[PATCH v4 0/5] perf cs-etm: Fix pid tracing with VHE

[PATCH v4 0/5] perf cs-etm: Fix pid tracing with VHE

[Leo Yan]

This patch set is to follow up the patch series "coresight: etm-perf:
Fix pid tracing with VHE" [1].

Since the kernel and documentation patches have been picked up by
Mathieu Poirier and will go through the char-misc-next branch [2] to the
mainline kernel; the rest patches are for the perf tool, so combine
these patches into this patch set.

The patch set can be cleanly applied on perf/core branch with:

  commit 6db59d357e8e ("perf arm64/s390: Fix printf conversion specifier for IP addresses")

And this patch set has been verified on Arm Juno-r2 board.

Changes from v3:
* Added Reviewed-by tags (Mathieu/Mike/Suzuki);
* Changed to use the existed macros for option bits in patch 02/05
  (Mathieu).


[1] https://lore.kernel.org/patchwork/cover/1376776/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git/log/?h=char-misc-next


Leo Yan (2):
  tools headers UAPI: Update tools' copy of linux/coresight-pmu.h
  perf cs-etm: Add helper cs_etm__get_pid_fmt()

Suzuki K Poulose (3):
  perf cs-etm: Fix bitmap for option
  perf cs-etm: Support PID tracing in config
  perf cs-etm: Detect pid in VMID for kernel running at EL2

 tools/include/linux/coresight-pmu.h           | 20 ++++--
 tools/perf/arch/arm/util/cs-etm.c             | 69 ++++++++++++++-----
 .../perf/util/cs-etm-decoder/cs-etm-decoder.c | 38 ++++++++--
 tools/perf/util/cs-etm.c                      | 42 +++++++++++
 tools/perf/util/cs-etm.h                      |  1 +
 5 files changed, 145 insertions(+), 25 deletions(-)

-- 
2.25.1


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[PATCH v4 1/5] tools headers UAPI: Update tools' copy of linux/coresight-pmu.h

[Leo Yan]

To get the changes in the commit:

  "coresight: etm-perf: Clarify comment on perf options".

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 tools/include/linux/coresight-pmu.h | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h
index b0e35eec6499..5dc47cfdcf07 100644
--- a/tools/include/linux/coresight-pmu.h
+++ b/tools/include/linux/coresight-pmu.h
@@ -10,11 +10,18 @@
 #define CORESIGHT_ETM_PMU_NAME "cs_etm"
 #define CORESIGHT_ETM_PMU_SEED  0x10
 
-/* ETMv3.5/PTM's ETMCR config bit */
-#define ETM_OPT_CYCACC  12
-#define ETM_OPT_CTXTID	14
-#define ETM_OPT_TS      28
-#define ETM_OPT_RETSTK	29
+/*
+ * Below are the definition of bit offsets for perf option, and works as
+ * arbitrary values for all ETM versions.
+ *
+ * Most of them are orignally from ETMv3.5/PTM's ETMCR config, therefore,
+ * ETMv3.5/PTM doesn't define ETMCR config bits with prefix "ETM3_" and
+ * directly use below macros as config bits.
+ */
+#define ETM_OPT_CYCACC		12
+#define ETM_OPT_CTXTID		14
+#define ETM_OPT_TS		28
+#define ETM_OPT_RETSTK		29
 
 /* ETMv4 CONFIGR programming bits for the ETM OPTs */
 #define ETM4_CFG_BIT_CYCACC	4
-- 
2.25.1


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[PATCH v4 2/5] perf cs-etm: Fix bitmap for option

[Leo Yan]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

When set option with macros ETM_OPT_CTXTID and ETM_OPT_TS, it wrongly
takes these two values (14 and 28 prespectively) as bit masks, but
actually both are the offset for bits.  But this doesn't lead to
further failure due to the AND logic operation will be always true for
ETM_OPT_CTXTID / ETM_OPT_TS.

This patch uses the BIT() macro for option bits, thus it can request the
correct bitmaps for "contextid" and "timestamp" when calling
cs_etm_set_option().

