diff options
Diffstat (limited to 'src/plugins/perfmon/arm/events.c')
| -rw-r--r-- | src/plugins/perfmon/arm/events.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/src/plugins/perfmon/arm/events.c b/src/plugins/perfmon/arm/events.c new file mode 100644 index 00000000000..f2406b3ea05 --- /dev/null +++ b/src/plugins/perfmon/arm/events.c @@ -0,0 +1,227 @@ +/* + * Copyright (c) 2022 Arm and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <vnet/vnet.h> +#include <vppinfra/linux/sysfs.h> +#include <perfmon/perfmon.h> +#include <perfmon/arm/events.h> +#include <perfmon/arm/dispatch_wrapper.h> +#include <linux/perf_event.h> +#include <dirent.h> + +VLIB_REGISTER_LOG_CLASS (if_default_log, static) = { + .class_name = "perfmon", +}; + +#define log_debug(fmt, ...) \ + vlib_log_debug (if_default_log.class, fmt, __VA_ARGS__) +#define log_warn(fmt, ...) \ + vlib_log_warn (if_default_log.class, fmt, __VA_ARGS__) +#define log_err(fmt, ...) vlib_log_err (if_default_log.class, fmt, __VA_ARGS__) + +/* + * config1 = 2 : user access enabled and always 32-bit + * config1 = 3 : user access enabled and always 64-bit + * + * Since there is no discovery into whether 64b counters are supported + * or not, first attempt to request 64b counters, then fall back to + * 32b if perf_event_open returns EOPNOTSUPP + */ +static perfmon_event_t events[] = { +#define _(event, n, desc) \ + [ARMV8_PMUV3_##n] = { \ + .type = PERF_TYPE_RAW, \ + .config = event, \ + .config1 = 3, \ + .name = #n, \ + .description = desc, \ + .exclude_kernel = 1, \ + }, + foreach_perf_arm_event +#undef _ +}; + +u8 * +format_arm_config (u8 *s, va_list *args) +{ + u64 config = va_arg (*args, u64); + + s = format (s, "event=0x%02x", config & 0xff); + + return s; +} + +static clib_error_t * +arm_init (vlib_main_t *vm, perfmon_source_t *src) +{ + clib_error_t *err; + + /* + check /proc/sys/kernel/perf_user_access flag to check if userspace + access to perf counters is enabled (disabled by default) + - if this file doesn't exist, we are on an unsupported kernel ver + - if the file exists and is 0, user access needs to be granted + with 'sudo sysctl kernel/perf_user_access=1' + */ + u32 perf_user_access_enabled; + char *path = "/proc/sys/kernel/perf_user_access"; + err = clib_sysfs_read (path, "%u", &perf_user_access_enabled); + if (err) + { + if (err->code == ENOENT) /* No such file or directory */ + { + return clib_error_create ( + "linux kernel version is unsupported, please upgrade to v5.17+ " + "- user access to perf counters is not possible"); + } + return clib_error_return_unix (0, "failed to read: %s", path); + } + + if (perf_user_access_enabled == 1) + log_debug ("user access to perf counters is enabled in %s", path); + else + { + return clib_error_create ( + "user access to perf counters is not enabled: run" + " \'sudo sysctl kernel/perf_user_access=1\'"); + } + + /* + perfmon/arm/events.h has up to 0xFF/256 possible PMUv3 event codes + supported - create a bitmap to store whether each event is + implemented or not + */ + uword *bitmap = NULL; + clib_bitmap_alloc (bitmap, 256); + + struct dirent *dir_entry; + const char *event_path = + "/sys/bus/event_source/devices/armv8_pmuv3_0/events"; + DIR *event_dir = opendir (event_path); + + if (event_dir == NULL) + { + err = + clib_error_return_unix (0, "error listing directory: %s", event_path); + log_err ("%U", format_clib_error, err); + return err; + } + + while ((dir_entry = readdir (event_dir)) != NULL) + { + if (dir_entry->d_name[0] != '.') + { + u8 *s = NULL; + u8 *tmpstr = NULL; + unformat_input_t input; + u32 config; + + s = format (s, "%s/%s%c", event_path, dir_entry->d_name, 0); + err = clib_sysfs_read ((char *) s, "%s", &tmpstr); + if (err) + { + log_err ("%U", format_clib_error, err); + continue; + } + unformat_init_vector (&input, tmpstr); + if (unformat (&input, "event=0x%x", &config)) + { + /* it's possible to have have event codes up to 0xFFFF */ + if (config < 0xFF) /* perfmon supports < 0xFF */ + { + clib_bitmap_set (bitmap, config, 1); + } + log_debug ("found supported event in sysfs: %s \'%s\' 0x%x", + dir_entry->d_name, tmpstr, config); + } + else + { + err = clib_error_create ("error parsing event: %s %s", + dir_entry->d_name, tmpstr); + log_err ("%U", format_clib_error, err); + continue; + } + } + } + closedir (event_dir); + + for (int i = 0; i < ARRAY_LEN (events); i++) + { + if (clib_bitmap_get (bitmap, events[i].config)) + events[i].implemented = 1; + } + clib_bitmap_free (bitmap); + + return 0; +} + +u8 +arm_bundle_supported (perfmon_bundle_t *b) +{ + clib_bitmap_alloc (b->event_disabled, b->n_events); + for (u32 i = 0; i < b->n_events; i++) + { + perfmon_event_t *e = b->src->events + b->events[i]; + if (!e->implemented) + { + log_debug ( + "bundle \'%s\': perf event %s is not implemented on this CPU", + b->name, e->name); + clib_bitmap_set (b->event_disabled, i, 1); + } + } + + /* if no events are implemented, fail and do not register bundle */ + if (clib_bitmap_count_set_bits (b->event_disabled) == b->n_events) + { + return 0; + } + + /* disable columns that use unimplemented events */ + clib_bitmap_alloc (b->column_disabled, b->n_columns); + if (b->column_events) + { + u32 disabled_event; + /* iterate through set bits */ + clib_bitmap_foreach (disabled_event, b->event_disabled) + { + for (u32 j = 0; j < b->n_columns; j++) + { + if (clib_bitmap_get (b->column_disabled, j)) + continue; + if (GET_BIT (b->column_events[j], disabled_event)) + { + clib_bitmap_set (b->column_disabled, j, 1); + log_debug ( + "bundle \'%s\': disabling column %d as event unsupported", + b->name, j); + } + } + } + } + + return 1; +} + +PERFMON_REGISTER_SOURCE (arm) = { + .name = "arm", + .description = "Arm PMU events", + .events = events, + .n_events = ARRAY_LEN (events), + .init_fn = arm_init, + .format_config = format_arm_config, + .bundle_support = arm_bundle_supported, + .config_dispatch_wrapper = arm_config_dispatch_wrapper, +}; |