Merge tag 'for-linus-4.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from David Vrabel:
 "Regression and bug fixes for 4.6-rc2:

   - safely migrate event channels between CPUs
   - fix CPU hotplug
   - maintainer changes"

* tag 'for-linus-4.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  MAINTAINERS: xen: Konrad to step down and Juergen to pick up
  xen/events: Mask a moving irq
  Xen on ARM and ARM64: update MAINTAINERS info
  xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()
  xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op

MAINTAINERS

@@ -12205,9 +12205,9 @@ S:	Maintained
 F:	drivers/media/tuners/tuner-xc2028.*
 
 XEN HYPERVISOR INTERFACE
-M:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
 M:	Boris Ostrovsky <boris.ostrovsky@oracle.com>
 M:	David Vrabel <david.vrabel@citrix.com>
+M:	Juergen Gross <jgross@suse.com>
 L:	xen-devel@lists.xenproject.org (moderated for non-subscribers)
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git
 S:	Supported
@@ -12219,16 +12219,16 @@ F:	include/xen/
 F:	include/uapi/xen/
 
 XEN HYPERVISOR ARM
-M:	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+M:	Stefano Stabellini <sstabellini@kernel.org>
 L:	xen-devel@lists.xenproject.org (moderated for non-subscribers)
-S:	Supported
+S:	Maintained
 F:	arch/arm/xen/
 F:	arch/arm/include/asm/xen/
 
 XEN HYPERVISOR ARM64
-M:	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+M:	Stefano Stabellini <sstabellini@kernel.org>
 L:	xen-devel@lists.xenproject.org (moderated for non-subscribers)
-S:	Supported
+S:	Maintained
 F:	arch/arm64/xen/
 F:	arch/arm64/include/asm/xen/
 

arch/x86/xen/apic.c

@@ -66,7 +66,7 @@ static u32 xen_apic_read(u32 reg)
 
 	ret = HYPERVISOR_platform_op(&op);
 	if (ret)
-		return 0;
+		op.u.pcpu_info.apic_id = BAD_APICID;
 
 	return op.u.pcpu_info.apic_id << 24;
 }
@@ -142,6 +142,14 @@ static void xen_silent_inquire(int apicid)
 {
 }
 
+static int xen_cpu_present_to_apicid(int cpu)
+{
+	if (cpu_present(cpu))
+		return xen_get_apic_id(xen_apic_read(APIC_ID));
+	else
+		return BAD_APICID;
+}
+
 static struct apic xen_pv_apic = {
 	.name 				= "Xen PV",
 	.probe 				= xen_apic_probe_pv,
@@ -162,7 +170,7 @@ static struct apic xen_pv_apic = {
 
 	.ioapic_phys_id_map		= default_ioapic_phys_id_map, /* Used on 32-bit */
 	.setup_apic_routing		= NULL,
-	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.cpu_present_to_apicid		= xen_cpu_present_to_apicid,
 	.apicid_to_cpu_present		= physid_set_mask_of_physid, /* Used on 32-bit */
 	.check_phys_apicid_present	= default_check_phys_apicid_present, /* smp_sanity_check needs it */
 	.phys_pkg_id			= xen_phys_pkg_id, /* detect_ht */

arch/x86/xen/smp.c

@@ -545,6 +545,8 @@ static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
 	 * data back is to call:
 	 */
 	tick_nohz_idle_enter();
+
+	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 }
 
 #else /* !CONFIG_HOTPLUG_CPU */

drivers/xen/events/events_base.c

@@ -484,9 +484,19 @@ static void eoi_pirq(struct irq_data *data)
 	struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 	int rc = 0;
 
-	irq_move_irq(data);
+	if (!VALID_EVTCHN(evtchn))
+		return;
 
-	if (VALID_EVTCHN(evtchn))
+	if (unlikely(irqd_is_setaffinity_pending(data))) {
+		int masked = test_and_set_mask(evtchn);
+
+		clear_evtchn(evtchn);
+
+		irq_move_masked_irq(data);
+
+		if (!masked)
+			unmask_evtchn(evtchn);
+	} else
 		clear_evtchn(evtchn);
 
 	if (pirq_needs_eoi(data->irq)) {
@@ -1357,9 +1367,19 @@ static void ack_dynirq(struct irq_data *data)
 {
 	int evtchn = evtchn_from_irq(data->irq);
 
-	irq_move_irq(data);
+	if (!VALID_EVTCHN(evtchn))
+		return;
 
-	if (VALID_EVTCHN(evtchn))
+	if (unlikely(irqd_is_setaffinity_pending(data))) {
+		int masked = test_and_set_mask(evtchn);
+
+		clear_evtchn(evtchn);
+
+		irq_move_masked_irq(data);
+
+		if (!masked)
+			unmask_evtchn(evtchn);
+	} else
 		clear_evtchn(evtchn);
 }