[PATCH v2 3/5] xen/events: only register debug interrupt for 2-level events

[Juergen Gross <jgross@xxxxxxxx>]

xen_debug_interrupt() is specific to 2-level event handling. So don't
register it with fifo event handling being active.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
V2:
- rename fifo_events variable to xen_fifo_events (Jan Beulich)
---
 arch/x86/xen/smp.c               | 19 +++++++++++--------
 arch/x86/xen/xen-ops.h           |  2 ++
 drivers/xen/events/events_base.c | 10 ++++++----
 3 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 2097fa0ebdb5..c1b2f764b29a 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -88,14 +88,17 @@ int xen_smp_intr_init(unsigned int cpu)
        per_cpu(xen_callfunc_irq, cpu).irq = rc;
        per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
 
-       debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
-       rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
-                                    IRQF_PERCPU | IRQF_NOBALANCING,
-                                    debug_name, NULL);
-       if (rc < 0)
-               goto fail;
-       per_cpu(xen_debug_irq, cpu).irq = rc;
-       per_cpu(xen_debug_irq, cpu).name = debug_name;
+       if (!xen_fifo_events) {
+               debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
+               rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu,
+                                            xen_debug_interrupt,
+                                            IRQF_PERCPU | IRQF_NOBALANCING,
+                                            debug_name, NULL);
+               if (rc < 0)
+                       goto fail;
+               per_cpu(xen_debug_irq, cpu).irq = rc;
+               per_cpu(xen_debug_irq, cpu).name = debug_name;
+       }
 
        callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
        rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 45d556f71858..9546c3384c75 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -29,6 +29,8 @@ extern struct start_info *xen_start_info;
 extern struct shared_info xen_dummy_shared_info;
 extern struct shared_info *HYPERVISOR_shared_info;
 
+extern bool xen_fifo_events;
+
 void xen_setup_mfn_list_list(void);
 void xen_build_mfn_list_list(void);
 void xen_setup_machphys_mapping(void);
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 1c25580c7691..6038c4c35db5 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -2050,8 +2050,8 @@ void xen_setup_callback_vector(void) {}
 static inline void xen_alloc_callback_vector(void) {}
 #endif
 
-static bool fifo_events = true;
-module_param(fifo_events, bool, 0);
+bool xen_fifo_events = true;
+module_param_named(fifo_events, xen_fifo_events, bool, 0);
 
 static int xen_evtchn_cpu_prepare(unsigned int cpu)
 {
@@ -2080,10 +2080,12 @@ void __init xen_init_IRQ(void)
        int ret = -EINVAL;
        evtchn_port_t evtchn;
 
-       if (fifo_events)
+       if (xen_fifo_events)
                ret = xen_evtchn_fifo_init();
-       if (ret < 0)
+       if (ret < 0) {
                xen_evtchn_2l_init();
+               xen_fifo_events = false;
+       }
 
        xen_cpu_init_eoi(smp_processor_id());
 
-- 
2.26.2