/* * Hypervisor supplied "24x7" performance counter support * * Author: Cody P Schafer * Copyright 2014 IBM Corporation. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #define pr_fmt(fmt) "hv-24x7: " fmt #include #include #include #include #include #include #include #include #include #include #include "hv-24x7.h" #include "hv-24x7-catalog.h" #include "hv-common.h" /* Version of the 24x7 hypervisor API that we should use in this machine. */ static int interface_version; /* Whether we have to aggregate result data for some domains. */ static bool aggregate_result_elements; static bool domain_is_valid(unsigned domain) { switch (domain) { #define DOMAIN(n, v, x, c) \ case HV_PERF_DOMAIN_##n: \ /* fall through */ #include "hv-24x7-domains.h" #undef DOMAIN return true; default: return false; } } static bool is_physical_domain(unsigned domain) { switch (domain) { #define DOMAIN(n, v, x, c) \ case HV_PERF_DOMAIN_##n: \ return c; #include "hv-24x7-domains.h" #undef DOMAIN default: return false; } } /* Domains for which more than one result element are returned for each event. */ static bool domain_needs_aggregation(unsigned int domain) { return aggregate_result_elements && (domain == HV_PERF_DOMAIN_PHYS_CORE || (domain >= HV_PERF_DOMAIN_VCPU_HOME_CORE && domain <= HV_PERF_DOMAIN_VCPU_REMOTE_NODE)); } static const char *domain_name(unsigned domain) { if (!domain_is_valid(domain)) return NULL; switch (domain) { case HV_PERF_DOMAIN_PHYS_CHIP: return "Physical Chip"; case HV_PERF_DOMAIN_PHYS_CORE: return "Physical Core"; case HV_PERF_DOMAIN_VCPU_HOME_CORE: return "VCPU Home Core"; case HV_PERF_DOMAIN_VCPU_HOME_CHIP: return "VCPU Home Chip"; case HV_PERF_DOMAIN_VCPU_HOME_NODE: return "VCPU Home Node"; case HV_PERF_DOMAIN_VCPU_REMOTE_NODE: return "VCPU Remote Node"; } WARN_ON_ONCE(domain); return NULL; } static bool catalog_entry_domain_is_valid(unsigned domain) { /* POWER8 doesn't support virtual domains. */ if (interface_version == 1) return is_physical_domain(domain); else return domain_is_valid(domain); } /* * TODO: Merging events: * - Think of the hcall as an interface to a 4d array of counters: * - x = domains * - y = indexes in the domain (core, chip, vcpu, node, etc) * - z = offset into the counter space * - w = lpars (guest vms, "logical partitions") * - A single request is: x,y,y_last,z,z_last,w,w_last * - this means we can retrieve a rectangle of counters in y,z for a single x. * * - Things to consider (ignoring w): * - input cost_per_request = 16 * - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs * - limited number of requests per hcall (must fit into 4K bytes) * - 4k = 16 [buffer header] - 16 [request size] * request_count * - 255 requests per hcall * - sometimes it will be more efficient to read extra data and discard */ /* * Example usage: * perf stat -e 'hv_24x7/domain=2,offset=8,vcpu=0,lpar=0xffffffff/' */ /* u3 0-6, one of HV_24X7_PERF_DOMAIN */ EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3); /* u16 */ EVENT_DEFINE_RANGE_FORMAT(core, config, 16, 31); EVENT_DEFINE_RANGE_FORMAT(chip, config, 16, 31); EVENT_DEFINE_RANGE_FORMAT(vcpu, config, 16, 31); /* u32, see "data_offset" */ EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63); /* u16 */ EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15); EVENT_DEFINE_RANGE(reserved1, config, 4, 15); EVENT_DEFINE_RANGE(reserved2, config1, 16, 63); EVENT_DEFINE_RANGE(reserved3, config2, 0, 63); static struct attribute *format_attrs[] = { &format_attr_domain.attr, &format_attr_offset.attr, &format_attr_core.attr, &format_attr_chip.attr, &format_attr_vcpu.attr, &format_attr_lpar.attr, NULL, }; static struct attribute_group format_group = { .name = "format", .attrs = format_attrs, }; static struct attribute_group event_group = { .name = "events", /* .attrs is set in init */ }; static struct attribute_group event_desc_group = { .name = "event_descs", /* .attrs is set in init */ }; static struct attribute_group event_long_desc_group = { .name = "event_long_descs", /* .attrs is set in init */ }; static struct kmem_cache *hv_page_cache; DEFINE_PER_CPU(int, hv_24x7_txn_flags); DEFINE_PER_CPU(int, hv_24x7_txn_err); struct hv_24x7_hw { struct perf_event *events[255]; }; DEFINE_PER_CPU(struct hv_24x7_hw, hv_24x7_hw); /* * request_buffer and result_buffer are not required to be 4k aligned, * but are not allowed to cross any 4k boundary. Aligning them to 4k is * the simplest way to ensure that. */ #define H24x7_DATA_BUFFER_SIZE 4096 DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096); DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096); static unsigned int max_num_requests(int interface_version) { return (H24x7_DATA_BUFFER_SIZE - sizeof(struct hv_24x7_request_buffer)) / H24x7_REQUEST_SIZE(interface_version); } static char *event_name(struct hv_24x7_event_data *ev, int *len) { *len = be16_to_cpu(ev->event_name_len) - 2; return (char *)ev->remainder; } static char *event_desc(struct hv_24x7_event_data *ev, int *len) { unsigned nl = be16_to_cpu(ev->event_name_len); __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2); *len = be16_to_cpu(*desc_len) - 2; return (char *)ev->remainder + nl; } static char *event_long_desc(struct hv_24x7_event_data *ev, int *len) { unsigned nl = be16_to_cpu(ev->event_name_len); __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2); unsigned desc_len = be16_to_cpu(*desc_len_); __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2); *len = be16_to_cpu(*long_desc_len) - 2; return (char *)ev->remainder + nl + desc_len; } static bool event_fixed_portion_is_within(struct hv_24x7_event_data *ev, void *end) { void *start = ev; return (start + offsetof(struct hv_24x7_event_data, remainder)) < end; } /* * Things we don't check: * - padding for desc, name, and long/detailed desc is required to be '\0' * bytes. * * Return NULL if we pass end, * Otherwise return the address of the byte just following the event. */ static void *event_end(struct hv_24x7_event_data *ev, void *end) { void *start = ev; __be16 *dl_, *ldl_; unsigned dl, ldl; unsigned nl = be16_to_cpu(ev->event_name_len); if (nl < 2) { pr_debug("%s: name length too short: %d", __func__, nl); return NULL; } if (start + nl > end) { pr_debug("%s: start=%p + nl=%u > end=%p", __func__, start, nl, end); return NULL; } dl_ = (__be16 *)(ev->remainder + nl - 2); if (!IS_ALIGNED((uintptr_t)dl_, 2)) pr_warn("desc len not aligned %p", dl_); dl = be16_to_cpu(*dl_); if (dl < 2) { pr_debug("%s: desc len too short: %d", __func__, dl); return NULL; } if (start + nl + dl > end) { pr_debug("%s: (start=%p + nl=%u + dl=%u)=%p > end=%p", __func__, start, nl, dl, start + nl + dl, end); return NULL; } ldl_ = (__be16 *)(ev->remainder + nl + dl - 2); if (!IS_ALIGNED((uintptr_t)ldl_, 2)) pr_warn("long desc len not aligned %p", ldl_); ldl = be16_to_cpu(*ldl_); if (ldl < 2) { pr_debug("%s: long desc len too short (ldl=%u)", __func__, ldl); return NULL; } if (start + nl + dl + ldl > end) { pr_debug("%s: start=%p + nl=%u + dl=%u + ldl=%u > end=%p", __func__, start, nl, dl, ldl, end); return NULL; } return start + nl + dl + ldl; } static long h_get_24x7_catalog_page_(unsigned long phys_4096, unsigned long version, unsigned long index) { pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)", phys_4096, version, index); WARN_ON(!IS_ALIGNED(phys_4096, 4096)); return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE, phys_4096, version, index); } static long h_get_24x7_catalog_page(char page[], u64 version, u32 index) { return h_get_24x7_catalog_page_(virt_to_phys(page), version, index); } /* * Each event we find in the catalog, will have a sysfs entry. Format the * data for this sysfs entry based on the event's domain. * * Events belonging to the Chip domain can only be monitored in that domain. * i.e the domain for these events is a fixed/knwon value. * * Events belonging to the Core domain can be monitored either in the physical * core or in one of the virtual CPU domains. So the domain value for these * events must be specified by the user (i.e is a required parameter). Format * the Core events with 'domain=?' so the perf-tool can error check required * parameters. * * NOTE: For the Core domain events, rather than making domain a required * parameter we could default it to PHYS_CORE and allowe users to * override the domain to one of the VCPU domains. * * However, this can make the interface a little inconsistent. * * If we set domain=2 (PHYS_CHIP) and allow user to override this field * the user may be tempted to also modify the "offset=x" field in which * can lead to confusing usage. Consider the HPM_PCYC (offset=0x18) and * HPM_INST (offset=0x20) events. With: * * perf stat -e hv_24x7/HPM_PCYC,offset=0x20/ * * we end up monitoring HPM_INST, while the command line has HPM_PCYC. * * By not assigning a default value to the domain for the Core events, * we can have simple guidelines: * * - Specifying values for parameters with "=?" is required. * * - Specifying (i.e overriding) values for other parameters * is undefined. */ static char *event_fmt(struct hv_24x7_event_data *event, unsigned domain) { const char *sindex; const char *lpar; const char *domain_str; char buf[8]; switch (domain) { case HV_PERF_DOMAIN_PHYS_CHIP: snprintf(buf, sizeof(buf), "%d", domain); domain_str = buf; lpar = "0x0"; sindex = "chip"; break; case HV_PERF_DOMAIN_PHYS_CORE: domain_str = "?"; lpar = "0x0"; sindex = "core"; break; default: domain_str = "?"; lpar = "?"; sindex = "vcpu"; } return kasprintf(GFP_KERNEL, "domain=%s,offset=0x%x,%s=?,lpar=%s", domain_str, be16_to_cpu(event->event_counter_offs) + be16_to_cpu(event->event_group_record_offs), sindex, lpar); } /* Avoid trusting fw to NUL terminate strings */ static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp) { return kasprintf(gfp, "%.