[PATCH v4] perf: cs-etm: update ETM metadata format
Mathieu Poirier
mathieu.poirier at linaro.org
Wed Jan 27 13:32:42 EST 2021
On Wed, Jan 27, 2021 at 05:53:50PM +0000, Mike Leach wrote:
> The current fixed metadata version format (version 0), means that adding
> metadata parameter items renders files from a previous version of perf
> unreadable. Per CPU parameters appear in a fixed order, but there is no
> field to indicate the number of ETM parameters per CPU.
>
> This patch updates the per CPU parameter blocks to include a NR_PARAMs
> value which indicates the number of parameters in the block.
>
> The header version is incremented to 1. Fixed ordering is retained,
> new ETM parameters are added to the end of the list.
>
> The reader code is updated to be able to read current version 0 files,
> For version 1, the reader will read the number of parameters in the
> per CPU block. This allows the reader to process older or newer files
> that may have different numbers of parameters than in use at the
> time perf was built.
Thanks for the re-spin, I will look at it later this week. One question I had
is if this patch is needed to support the ETE extension Anshuman is working on?
>
> Changes since v3
> 1. Fixed index bug (Leo)
>
> Changes since v2
> 1. Add error path print to improve --dump logging
> 2. Replace some hardcoded values with enum consts (Mathieu).
>
> Changes since v1 (from Review by Leo):
> 1. Split printing routine into sub functions per version
> 2. Renamed NR_PARAMs to NR_TRC_PARAMs to emphasise use as count of trace
> related parameters, not total block parameter.
> 3. Misc other fixes.
>
> Signed-off-by: Mike Leach <mike.leach at linaro.org>
> ---
> tools/perf/arch/arm/util/cs-etm.c | 7 +-
> tools/perf/util/cs-etm.c | 235 ++++++++++++++++++++++++------
> tools/perf/util/cs-etm.h | 30 +++-
> 3 files changed, 223 insertions(+), 49 deletions(-)
>
> diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
> index bd446aba64f7..b0470f2a955a 100644
> --- a/tools/perf/arch/arm/util/cs-etm.c
> +++ b/tools/perf/arch/arm/util/cs-etm.c
> @@ -572,7 +572,7 @@ static void cs_etm_get_metadata(int cpu, u32 *offset,
> struct auxtrace_record *itr,
> struct perf_record_auxtrace_info *info)
> {
> - u32 increment;
> + u32 increment, nr_trc_params;
> u64 magic;
> struct cs_etm_recording *ptr =
> container_of(itr, struct cs_etm_recording, itr);
> @@ -607,6 +607,7 @@ static void cs_etm_get_metadata(int cpu, u32 *offset,
>
> /* How much space was used */
> increment = CS_ETMV4_PRIV_MAX;
> + nr_trc_params = CS_ETMV4_PRIV_MAX - CS_ETMV4_TRCCONFIGR;
> } else {
> magic = __perf_cs_etmv3_magic;
> /* Get configuration register */
> @@ -624,11 +625,13 @@ static void cs_etm_get_metadata(int cpu, u32 *offset,
>
> /* How much space was used */
> increment = CS_ETM_PRIV_MAX;
> + nr_trc_params = CS_ETM_PRIV_MAX - CS_ETM_ETMCR;
> }
>
> /* Build generic header portion */
> info->priv[*offset + CS_ETM_MAGIC] = magic;
> info->priv[*offset + CS_ETM_CPU] = cpu;
> + info->priv[*offset + CS_ETM_NR_TRC_PARAMS] = nr_trc_params;
> /* Where the next CPU entry should start from */
> *offset += increment;
> }
> @@ -674,7 +677,7 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
>
> /* First fill out the session header */
> info->type = PERF_AUXTRACE_CS_ETM;
> - info->priv[CS_HEADER_VERSION_0] = 0;
> + info->priv[CS_HEADER_VERSION] = CS_HEADER_CURRENT_VERSION;
> info->priv[CS_PMU_TYPE_CPUS] = type << 32;
> info->priv[CS_PMU_TYPE_CPUS] |= nr_cpu;
> info->priv[CS_ETM_SNAPSHOT] = ptr->snapshot_mode;
