2 files changed, 14 insertions, 4 deletions

diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index 2ed395b817cb..bc508dae286c 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -575,8 +575,12 @@ class TracepointProvider(Provider):
     def update_fields(self, fields_filter):
         """Refresh fields, applying fields_filter"""
         self.fields = [field for field in self._get_available_fields()
-                       if self.is_field_wanted(fields_filter, field) or
-                       ARCH.tracepoint_is_child(field)]
+                       if self.is_field_wanted(fields_filter, field)]
+        # add parents for child fields - otherwise we won't see any output!
+        for field in self._fields:
+            parent = ARCH.tracepoint_is_child(field)
+            if (parent and parent not in self._fields):
+                self.fields.append(parent)
 
     @staticmethod
     def _get_online_cpus():
@@ -735,8 +739,12 @@ class DebugfsProvider(Provider):
     def update_fields(self, fields_filter):
         """Refresh fields, applying fields_filter"""
         self._fields = [field for field in self._get_available_fields()
-                        if self.is_field_wanted(fields_filter, field) or
-                        ARCH.debugfs_is_child(field)]
+                        if self.is_field_wanted(fields_filter, field)]
+        # add parents for child fields - otherwise we won't see any output!
+        for field in self._fields:
+            parent = ARCH.debugfs_is_child(field)
+            if (parent and parent not in self._fields):
+                self.fields.append(parent)
 
     @property
     def fields(self):
diff --git a/tools/kvm/kvm_stat/kvm_stat.txt b/tools/kvm/kvm_stat/kvm_stat.txt
index 0811d860fe75..c057ba52364e 100644
--- a/tools/kvm/kvm_stat/kvm_stat.txt
+++ b/tools/kvm/kvm_stat/kvm_stat.txt
@@ -34,6 +34,8 @@ INTERACTIVE COMMANDS
 *c*::   clear filter
 
 *f*::   filter by regular expression
+ ::     *Note*: Child events pull in their parents, and parents' stats summarize
+                all child events, not just the filtered ones
 
 *g*::   filter by guest name/PID