*s", max_len, maybe_str); } static ssize_t device_show_string(struct device *dev, struct device_attribute *attr, char *buf) { struct dev_ext_attribute *d; d = container_of(attr, struct dev_ext_attribute, attr); return sprintf(buf, "%s\n", (char *)d->var); } static struct attribute *device_str_attr_create_(char *name, char *str) { struct dev_ext_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL); if (!attr) return NULL; sysfs_attr_init(&attr->attr.attr); attr->var = str; attr->attr.attr.name = name; attr->attr.attr.mode = 0444; attr->attr.show = device_show_string; return &attr->attr.attr; } /* * Allocate and initialize strings representing event attributes. * * NOTE: The strings allocated here are never destroyed and continue to * exist till shutdown. This is to allow us to create as many events * from the catalog as possible, even if we encounter errors with some. * In case of changes to error paths in future, these may need to be * freed by the caller. */ static struct attribute *device_str_attr_create(char *name, int name_max, int name_nonce, char *str, size_t str_max) { char *n; char *s = memdup_to_str(str, str_max, GFP_KERNEL); struct attribute *a; if (!s) return NULL; if (!name_nonce) n = kasprintf(GFP_KERNEL, "%.*s", name_max, name); else n = kasprintf(GFP_KERNEL, "%.*s__%d", name_max, name, name_nonce); if (!n) goto out_s; a = device_str_attr_create_(n, s); if (!a) goto out_n; return a; out_n: kfree(n); out_s: kfree(s); return NULL; } static struct attribute *event_to_attr(unsigned ix, struct hv_24x7_event_data *event, unsigned domain, int nonce) { int event_name_len; char *ev_name, *a_ev_name, *val; struct attribute *attr; if (!domain_is_valid(domain)) { pr_warn("catalog event %u has invalid domain %u\n", ix, domain); return NULL; } val = event_fmt(event, domain); if (!val) return NULL; ev_name = event_name(event, &event_name_len); if (!nonce) a_ev_name = kasprintf(GFP_KERNEL, "%.*s", (int)event_name_len, ev_name); else a_ev_name = kasprintf(GFP_KERNEL, "%.*s__%d", (int)event_name_len, ev_name, nonce); if (!a_ev_name) goto out_val; attr = device_str_attr_create_(a_ev_name, val); if (!attr) goto out_name; return attr; out_name: kfree(a_ev_name); out_val: kfree(val); return NULL; } static struct attribute *event_to_desc_attr(struct hv_24x7_event_data *event, int nonce) { int nl, dl; char *name = event_name(event, &nl); char *desc = event_desc(event, &dl); /* If there isn't a description, don't create the sysfs file */ if (!dl) return NULL; return device_str_attr_create(name, nl, nonce, desc, dl); } static struct attribute * event_to_long_desc_attr(struct hv_24x7_event_data *event, int nonce) { int nl, dl; char *name = event_name(event, &nl); char *desc = event_long_desc(event, &dl); /* If there isn't a description, don't create the sysfs file */ if (!dl) return NULL; return device_str_attr_create(name, nl, nonce, desc, dl); } static int event_data_to_attrs(unsigned ix, struct attribute **attrs, struct hv_24x7_event_data *event, int nonce) { *attrs = event_to_attr(ix, event, event->domain, nonce); if (!*attrs) return -1; return 0; } /* */ struct event_uniq { struct rb_node node; const char *name; int nl; unsigned ct; unsigned domain; }; static int memord(const void *d1, size_t s1, const void *d2, size_t s2) { if (s1 < s2) return 1; if (s1 > s2) return -1; return memcmp(d1, d2, s1); } static int ev_uniq_ord(const void *v1, size_t s1, unsigned d1, const void *v2, size_t s2, unsigned d2) { int r = memord(v1, s1, v2, s2); if (r) return r; if (d1 > d2) return 1; if (d2 > d1) return -1; return 0; } static int event_uniq_add(struct rb_root *root, const char *name, int nl, unsigned domain) { struct rb_node **new = &(root->rb_node), *parent = NULL; struct event_uniq *data; /* Figure out where to put new node */ while (*new) { struct event_uniq *it; int result; it = container_of(*new, struct event_uniq, node); result = ev_uniq_ord(name, nl, domain, it->name, it->nl, it->domain); parent = *new; if (result < 0) new = &((*new)->rb_left); else if (result > 0) new = &((*new)->rb_right); else { it->ct++; pr_info("found a duplicate event %.