Hi Eric,

On Fri, Feb 6, 2026 at 6:25 PM Eric Lin [off-list ref] wrote:

Hi Anup,

On Sat, Nov 1, 2025 at 11:45 PM Anup Patel [off-list ref] wrote:

quoted

From: Mayuresh Chitale <redacted>

Add bare bones support for RISC-V trace decoder so that the data received
from the hardware by the RISC-V trace perf driver can be written to the
perf record output file.

Co-developed-by: Anup Patel <redacted>
Signed-off-by: Anup Patel <redacted>
Signed-off-by: Mayuresh Chitale <redacted>
---
 tools/perf/util/Build             |  1 +
 tools/perf/util/auxtrace.c        |  3 +
 tools/perf/util/rvtrace-decoder.c | 91 +++++++++++++++++++++++++++++++
 tools/perf/util/rvtrace.h         |  2 +
 4 files changed, 97 insertions(+)
 create mode 100644 tools/perf/util/rvtrace-decoder.c

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 4be313cd115a..f736cea51fd8 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build

@@ -145,6 +145,7 @@ perf-util-$(CONFIG_AUXTRACE) += cs-etm.o
 perf-util-$(CONFIG_AUXTRACE) += cs-etm-decoder/
 endif
 perf-util-$(CONFIG_AUXTRACE) += cs-etm-base.o
+perf-util-$(CONFIG_AUXTRACE) += rvtrace-decoder.o

 perf-util-y += parse-branch-options.o
 perf-util-y += dump-insn.o

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index c905563e0d8a..299991d5d305 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c

@@ -54,6 +54,7 @@
 #include "arm-spe.h"
 #include "hisi-ptt.h"
 #include "s390-cpumsf.h"
+#include "rvtrace.h"
 #include "util/mmap.h"
 #include "powerpc-vpadtl.h"

@@ -1395,6 +1396,8 @@ int perf_event__process_auxtrace_info(struct perf_session *session,
                err = powerpc_vpadtl_process_auxtrace_info(event, session);
                break;
        case PERF_AUXTRACE_RISCV_TRACE:
+               err = rvtrace__process_auxtrace_info(event, session);
+               break;
        case PERF_AUXTRACE_UNKNOWN:
        default:
                return -EINVAL;

diff --git a/tools/perf/util/rvtrace-decoder.c b/tools/perf/util/rvtrace-decoder.c
new file mode 100644
index 000000000000..58db5ca62c1a
--- /dev/null
+++ b/tools/perf/util/rvtrace-decoder.c

@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISC-V trace Decoder
+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include "evlist.h"
+#include <internal/lib.h>
+#include "rvtrace.h"
+
+struct rvtrace_decoder {
+       struct auxtrace auxtrace;
+       u32 auxtrace_type;
+       struct perf_session *session;
+       struct machine *machine;
+       u32 pmu_type;
+};
+
+static int rvtrace_process_event(struct perf_session *session __maybe_unused,
+                                union perf_event *event __maybe_unused,
+                                struct perf_sample *sample __maybe_unused,
+                                const struct perf_tool *tool __maybe_unused)
+{
+       return 0;
+}
+
+static int rvtrace_process_auxtrace_event(struct perf_session *session __maybe_unused,
+                                         union perf_event *event __maybe_unused,
+                                         const struct perf_tool *tool __maybe_unused)
+{
+       return 0;
+}
+
+static int rvtrace_flush(struct perf_session *session __maybe_unused,
+                        const struct perf_tool *tool __maybe_unused)
+{
+       return 0;
+}
+
+static void rvtrace_free_events(struct perf_session *session __maybe_unused)
+{
+}
+
+static void rvtrace_free(struct perf_session *session)
+{
+       struct rvtrace_decoder *ptr = container_of(session->auxtrace, struct rvtrace_decoder,
+                                           auxtrace);
+
+       session->auxtrace = NULL;
+       free(ptr);
+}
+
+static bool rvtrace_evsel_is_auxtrace(struct perf_session *session,
+                                     struct evsel *evsel)
+{
+       struct rvtrace_decoder *ptr = container_of(session->auxtrace,
+                                                  struct rvtrace_decoder, auxtrace);
+
+       return evsel->core.attr.type == ptr->pmu_type;
+}
+
+int rvtrace__process_auxtrace_info(union perf_event *event,
+                                  struct perf_session *session)
+{
+       struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
+       struct rvtrace_decoder *ptr;
+
+       if (auxtrace_info->header.size < RVTRACE_AUXTRACE_PRIV_SIZE +
+           sizeof(struct perf_record_auxtrace_info))
+               return -EINVAL;
+
+       ptr = zalloc(sizeof(*ptr));
+       if (!ptr)
+               return -ENOMEM;
+
+       ptr->session = session;
+       ptr->machine = &session->machines.host;
+       ptr->auxtrace_type = auxtrace_info->type;
+       ptr->pmu_type = auxtrace_info->priv[0];
+
+       ptr->auxtrace.process_event = rvtrace_process_event;
+       ptr->auxtrace.process_auxtrace_event = rvtrace_process_auxtrace_event;
+       ptr->auxtrace.flush_events = rvtrace_flush;
+       ptr->auxtrace.free_events = rvtrace_free_events;
+       ptr->auxtrace.free = rvtrace_free;
+       ptr->auxtrace.evsel_is_auxtrace = rvtrace_evsel_is_auxtrace;
+       session->auxtrace = &ptr->auxtrace;
+
+       return 0;
+}

diff --git a/tools/perf/util/rvtrace.h b/tools/perf/util/rvtrace.h
index 93c041db8660..fdf2e5866c85 100644
--- a/tools/perf/util/rvtrace.h
+++ b/tools/perf/util/rvtrace.h

@@ -15,4 +15,6 @@

 #define RVTRACE_AUXTRACE_PRIV_SIZE     sizeof(u64)

+int rvtrace__process_auxtrace_info(union perf_event *event, struct perf_session *session);
+struct auxtrace_record *rvtrace_record_init(int *err);

It looks like the implementation of `rvtrace_recording_init` in the
auxtrace.c file is static (private), and the arguments don't match
this declaration.
Should we remove "static" from auxtrace.c and update this prototype
to: "struct auxtrace_record *rvtrace_recording_init(int *err, struct
perf_pmu *rvtrace_pmu);"?

Or should we simply remove this declaration from the header? Thanks.

The declaration should be removed from the header.

Regards,
Eric Lin,

quoted

 #endif
--
2.43.0


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv