Re: [PATCH 01/11] perf intel-pt: Add new packets for PEBS via PT

Arnaldo Carvalho de Melo
2019-06-12T00:09:53Z

Em Mon, Jun 10, 2019 at 10:27:53AM +0300, Adrian Hunter escreveu:
> Add 3 new packets to supports PEBS via PT, namely Block Begin Packet (BBP),
> Block Item Packet (BIP) and Block End Packet (BEP). PEBS data is encoded
> into multiple BIP packets that come between BBP and BEP. The BEP packet
> might be associated with a FUP packet. That is indicated by using a
> separate packet type (INTEL_PT_BEP_IP) similar to other packets types with
> the _IP suffix.
>
> Refer to the Intel SDM for more information about PEBS via PT.

In these cases would be nice to provide an URL and page number, for
convenience.

- Arnaldo

> Decoding of BIP packets conflicts with single-byte TNT packets. Since BIP
> packets only occur in the context of a block (i.e. between BBP and BEP),
> that context must be recorded and passed to the packet decoder.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
> .../util/intel-pt-decoder/intel-pt-decoder.c | 38 ++++-
> .../intel-pt-decoder/intel-pt-pkt-decoder.c | 140 +++++++++++++++++-
> .../intel-pt-decoder/intel-pt-pkt-decoder.h | 21 ++-
> tools/perf/util/intel-pt.c | 3 +-
> 4 files changed, 193 insertions(+), 9 deletions(-)
>
> 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 9eb778f9c911..44218f9cf16a 100644
> --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> @@ -140,6 +140,7 @@ struct intel_pt_decoder {
> int mtc_shift;
> struct intel_pt_stack stack;
> enum intel_pt_pkt_state pkt_state;
> + enum intel_pt_pkt_ctx pkt_ctx;
> struct intel_pt_pkt packet;
> struct intel_pt_pkt tnt;
> int pkt_step;
> @@ -558,7 +559,7 @@ static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
> memcpy(buf + len, decoder->buf, n);
> len += n;
>
> - ret = intel_pt_get_packet(buf, len, &decoder->packet);
> + ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx);
> if (ret < (int)old_len) {
> decoder->next_buf = decoder->buf;
> decoder->next_len = decoder->len;
> @@ -593,6 +594,7 @@ static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
> {
> struct intel_pt_pkt_info pkt_info;
> const unsigned char *buf = decoder->buf;
> + enum intel_pt_pkt_ctx pkt_ctx = decoder->pkt_ctx;
> size_t len = decoder->len;
> int ret;
>
> @@ -611,7 +613,8 @@ static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
> if (!len)
> return INTEL_PT_NEED_MORE_BYTES;
>
> - ret = intel_pt_get_packet(buf, len, &pkt_info.packet);
> + ret = intel_pt_get_packet(buf, len, &pkt_info.packet,
> + &pkt_ctx);
> if (!ret)
> return INTEL_PT_NEED_MORE_BYTES;
> if (ret < 0)
> @@ -686,6 +689,10 @@ static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
> case INTEL_PT_MNT:
> case INTEL_PT_PTWRITE:
> case INTEL_PT_PTWRITE_IP:
> + case INTEL_PT_BBP:
> + case INTEL_PT_BIP:
> + case INTEL_PT_BEP:
> + case INTEL_PT_BEP_IP:
> return 0;
>
> case INTEL_PT_MTC:
> @@ -878,7 +885,7 @@ static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
> }
>
> ret = intel_pt_get_packet(decoder->buf, decoder->len,
> - &decoder->packet);
> + &decoder->packet, &decoder->pkt_ctx);
> if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 &&
> decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
> ret = intel_pt_get_split_packet(decoder);
> @@ -1624,6 +1631,10 @@ static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