*s, ct=%u\n", nl, name, it->ct); return it->ct; } } data = kmalloc(sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; *data = (struct event_uniq) { .name = name, .nl = nl, .ct = 0, .domain = domain, }; /* Add new node and rebalance tree. */ rb_link_node(&data->node, parent, new); rb_insert_color(&data->node, root); /* data->ct */ return 0; } static void event_uniq_destroy(struct rb_root *root) { /* * the strings we point to are in the giant block of memory filled by * the catalog, and are freed separately. */ struct event_uniq *pos, *n; rbtree_postorder_for_each_entry_safe(pos, n, root, node) kfree(pos); } /* * ensure the event structure's sizes are self consistent and don't cause us to * read outside of the event * * On success, return the event length in bytes. * Otherwise, return -1 (and print as appropriate). */ static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event, size_t event_idx, size_t event_data_bytes, size_t event_entry_count, size_t offset, void *end) { ssize_t ev_len; void *ev_end, *calc_ev_end; if (offset >= event_data_bytes) return -1; if (event_idx >= event_entry_count) { pr_devel("catalog event data has %zu bytes of padding after last event\n", event_data_bytes - offset); return -1; } if (!event_fixed_portion_is_within(event, end)) { pr_warn("event %zu fixed portion is not within range\n", event_idx); return -1; } ev_len = be16_to_cpu(event->length); if (ev_len % 16) pr_info("event %zu has length %zu not divisible by 16: event=%pK\n", event_idx, ev_len, event); ev_end = (__u8 *)event + ev_len; if (ev_end > end) { pr_warn("event %zu has .length=%zu, ends after buffer end: ev_end=%pK > end=%pK, offset=%zu\n", event_idx, ev_len, ev_end, end, offset); return -1; } calc_ev_end = event_end(event, end); if (!calc_ev_end) { pr_warn("event %zu has a calculated length which exceeds buffer length %zu: event=%pK end=%pK, offset=%zu\n", event_idx, event_data_bytes, event, end, offset); return -1; } if (calc_ev_end > ev_end) { pr_warn("event %zu exceeds it's own length: event=%pK, end=%pK, offset=%zu, calc_ev_end=%pK\n", event_idx, event, ev_end, offset, calc_ev_end); return -1; } return ev_len; } #define MAX_4K (SIZE_MAX / 4096) static int create_events_from_catalog(struct attribute ***events_, struct attribute ***event_descs_, struct attribute ***event_long_descs_) { long hret; size_t catalog_len, catalog_page_len, event_entry_count, event_data_len, event_data_offs, event_data_bytes, junk_events, event_idx, event_attr_ct, i, attr_max, event_idx_last, desc_ct, long_desc_ct; ssize_t ct, ev_len; uint64_t catalog_version_num; struct attribute **events, **event_descs, **event_long_descs; struct hv_24x7_catalog_page_0 *page_0 = kmem_cache_alloc(hv_page_cache, GFP_KERNEL); void *page = page_0; void *event_data, *end; struct hv_24x7_event_data *event; struct rb_root ev_uniq = RB_ROOT; int ret = 0; if (!page) { ret = -ENOMEM; goto e_out; } hret = h_get_24x7_catalog_page(page, 0, 0); if (hret) { ret = -EIO; goto e_free; } catalog_version_num = be64_to_cpu(page_0->version); catalog_page_len = be32_to_cpu(page_0->length); if (MAX_4K < catalog_page_len) { pr_err("invalid page count: %zu\n", catalog_page_len); ret = -EIO; goto e_free; } catalog_len = catalog_page_len * 4096; event_entry_count = be16_to_cpu(page_0->event_entry_count); event_data_offs = be16_to_cpu(page_0->event_data_offs); event_data_len = be16_to_cpu(page_0->event_data_len); pr_devel("cv %llu cl %zu eec %zu edo %zu edl %zu\n", catalog_version_num, catalog_len, event_entry_count, event_data_offs, event_data_len); if ((MAX_4K < event_data_len) || (MAX_4K < event_data_offs) || (MAX_4K - event_data_offs < event_data_len)) { pr_err("invalid event data offs %zu and/or len %zu\n", event_data_offs, event_data_len); ret = -EIO; goto e_free; } if ((event_data_offs + event_data_len) > catalog_page_len) { pr_err("event data %zu-%zu does not fit inside catalog 0-%zu\n", event_data_offs, event_data_offs + event_data_len, catalog_page_len); ret = -EIO; goto e_free; } if (SIZE_MAX - 1 < event_entry_count) { pr_err("event_entry_count %zu is invalid\n", event_entry_count); ret = -EIO; goto e_free; } event_data_bytes = event_data_len * 4096; /* * event data can span several pages, events can cross between these * pages. Use vmalloc to make this easier. */ event_data = vmalloc(event_data_bytes); if (!event_data) { pr_err("could not allocate event data\n"); ret = -ENOMEM; goto e_free; } end = event_data + event_data_bytes; /* * using vmalloc_to_phys() like this only works if PAGE_SIZE is * divisible by 4096 */ BUILD_BUG_ON(PAGE_SIZE % 4096); for (i = 0; i < event_data_len; i++) { hret = h_get_24x7_catalog_page_( vmalloc_to_phys(event_data + i * 4096), catalog_version_num, i + event_data_offs); if (hret) { pr_err("Failed to get event data in page %zu: rc=%ld\n", i + event_data_offs, hret); ret = -EIO; goto e_event_data; } } /* * scan the catalog to determine the number of attributes we need, and * verify it at the same time. */ for (junk_events = 0, event = event_data, event_idx = 0, attr_max = 0; ; event_idx++, event = (void *)event + ev_len) { size_t offset = (void *)event - (void *)event_data; char *name; int nl; ev_len = catalog_event_len_validate(event, event_idx, event_data_bytes, event_entry_count, offset, end); if (ev_len < 0) break; name = event_name(event, &nl); if (event->event_group_record_len == 0) { pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n", event_idx, nl, name); junk_events++; continue; } if (!catalog_entry_domain_is_valid(event->domain)) { pr_info("event %zu (%.