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[Extract the change as a separate patch for easier review]
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 tools/perf/arch/arm/util/cs-etm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index bd446aba64f7..ad8421e8b651 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -169,17 +169,17 @@ static int cs_etm_set_option(struct auxtrace_record *itr,
 		    !cpu_map__has(online_cpus, i))
 			continue;
 
-		if (option & ETM_OPT_CTXTID) {
+		if (option & BIT(ETM_OPT_CTXTID)) {
 			err = cs_etm_set_context_id(itr, evsel, i);
 			if (err)
 				goto out;
 		}
-		if (option & ETM_OPT_TS) {
+		if (option & BIT(ETM_OPT_TS)) {
 			err = cs_etm_set_timestamp(itr, evsel, i);
 			if (err)
 				goto out;
 		}
-		if (option & ~(ETM_OPT_CTXTID | ETM_OPT_TS))
+		if (option & ~(BIT(ETM_OPT_CTXTID) | BIT(ETM_OPT_TS)))
 			/* Nothing else is currently supported */
 			goto out;
 	}
@@ -406,7 +406,7 @@ static int cs_etm_recording_options(struct auxtrace_record *itr,
 		evsel__set_sample_bit(cs_etm_evsel, CPU);
 
 		err = cs_etm_set_option(itr, cs_etm_evsel,
-					ETM_OPT_CTXTID | ETM_OPT_TS);
+					BIT(ETM_OPT_CTXTID) | BIT(ETM_OPT_TS));
 		if (err)
 			goto out;
 	}
-- 
2.25.1


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[PATCH v4 3/5] perf cs-etm: Support PID tracing in config

[Leo Yan]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

If the kernel is running at EL2, the pid of a task is exposed via VMID
instead of the CONTEXTID.  Add support for this in the perf tool.

This patch respects user setting if user has specified any configs
from "contextid", "contextid1" or "contextid2"; otherwise, it
dynamically sets config based on PMU format "contextid".

Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Al Grant <al.grant@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Co-developed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 tools/include/linux/coresight-pmu.h |  3 ++
 tools/perf/arch/arm/util/cs-etm.c   | 61 +++++++++++++++++++++++------
 2 files changed, 52 insertions(+), 12 deletions(-)

diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h
index 5dc47cfdcf07..4ac5c081af93 100644
--- a/tools/include/linux/coresight-pmu.h
+++ b/tools/include/linux/coresight-pmu.h
@@ -20,14 +20,17 @@
  */
 #define ETM_OPT_CYCACC		12
 #define ETM_OPT_CTXTID		14
+#define ETM_OPT_CTXTID2		15
 #define ETM_OPT_TS		28
 #define ETM_OPT_RETSTK		29
 
 /* ETMv4 CONFIGR programming bits for the ETM OPTs */
 #define ETM4_CFG_BIT_CYCACC	4
 #define ETM4_CFG_BIT_CTXTID	6
+#define ETM4_CFG_BIT_VMID	7
 #define ETM4_CFG_BIT_TS		11
 #define ETM4_CFG_BIT_RETSTK	12
+#define ETM4_CFG_BIT_VMID_OPT	15
 
 static inline int coresight_get_trace_id(int cpu)
 {
diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index ad8421e8b651..08c329d6b2a5 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -67,6 +67,7 @@ static int cs_etm_set_context_id(struct auxtrace_record *itr,
 	char path[PATH_MAX];
 	int err = -EINVAL;
 	u32 val;
+	u64 contextid;
 
 	ptr = container_of(itr, struct cs_etm_recording, itr);
 	cs_etm_pmu = ptr->cs_etm_pmu;
@@ -86,25 +87,59 @@ static int cs_etm_set_context_id(struct auxtrace_record *itr,
 		goto out;
 	}
 
