tools/kvm_stat: document list of interactive commands

Apart from the source code, there does not seem to be a place that documents
the interactive capabilities of kvm_stat yet.
Signed-off-by: NStefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

tools/kvm/kvm_stat/kvm_stat

@@ -1052,6 +1052,13 @@ Requirements:
   CAP_SYS_ADMIN and perf events are used.
 - CAP_SYS_RESOURCE if the hard limit is not high enough to allow
   the large number of files that are possibly opened.
+
+Interactive Commands:
+   f     filter by regular expression
+   p     filter by PID
+   q     quit
+   x     toggle reporting of stats for individual child trace events
+Press any other key to refresh statistics immediately.
 """
 
     class PlainHelpFormatter(optparse.IndentedHelpFormatter):

tools/kvm/kvm_stat/kvm_stat.txt

@@ -18,11 +18,27 @@ state transitions such as guest mode entry and exit.
 This tool is useful for observing guest behavior from the host perspective.
 Often conclusions about performance or buggy behavior can be drawn from the
 output.
+While running in regular mode, use any of the keys listed in section
+'Interactive Commands' below.
+Use batch and logging modes for scripting purposes.
 
 The set of KVM kernel module trace events may be specific to the kernel version
 or architecture.  It is best to check the KVM kernel module source code for the
 meaning of events.
 
+INTERACTIVE COMMANDS
+--------------------
+[horizontal]
+*f*::	filter by regular expression
+
+*p*::	filter by PID
+
+*q*::	quit
+
+*x*::	toggle reporting of stats for child trace events
+
+Press any other key to refresh statistics immediately.
+
 OPTIONS
 -------
 -1::