*s) has invalid domain %d\n", event_idx, nl, name, event->domain); junk_events++; continue; } attr_max++; } event_idx_last = event_idx; if (event_idx_last != event_entry_count) pr_warn("event buffer ended before listed # of events were parsed (got %zu, wanted %zu, junk %zu)\n", event_idx_last, event_entry_count, junk_events); events = kmalloc_array(attr_max + 1, sizeof(*events), GFP_KERNEL); if (!events) { ret = -ENOMEM; goto e_event_data; } event_descs = kmalloc_array(event_idx + 1, sizeof(*event_descs), GFP_KERNEL); if (!event_descs) { ret = -ENOMEM; goto e_event_attrs; } event_long_descs = kmalloc_array(event_idx + 1, sizeof(*event_long_descs), GFP_KERNEL); if (!event_long_descs) { ret = -ENOMEM; goto e_event_descs; } /* Iterate over the catalog filling in the attribute vector */ for (junk_events = 0, event_attr_ct = 0, desc_ct = 0, long_desc_ct = 0, event = event_data, event_idx = 0; event_idx < event_idx_last; event_idx++, ev_len = be16_to_cpu(event->length), event = (void *)event + ev_len) { char *name; int nl; int nonce; /* * these are the only "bad" events that are intermixed and that * we can ignore without issue. make sure to skip them here */ if (event->event_group_record_len == 0) continue; if (!catalog_entry_domain_is_valid(event->domain)) continue; name = event_name(event, &nl); nonce = event_uniq_add(&ev_uniq, name, nl, event->domain); ct = event_data_to_attrs(event_idx, events + event_attr_ct, event, nonce); if (ct < 0) { pr_warn("event %zu (%.*s) creation failure, skipping\n", event_idx, nl, name); junk_events++; } else { event_attr_ct++; event_descs[desc_ct] = event_to_desc_attr(event, nonce); if (event_descs[desc_ct]) desc_ct++; event_long_descs[long_desc_ct] = event_to_long_desc_attr(event, nonce); if (event_long_descs[long_desc_ct]) long_desc_ct++; } } pr_info("read %zu catalog entries, created %zu event attrs (%zu failures), %zu descs\n", event_idx, event_attr_ct, junk_events, desc_ct); events[event_attr_ct] = NULL; event_descs[desc_ct] = NULL; event_long_descs[long_desc_ct] = NULL; event_uniq_destroy(&ev_uniq); vfree(event_data); kmem_cache_free(hv_page_cache, page); *events_ = events; *event_descs_ = event_descs; *event_long_descs_ = event_long_descs; return 0; e_event_descs: kfree(event_descs); e_event_attrs: kfree(events); e_event_data: vfree(event_data); e_free: kmem_cache_free(hv_page_cache, page); e_out: *events_ = NULL; *event_descs_ = NULL; *event_long_descs_ = NULL; return ret; } static ssize_t catalog_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t offset, size_t count) { long hret; ssize_t ret = 0; size_t catalog_len = 0, catalog_page_len = 0; loff_t page_offset = 0; loff_t offset_in_page; size_t copy_len; uint64_t catalog_version_num = 0; void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); struct hv_24x7_catalog_page_0 *page_0 = page; if (!page) return -ENOMEM; hret = h_get_24x7_catalog_page(page, 0, 0); if (hret) { ret = -EIO; goto e_free; } catalog_version_num = be64_to_cpu(page_0->version); catalog_page_len = be32_to_cpu(page_0->length); catalog_len = catalog_page_len * 4096; page_offset = offset / 4096; offset_in_page = offset % 4096; if (page_offset >= catalog_page_len) goto e_free; if (page_offset != 0) { hret = h_get_24x7_catalog_page(page, catalog_version_num, page_offset); if (hret) { ret = -EIO; goto e_free; } } copy_len = 4096 - offset_in_page; if (copy_len > count) copy_len = count; memcpy(buf, page+offset_in_page, copy_len); ret = copy_len; e_free: if (hret) pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:" " rc=%ld\n", catalog_version_num, page_offset, hret); kmem_cache_free(hv_page_cache, page); pr_devel("catalog_read: offset=%lld(%lld) count=%zu " "catalog_len=%zu(%zu) => %zd\n", offset, page_offset, count, catalog_len, catalog_page_len, ret); return ret; } static ssize_t domains_show(struct device *dev, struct device_attribute *attr, char *page) { int d, n, count = 0; const char *str; for (d = 0; d < HV_PERF_DOMAIN_MAX; d++) { str = domain_name(d); if (!str) continue; n = sprintf(page, "%d: %s\n", d, str); if (n < 0) break; count += n; page += n; } return count; } #define PAGE_0_ATTR(_name, _fmt, _expr) \ static ssize_t _name##_show(struct device *dev, \ struct device_attribute *dev_attr, \ char *buf) \ { \ long hret; \ ssize_t ret = 0; \ void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \ struct hv_24x7_catalog_page_0 *page_0 = page; \ if (!page) \ return -ENOMEM; \ hret = h_get_24x7_catalog_page(page, 0, 0); \ if (hret) { \ ret = -EIO; \ goto e_free; \ } \ ret = sprintf(buf, _fmt, _expr); \ e_free: \ kmem_cache_free(hv_page_cache, page); \ return ret; \ } \ static DEVICE_ATTR_RO(_name) PAGE_0_ATTR(catalog_version, "%lld\n", (unsigned long long)be64_to_cpu(page_0->version)); PAGE_0_ATTR(catalog_len, "%lld\n", (unsigned long long)be32_to_cpu(page_0->length) * 4096); static