perf intel-pt: Parse VM Time Correlation options and set up decoding

Add parsing and validation of VM Time Correlation options, and pass
parameters to the decoder. Also update the Intel PT documentation
accordingly.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210430070309.17624-13-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 97 insertions, 1 deletions

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index 858b679d00be..2a5fe1514e65 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -1018,6 +1018,19 @@ static bool intel_pt_have_tsc(struct intel_pt *pt)
 	return have_tsc;
 }
 
+static bool intel_pt_have_mtc(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 & pt->mtc_bit))
+			return true;
+	}
+	return false;
+}
+
 static bool intel_pt_sampling_mode(struct intel_pt *pt)
 {
 	struct evsel *evsel;
@@ -1182,6 +1195,8 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
 	params.tsc_ctc_ratio_n = pt->tsc_ctc_ratio_n;
 	params.tsc_ctc_ratio_d = pt->tsc_ctc_ratio_d;
 	params.quick = pt->synth_opts.quick;
+	params.vm_time_correlation = pt->synth_opts.vm_time_correlation;
+	params.vm_tm_corr_dry_run = pt->synth_opts.vm_tm_corr_dry_run;
 	params.first_timestamp = pt->first_timestamp;
 
 	if (pt->filts.cnt > 0)
@@ -2465,7 +2480,7 @@ static int intel_pt_run_decoder(struct intel_pt_queue *ptq, u64 *timestamp)
 		if (pt->per_cpu_mmaps &&
 		    (pt->have_sched_switch == 1 || pt->have_sched_switch == 3) &&
 		    !pt->timeless_decoding && intel_pt_tracing_kernel(pt) &&
-		    !pt->sampling_mode) {
+		    !pt->sampling_mode && !pt->synth_opts.vm_time_correlation) {
 			pt->switch_ip = intel_pt_switch_ip(pt, &pt->ptss_ip);
 			if (pt->switch_ip) {
 				intel_pt_log("switch_ip: %"PRIx64" ptss_ip: %"PRIx64"\n",
@@ -3496,6 +3511,65 @@ static int intel_pt_setup_time_ranges(struct intel_pt *pt,
 	return 0;
 }
 
+static int intel_pt_parse_vm_tm_corr_arg(struct intel_pt *pt, char **args)
+{
+	struct intel_pt_vmcs_info *vmcs_info;
+	u64 tsc_offset, vmcs;
+	char *p = *args;
+
+	errno = 0;
+
+	p = skip_spaces(p);
+	if (!*p)
+		return 1;
+
+	tsc_offset = strtoull(p, &p, 0);
+	if (errno)
+		return -errno;
+	p = skip_spaces(p);
+	if (*p != ':') {
+		pt->dflt_tsc_offset = tsc_offset;
+		*args = p;
+		return 0;
+	}
+	while (1) {
+		vmcs = strtoull(p, &p, 0);
+		if (errno)
+			return -errno;
+		if (!vmcs)
+			return -EINVAL;
+		vmcs_info = intel_pt_findnew_vmcs(&pt->vmcs_info, vmcs, tsc_offset);
+		if (!vmcs_info)
+			return -ENOMEM;
+		p = skip_spaces(p);
+		if (*p != ',')
+			break;
+		p += 1;
+	}
+	*args = p;
+	return 0;
+}
+
+static int intel_pt_parse_vm_tm_corr_args(struct intel_pt *pt)
+{
+	char *args = pt->synth_opts.vm_tm_corr_args;
+	int ret;
+
+	if (!args)
+		return 0;
+
+	do {
+		ret = intel_pt_parse_vm_tm_corr_arg(pt, &args);
+	} while (!ret);
+
+	if (ret < 0) {
+		pr_err("Failed to parse VM Time Correlation options\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 static const char * const intel_pt_info_fmts[] = {
 	[INTEL_PT_PMU_TYPE]		= "  PMU Type            %"PRId64"\n",
 	[INTEL_PT_TIME_SHIFT]		= "  Time Shift          %"PRIu64"\n",
@@ -3667,6 +3741,28 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
 	pt->sampling_mode = intel_pt_sampling_mode(pt);
 	pt->est_tsc = !pt->timeless_decoding;
 
+	if (pt->synth_opts.vm_time_correlation) {
+		if (pt->timeless_decoding) {
+			pr_err("Intel PT has no time information for VM Time Correlation\n");
+			err = -EINVAL;
+			goto err_free_queues;
+		}
+		if (session->itrace_synth_opts->ptime_range) {
+			pr_err("Time ranges cannot be specified with VM Time Correlation\n");
+			err = -EINVAL;
+			goto err_free_queues;
+		}
+		/* Currently TSC Offset is calculated using MTC packets */
+		if (!intel_pt_have_mtc(pt)) {
+			pr_err("MTC packets must have been enabled for VM Time Correlation\n");
+			err = -EINVAL;
+			goto err_free_queues;
+		}
+		err = intel_pt_parse_vm_tm_corr_args(pt);
+		if (err)
+			goto err_free_queues;
+	}
+
 	pt->unknown_thread = thread__new(999999999, 999999999);
 	if (!pt->unknown_thread) {
 		err = -ENOMEM;