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index a2a369e2fbb6..f9af3fe0ed83 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -2435,7 +2435,7 @@ static bool cs_etm__is_timeless_decoding(struct cs_etm_auxtrace *etm)
> }
>
> static const char * const cs_etm_global_header_fmts[] = {
> - [CS_HEADER_VERSION_0] = " Header version %llx\n",
> + [CS_HEADER_VERSION] = " Header version %llx\n",
> [CS_PMU_TYPE_CPUS] = " PMU type/num cpus %llx\n",
> [CS_ETM_SNAPSHOT] = " Snapshot %llx\n",
> };
> @@ -2443,6 +2443,7 @@ static const char * const cs_etm_global_header_fmts[] = {
> static const char * const cs_etm_priv_fmts[] = {
> [CS_ETM_MAGIC] = " Magic number %llx\n",
> [CS_ETM_CPU] = " CPU %lld\n",
> + [CS_ETM_NR_TRC_PARAMS] = " NR_TRC_PARAMS %llx\n",
> [CS_ETM_ETMCR] = " ETMCR %llx\n",
> [CS_ETM_ETMTRACEIDR] = " ETMTRACEIDR %llx\n",
> [CS_ETM_ETMCCER] = " ETMCCER %llx\n",
> @@ -2452,6 +2453,7 @@ static const char * const cs_etm_priv_fmts[] = {
> static const char * const cs_etmv4_priv_fmts[] = {
> [CS_ETM_MAGIC] = " Magic number %llx\n",
> [CS_ETM_CPU] = " CPU %lld\n",
> + [CS_ETM_NR_TRC_PARAMS] = " NR_TRC_PARAMS %llx\n",
> [CS_ETMV4_TRCCONFIGR] = " TRCCONFIGR %llx\n",
> [CS_ETMV4_TRCTRACEIDR] = " TRCTRACEIDR %llx\n",
> [CS_ETMV4_TRCIDR0] = " TRCIDR0 %llx\n",
> @@ -2461,26 +2463,167 @@ static const char * const cs_etmv4_priv_fmts[] = {
> [CS_ETMV4_TRCAUTHSTATUS] = " TRCAUTHSTATUS %llx\n",
> };
>
> -static void cs_etm__print_auxtrace_info(__u64 *val, int num)
> +static const char * const param_unk_fmt =
> + " Unknown parameter [%d] %llx\n";
> +static const char * const magic_unk_fmt =
> + " Magic number Unknown %llx\n";
> +
> +static int cs_etm__print_cpu_metadata_v0(__u64 *val, int *offset)
> {
> - int i, j, cpu = 0;
> + int i = *offset, j, nr_params = 0, fmt_offset;
> + __u64 magic;
>
> - for (i = 0; i < CS_HEADER_VERSION_0_MAX; i++)
> - fprintf(stdout, cs_etm_global_header_fmts[i], val[i]);
> + /* check magic value */
> + magic = val[i + CS_ETM_MAGIC];
> + if ((magic != __perf_cs_etmv3_magic) &&
> + (magic != __perf_cs_etmv4_magic)) {
> + /* failure - note bad magic value */
> + fprintf(stdout, magic_unk_fmt, magic);
> + return -EINVAL;
> + }
> +
> + /* print common header block */
> + fprintf(stdout, cs_etm_priv_fmts[CS_ETM_MAGIC], val[i++]);
> + fprintf(stdout, cs_etm_priv_fmts[CS_ETM_CPU], val[i++]);
> +
> + if (magic == __perf_cs_etmv3_magic) {
> + nr_params = CS_ETM_NR_TRC_PARAMS_V0;
> + fmt_offset = CS_ETM_ETMCR;
> + /* after common block, offset format index past NR_PARAMS */
> + for (j = fmt_offset; j < nr_params + fmt_offset; j++, i++)
> + fprintf(stdout, cs_etm_priv_fmts[j], val[i]);
> + } else if (magic == __perf_cs_etmv4_magic) {
> + nr_params = CS_ETMV4_NR_TRC_PARAMS_V0;
> + fmt_offset = CS_ETMV4_TRCCONFIGR;
> + /* after common block, offset format index past NR_PARAMS */
> + for (j = fmt_offset; j < nr_params + fmt_offset; j++, i++)
> + fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]);
> + }
> + *offset = i;
> + return 0;
> +}
> +
> +static int cs_etm__print_cpu_metadata_v1(__u64 *val, int *offset)
> +{
> + int i = *offset, j, total_params = 0;
> + __u64 magic;
> +
> + magic = val[i + CS_ETM_MAGIC];
> + /* total params to print is NR_PARAMS + common block size for v1 */
> + total_params = val[i + CS_ETM_NR_TRC_PARAMS] + CS_ETM_COMMON_BLK_MAX_V1;
>
> - for (i = CS_HEADER_VERSION_0_MAX; cpu < num; cpu++) {
> - if (val[i] == __perf_cs_etmv3_magic)
> - for (j = 0; j < CS_ETM_PRIV_MAX; j++, i++)