BIN_ATTR_RO(catalog, 0/* real length varies */); static DEVICE_ATTR_RO(domains); static struct bin_attribute *if_bin_attrs[] = { &bin_attr_catalog, NULL, }; static struct attribute *if_attrs[] = { &dev_attr_catalog_len.attr, &dev_attr_catalog_version.attr, &dev_attr_domains.attr, NULL, }; static struct attribute_group if_group = { .name = "interface", .bin_attrs = if_bin_attrs, .attrs = if_attrs, }; static const struct attribute_group *attr_groups[] = { &format_group, &event_group, &event_desc_group, &event_long_desc_group, &if_group, NULL, }; /* * Start the process for a new H_GET_24x7_DATA hcall. */ static void init_24x7_request(struct hv_24x7_request_buffer *request_buffer, struct hv_24x7_data_result_buffer *result_buffer) { memset(request_buffer, 0, H24x7_DATA_BUFFER_SIZE); memset(result_buffer, 0, H24x7_DATA_BUFFER_SIZE); request_buffer->interface_version = interface_version; /* memset above set request_buffer->num_requests to 0 */ } /* * Commit (i.e perform) the H_GET_24x7_DATA hcall using the data collected * by 'init_24x7_request()' and 'add_event_to_24x7_request()'. */ static int make_24x7_request(struct hv_24x7_request_buffer *request_buffer, struct hv_24x7_data_result_buffer *result_buffer) { long ret; /* * NOTE: Due to variable number of array elements in request and * result buffer(s), sizeof() is not reliable. Use the actual * allocated buffer size, H24x7_DATA_BUFFER_SIZE. */ ret = plpar_hcall_norets(H_GET_24X7_DATA, virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE, virt_to_phys(result_buffer), H24x7_DATA_BUFFER_SIZE); if (ret) { struct hv_24x7_request *req; req = request_buffer->requests; pr_notice_ratelimited("hcall failed: [%d %#x %#x %d] => ret 0x%lx (%ld) detail=0x%x failing ix=%x\n", req->performance_domain, req->data_offset, req->starting_ix, req->starting_lpar_ix, ret, ret, result_buffer->detailed_rc, result_buffer->failing_request_ix); return -EIO; } return 0; } /* * Add the given @event to the next slot in the 24x7 request_buffer. * * Note that H_GET_24X7_DATA hcall allows reading several counters' * values in a single HCALL. We expect the caller to add events to the * request buffer one by one, make the HCALL and process the results. */ static int add_event_to_24x7_request(struct perf_event *event, struct hv_24x7_request_buffer *request_buffer) { u16 idx; int i; size_t req_size; struct hv_24x7_request *req; if (request_buffer->num_requests >= max_num_requests(request_buffer->interface_version)) { pr_devel("Too many requests for 24x7 HCALL %d\n", request_buffer->num_requests); return -EINVAL; } switch (event_get_domain(event)) { case HV_PERF_DOMAIN_PHYS_CHIP: idx = event_get_chip(event); break; case HV_PERF_DOMAIN_PHYS_CORE: idx = event_get_core(event); break; default: idx = event_get_vcpu(event); } req_size = H24x7_REQUEST_SIZE(request_buffer->interface_version); i = request_buffer->num_requests++; req = (void *) request_buffer->requests + i * req_size; req->performance_domain = event_get_domain(event); req->data_size = cpu_to_be16(8); req->data_offset = cpu_to_be32(event_get_offset(event)); req->starting_lpar_ix = cpu_to_be16(event_get_lpar(event)); req->max_num_lpars = cpu_to_be16(1); req->starting_ix = cpu_to_be16(idx); req->max_ix = cpu_to_be16(1); if (request_buffer->interface_version > 1) { if (domain_needs_aggregation(req->performance_domain)) req->max_num_thread_groups = -1; else if (req->performance_domain != HV_PERF_DOMAIN_PHYS_CHIP) { req->starting_thread_group_ix = idx % 2; req->max_num_thread_groups = 1; } } return 0; } /** * get_count_from_result - get event count from all result elements in result * * If the event corresponding to this result needs aggregation of the result * element values, then this function does that. * * @event: Event associated with @res. * @resb: Result buffer containing @res. * @res: Result to work on. * @countp: Output variable containing the event count. * @next: Optional output variable pointing to the next result in @resb. */ static int get_count_from_result(struct perf_event *event, struct hv_24x7_data_result_buffer *resb, struct hv_24x7_result *res, u64 *countp, struct hv_24x7_result **next) { u16 num_elements = be16_to_cpu(res->num_elements_returned); u16 data_size = be16_to_cpu(res->result_element_data_size); unsigned int data_offset; void *element_data; int i; u64 count; /* * We can bail out early if the result is empty. */ if (!num_elements) { pr_debug("Result of request %hhu is empty, nothing to do\n", res->result_ix); if (next) *next = (struct hv_24x7_result *) res->elements; return -ENODATA; } /* * Since we always specify 1 as the maximum for the smallest resource * we're requesting, there should to be only one element per result. * Except when an event needs aggregation, in which case there are more. */ if (num_elements != 1 && !domain_needs_aggregation(event_get_domain(event))) { pr_err("Error: result of request %hhu has %hu elements\n", res->result_ix, num_elements); return -EIO; } if (data_size != sizeof(u64)) { pr_debug("Error: result of request %hhu has data of %hu bytes\n", res->result_ix, data_size); return -ENOTSUPP; } if (resb->interface_version == 1) data_offset = offsetof(struct hv_24x7_result_element_v1, element_data); else data_offset = offsetof(struct hv_24x7_result_element_v2, element_data); /* Go through the result elements in the result. */ for (i = count = 0, element_data = res->elements + data_offset; i < num_elements; i++, element_data += data_size + data_offset) count += be64_to_cpu(*((u64 *) element_data)); *countp = count; /* The next result is after the last result element. */ if (next) *next = element_data - data_offset; return 0; } static int single_24x7_request(struct perf_event *event, u64 *count) { int ret; struct hv_24x7_request_buffer *request_buffer; struct hv_24x7_data_result_buffer *result_buffer; BUILD_BUG_ON(sizeof(*request_buffer) > 4096); BUILD_BUG_ON(sizeof(*result_buffer) > 4096); request_buffer = (void *)get_cpu_var(hv_24x7_reqb); result_buffer = (void *)get_cpu_var(hv_24x7_resb); init_24x7_request(request_buffer, result_buffer); ret = add_event_to_24x7_request(event, request_buffer); if (ret) goto out; ret = make_24x7_request(request_buffer, result_buffer); if (ret) goto out; /* process result from hcall */ ret = get_count_from_result(event, result_buffer, result_buffer->results, count, NULL); out: put_cpu_var(hv_24x7_reqb); put_cpu_var(hv_24x7_resb); return ret; } static int h_24x7_event_init(struct perf_event *event) { struct hv_perf_caps caps; unsigned domain; unsigned long hret; u64 ct; /* Not our event */ if (event->attr.type != event->pmu->type) return -ENOENT; /* Unused areas must be 0 */ if (event_get_reserved1(event) || event_get_reserved2(event) || event_get_reserved3(event)) { pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n", event->attr.config, event_get_reserved1(event), event->attr.config1, event_get_reserved2(event), event->attr.config2, event_get_reserved3(event)); return -EINVAL; } /* no branch sampling */ if (has_branch_stack(event)) return -EOPNOTSUPP; /* offset must be 8 byte aligned */ if (event_get_offset(event) % 8) { pr_devel("bad alignment\n"); return -EINVAL; } domain = event_get_domain(event); if (domain >= HV_PERF_DOMAIN_MAX) { pr_devel("invalid domain %d\n", domain); return -EINVAL; } hret = hv_perf_caps_get(&caps); if (hret) { pr_devel("could not get capabilities: rc=%ld\n", hret); return -EIO; } /* Physical domains & other lpars require extra capabilities */ if (!caps.collect_privileged && (is_physical_domain(domain) || (event_get_lpar(event) != event_get_lpar_max()))) { pr_devel("hv permissions disallow: is_physical_domain:%d, lpar=0x%llx\n", is_physical_domain(domain), event_get_lpar(event)); return -EACCES; } /* Get the initial value of the counter for this event */ if (single_24x7_request(event, &ct)) { pr_devel("test hcall failed\n"); return -EIO; } (void)local64_xchg(&event->hw.prev_count, ct); return 0; } static u64 h_24x7_get_value(struct perf_event *event) { u64 ct; if (single_24x7_request(event, &ct)) /* We checked this in event init, shouldn't fail here... */ return 0; return ct; } static void update_event_count(struct perf_event *event, u64 now) { s64 prev; prev = local64_xchg(&event->hw.prev_count, now); local64_add(now - prev, &event->count); } static void h_24x7_event_read(struct perf_event *event) { u64 now; struct hv_24x7_request_buffer *request_buffer; struct hv_24x7_hw *h24x7hw; int txn_flags; txn_flags = __this_cpu_read(hv_24x7_txn_flags); /* * If in a READ transaction, add this counter to the list of * counters to read during the next HCALL (i.e commit_txn()). * If not in a READ transaction, go ahead and make the HCALL * to read this counter by itself. */ if (txn_flags & PERF_PMU_TXN_READ) { int i; int ret; if (__this_cpu_read(hv_24x7_txn_err)) return; request_buffer = (void *)get_cpu_var(hv_24x7_reqb); ret = add_event_to_24x7_request(event, request_buffer); if (ret) { __this_cpu_write(hv_24x7_txn_err, ret); } else { /* * Associate the event with the HCALL request index, * so ->commit_txn() can quickly find/update count. */ i = request_buffer->num_requests - 1; h24x7hw = &get_cpu_var(hv_24x7_hw); h24x7hw->events[i] = event; put_cpu_var(h24x7hw); /* * Clear the event count so we can compute the _change_ * in the 24x7 raw counter value at the end of the txn. * * Note that we could alternatively read the 24x7 value * now and save its value in event->hw.prev_count. But * that would require issuing a hcall, which would then * defeat the purpose of using the txn interface. */ local64_set(&event->count, 0); } put_cpu_var(hv_24x7_reqb); } else { now = h_24x7_get_value(event); update_event_count(event, now); } } static void h_24x7_event_start(struct