1 /* 2 * Hypervisor supplied "24x7" performance counter support 3 * 4 * Author: Cody P Schafer <cody@linux.vnet.ibm.com> 5 * Copyright 2014 IBM Corporation. 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #define pr_fmt(fmt) "hv-24x7: " fmt 14 15 #include <linux/perf_event.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <asm/firmware.h> 19 #include <asm/hvcall.h> 20 #include <asm/io.h> 21 22 #include "hv-24x7.h" 23 #include "hv-24x7-catalog.h" 24 #include "hv-common.h" 25 26 /* 27 * TODO: Merging events: 28 * - Think of the hcall as an interface to a 4d array of counters: 29 * - x = domains 30 * - y = indexes in the domain (core, chip, vcpu, node, etc) 31 * - z = offset into the counter space 32 * - w = lpars (guest vms, "logical partitions") 33 * - A single request is: x,y,y_last,z,z_last,w,w_last 34 * - this means we can retrieve a rectangle of counters in y,z for a single x. 35 * 36 * - Things to consider (ignoring w): 37 * - input cost_per_request = 16 38 * - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs 39 * - limited number of requests per hcall (must fit into 4K bytes) 40 * - 4k = 16 [buffer header] - 16 [request size] * request_count 41 * - 255 requests per hcall 42 * - sometimes it will be more efficient to read extra data and discard 43 */ 44 45 /* 46 * Example usage: 47 * perf stat -e 'hv_24x7/domain=2,offset=8,starting_index=0,lpar=0xffffffff/' 48 */ 49 50 /* u3 0-6, one of HV_24X7_PERF_DOMAIN */ 51 EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3); 52 /* u16 */ 53 EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 16, 31); 54 /* u32, see "data_offset" */ 55 EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63); 56 /* u16 */ 57 EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15); 58 59 EVENT_DEFINE_RANGE(reserved1, config, 4, 15); 60 EVENT_DEFINE_RANGE(reserved2, config1, 16, 63); 61 EVENT_DEFINE_RANGE(reserved3, config2, 0, 63); 62 63 static struct attribute *format_attrs[] = { 64 &format_attr_domain.attr, 65 &format_attr_offset.attr, 66 &format_attr_starting_index.attr, 67 &format_attr_lpar.attr, 68 NULL, 69 }; 70 71 static struct attribute_group format_group = { 72 .name = "format", 73 .attrs = format_attrs, 74 }; 75 76 static struct kmem_cache *hv_page_cache; 77 78 static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096, 79 unsigned long version, 80 unsigned long index) 81 { 82 pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)", 83 phys_4096, 84 version, 85 index); 86 WARN_ON(!IS_ALIGNED(phys_4096, 4096)); 87 return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE, 88 phys_4096, 89 version, 90 index); 91 } 92 93 static unsigned long h_get_24x7_catalog_page(char page[], 94 u64 version, u32 index) 95 { 96 return h_get_24x7_catalog_page_(virt_to_phys(page), 97 version, index); 98 } 99 100 static ssize_t catalog_read(struct file *filp, struct kobject *kobj, 101 struct bin_attribute *bin_attr, char *buf, 102 loff_t offset, size_t count) 103 { 104 unsigned long hret; 105 ssize_t ret = 0; 106 size_t catalog_len = 0, catalog_page_len = 0; 107 loff_t page_offset = 0; 108 loff_t offset_in_page; 109 size_t copy_len; 110 uint64_t catalog_version_num = 0; 111 void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); 112 struct hv_24x7_catalog_page_0 *page_0 = page; 113 if (!page) 114 return -ENOMEM; 115 116 hret = h_get_24x7_catalog_page(page, 0, 0); 117 if (hret) { 118 ret = -EIO; 119 goto e_free; 120 } 121 122 catalog_version_num = be64_to_cpu(page_0->version); 123 catalog_page_len = be32_to_cpu(page_0->length); 124 catalog_len = catalog_page_len * 4096; 125 126 page_offset = offset / 4096; 127 offset_in_page = offset % 4096; 128 129 if (page_offset >= catalog_page_len) 130 goto e_free; 131 132 if (page_offset != 0) { 133 hret = h_get_24x7_catalog_page(page, catalog_version_num, 134 page_offset); 135 if (hret) { 136 ret = -EIO; 137 goto e_free; 138 } 139 } 140 141 copy_len = 4096 - offset_in_page; 142 if (copy_len > count) 143 copy_len = count; 144 145 memcpy(buf, page+offset_in_page, copy_len); 146 ret = copy_len; 147 148 e_free: 149 if (hret) 150 pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:" 