> case INTEL_PT_MWAIT:
> case INTEL_PT_PWRE:
> case INTEL_PT_PWRX:
> + case INTEL_PT_BBP:
> + case INTEL_PT_BIP:
> + case INTEL_PT_BEP:
> + case INTEL_PT_BEP_IP:
> decoder->have_tma = false;
> intel_pt_log("ERROR: Unexpected packet\n");
> err = -EAGAIN;
> @@ -1717,6 +1728,10 @@ static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
> case INTEL_PT_MWAIT:
> case INTEL_PT_PWRE:
> case INTEL_PT_PWRX:
> + case INTEL_PT_BBP:
> + case INTEL_PT_BIP:
> + case INTEL_PT_BEP:
> + case INTEL_PT_BEP_IP:
> intel_pt_log("ERROR: Missing TIP after FUP\n");
> decoder->pkt_state = INTEL_PT_STATE_ERR3;
> decoder->pkt_step = 0;
> @@ -2038,6 +2053,12 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
> decoder->state.pwrx_payload = decoder->packet.payload;
> return 0;
>
> + case INTEL_PT_BBP:
> + case INTEL_PT_BIP:
> + case INTEL_PT_BEP:
> + case INTEL_PT_BEP_IP:
> + break;
> +
> default:
> return intel_pt_bug(decoder);
> }
> @@ -2076,6 +2097,10 @@ static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
> case INTEL_PT_MWAIT:
> case INTEL_PT_PWRE:
> case INTEL_PT_PWRX:
> + case INTEL_PT_BBP:
> + case INTEL_PT_BIP:
> + case INTEL_PT_BEP:
> + case INTEL_PT_BEP_IP:
> intel_pt_log("ERROR: Unexpected packet\n");
> err = -ENOENT;
> goto out;
> @@ -2282,6 +2307,10 @@ static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
> case INTEL_PT_MWAIT:
> case INTEL_PT_PWRE:
> case INTEL_PT_PWRX:
> + case INTEL_PT_BBP:
> + case INTEL_PT_BIP:
> + case INTEL_PT_BEP:
> + case INTEL_PT_BEP_IP:
> default:
> break;
> }
> @@ -2632,11 +2661,12 @@ static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
> static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
> size_t *rem)
> {
> + enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
> struct intel_pt_pkt packet;
> int ret;
>
> while (len) {
> - ret = intel_pt_get_packet(buf, len, &packet);
> + ret = intel_pt_get_packet(buf, len, &packet, &ctx);
> if (ret <= 0)
> return false;
> if (packet.type == INTEL_PT_TSC) {
> diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.c
> index d426761a549d..2b2793b339c0 100644
> --- a/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.c
> +++ b/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.c
> @@ -71,6 +71,10 @@ static const char * const packet_name[] = {
> [INTEL_PT_MWAIT] = "MWAIT",
> [INTEL_PT_PWRE] = "PWRE",
> [INTEL_PT_PWRX] = "PWRX",
> + [INTEL_PT_BBP] = "BBP",
> + [INTEL_PT_BIP] = "BIP",
> + [INTEL_PT_BEP] = "BEP",
> + [INTEL_PT_BEP_IP] = "BEP",
> };
>
> const char *intel_pt_pkt_name(enum intel_pt_pkt_type type)
> @@ -289,6 +293,55 @@ static int intel_pt_get_pwrx(const unsigned char *buf, size_t len,
> return 7;
> }
>
> +static int intel_pt_get_bbp(const unsigned char *buf, size_t len,
> + struct intel_pt_pkt *packet)
> +{
> + if (len < 3)
> + return INTEL_PT_NEED_MORE_BYTES;
> + packet->type = INTEL_PT_BBP;
> + packet->count = buf[2] >> 7;
> + packet->payload = buf[2] & 0x1f;
> + return 3;
> +}
> +
> +static int intel_pt_get_bip_4(const unsigned char *buf, size_t len,
> + struct intel_pt_pkt *packet)
> +{
> + if (len < 5)
> + return INTEL_PT_NEED_MORE_BYTES;
> + packet->type = INTEL_PT_BIP;
> + packet->count = buf[0] >> 3;
> + memcpy_le64(&packet->payload, buf + 1, 4);
> + return 5;
> +}
> +
> +static int intel_pt_get_bip_8(const unsigned char *buf, size_t len,
> + struct intel_pt_pkt *packet)
> +{
