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

Juergen Gross
2020-10-22T09:49:25Z

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>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
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