> + if (magic == __perf_cs_etmv3_magic) {
> + for (j = 0; j < total_params; j++, i++) {
> + /* if newer record - could be excess params */
> + if (j >= CS_ETM_PRIV_MAX)
> + fprintf(stdout, param_unk_fmt, j, val[i]);
> + else
> fprintf(stdout, cs_etm_priv_fmts[j], val[i]);
> - else if (val[i] == __perf_cs_etmv4_magic)
> - for (j = 0; j < CS_ETMV4_PRIV_MAX; j++, i++)
> + }
> + } else if (magic == __perf_cs_etmv4_magic) {
> + for (j = 0; j < total_params; j++, i++) {
> + /* if newer record - could be excess params */
> + if (j >= CS_ETMV4_PRIV_MAX)
> + fprintf(stdout, param_unk_fmt, j, val[i]);
> + else
> fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]);
> - else
> - /* failure.. return */
> + }
> + } else {
> + /* failure - note bad magic value and error out */
> + fprintf(stdout, magic_unk_fmt, magic);
> + return -EINVAL;
> + }
> + *offset = i;
> + return 0;
> +}
> +
> +static void cs_etm__print_auxtrace_info(__u64 *val, int num)
> +{
> + int i, cpu = 0, version, err;
> +
> + /* bail out early on bad header version */
> + version = val[0];
> + if (version > CS_HEADER_CURRENT_VERSION) {
> + /* failure.. return */
> + fprintf(stdout, " Unknown Header Version = %x, ", version);
> + fprintf(stdout, "Version supported <= %x\n", CS_HEADER_CURRENT_VERSION);
> + return;
> + }
> +
> + for (i = 0; i < CS_HEADER_VERSION_MAX; i++)
> + fprintf(stdout, cs_etm_global_header_fmts[i], val[i]);
> +
> + for (i = CS_HEADER_VERSION_MAX; cpu < num; cpu++) {
> + if (version == 0)
> + err = cs_etm__print_cpu_metadata_v0(val, &i);
> + else if (version == 1)
> + err = cs_etm__print_cpu_metadata_v1(val, &i);
> + if (err)
> return;
> }
> }
>
> +/*
> + * Read a single cpu parameter block from the auxtrace_info priv block.
> + *
> + * For version 1 there is a per cpu nr_params entry. If we are handling
> + * version 1 file, then there may be less, the same, or more params
> + * indicated by this value than the compile time number we understand.
> + *
> + * For a version 0 info block, there are a fixed number, and we need to
> + * fill out the nr_param value in the metadata we create.
> + */
> +static u64 *cs_etm__create_meta_blk(u64 *buff_in, int *buff_in_offset,
> + int out_blk_size, int nr_params_v0)
> +{
> + u64 *metadata = NULL;
> + int hdr_version;
> + int nr_in_params, nr_out_params, nr_cmn_params;
> + int i, k;
> +
> + metadata = zalloc(sizeof(*metadata) * out_blk_size);
> + if (!metadata)
> + return NULL;
> +
> + /* read block current index & version */
> + i = *buff_in_offset;
> + hdr_version = buff_in[CS_HEADER_VERSION];
> +
> + if (!hdr_version) {
> + /* read version 0 info block into a version 1 metadata block */
> + nr_in_params = nr_params_v0;
> + metadata[CS_ETM_MAGIC] = buff_in[i + CS_ETM_MAGIC];
> + metadata[CS_ETM_CPU] = buff_in[i + CS_ETM_CPU];
> + metadata[CS_ETM_NR_TRC_PARAMS] = nr_in_params;
> + /* remaining block params at offset +1 from source */
> + for (k = CS_ETM_ETMCR - 1; k < nr_in_params; k++)
> + metadata[k+1] = buff_in[i + k];
> + /* version 0 has 2 common params */
> + nr_cmn_params = 2;
> + } else {
> + /* read version 1 info block - input and output nr_params may differ */
> + /* version 1 has 3 common params */
> + nr_cmn_params = 3;
> + nr_in_params = buff_in[i + CS_ETM_NR_TRC_PARAMS];
> +
> + /* if input has more params than output - skip excess */
> + nr_out_params = nr_in_params + nr_cmn_params;
> + if (nr_out_params > out_blk_size)
> + nr_out_params = out_blk_size;
> +
> + for (k = CS_ETM_MAGIC; k < nr_out_params; k++)
> + metadata[k] = buff_in[i + k];
