[v8,1/6] eal: trace: add trace point emit for blob

diff --git a/app/test/test_trace.c b/app/test/test_trace.c
index 6bedf14024..ad4a394a29 100644
--- a/app/test/test_trace.c
+++ b/app/test/test_trace.c
@@ -4,6 +4,7 @@ 
 
 #include <rte_eal_trace.h>
 #include <rte_lcore.h>
+#include <rte_random.h>
 #include <rte_trace.h>
 
 #include "test.h"
@@ -177,7 +178,12 @@  test_fp_trace_points(void)
 static int
 test_generic_trace_points(void)
 {
+	uint8_t arr[RTE_TRACE_BLOB_LEN_MAX];
 	int tmp;
+	int i;
+
+	for (i = 0; i < RTE_TRACE_BLOB_LEN_MAX; i++)
+		arr[i] = i;
 
 	rte_eal_trace_generic_void();
 	rte_eal_trace_generic_u64(0x10000000000000);
@@ -195,6 +201,11 @@  test_generic_trace_points(void)
 	rte_eal_trace_generic_ptr(&tmp);
 	rte_eal_trace_generic_str("my string");
 	rte_eal_trace_generic_size_t(sizeof(void *));
+	rte_eal_trace_generic_blob(arr, 0);
+	rte_eal_trace_generic_blob(arr, 17);
+	rte_eal_trace_generic_blob(arr, RTE_TRACE_BLOB_LEN_MAX);
+	rte_eal_trace_generic_blob(arr, rte_rand() %
+					RTE_TRACE_BLOB_LEN_MAX);
 	RTE_EAL_TRACE_GENERIC_FUNC;
 
 	return TEST_SUCCESS;
diff --git a/doc/guides/prog_guide/trace_lib.rst b/doc/guides/prog_guide/trace_lib.rst
index 9a8f38073d..3e0ea5835c 100644
--- a/doc/guides/prog_guide/trace_lib.rst
+++ b/doc/guides/prog_guide/trace_lib.rst
@@ -352,3 +352,15 @@  event ID.
 The ``packet.header`` and ``packet.context`` will be written in the slow path
 at the time of trace memory creation. The ``trace.header`` and trace payload
 will be emitted when the tracepoint function is invoked.
+
+Limitations
+-----------
+
+- The ``rte_trace_point_emit_blob()`` function can capture a maximum blob of
+  length ``RTE_TRACE_BLOB_LEN_MAX`` bytes. The application can call
+  ``rte_trace_point_emit_blob()`` multiple times with length less than or equal to
+  ``RTE_TRACE_BLOB_LEN_MAX``, if it needs to capture more than ``RTE_TRACE_BLOB_LEN_MAX``
+  bytes.
+- If the length passed to the ``rte_trace_point_emit_blob()`` is less than
+  ``RTE_TRACE_BLOB_LEN_MAX``, then the trailing ``(RTE_TRACE_BLOB_LEN_MAX - len)``
+  bytes in the trace are set to zero.
diff --git a/lib/eal/common/eal_common_trace_points.c b/lib/eal/common/eal_common_trace_points.c
index 0b0b254615..051f89809c 100644
--- a/lib/eal/common/eal_common_trace_points.c
+++ b/lib/eal/common/eal_common_trace_points.c
@@ -40,6 +40,8 @@  RTE_TRACE_POINT_REGISTER(rte_eal_trace_generic_size_t,
 	lib.eal.generic.size_t)
 RTE_TRACE_POINT_REGISTER(rte_eal_trace_generic_func,
 	lib.eal.generic.func)
+RTE_TRACE_POINT_REGISTER(rte_eal_trace_generic_blob,
+	lib.eal.generic.blob)
 
 RTE_TRACE_POINT_REGISTER(rte_eal_trace_alarm_set,
 	lib.eal.alarm.set)
diff --git a/lib/eal/include/rte_eal_trace.h b/lib/eal/include/rte_eal_trace.h
index 5ef4398230..6f5c022558 100644
--- a/lib/eal/include/rte_eal_trace.h
+++ b/lib/eal/include/rte_eal_trace.h
@@ -143,6 +143,12 @@  RTE_TRACE_POINT(
 	rte_trace_point_emit_string(func);
 )
 
