[PATCH 07/25] perf intel-pt: decoder: Add CFE and EVD processing

From: Adrian Hunter
Date: Mon Jan 24 2022 - 03:42:40 EST


As of Intel SDM (https://www.intel.com/sdm) version 076, there is a new
Intel PT feature called Event Trace which requires 2 new packets CFE and
EVD. Each Event Trace event is represented by a CFE packet that is
preceded by zero or more EVD packets. It may be bound to a following FUP
packet that provides the IP.

Event Trace exposes details about asynchronous events. The CFE packet
contains a type field to identify one of the following:

1 INTR interrupt, fault, exception, NMI
2 IRET interrupt return
3 SMI system management interrupt
4 RSM resume from system management mode
5 SIPI startup interprocessor interrupt
6 INIT INIT signal
7 VMENTRY VM-Entry
8 VMEXIT VM-Entry
9 VMEXIT_INTR VM-Exit due to interrupt
10 SHUTDOWN Shutdown

For more details, refer to the Intel SDM, Intel Processor Trace chapter.

Add processing to the decoder for the new packets.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
.../util/intel-pt-decoder/intel-pt-decoder.c | 62 +++++++++++++++++++
.../util/intel-pt-decoder/intel-pt-decoder.h | 17 +++++
2 files changed, 79 insertions(+)

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 5792d536b458..1a39119706d6 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -213,6 +213,8 @@ struct intel_pt_decoder {
bool set_fup_pwre;
bool set_fup_exstop;
bool set_fup_bep;
+ bool set_fup_cfe_ip;
+ bool set_fup_cfe;
bool sample_cyc;
unsigned int fup_tx_flags;
unsigned int tx_flags;
@@ -223,6 +225,7 @@ struct intel_pt_decoder {
uint64_t timestamp_insn_cnt;
uint64_t sample_insn_cnt;
uint64_t stuck_ip;
+ struct intel_pt_pkt fup_cfe_pkt;
int max_loops;
int no_progress;
int stuck_ip_prd;
@@ -231,6 +234,8 @@ struct intel_pt_decoder {
const unsigned char *next_buf;
size_t next_len;
unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
+ int evd_cnt;
+ struct intel_pt_evd evd[INTEL_PT_MAX_EVDS];
};

static uint64_t intel_pt_lower_power_of_2(uint64_t x)
@@ -1214,6 +1219,9 @@ static void intel_pt_clear_fup_event(struct intel_pt_decoder *decoder)
decoder->set_fup_pwre = false;
decoder->set_fup_exstop = false;
decoder->set_fup_bep = false;
+ decoder->set_fup_cfe_ip = false;
+ decoder->set_fup_cfe = false;
+ decoder->evd_cnt = 0;
}

static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
@@ -1223,6 +1231,23 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)

decoder->state.type &= ~INTEL_PT_BRANCH;

+ if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
+ bool ip = decoder->set_fup_cfe_ip;
+
+ decoder->set_fup_cfe_ip = false;
+ decoder->set_fup_cfe = false;
+ decoder->state.type |= INTEL_PT_EVT;
+ if (!ip && decoder->pge)
+ decoder->state.type |= INTEL_PT_BRANCH;
+ decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
+ decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
+ decoder->state.evd_cnt = decoder->evd_cnt;
+ decoder->state.evd = decoder->evd;
+ decoder->evd_cnt = 0;
+ if (ip || decoder->pge)
+ decoder->state.flags |= INTEL_PT_FUP_IP;
+ ret = true;
+ }
if (decoder->set_fup_tx_flags) {
decoder->set_fup_tx_flags = false;
decoder->tx_flags = decoder->fup_tx_flags;
@@ -1540,6 +1565,19 @@ static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
return 0;
}

+static int intel_pt_evd(struct intel_pt_decoder *decoder)
+{
+ if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
+ intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
+ return -ENOSYS;
+ }
+ decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
+ .type = decoder->packet.count,
+ .payload = decoder->packet.payload,
+ };
+ return 0;
+}
+
static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
{
timestamp |= (ref_timestamp & (0xffULL << 56));
@@ -3250,8 +3288,32 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
goto next;

case INTEL_PT_CFE:
+ decoder->fup_cfe_pkt = decoder->packet;
+ decoder->set_fup_cfe = true;
+ if (!decoder->pge) {
+ intel_pt_fup_event(decoder);
+ return 0;
+ }
+ break;
+
case INTEL_PT_CFE_IP:
+ decoder->fup_cfe_pkt = decoder->packet;
+ err = intel_pt_get_next_packet(decoder);
+ if (err)
+ return err;
+ if (decoder->packet.type == INTEL_PT_FUP) {
+ decoder->set_fup_cfe_ip = true;
+ no_tip = true;
+ } else {
+ intel_pt_log_at("ERROR: Missing FUP after CFE",
+ decoder->pos);
+ }
+ goto next;
+
case INTEL_PT_EVD:
+ err = intel_pt_evd(decoder);
+ if (err)
+ return err;
break;

default:
diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h
index 8fd68f7a0963..59ef4b41ec67 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h
@@ -35,6 +35,7 @@ enum intel_pt_sample_type {
INTEL_PT_TRACE_END = 1 << 10,
INTEL_PT_BLK_ITEMS = 1 << 11,
INTEL_PT_PSB_EVT = 1 << 12,
+ INTEL_PT_EVT = 1 << 13,
};

enum intel_pt_period_type {
@@ -209,6 +210,18 @@ struct intel_pt_vmcs_info {
bool error_printed;
};

+/*
+ * Maximum number of event trace data in one go, assuming at most 1 per type
+ * and 6-bits of type in the EVD packet.
+ */
+#define INTEL_PT_MAX_EVDS 64
+
+/* Event trace data from EVD packet */
+struct intel_pt_evd {
+ int type;
+ uint64_t payload;
+};
+
struct intel_pt_state {
enum intel_pt_sample_type type;
bool from_nr;
@@ -234,6 +247,10 @@ struct intel_pt_state {
int insn_len;
char insn[INTEL_PT_INSN_BUF_SZ];
struct intel_pt_blk_items items;
+ int cfe_type;
+ int cfe_vector;
+ int evd_cnt;
+ struct intel_pt_evd *evd;
};

struct intel_pt_insn;
--
2.25.1