+	/* User has configured for PID tracing, respects it. */
+	contextid = evsel->core.attr.config &
+			(BIT(ETM_OPT_CTXTID) | BIT(ETM_OPT_CTXTID2));
+
 	/*
-	 * TRCIDR2.CIDSIZE, bit [9-5], indicates whether contextID tracing
-	 * is supported:
-	 *  0b00000 Context ID tracing is not supported.
-	 *  0b00100 Maximum of 32-bit Context ID size.
-	 *  All other values are reserved.
+	 * If user doesn't configure the contextid format, parse PMU format and
+	 * enable PID tracing according to the "contextid" format bits:
+	 *
+	 *   If bit ETM_OPT_CTXTID is set, trace CONTEXTIDR_EL1;
+	 *   If bit ETM_OPT_CTXTID2 is set, trace CONTEXTIDR_EL2.
 	 */
-	val = BMVAL(val, 5, 9);
-	if (!val || val != 0x4) {
-		err = -EINVAL;
-		goto out;
+	if (!contextid)
+		contextid = perf_pmu__format_bits(&cs_etm_pmu->format,
+						  "contextid");
+
+	if (contextid & BIT(ETM_OPT_CTXTID)) {
+		/*
+		 * TRCIDR2.CIDSIZE, bit [9-5], indicates whether contextID
+		 * tracing is supported:
+		 *  0b00000 Context ID tracing is not supported.
+		 *  0b00100 Maximum of 32-bit Context ID size.
+		 *  All other values are reserved.
+		 */
+		val = BMVAL(val, 5, 9);
+		if (!val || val != 0x4) {
+			pr_err("%s: CONTEXTIDR_EL1 isn't supported\n",
+			       CORESIGHT_ETM_PMU_NAME);
+			err = -EINVAL;
+			goto out;
+		}
+	}
+
+	if (contextid & BIT(ETM_OPT_CTXTID2)) {
+		/*
+		 * TRCIDR2.VMIDOPT[30:29] != 0 and
+		 * TRCIDR2.VMIDSIZE[14:10] == 0b00100 (32bit virtual contextid)
+		 * We can't support CONTEXTIDR in VMID if the size of the
+		 * virtual context id is < 32bit.
+		 * Any value of VMIDSIZE >= 4 (i.e, > 32bit) is fine for us.
+		 */
+		if (!BMVAL(val, 29, 30) || BMVAL(val, 10, 14) < 4) {
+			pr_err("%s: CONTEXTIDR_EL2 isn't supported\n",
+			       CORESIGHT_ETM_PMU_NAME);
+			err = -EINVAL;
+			goto out;
+		}
 	}
 
 	/* All good, let the kernel know */
-	evsel->core.attr.config |= (1 << ETM_OPT_CTXTID);
+	evsel->core.attr.config |= contextid;
 	err = 0;
 
 out:
-
 	return err;
 }
 
@@ -485,7 +520,9 @@ static u64 cs_etmv4_get_config(struct auxtrace_record *itr)
 		config |= BIT(ETM4_CFG_BIT_TS);
 	if (config_opts & BIT(ETM_OPT_RETSTK))
 		config |= BIT(ETM4_CFG_BIT_RETSTK);
-
+	if (config_opts & BIT(ETM_OPT_CTXTID2))
+		config |= BIT(ETM4_CFG_BIT_VMID) |
+			  BIT(ETM4_CFG_BIT_VMID_OPT);
 	return config;
 }
 
-- 
2.25.1


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[PATCH v4 4/5] perf cs-etm: Add helper cs_etm__get_pid_fmt()

[Leo Yan]

This patch adds helper function cs_etm__get_pid_fmt(), by passing
parameter "traceID", it returns the PID format.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 tools/perf/util/cs-etm.c | 42 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/cs-etm.h |  1 +
 2 files changed, 43 insertions(+)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index a2a369e2fbb6..b9c1d329a7f1 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/coresight-pmu.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/log2.h>
@@ -156,6 +157,47 @@ int cs_etm__get_cpu(u8 trace_chan_id, int *cpu)
 	return 0;
 }
 
