[PATCH] Make sure hypervisor is excluded from ocount and operf

[Maynard J. <may...@us...>]

Make sure hypervisor is excluded from ocount and operf

Since we have no interface support in the event specification to
allow the user to select or de-select counting events in hypervisor,
and also since the output of ocount and opreport do not support the
concept of hypervisor, we should exclude hypervisor from counting
and profiling.  There's a bug in the current code such that the
user may or may not get hypervisor events included.  This patch
explicitly excludes hypervisor.

Signed-off-by: Maynard Johnson <may...@us...>
---
 libpe_utils/op_pe_utils.cpp |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/libpe_utils/op_pe_utils.cpp b/libpe_utils/op_pe_utils.cpp
index f6decd0..1aff7ce 100644
--- a/libpe_utils/op_pe_utils.cpp
+++ b/libpe_utils/op_pe_utils.cpp
@@ -860,6 +860,7 @@ void op_pe_utils::op_process_events_list(set<string> & passed_evts,
 		pclose(fp);
 		char * event_str = op_xstrndup(event_spec.c_str(), event_spec.length());
 		operf_event_t event;
+		memset(&event, 0, sizeof(event));
 		strncpy(event.name, strtok(event_str, ":"), OP_MAX_EVT_NAME_LEN - 1);
 		if (do_profiling)
 			event.count = atoi(strtok(NULL, ":"));
@@ -879,6 +880,24 @@ void op_pe_utils::op_process_events_list(set<string> & passed_evts,
 		event.evt_um = 0UL;
 		event.no_kernel = 0;
 		event.no_user = 0;
+		/* Explicitly exclude hypervisor samples since we currently do not have any
+		 * interface support for such.  If we did not do this, we could see situations
+		 * on hypervisor-controlled systems like the following:
+		 * 	$ ocount -e PM_RUN_CYC:0:0:0 /bin/true
+		 *
+		 * 	Events were actively counted for 398213 nanoseconds.
+		 * 	Event counts (actual) for /bin/true:
+		 *	        Event                         Count                    % time counted
+		 *	        PM_RUN_CYC_GRP1:0x0:0:0       123,260                  100.00
+		 *
+		 * Note that the event spec explicitly excludes both kernel and user events, yet
+		 * the output shows a non-zero count. The user could "assume" those counts are from
+		 * hypervisor, but that's ugly.
+		 *
+		 * FIXME: Add full hypervisor support by adding another bit in the event specification
+		 * and documenting it in the man pages and user guide.
+		 */
+		event.no_hv = 1;
 		event.throttled = false;
 		event.mode_specified = false;
 		event.umask_specified = false;
-- 
1.7.1