Xen supports the notion of a debug interrupt which can be triggered
from the console. For now this is implemented to show pending events,
masks and each CPU's pending event set.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
arch/x86/xen/events.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
arch/x86/xen/smp.c | 19 ++++++++++++++-----
arch/x86/xen/xen-ops.h | 3 +++
3 files changed, 64 insertions(+), 5 deletions(-)
diff --git a/arch/x86/xen/events.c b/arch/x86/xen/events.c
--- a/arch/x86/xen/events.c
+++ b/arch/x86/xen/events.c
@@ -455,6 +455,53 @@
notify_remote_via_irq(irq);
}
+irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
+{
+ struct shared_info *sh = HYPERVISOR_shared_info;
+ int cpu = smp_processor_id();
+ int i;
+ unsigned long flags;
+ static DEFINE_SPINLOCK(debug_lock);
+
+ spin_lock_irqsave(&debug_lock, flags);
+
+ printk("vcpu %d\n ", cpu);
+
+ for_each_online_cpu(i) {
+ struct vcpu_info *v = per_cpu(xen_vcpu, i);
+ printk("%d: masked=%d pending=%d event_sel %08lx\n ", i,
+ (get_irq_regs() && i == cpu) ? !(get_irq_regs()->flags & X86_EFLAGS_IF) : v->evtchn_upcall_mask,
+ v->evtchn_upcall_pending,
+ v->evtchn_pending_sel);
+ }
+ printk("pending:\n ");
+ for(i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
+ printk("%08lx%s", sh->evtchn_pending[i],
+ i % 8 == 0 ? "\n " : " ");
+ printk("\nmasks:\n ");
+ for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
+ printk("%08lx%s", sh->evtchn_mask[i],
+ i % 8 == 0 ? "\n " : " ");
+
+ printk("\nunmasked:\n ");
+ for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
+ printk("%08lx%s", sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
+ i % 8 == 0 ? "\n " : " ");
+
+ printk("\npending list:\n");
+ for(i = 0; i < NR_EVENT_CHANNELS; i++) {
+ if (sync_test_bit(i, sh->evtchn_pending)) {
+ printk(" %d: event %d -> irq %d\n",
+ cpu_evtchn[i], i,
+ evtchn_to_irq[i]);
+ }
+ }
+
+ spin_unlock_irqrestore(&debug_lock, flags);
+
+ return IRQ_HANDLED;
+}
+
/*
* Search the CPUs pending events bitmasks. For each one found, map
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -36,8 +36,9 @@
#include "mmu.h"
static cpumask_t cpu_initialized_map;
-static DEFINE_PER_CPU(int, resched_irq);
-static DEFINE_PER_CPU(int, callfunc_irq);
+static DEFINE_PER_CPU(int, resched_irq) = -1;
+static DEFINE_PER_CPU(int, callfunc_irq) = -1;
+static DEFINE_PER_CPU(int, debug_irq) = -1;
/*
* Structure and data for smp_call_function(). This is designed to minimise
@@ -89,9 +90,7 @@
static int xen_smp_intr_init(unsigned int cpu)
{
int rc;
- const char *resched_name, *callfunc_name;
-
- per_cpu(resched_irq, cpu) = per_cpu(callfunc_irq, cpu) = -1;
+ const char *resched_name, *callfunc_name, *debug_name;
resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
@@ -115,6 +114,14 @@
goto fail;
per_cpu(callfunc_irq, cpu) = rc;
+ debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
+ rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
+ IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING,
+ debug_name, NULL);
+ if (rc < 0)
+ goto fail;
+ per_cpu(debug_irq, cpu) = rc;
+
return 0;
fail:
@@ -122,6 +129,8 @@
unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL);
if (per_cpu(callfunc_irq, cpu) >= 0)
unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL);
+ if (per_cpu(debug_irq, cpu) >= 0)
+ unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL);
return rc;
}
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -2,6 +2,7 @@
#define XEN_OPS_H
#include <linux/init.h>
+#include <linux/irqreturn.h>
/* These are code, but not functions. Defined in entry.S */
extern const char xen_hypervisor_callback[];
@@ -29,6 +30,8 @@
int xen_set_wallclock(unsigned long time);
unsigned long long xen_sched_clock(void);
+irqreturn_t xen_debug_interrupt(int irq, void *dev_id);
+
bool xen_vcpu_stolen(int vcpu);
void xen_mark_init_mm_pinned(void);
--