+RTE_TRACE_POINT(
+	rte_eal_trace_generic_blob,
+	RTE_TRACE_POINT_ARGS(const void *in, uint8_t len),
+	rte_trace_point_emit_blob(in, len);
+)
+
 #define RTE_EAL_TRACE_GENERIC_FUNC rte_eal_trace_generic_func(__func__)
 
 /* Interrupt */
diff --git a/lib/eal/include/rte_trace_point.h b/lib/eal/include/rte_trace_point.h
index 0f8700974f..4d6b5700dd 100644
--- a/lib/eal/include/rte_trace_point.h
+++ b/lib/eal/include/rte_trace_point.h
@@ -144,6 +144,16 @@  _tp _args \
 #define rte_trace_point_emit_ptr(val)
 /** Tracepoint function payload for string datatype */
 #define rte_trace_point_emit_string(val)
+/**
+ * Tracepoint function to capture a blob.
+ *
+ * @param val
+ *   Pointer to the array to be captured.
+ * @param len
+ *   Length to be captured. The maximum supported length is
+ *   RTE_TRACE_BLOB_LEN_MAX bytes.
+ */
+#define rte_trace_point_emit_blob(val, len)
 
 #endif /* __DOXYGEN__ */
 
@@ -152,6 +162,9 @@  _tp _args \
 /** @internal Macro to define event header size. */
 #define __RTE_TRACE_EVENT_HEADER_SZ sizeof(uint64_t)
 
+/** Macro to define maximum emit length of blob. */
+#define RTE_TRACE_BLOB_LEN_MAX 64
+
 /**
  * Enable recording events of the given tracepoint in the trace buffer.
  *
@@ -374,12 +387,30 @@  do { \
 	mem = RTE_PTR_ADD(mem, __RTE_TRACE_EMIT_STRING_LEN_MAX); \
 } while (0)
 
+#define rte_trace_point_emit_blob(in, len) \
+do { \
+	if (unlikely(in == NULL)) \
+		return; \
+	if (len > RTE_TRACE_BLOB_LEN_MAX) \
+		len = RTE_TRACE_BLOB_LEN_MAX; \
+	__rte_trace_point_emit(len, uint8_t); \
+	memcpy(mem, in, len); \
+	memset(RTE_PTR_ADD(mem, len), 0, RTE_TRACE_BLOB_LEN_MAX - len); \
+	mem = RTE_PTR_ADD(mem, RTE_TRACE_BLOB_LEN_MAX); \
+} while (0)
+
 #else
 
 #define __rte_trace_point_emit_header_generic(t) RTE_SET_USED(t)
 #define __rte_trace_point_emit_header_fp(t) RTE_SET_USED(t)
 #define __rte_trace_point_emit(in, type) RTE_SET_USED(in)
 #define rte_trace_point_emit_string(in) RTE_SET_USED(in)
+#define rte_trace_point_emit_blob(in, len) \
+do { \
+	RTE_SET_USED(in); \
+	RTE_SET_USED(len); \
+} while (0)
+
 
 #endif /* ALLOW_EXPERIMENTAL_API */
 #endif /* _RTE_TRACE_POINT_REGISTER_H_ */
diff --git a/lib/eal/include/rte_trace_point_register.h b/lib/eal/include/rte_trace_point_register.h
index a32f4d731b..a9682d3f22 100644
--- a/lib/eal/include/rte_trace_point_register.h
+++ b/lib/eal/include/rte_trace_point_register.h
@@ -47,6 +47,15 @@  do { \
 		RTE_STR(in)"[32]", "string_bounded_t"); \
 } while (0)
 
+#define rte_trace_point_emit_blob(in, len) \
+do { \
+	RTE_SET_USED(in); \
+	__rte_trace_point_emit(len, uint8_t); \
+	__rte_trace_point_emit_field(RTE_TRACE_BLOB_LEN_MAX, \
+		RTE_STR(in)"[" RTE_STR(RTE_TRACE_BLOB_LEN_MAX)"]", \
+		RTE_STR(uint8_t)); \
+} while (0)
+
 #ifdef __cplusplus
 }
 #endif