_debug("wants to seize %04x:%02x:%02x.%d\n",
 		 domain, bus, slot, func);
 
-	spin_lock_irqsave(&device_ids_lock, flags);
-	list_add_tail(&pci_dev_id->slot_list, &pcistub_device_ids);
-	spin_unlock_irqrestore(&device_ids_lock, flags);
+	pcistub_device_id_add_list(pci_dev_id, domain, bus, devfn);
 
 	return 0;
 }

include/linux/cpuhotplug.h

@@ -43,6 +43,8 @@ enum cpuhp_state {
 	CPUHP_CPUIDLE_COUPLED_PREPARE,
 	CPUHP_POWERPC_PMAC_PREPARE,
 	CPUHP_POWERPC_MMU_CTX_PREPARE,
+	CPUHP_XEN_PREPARE,
+	CPUHP_XEN_EVTCHN_PREPARE,
 	CPUHP_NOTIFY_PREPARE,
 	CPUHP_ARM_SHMOBILE_SCU_PREPARE,
 	CPUHP_SH_SH3X_PREPARE,

include/xen/xen.h

@@ -38,8 +38,7 @@ extern enum xen_domain_type xen_domain_type;
  */
 #include <xen/features.h>
 #define xen_pvh_domain() (xen_pv_domain() && \
-			  xen_feature(XENFEAT_auto_translated_physmap) && \
-			  xen_have_vector_callback)
+			  xen_feature(XENFEAT_auto_translated_physmap))
 #else
 #define xen_pvh_domain()	(0)
 #endif