Re: [PATCH v2 4/9] perf cs-etm: Save TRCDEVARCH register

From: Leo Yan
Date: Tue Aug 24 2021 - 03:14:48 EST

Next message: Leo Yan: "Re: [PATCH v2 5/9] perf cs-etm: Fix typo"
Previous message: Vitaly Kuznetsov: "Re: [PATCH v2 4/4] KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Fri, Aug 06, 2021 at 02:41:04PM +0100, James Clark wrote:
> When ETE is present save the TRCDEVARCH register and set a new magic
> number. It will be used to configure the decoder in a later commit.
>
> Old versions of perf will not be able to open files with this new magic
> number, but old files will still work with newer versions of perf.
>
> Signed-off-by: James Clark <james.clark@xxxxxxx>
> ---
> tools/perf/arch/arm/util/cs-etm.c | 49 +++++++++++++++++++++++++++----
> tools/perf/util/cs-etm.c | 16 ++++++++--
> tools/perf/util/cs-etm.h | 10 +++++++
> 3 files changed, 68 insertions(+), 7 deletions(-)
>
> diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
> index ecb6fa55a210..e3500b79d972 100644
> --- a/tools/perf/arch/arm/util/cs-etm.c
> +++ b/tools/perf/arch/arm/util/cs-etm.c
> @@ -47,15 +47,17 @@ static const char *metadata_etmv3_ro[CS_ETM_PRIV_MAX] = {
> [CS_ETM_ETMIDR] = "mgmt/etmidr",
> };
>
> -static const char *metadata_etmv4_ro[CS_ETMV4_PRIV_MAX] = {
> +static const char * const metadata_etmv4_ro[] = {
> [CS_ETMV4_TRCIDR0] = "trcidr/trcidr0",
> [CS_ETMV4_TRCIDR1] = "trcidr/trcidr1",
> [CS_ETMV4_TRCIDR2] = "trcidr/trcidr2",
> [CS_ETMV4_TRCIDR8] = "trcidr/trcidr8",
> [CS_ETMV4_TRCAUTHSTATUS] = "mgmt/trcauthstatus",
> + [CS_ETE_TRCDEVARCH] = "mgmt/trcdevarch"
> };
>
> static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu);
> +static bool cs_etm_is_ete(struct auxtrace_record *itr, int cpu);
>
> static int cs_etm_set_context_id(struct auxtrace_record *itr,
> struct evsel *evsel, int cpu)
> @@ -533,7 +535,7 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
> struct evlist *evlist __maybe_unused)
> {
> int i;
> - int etmv3 = 0, etmv4 = 0;
> + int etmv3 = 0, etmv4 = 0, ete = 0;
> struct perf_cpu_map *event_cpus = evlist->core.cpus;
> struct perf_cpu_map *online_cpus = perf_cpu_map__new(NULL);
>
> @@ -544,7 +546,9 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
> !cpu_map__has(online_cpus, i))
> continue;
>
> - if (cs_etm_is_etmv4(itr, i))
> + if (cs_etm_is_ete(itr, i))
> + ete++;
> + else if (cs_etm_is_etmv4(itr, i))
> etmv4++;
> else
> etmv3++;
> @@ -555,7 +559,9 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
> if (!cpu_map__has(online_cpus, i))
> continue;
>
> - if (cs_etm_is_etmv4(itr, i))
> + if (cs_etm_is_ete(itr, i))
> + ete++;
> + else if (cs_etm_is_etmv4(itr, i))
> etmv4++;
> else
> etmv3++;
> @@ -565,6 +571,7 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
> perf_cpu_map__put(online_cpus);
>
> return (CS_ETM_HEADER_SIZE +
> + (ete * CS_ETE_PRIV_SIZE) +
> (etmv4 * CS_ETMV4_PRIV_SIZE) +
> (etmv3 * CS_ETMV3_PRIV_SIZE));
> }
> @@ -607,6 +614,27 @@ static int cs_etm_get_ro(struct perf_pmu *pmu, int cpu, const char *path)
> return val;
> }
>
> +#define TRCDEVARCH_ARCHPART_SHIFT 0
> +#define TRCDEVARCH_ARCHPART_MASK GENMASK(11, 0)
> +#define TRCDEVARCH_ARCHPART(x) (((x) & TRCDEVARCH_ARCHPART_MASK) >> TRCDEVARCH_ARCHPART_SHIFT)
> +
> +#define TRCDEVARCH_ARCHVER_SHIFT 12
> +#define TRCDEVARCH_ARCHVER_MASK GENMASK(15, 12)
> +#define TRCDEVARCH_ARCHVER(x) (((x) & TRCDEVARCH_ARCHVER_MASK) >> TRCDEVARCH_ARCHVER_SHIFT)
> +
> +static bool cs_etm_is_ete(struct auxtrace_record *itr, int cpu)
> +{
> + struct cs_etm_recording *ptr = container_of(itr, struct cs_etm_recording, itr);
> + struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
> + int trcdevarch = cs_etm_get_ro(cs_etm_pmu, cpu, metadata_etmv4_ro[CS_ETE_TRCDEVARCH]);
> +
> + /*
> + * ETE if ARCHVER is 5 (ARCHVER is 4 for ETM) and ARCHPART is 0xA13.
> + * See ETM_DEVARCH_ETE_ARCH in coresight-etm4x.h
> + */
> + return TRCDEVARCH_ARCHVER(trcdevarch) == 5 && TRCDEVARCH_ARCHPART(trcdevarch) == 0xA13;
> +}
> +
> static void cs_etm_save_etmv4_header(__u64 data[], struct auxtrace_record *itr, int cpu)
> {
> struct cs_etm_recording *ptr = container_of(itr, struct cs_etm_recording, itr);
> @@ -640,7 +668,18 @@ static void cs_etm_get_metadata(int cpu, u32 *offset,
> struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
>
> /* first see what kind of tracer this cpu is affined to */
> - if (cs_etm_is_etmv4(itr, cpu)) {
> + if (cs_etm_is_ete(itr, cpu)) {
> + magic = __perf_cs_ete_magic;
> + /* ETE uses the same registers as ETMv4 plus TRCDEVARCH */
> + cs_etm_save_etmv4_header(&info->priv[*offset], itr, cpu);
> + info->priv[*offset + CS_ETE_TRCDEVARCH] =
> + cs_etm_get_ro(cs_etm_pmu, cpu,
> + metadata_etmv4_ro[CS_ETE_TRCDEVARCH]);
> +
> + /* How much space was used */
> + increment = CS_ETE_PRIV_MAX;
> + nr_trc_params = CS_ETE_PRIV_MAX - CS_ETM_COMMON_BLK_MAX_V1;
> + } else if (cs_etm_is_etmv4(itr, cpu)) {
> magic = __perf_cs_etmv4_magic;
> cs_etm_save_etmv4_header(&info->priv[*offset], itr, cpu);
>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index f4b2bff533f3..d540512a3c96 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -2512,6 +2512,7 @@ static const char * const cs_etmv4_priv_fmts[] = {
> [CS_ETMV4_TRCIDR2] = " TRCIDR2 %llx\n",
> [CS_ETMV4_TRCIDR8] = " TRCIDR8 %llx\n",
> [CS_ETMV4_TRCAUTHSTATUS] = " TRCAUTHSTATUS %llx\n",
> + [CS_ETE_TRCDEVARCH] = " TRCDEVARCH %llx\n"
> };
>
> static const char * const param_unk_fmt =
> @@ -2571,10 +2572,15 @@ static int cs_etm__print_cpu_metadata_v1(__u64 *val, int *offset)
> else
> fprintf(stdout, cs_etm_priv_fmts[j], val[i]);
> }
> - } else if (magic == __perf_cs_etmv4_magic) {
> + } else if (magic == __perf_cs_etmv4_magic || magic == __perf_cs_ete_magic) {
> + /*
> + * ETE and ETMv4 can be printed in the same block because the number of parameters
> + * is saved and they share the list of parameter names. ETE is also only supported
> + * in V1 files.
> + */
> for (j = 0; j < total_params; j++, i++) {
> /* if newer record - could be excess params */
> - if (j >= CS_ETMV4_PRIV_MAX)
> + if (j >= CS_ETE_PRIV_MAX)
> fprintf(stdout, param_unk_fmt, j, val[i]);
> else
> fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]);
> @@ -2943,6 +2949,12 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
>
> /* The traceID is our handle */
> trcidr_idx = CS_ETMV4_TRCTRACEIDR;
> + } else if (ptr[i] == __perf_cs_ete_magic) {
> + metadata[j] =
> + cs_etm__create_meta_blk(ptr, &i, CS_ETE_PRIV_MAX, -1);