> +
> + /* record the actual nr params we copied */
> + metadata[CS_ETM_NR_TRC_PARAMS] = nr_out_params - nr_cmn_params;
> + }
> +
> + /* adjust in offset by number of in params used */
> + i += nr_in_params + nr_cmn_params;
> + *buff_in_offset = i;
> + return metadata;
> +}
> +
> int cs_etm__process_auxtrace_info(union perf_event *event,
> struct perf_session *session)
> {
> @@ -2492,11 +2635,12 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
> int info_header_size;
> int total_size = auxtrace_info->header.size;
> int priv_size = 0;
> - int num_cpu;
> - int err = 0, idx = -1;
> - int i, j, k;
> + int num_cpu, trcidr_idx;
> + int err = 0;
> + int i, j;
> u64 *ptr, *hdr = NULL;
> u64 **metadata = NULL;
> + u64 hdr_version;
>
> /*
> * sizeof(auxtrace_info_event::type) +
> @@ -2512,16 +2656,21 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
> /* First the global part */
> ptr = (u64 *) auxtrace_info->priv;
>
> - /* Look for version '0' of the header */
> - if (ptr[0] != 0)
> + /* Look for version of the header */
> + hdr_version = ptr[0];
> + if (hdr_version > CS_HEADER_CURRENT_VERSION) {
> + /* print routine will print an error on bad version */
> + if (dump_trace)
> + cs_etm__print_auxtrace_info(auxtrace_info->priv, 0);
> return -EINVAL;
> + }
>
> - hdr = zalloc(sizeof(*hdr) * CS_HEADER_VERSION_0_MAX);
> + hdr = zalloc(sizeof(*hdr) * CS_HEADER_VERSION_MAX);
> if (!hdr)
> return -ENOMEM;
>
> /* Extract header information - see cs-etm.h for format */
> - for (i = 0; i < CS_HEADER_VERSION_0_MAX; i++)
> + for (i = 0; i < CS_HEADER_VERSION_MAX; i++)
> hdr[i] = ptr[i];
> num_cpu = hdr[CS_PMU_TYPE_CPUS] & 0xffffffff;
> pmu_type = (unsigned int) ((hdr[CS_PMU_TYPE_CPUS] >> 32) &
> @@ -2552,35 +2701,31 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
> */
> for (j = 0; j < num_cpu; j++) {
> if (ptr[i] == __perf_cs_etmv3_magic) {
> - metadata[j] = zalloc(sizeof(*metadata[j]) *
> - CS_ETM_PRIV_MAX);
> - if (!metadata[j]) {
> - err = -ENOMEM;
> - goto err_free_metadata;
> - }
> - for (k = 0; k < CS_ETM_PRIV_MAX; k++)
> - metadata[j][k] = ptr[i + k];
> + metadata[j] =
> + cs_etm__create_meta_blk(ptr, &i,
> + CS_ETM_PRIV_MAX,
> + CS_ETM_NR_TRC_PARAMS_V0);
>
> /* The traceID is our handle */
> - idx = metadata[j][CS_ETM_ETMTRACEIDR];
> - i += CS_ETM_PRIV_MAX;
> + trcidr_idx = CS_ETM_ETMTRACEIDR;
> +
> } else if (ptr[i] == __perf_cs_etmv4_magic) {
> - metadata[j] = zalloc(sizeof(*metadata[j]) *
> - CS_ETMV4_PRIV_MAX);
> - if (!metadata[j]) {
> - err = -ENOMEM;
> - goto err_free_metadata;
> - }
> - for (k = 0; k < CS_ETMV4_PRIV_MAX; k++)
> - metadata[j][k] = ptr[i + k];
> + metadata[j] =
> + cs_etm__create_meta_blk(ptr, &i,
> + CS_ETMV4_PRIV_MAX,
> + CS_ETMV4_NR_TRC_PARAMS_V0);
>
> /* The traceID is our handle */
> - idx = metadata[j][CS_ETMV4_TRCTRACEIDR];
> - i += CS_ETMV4_PRIV_MAX;
> + trcidr_idx = CS_ETMV4_TRCTRACEIDR;
> + }
> +
> + if (!metadata[j]) {
> + err = -ENOMEM;
> + goto err_free_metadata;
> }
>
> /* Get an RB node for this CPU */
> - inode = intlist__findnew(traceid_list, idx);
> + inode = intlist__findnew(traceid_list, metadata[j][trcidr_idx]);
>
> /* Something went wrong, no need to continue */
> if (!inode) {
> @@ -2601,7 +2746,7 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
> }
>
> /*
> - * Each of CS_HEADER_VERSION_0_MAX, CS_ETM_PRIV_MAX and
> + * Each of CS_HEADER_VERSION_MAX, CS_ETM_PRIV_MAX and
> * CS_ETMV4_PRIV_MAX mark how many double words are in the
> * global metadata, and each cpu's metadata respectively.
