1 files changed, 30 insertions, 1 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index df30ee08bdd4..4b1dfba70f7c 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -24,6 +24,7 @@
 #include <linux/sysctl.h>
 
 #include <asm/irq_regs.h>
+#include <linux/kvm_para.h>
 #include <linux/perf_event.h>
 
 int watchdog_enabled = 1;
@@ -280,6 +281,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
                         __this_cpu_write(softlockup_touch_sync, false);
                         sched_clock_tick();
                 }
+
+                /* Clear the guest paused flag on watchdog reset */
+                kvm_check_and_clear_guest_paused();
                 __touch_watchdog();
                 return HRTIMER_RESTART;
         }
@@ -292,6 +296,14 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
          */
         duration = is_softlockup(touch_ts);
         if (unlikely(duration)) {
+                /*
+                 * If a virtual machine is stopped by the host it can look to
+                 * the watchdog like a soft lockup, check to see if the host
+                 * stopped the vm before we issue the warning
+                 */
+                if (kvm_check_and_clear_guest_paused())
+                        return HRTIMER_RESTART;
+
                 /* only warn once */
                 if (__this_cpu_read(soft_watchdog_warn) == true)
                         return HRTIMER_RESTART;
@@ -360,6 +372,13 @@ static int watchdog(void *unused)
 
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
+/*
+ * People like the simple clean cpu node info on boot.
+ * Reduce the watchdog noise by only printing messages
+ * that are different from what cpu0 displayed.
+ */
+static unsigned long cpu0_err;
+
 static int watchdog_nmi_enable(int cpu)
 {
         struct perf_event_attr *wd_attr;
@@ -378,11 +397,21 @@ static int watchdog_nmi_enable(int cpu)
 
         /* Try to register using hardware perf events */
         event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
+
+        /* save cpu0 error for future comparision */
+        if (cpu == 0 && IS_ERR(event))
+                cpu0_err = PTR_ERR(event);
+
         if (!IS_ERR(event)) {
-                pr_info("enabled, takes one hw-pmu counter.\n");
+                /* only print for cpu0 or different than cpu0 */
+                if (cpu == 0 || cpu0_err)
+                        pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
                 goto out_save;
         }
 
+        /* skip displaying the same error again */
+        if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
+                return PTR_ERR(event);
 
         /* vary the KERN level based on the returned errno */
         if (PTR_ERR(event) == -EOPNOTSUPP)