The last parameter is passed with '-1', means the ETE metadata block
uses version 1, nr_params_v0 is not used thus pass '-1' for it.

It is fine for me.

> +
> + /* ETE shares first part of metadata with ETMv4 */
> + trcidr_idx = CS_ETMV4_TRCTRACEIDR;
> }
>
> if (!metadata[j]) {
> diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
> index d65c7b19407d..08b84c21f065 100644
> --- a/tools/perf/util/cs-etm.h
> +++ b/tools/perf/util/cs-etm.h
> @@ -76,6 +76,14 @@ enum {
> /* 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)
>
> +/* ETE metadata is ETMv4 plus TRCDEVARCH register and doesn't support header V0 since it was
> + * added in header V1
> + */
> +enum {
> + CS_ETE_TRCDEVARCH = CS_ETMV4_PRIV_MAX,
> + CS_ETE_PRIV_MAX
> +};
> +
> /*
> * ETMv3 exception encoding number:
> * See Embedded Trace Macrocell specification (ARM IHI 0014Q)
> @@ -187,8 +195,10 @@ struct cs_etm_packet_queue {
>
> #define __perf_cs_etmv3_magic 0x3030303030303030ULL
> #define __perf_cs_etmv4_magic 0x4040404040404040ULL
> +#define __perf_cs_ete_magic 0x5050505050505050ULL
> #define CS_ETMV3_PRIV_SIZE (CS_ETM_PRIV_MAX * sizeof(u64))
> #define CS_ETMV4_PRIV_SIZE (CS_ETMV4_PRIV_MAX * sizeof(u64))
> +#define CS_ETE_PRIV_SIZE (CS_ETE_PRIV_MAX * sizeof(u64))

I went through the patch twice and looks good to me:

Reviewed-by: Leo Yan <leo.yan@xxxxxxxxxx>

>
> #ifdef HAVE_CSTRACE_SUPPORT
> int cs_etm__process_auxtrace_info(union perf_event *event,
> --
> 2.28.0
>

Next message: Leo Yan: "Re: [PATCH v2 5/9] perf cs-etm: Fix typo"
Previous message: Vitaly Kuznetsov: "Re: [PATCH v2 4/4] KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]