> + if (len < 9)
> + return INTEL_PT_NEED_MORE_BYTES;
> + packet->type = INTEL_PT_BIP;
> + packet->count = buf[0] >> 3;
> + memcpy_le64(&packet->payload, buf + 1, 8);
> + return 9;
> +}
> +
> +static int intel_pt_get_bep(size_t len, struct intel_pt_pkt *packet)
> +{
> + if (len < 2)
> + return INTEL_PT_NEED_MORE_BYTES;
> + packet->type = INTEL_PT_BEP;
> + return 2;
> +}
> +
> +static int intel_pt_get_bep_ip(size_t len, struct intel_pt_pkt *packet)
> +{
> + if (len < 2)
> + return INTEL_PT_NEED_MORE_BYTES;
> + packet->type = INTEL_PT_BEP_IP;
> + return 2;
> +}
> +
> static int intel_pt_get_ext(const unsigned char *buf, size_t len,
> struct intel_pt_pkt *packet)
> {
> @@ -329,6 +382,12 @@ static int intel_pt_get_ext(const unsigned char *buf, size_t len,
> return intel_pt_get_pwre(buf, len, packet);
> case 0xA2: /* PWRX */
> return intel_pt_get_pwrx(buf, len, packet);
> + case 0x63: /* BBP */
> + return intel_pt_get_bbp(buf, len, packet);
> + case 0x33: /* BEP no IP */
> + return intel_pt_get_bep(len, packet);
> + case 0xb3: /* BEP with IP */
> + return intel_pt_get_bep_ip(len, packet);
> default:
> return INTEL_PT_BAD_PACKET;
> }
> @@ -477,7 +536,8 @@ static int intel_pt_get_mtc(const unsigned char *buf, size_t len,
> }
>
> static int intel_pt_do_get_packet(const unsigned char *buf, size_t len,
> - struct intel_pt_pkt *packet)
> + struct intel_pt_pkt *packet,
> + enum intel_pt_pkt_ctx ctx)
> {
> unsigned int byte;
>
> @@ -487,6 +547,22 @@ static int intel_pt_do_get_packet(const unsigned char *buf, size_t len,
> return INTEL_PT_NEED_MORE_BYTES;
>
> byte = buf[0];
> +
> + switch (ctx) {
> + case INTEL_PT_NO_CTX:
> + break;
> + case INTEL_PT_BLK_4_CTX:
> + if ((byte & 0x7) == 4)
> + return intel_pt_get_bip_4(buf, len, packet);
> + break;
> + case INTEL_PT_BLK_8_CTX:
> + if ((byte & 0x7) == 4)
> + return intel_pt_get_bip_8(buf, len, packet);
> + break;
> + default:
> + break;
> + };
> +
> if (!(byte & BIT(0))) {
> if (byte == 0)
> return intel_pt_get_pad(packet);
> @@ -525,15 +601,65 @@ static int intel_pt_do_get_packet(const unsigned char *buf, size_t len,
> }
> }
>
> +void intel_pt_upd_pkt_ctx(const struct intel_pt_pkt *packet,
> + enum intel_pt_pkt_ctx *ctx)
> +{
> + switch (packet->type) {
> + case INTEL_PT_BAD:
> + case INTEL_PT_PAD:
> + case INTEL_PT_TSC:
> + case INTEL_PT_TMA:
> + case INTEL_PT_MTC:
> + case INTEL_PT_FUP:
> + case INTEL_PT_CYC:
> + case INTEL_PT_CBR:
> + case INTEL_PT_MNT:
> + case INTEL_PT_EXSTOP:
> + case INTEL_PT_EXSTOP_IP:
> + case INTEL_PT_PWRE:
> + case INTEL_PT_PWRX:
> + case INTEL_PT_BIP:
> + break;
> + case INTEL_PT_TNT:
> + case INTEL_PT_TIP:
> + case INTEL_PT_TIP_PGD:
> + case INTEL_PT_TIP_PGE:
> + case INTEL_PT_MODE_EXEC:
> + case INTEL_PT_MODE_TSX:
> + case INTEL_PT_PIP:
> + case INTEL_PT_OVF:
> + case INTEL_PT_VMCS:
> + case INTEL_PT_TRACESTOP:
> + case INTEL_PT_PSB:
> + case INTEL_PT_PSBEND:
> + case INTEL_PT_PTWRITE:
> + case INTEL_PT_PTWRITE_IP:
> + case INTEL_PT_MWAIT:
> + case INTEL_PT_BEP:
> + case INTEL_PT_BEP_IP:
> + *ctx = INTEL_PT_NO_CTX;
> + break;
> + case INTEL_PT_BBP:
> + if (packet->count)
> + *ctx = INTEL_PT_BLK_4_CTX;
> + else
> + *ctx = INTEL_PT_BLK_8_CTX;
> + break;
> + default:
> + break;
> + }
> +}
> +
> int intel_pt_get_packet(const unsigned char *buf, size_t len,
> - struct intel_pt_pkt *packet)
> + struct intel_pt_pkt *packet, enum intel_pt_pkt_ctx *ctx)