perf_event *event, int flags) { if (flags & PERF_EF_RELOAD) local64_set(&event->hw.prev_count, h_24x7_get_value(event)); } static void h_24x7_event_stop(struct perf_event *event, int flags) { h_24x7_event_read(event); } static int h_24x7_event_add(struct perf_event *event, int flags) { if (flags & PERF_EF_START) h_24x7_event_start(event, flags); return 0; } /* * 24x7 counters only support READ transactions. They are * always counting and dont need/support ADD transactions. * Cache the flags, but otherwise ignore transactions that * are not PERF_PMU_TXN_READ. */ static void h_24x7_event_start_txn(struct pmu *pmu, unsigned int flags) { struct hv_24x7_request_buffer *request_buffer; struct hv_24x7_data_result_buffer *result_buffer; /* We should not be called if we are already in a txn */ WARN_ON_ONCE(__this_cpu_read(hv_24x7_txn_flags)); __this_cpu_write(hv_24x7_txn_flags, flags); if (flags & ~PERF_PMU_TXN_READ) return; request_buffer = (void *)get_cpu_var(hv_24x7_reqb); result_buffer = (void *)get_cpu_var(hv_24x7_resb); init_24x7_request(request_buffer, result_buffer); put_cpu_var(hv_24x7_resb); put_cpu_var(hv_24x7_reqb); } /* * Clean up transaction state. * * NOTE: Ignore state of request and result buffers for now. * We will initialize them during the next read/txn. */ static void reset_txn(void) { __this_cpu_write(hv_24x7_txn_flags, 0); __this_cpu_write(hv_24x7_txn_err, 0); } /* * 24x7 counters only support READ transactions. They are always counting * and dont need/support ADD transactions. Clear ->txn_flags but otherwise * ignore transactions that are not of type PERF_PMU_TXN_READ. * * For READ transactions, submit all pending 24x7 requests (i.e requests * that were queued by h_24x7_event_read()), to the hypervisor and update * the event counts. */ static int h_24x7_event_commit_txn(struct pmu *pmu) { struct hv_24x7_request_buffer *request_buffer; struct hv_24x7_data_result_buffer *result_buffer; struct hv_24x7_result *res, *next_res; u64 count; int i, ret, txn_flags; struct hv_24x7_hw *h24x7hw; txn_flags = __this_cpu_read(hv_24x7_txn_flags); WARN_ON_ONCE(!txn_flags); ret = 0; if (txn_flags & ~PERF_PMU_TXN_READ) goto out; ret = __this_cpu_read(hv_24x7_txn_err); if (ret) goto out; request_buffer = (void *)get_cpu_var(hv_24x7_reqb); result_buffer = (void *)get_cpu_var(hv_24x7_resb); ret = make_24x7_request(request_buffer, result_buffer); if (ret) goto put_reqb; h24x7hw = &get_cpu_var(hv_24x7_hw); /* Go through results in the result buffer to update event counts. */ for (i = 0, res = result_buffer->results; i < result_buffer->num_results; i++, res = next_res) { struct perf_event *event = h24x7hw->events[res->result_ix]; ret = get_count_from_result(event, result_buffer, res, &count, &next_res); if (ret) break; update_event_count(event, count); } put_cpu_var(hv_24x7_hw); put_reqb: put_cpu_var(hv_24x7_resb); put_cpu_var(hv_24x7_reqb); out: reset_txn(); return ret; } /* * 24x7 counters only support READ transactions. They are always counting * and dont need/support ADD transactions. However, regardless of type * of transaction, all we need to do is cleanup, so we don't have to check * the type of transaction. */ static void h_24x7_event_cancel_txn(struct pmu *pmu) { WARN_ON_ONCE(!__this_cpu_read(hv_24x7_txn_flags)); reset_txn(); } static struct pmu h_24x7_pmu = { .task_ctx_nr = perf_invalid_context, .name = "hv_24x7", .attr_groups = attr_groups, .event_init = h_24x7_event_init, .add = h_24x7_event_add, .del = h_24x7_event_stop, .start = h_24x7_event_start, .stop = h_24x7_event_stop, .read = h_24x7_event_read, .start_txn = h_24x7_event_start_txn, .commit_txn = h_24x7_event_commit_txn, .cancel_txn = h_24x7_event_cancel_txn, .capabilities = PERF_PMU_CAP_NO_EXCLUDE, }; static int hv_24x7_init(void) { int r; unsigned long hret; struct hv_perf_caps caps; if (!firmware_has_feature(FW_FEATURE_LPAR)) { pr_debug("not a virtualized system, not enabling\n"); return -ENODEV; } else if (!cur_cpu_spec->oprofile_cpu_type) return -ENODEV; /* POWER8 only supports v1, while POWER9 only supports v2. */ if (!strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power8")) interface_version = 1; else { interface_version = 2; /* SMT8 in POWER9 needs to aggregate result elements. */ if (threads_per_core == 8) aggregate_result_elements = true; } hret = hv_perf_caps_get(&caps); if (hret) { pr_debug("could not obtain capabilities, not enabling, rc=%ld\n", hret); return -ENODEV; } hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL); if (!hv_page_cache) return -ENOMEM; /* sampling not supported */ h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; r = create_events_from_catalog(&event_group.attrs, &event_desc_group.attrs, &event_long_desc_group.attrs); if (r) return r; r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1); if (r) return r; return 0; } device_initcall(hv_24x7_init);