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@suse.com>
---
 arch/x86/xen/smp.c               | 19 +++++++++++--------
 arch/x86/xen/xen-ops.h           |  2 ++
 drivers/xen/events/events_base.c |  6 ++++--
 3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 2097fa0ebdb5..b544e511b3c2 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 (!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..e444c78b6e2b 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 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..bb18cce4db06 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -2050,7 +2050,7 @@ void xen_setup_callback_vector(void) {}
 static inline void xen_alloc_callback_vector(void) {}
 #endif
 
-static bool fifo_events = true;
+bool fifo_events = true;
 module_param(fifo_events, bool, 0);
 
 static int xen_evtchn_cpu_prepare(unsigned int cpu)
@@ -2082,8 +2082,10 @@ void __init xen_init_IRQ(void)
 
 	if (fifo_events)
 		ret = xen_evtchn_fifo_init();
-	if (ret < 0)
+	if (ret < 0) {
 		xen_evtchn_2l_init();
+		fifo_events = false;
+	}
 
 	xen_cpu_init_eoi(smp_processor_id());
 
-- 
2.26.2

On 22.10.2020 09:42, Juergen Gross wrote:
> --- a/drivers/xen/events/events_base.c
> +++ b/drivers/xen/events/events_base.c
> @@ -2050,7 +2050,7 @@ void xen_setup_callback_vector(void) {}
>  static inline void xen_alloc_callback_vector(void) {}
>  #endif
>  
> -static bool fifo_events = true;
> +bool fifo_events = true;

When making this non-static, perhaps better to also prefix it with
xen_?

Jan

On 22.10.20 09:54, Jan Beulich wrote:
> On 22.10.2020 09:42, Juergen Gross wrote:
>> --- a/drivers/xen/events/events_base.c
>> +++ b/drivers/xen/events/events_base.c
>> @@ -2050,7 +2050,7 @@ void xen_setup_callback_vector(void) {}
>>   static inline void xen_alloc_callback_vector(void) {}
>>   #endif
>>   
>> -static bool fifo_events = true;
>> +bool fifo_events = true;
> 
> When making this non-static, perhaps better to also prefix it with
> xen_?

Fine with me.


Juergen