> {
> int ret;
>
> - ret = intel_pt_do_get_packet(buf, len, packet);
> + ret = intel_pt_do_get_packet(buf, len, packet, *ctx);
> if (ret > 0) {
> while (ret < 8 && len > (size_t)ret && !buf[ret])
> ret += 1;
> + intel_pt_upd_pkt_ctx(packet, ctx);
> }
> return ret;
> }
> @@ -611,8 +737,10 @@ int intel_pt_pkt_desc(const struct intel_pt_pkt *packet, char *buf,
> return snprintf(buf, buf_len, "%s 0x%llx IP:0", name, payload);
> case INTEL_PT_PTWRITE_IP:
> return snprintf(buf, buf_len, "%s 0x%llx IP:1", name, payload);
> + case INTEL_PT_BEP:
> case INTEL_PT_EXSTOP:
> return snprintf(buf, buf_len, "%s IP:0", name);
> + case INTEL_PT_BEP_IP:
> case INTEL_PT_EXSTOP_IP:
> return snprintf(buf, buf_len, "%s IP:1", name);
> case INTEL_PT_MWAIT:
> @@ -630,6 +758,12 @@ int intel_pt_pkt_desc(const struct intel_pt_pkt *packet, char *buf,
> (unsigned int)((payload >> 4) & 0xf),
> (unsigned int)(payload & 0xf),
> (unsigned int)((payload >> 8) & 0xf));
> + case INTEL_PT_BBP:
> + return snprintf(buf, buf_len, "%s SZ %s-byte Type 0x%llx",
> + name, packet->count ? "4" : "8", payload);
> + case INTEL_PT_BIP:
> + return snprintf(buf, buf_len, "%s ID 0x%02x Value 0x%llx",
> + name, packet->count, payload);
> default:
> break;
> }
> diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.h b/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.h
> index 73ddc3a88d07..682b35282abc 100644
> --- a/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.h
> +++ b/tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.h
> @@ -59,6 +59,10 @@ enum intel_pt_pkt_type {
> INTEL_PT_MWAIT,
> INTEL_PT_PWRE,
> INTEL_PT_PWRX,
> + INTEL_PT_BBP,
> + INTEL_PT_BIP,
> + INTEL_PT_BEP,
> + INTEL_PT_BEP_IP,
> };
>
> struct intel_pt_pkt {
> @@ -67,10 +71,25 @@ struct intel_pt_pkt {
> uint64_t payload;
> };
>
> +/*
> + * Decoding of BIP packets conflicts with single-byte TNT packets. Since BIP
> + * packets only occur in the context of a block (i.e. between BBP and BEP), that
> + * context must be recorded and passed to the packet decoder.
> + */
> +enum intel_pt_pkt_ctx {
> + INTEL_PT_NO_CTX, /* BIP packets are invalid */
> + INTEL_PT_BLK_4_CTX, /* 4-byte BIP packets */
> + INTEL_PT_BLK_8_CTX, /* 8-byte BIP packets */
> +};
> +
> const char *intel_pt_pkt_name(enum intel_pt_pkt_type);
>
> int intel_pt_get_packet(const unsigned char *buf, size_t len,
> - struct intel_pt_pkt *packet);
> + struct intel_pt_pkt *packet,
> + enum intel_pt_pkt_ctx *ctx);
> +
> +void intel_pt_upd_pkt_ctx(const struct intel_pt_pkt *packet,
> + enum intel_pt_pkt_ctx *ctx);
>
> int intel_pt_pkt_desc(const struct intel_pt_pkt *packet, char *buf, size_t len);
>
> diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
> index 3cff8fe2eaa0..f43d3ac2db8b 100644
> --- a/tools/perf/util/intel-pt.c
> +++ b/tools/perf/util/intel-pt.c
> @@ -174,13 +174,14 @@ static void intel_pt_dump(struct intel_pt *pt __maybe_unused,
> int ret, pkt_len, i;
> char desc[INTEL_PT_PKT_DESC_MAX];
> const char *color = PERF_COLOR_BLUE;
> + enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
>
> color_fprintf(stdout, color,
> ". ... Intel Processor Trace data: size %zu bytes\n",
> len);
>
> while (len) {
> - ret = intel_pt_get_packet(buf, len, &packet);
> + ret = intel_pt_get_packet(buf, len, &packet, &ctx);
> if (ret > 0)
> pkt_len = ret;
> else
> --
> 2.17.1

--

- Arnaldo