From: Aristeu Rozanski <aris@redhat.com>
Date: Tue, 25 Nov 2008 10:33:30 -0500
Subject: [x86] nmi_watchdog: call do_nmi_callback from traps-xen
Message-id: 20081125153329.GF33010@redhat.com
O-Subject: Re: [RHEL5.3 PATCH] nmi_watchdog: call do_nmi_callback() from traps-xen
Bugzilla: 471111
RH-Acked-by: Chris Lalancette <clalance@redhat.com>
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>
RH-Acked-by: Bill Burns <bburns@redhat.com>
RH-Acked-by: Dave Anderson <anderson@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=471111

The NMI watchdog backport work is not complete because traps-xen.c wasn't
updated and the result is that the unknown_nmi_panic won't work on xen
kernels, affecting NEC machines with NMI buttons.

It's upstream, just compare with traps.c, since upstream traps-xen.c doesn't
exist upstream.

diff --git a/arch/i386/kernel/traps-xen.c b/arch/i386/kernel/traps-xen.c
index 3e4e34a..3613af6 100644
--- a/arch/i386/kernel/traps-xen.c
+++ b/arch/i386/kernel/traps-xen.c
@@ -788,26 +788,27 @@ void die_nmi (struct pt_regs *regs, const char *msg)
 static void default_do_nmi(struct pt_regs * regs)
 {
 	unsigned char reason = 0;
+	int cpu;
+
+	cpu = smp_processor_id();
 
 	/* Only the BSP gets external NMIs from the system.  */
-	if (!smp_processor_id())
+	if (!cpu)
 		reason = get_nmi_reason();
  
 	if (!(reason & 0xc0)) {
 		if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
 							== NOTIFY_STOP)
 			return;
-#ifdef CONFIG_X86_LOCAL_APIC
 		/*
 		 * Ok, so this is none of the documented NMI sources,
 		 * so it must be the NMI watchdog.
 		 */
-		if (nmi_watchdog) {
-			nmi_watchdog_tick(regs);
+		if (nmi_watchdog_tick(regs))
 			return;
-		}
-#endif
-		unknown_nmi_error(reason, regs);
+
+		if (!do_nmi_callback(regs, cpu))
+			unknown_nmi_error(reason, regs);
 		return;
 	}
 	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
diff --git a/arch/x86_64/kernel/traps-xen.c b/arch/x86_64/kernel/traps-xen.c
index 9357d42..696603b 100644
--- a/arch/x86_64/kernel/traps-xen.c
+++ b/arch/x86_64/kernel/traps-xen.c
@@ -787,17 +787,15 @@ asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
 		if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
 								== NOTIFY_STOP)
 			return;
-#ifdef CONFIG_X86_LOCAL_APIC
 		/*
 		 * Ok, so this is none of the documented NMI sources,
 		 * so it must be the NMI watchdog.
 		 */
-		if (nmi_watchdog > 0) {
-			nmi_watchdog_tick(regs,reason);
+		if (nmi_watchdog_tick(regs, reason))
 			return;
-		}
-#endif
-		unknown_nmi_error(reason, regs);
+
+		if (!do_nmi_callback2(regs, cpu))
+			unknown_nmi_error(reason, regs);
 		return;
 	}
 	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
diff --git a/include/asm-x86_64/mach-xen/asm/nmi.h b/include/asm-x86_64/mach-xen/asm/nmi.h
index 3c75095..cc2b01b 100644
--- a/include/asm-x86_64/mach-xen/asm/nmi.h
+++ b/include/asm-x86_64/mach-xen/asm/nmi.h
@@ -87,6 +87,7 @@ extern void release_lapic_nmi(void);
 extern void disable_timer_nmi_watchdog(void);
 extern void enable_timer_nmi_watchdog(void);
 extern int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason);
+extern int do_nmi_callback2(struct pt_regs *regs, int cpu);
 
 extern void nmi_watchdog_default(void);
 extern int setup_nmi_watchdog(char *);