+/*
+ * The returned PID format is presented by two bits:
+ *
+ *   Bit ETM_OPT_CTXTID: CONTEXTIDR or CONTEXTIDR_EL1 is traced;
+ *   Bit ETM_OPT_CTXTID2: CONTEXTIDR_EL2 is traced.
+ *
+ * It's possible that the two bits ETM_OPT_CTXTID and ETM_OPT_CTXTID2
+ * are enabled at the same time when the session runs on an EL2 kernel.
+ * This means the CONTEXTIDR_EL1 and CONTEXTIDR_EL2 both will be
+ * recorded in the trace data, the tool will selectively use
+ * CONTEXTIDR_EL2 as PID.
+ */
+int cs_etm__get_pid_fmt(u8 trace_chan_id, u64 *pid_fmt)
+{
+	struct int_node *inode;
+	u64 *metadata, val;
+
+	inode = intlist__find(traceid_list, trace_chan_id);
+	if (!inode)
+		return -EINVAL;
+
+	metadata = inode->priv;
+
+	if (metadata[CS_ETM_MAGIC] == __perf_cs_etmv3_magic) {
+		val = metadata[CS_ETM_ETMCR];
+		/* CONTEXTIDR is traced */
+		if (val & BIT(ETM_OPT_CTXTID))
+			*pid_fmt = BIT(ETM_OPT_CTXTID);
+	} else {
+		val = metadata[CS_ETMV4_TRCCONFIGR];
+		/* CONTEXTIDR_EL2 is traced */
+		if (val & (BIT(ETM4_CFG_BIT_VMID) | BIT(ETM4_CFG_BIT_VMID_OPT)))
+			*pid_fmt = BIT(ETM_OPT_CTXTID2);
+		/* CONTEXTIDR_EL1 is traced */
+		else if (val & BIT(ETM4_CFG_BIT_CTXTID))
+			*pid_fmt = BIT(ETM_OPT_CTXTID);
+	}
+
+	return 0;
+}
+
 void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq,
 					      u8 trace_chan_id)
 {
diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
index 4ad925d6d799..7cc3bba0017d 100644
--- a/tools/perf/util/cs-etm.h
+++ b/tools/perf/util/cs-etm.h
@@ -173,6 +173,7 @@ struct cs_etm_packet_queue {
 int cs_etm__process_auxtrace_info(union perf_event *event,
 				  struct perf_session *session);
 int cs_etm__get_cpu(u8 trace_chan_id, int *cpu);
+int cs_etm__get_pid_fmt(u8 trace_chan_id, u64 *pid_fmt);
 int cs_etm__etmq_set_tid(struct cs_etm_queue *etmq,
 			 pid_t tid, u8 trace_chan_id);
 bool cs_etm__etmq_is_timeless(struct cs_etm_queue *etmq);
-- 
2.25.1


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[PATCH v4 5/5] perf cs-etm: Detect pid in VMID for kernel running at EL2

[Leo Yan]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

The PID of the task could be traced as VMID when the kernel is running
at EL2.  Teach the decoder to look for VMID when the CONTEXTIDR (Arm32)
or CONTEXTIDR_EL1 (Arm64) is invalid but we have a valid VMID.

Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Al Grant <al.grant@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Co-developed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 .../perf/util/cs-etm-decoder/cs-etm-decoder.c | 38 +++++++++++++++++--
 1 file changed, 34 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
index 3f4bc4050477..4052c9ce6e2f 100644
--- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
+++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
@@ -6,6 +6,7 @@
  * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
  */
 
+#include <linux/coresight-pmu.h>
 #include <linux/err.h>
 #include <linux/list.h>
 #include <linux/zalloc.h>
@@ -491,13 +492,42 @@ cs_etm_decoder__set_tid(struct cs_etm_queue *etmq,
 			const ocsd_generic_trace_elem *elem,
 			const uint8_t trace_chan_id)
 {
-	pid_t tid;
+	pid_t tid = -1;
+	static u64 pid_fmt;
+	int ret;
 
-	/* Ignore PE_CONTEXT packets that don't have a valid contextID */
-	if (!elem->context.ctxt_id_valid)
+	/*
+	 * As all the ETMs run at the same exception level, the system should
+	 * have the same PID format crossing CPUs.  So cache the PID format
+	 * and reuse it for sequential decoding.
+	 */
+	if (!pid_fmt) {
+		ret = cs_etm__get_pid_fmt(trace_chan_id, &pid_fmt);
+		if (ret)
+			return OCSD_RESP_FATAL_SYS_ERR;
+	}
+
+	/*
+	 * Process the PE_CONTEXT packets if we have a valid contextID or VMID.
+	 * If the kernel is running at EL2, the PID is traced in CONTEXTIDR_EL2
+	 * as VMID, Bit ETM_OPT_CTXTID2 is set in this case.
+	 */
+	switch (pid_fmt) {
+	case BIT(ETM_OPT_CTXTID):
+		if (elem->context.ctxt_id_valid)
+			tid = elem->context.context_id;
+		break;
+	case BIT(ETM_OPT_CTXTID2):
+		if (elem->context.vmid_valid)
+			tid = elem->context.vmid;
+		break;
+	default:
+		break;
+	}
+
+	if (tid == -1)
 		return OCSD_RESP_CONT;
 
-	tid =  elem->context.context_id;
 	if (cs_etm__etmq_set_tid(etmq, tid, trace_chan_id))
 		return OCSD_RESP_FATAL_SYS_ERR;
 
-- 
2.25.1


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