> * The following tests if the correct number of double words was
> @@ -2703,6 +2848,12 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
> intlist__delete(traceid_list);
> err_free_hdr:
> zfree(&hdr);
> -
> + /*
> + * At this point, as a minimum we have valid header. Dump the rest of
> + * the info section - the print routines will error out on structural
> + * issues.
> + */
> + if (dump_trace)
> + cs_etm__print_auxtrace_info(auxtrace_info->priv, num_cpu);
> return err;
> }
> diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
> index 4ad925d6d799..e153d02df0de 100644
> --- a/tools/perf/util/cs-etm.h
> +++ b/tools/perf/util/cs-etm.h
> @@ -17,23 +17,37 @@ struct perf_session;
> */
> enum {
> /* Starting with 0x0 */
> - CS_HEADER_VERSION_0,
> + CS_HEADER_VERSION,
> /* PMU->type (32 bit), total # of CPUs (32 bit) */
> CS_PMU_TYPE_CPUS,
> CS_ETM_SNAPSHOT,
> - CS_HEADER_VERSION_0_MAX,
> + CS_HEADER_VERSION_MAX,
> };
>
> +/*
> + * Update the version for new format.
> + *
> + * New version 1 format adds a param count to the per cpu metadata.
> + * This allows easy adding of new metadata parameters.
> + * Requires that new params always added after current ones.
> + * Also allows client reader to handle file versions that are different by
> + * checking the number of params in the file vs the number expected.
> + */
> +#define CS_HEADER_CURRENT_VERSION 1
> +
> /* Beginning of header common to both ETMv3 and V4 */
> enum {
> CS_ETM_MAGIC,
> CS_ETM_CPU,
> + /* Number of trace config params in following ETM specific block */
> + CS_ETM_NR_TRC_PARAMS,
> + CS_ETM_COMMON_BLK_MAX_V1,
> };
>
> /* ETMv3/PTM metadata */
> enum {
> /* Dynamic, configurable parameters */
> - CS_ETM_ETMCR = CS_ETM_CPU + 1,
> + CS_ETM_ETMCR = CS_ETM_COMMON_BLK_MAX_V1,
> CS_ETM_ETMTRACEIDR,
> /* RO, taken from sysFS */
> CS_ETM_ETMCCER,
> @@ -41,10 +55,13 @@ enum {
> CS_ETM_PRIV_MAX,
> };
>
> +/* define fixed version 0 length - allow new format reader to read old files. */
> +#define CS_ETM_NR_TRC_PARAMS_V0 (CS_ETM_ETMIDR - CS_ETM_ETMCR + 1)
> +
> /* ETMv4 metadata */
> enum {
> /* Dynamic, configurable parameters */
> - CS_ETMV4_TRCCONFIGR = CS_ETM_CPU + 1,
> + CS_ETMV4_TRCCONFIGR = CS_ETM_COMMON_BLK_MAX_V1,
> CS_ETMV4_TRCTRACEIDR,
> /* RO, taken from sysFS */
> CS_ETMV4_TRCIDR0,
> @@ -55,6 +72,9 @@ enum {
> CS_ETMV4_PRIV_MAX,
> };
>
> +/* define fixed version 0 length - allow new format reader to read old files. */
> +#define CS_ETMV4_NR_TRC_PARAMS_V0 (CS_ETMV4_TRCAUTHSTATUS - CS_ETMV4_TRCCONFIGR + 1)
> +
> /*
> * ETMv3 exception encoding number:
> * See Embedded Trace Macrocell spcification (ARM IHI 0014Q)
> @@ -162,7 +182,7 @@ struct cs_etm_packet_queue {
>
> #define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb)
>
> -#define CS_ETM_HEADER_SIZE (CS_HEADER_VERSION_0_MAX * sizeof(u64))
> +#define CS_ETM_HEADER_SIZE (CS_HEADER_VERSION_MAX * sizeof(u64))
>
> #define __perf_cs_etmv3_magic 0x3030303030303030ULL
> #define __perf_cs_etmv4_magic 0x4040404040404040ULL
> --
> 2.17.1
>
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