[RFC PATCH V5 14/14] xen: register 3-level event channel

[Wei Liu <wei.liu2@citrix.com>]

CPU hotplug is supported.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 arch/x86/xen/enlighten.c |   12 ++++++++++++
 drivers/xen/events.c     |   22 +++++++++++++++++++++-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 3556678..18edf66 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -213,6 +213,18 @@ void xen_vcpu_restore(void)
 		    HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
 			BUG();
 	}
+
+	/*
+	 * If we use any extended event channel ABI, should try to
+	 * re-setup it in restore path. Currently only 3-level ABI is
+	 * implemented, so simplify the code a bit.
+	 */
+	if (xen_evtchn_extended & EVTCHN_EXTENDED_L3) {
+		int rc;
+		rc = xen_event_channel_register_extended(EVTCHN_EXTENDED_L3);
+		if (rc)
+			xen_set_event_channel_extended(EVTCHN_EXTENDED_NONE);
+	}
 }
 
 static void __init xen_banner(void)
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 6f21f27..b7e5bc1 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -2368,6 +2368,11 @@ static int __cpuinit xen_events_notifier_cb(struct notifier_block *self,
 				rc = NOTIFY_OK;
 			}
 		}
+		if (rc == NOTIFY_OK &&
+		    xen_evtchn_extended & EVTCHN_EXTENDED_L3) {
+			rc = xen_event_channel_register_3level_l2selector(cpu);
+			rc = (rc == 0 ? NOTIFY_OK : NOTIFY_BAD);
+		}
 		break;
 	default:
 		break;
@@ -2383,8 +2388,23 @@ void __init xen_init_IRQ(void)
 {
 	int i;
 	int cpu;
+	uint64_t evtchn_ext_abis;
+	int rc, fallback_to_default_evtchn = 0;
+
+	evtchn_ext_abis = xen_event_channel_query_extended_abis();
+
+	if (evtchn_ext_abis == EVTCHN_EXTENDED_NONE)
+		fallback_to_default_evtchn = 1;
+	else if (evtchn_ext_abis & EVTCHN_EXTENDED_L3) {
+		rc = xen_event_channel_register_extended(EVTCHN_EXTENDED_L3);
+		if (rc == 0)
+			xen_set_event_channel_extended(EVTCHN_EXTENDED_L3);
+		else
+			fallback_to_default_evtchn = 1;
+	}
 
-	xen_set_event_channel_extended(EVTCHN_EXTENDED_NONE);
+	if (fallback_to_default_evtchn)
+		xen_set_event_channel_extended(EVTCHN_EXTENDED_NONE);
 
 	evtchn_to_irq = kcalloc(xen_nr_event_channels, sizeof(*evtchn_to_irq),
 				    GFP_KERNEL);
-- 
1.7.10.4