perf intel-pt: Force 'quick' mode when TNT (Taken/Not-Taken packet) is disabled

It is not possible to walk the executable code without TNT packets, so
force 'quick' mode when TNT is disabled, because 'quick' mode does not walk
the code.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20220124084201.2699795-18-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index d76e4b8..ec43d36 100644 (file)
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -50,6 +50,7 @@
 #define INTEL_PT_CFG_PWR_EVT_EN        BIT_ULL(4)
 #define INTEL_PT_CFG_BRANCH_EN BIT_ULL(13)
 #define INTEL_PT_CFG_EVT_EN    BIT_ULL(31)
+#define INTEL_PT_CFG_TNT_DIS   BIT_ULL(55)
 
 struct range {
        u64 start;
@@ -972,6 +973,19 @@ static bool intel_pt_branch_enable(struct intel_pt *pt)
        return true;
 }
 
+static bool intel_pt_disabled_tnt(struct intel_pt *pt)
+{
+       struct evsel *evsel;
+       u64 config;
+
+       evlist__for_each_entry(pt->session->evlist, evsel) {
+               if (intel_pt_get_config(pt, &evsel->core.attr, &config) &&
+                   config & INTEL_PT_CFG_TNT_DIS)
+                       return true;
+       }
+       return false;
+}
+
 static unsigned int intel_pt_mtc_period(struct intel_pt *pt)
 {
        struct evsel *evsel;
@@ -1227,6 +1241,10 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
        params.first_timestamp = pt->first_timestamp;
        params.max_loops = pt->max_loops;
 
+       /* Cannot walk code without TNT, so force 'quick' mode */
+       if (params.branch_enable && intel_pt_disabled_tnt(pt) && !params.quick)
+               params.quick = 1;
+
        if (pt->filts.cnt > 0)
                params.pgd_ip = intel_pt_pgd_ip;