151 " rc=%ld\n", 152 catalog_version_num, page_offset, hret); 153 kmem_cache_free(hv_page_cache, page); 154 155 pr_devel("catalog_read: offset=%lld(%lld) count=%zu " 156 "catalog_len=%zu(%zu) => %zd\n", offset, page_offset, 157 count, catalog_len, catalog_page_len, ret); 158 159 return ret; 160 } 161 162 #define PAGE_0_ATTR(_name, _fmt, _expr) \ 163 static ssize_t _name##_show(struct device *dev, \ 164 struct device_attribute *dev_attr, \ 165 char *buf) \ 166 { \ 167 unsigned long hret; \ 168 ssize_t ret = 0; \ 169 void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \ 170 struct hv_24x7_catalog_page_0 *page_0 = page; \ 171 if (!page) \ 172 return -ENOMEM; \ 173 hret = h_get_24x7_catalog_page(page, 0, 0); \ 174 if (hret) { \ 175 ret = -EIO; \ 176 goto e_free; \ 177 } \ 178 ret = sprintf(buf, _fmt, _expr); \ 179 e_free: \ 180 kfree(page); \ 181 return ret; \ 182 } \ 183 static DEVICE_ATTR_RO(_name) 184 185 PAGE_0_ATTR(catalog_version, "%lld\n", 186 (unsigned long long)be64_to_cpu(page_0->version)); 187 PAGE_0_ATTR(catalog_len, "%lld\n", 188 (unsigned long long)be32_to_cpu(page_0->length) * 4096); 189 static BIN_ATTR_RO(catalog, 0/* real length varies */); 190 191 static struct bin_attribute *if_bin_attrs[] = { 192 &bin_attr_catalog, 193 NULL, 194 }; 195 196 static struct attribute *if_attrs[] = { 197 &dev_attr_catalog_len.attr, 198 &dev_attr_catalog_version.attr, 199 NULL, 200 }; 201 202 static struct attribute_group if_group = { 203 .name = "interface", 204 .bin_attrs = if_bin_attrs, 205 .attrs = if_attrs, 206 }; 207 208 static const struct attribute_group *attr_groups[] = { 209 &format_group, 210 &if_group, 211 NULL, 212 }; 213 214 static bool is_physical_domain(int domain) 215 { 216 return domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CHIP || 217 domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CORE; 218 } 219 220 static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix, 221 u16 lpar, u64 *res, 222 bool success_expected) 223 { 224 unsigned long ret = -ENOMEM; 225 226 /* 227 * request_buffer and result_buffer are not required to be 4k aligned, 228 * but are not allowed to cross any 4k boundary. Aligning them to 4k is 229 * the simplest way to ensure that. 230 */ 231 struct reqb { 232 struct hv_24x7_request_buffer buf; 233 struct hv_24x7_request req; 234 } __packed *request_buffer; 235 236 struct { 237 struct hv_24x7_data_result_buffer buf; 238 struct hv_24x7_result res; 239 struct hv_24x7_result_element elem; 240 __be64 result; 241 } __packed *result_buffer; 242 243 BUILD_BUG_ON(sizeof(*request_buffer) > 4096); 244 BUILD_BUG_ON(sizeof(*result_buffer) > 4096); 245 246 request_buffer = kmem_cache_zalloc(hv_page_cache, GFP_USER); 247 if (!request_buffer) 248 goto out; 249 250 result_buffer = kmem_cache_zalloc(hv_page_cache, GFP_USER); 251 if (!result_buffer) 252 goto out_free_request_buffer; 253 254 *request_buffer = (struct reqb) { 255 .buf = { 256 .interface_version = HV_24X7_IF_VERSION_CURRENT, 257 .num_requests = 1, 258 }, 259 .req = { 260 .performance_domain = domain, 261 .data_size = cpu_to_be16(8), 262 .data_offset = cpu_to_be32(offset), 263 .starting_lpar_ix = cpu_to_be16(lpar), 264 .max_num_lpars = cpu_to_be16(1), 265 .starting_ix = cpu_to_be16(ix), 266 .max_ix = cpu_to_be16(1), 267 } 268 }; 269 270 ret = plpar_hcall_norets(H_GET_24X7_DATA, 271 virt_to_phys(request_buffer), sizeof(*request_buffer), 272 virt_to_phys(result_buffer), sizeof(*result_buffer)); 273 274 if (ret) { 275 if (success_expected) 276 pr_err_ratelimited("hcall failed: %d %#x %#x %d => " 277 "0x%lx (%ld) detail=0x%x failing ix=%x\n", 278 domain, offset, ix, lpar, ret, ret, 279 result_buffer->buf.detailed_rc, 280 result_buffer->buf.failing_request_ix); 281 goto out_free_result_buffer; 282 } 283 284 *res = be64_to_cpu(result_buffer->result); 285 286 out_free_result_buffer: 287 kfree(result_buffer); 288 out_free_request_buffer: 289 kfree(request_buffer); 290 out: 291 return ret; 292 } 293 294 static unsigned long event_24x7_request(struct perf_event *event, u64 *res, 295 bool success_expected) 296 { 297 return single_24x7_request(event_get_domain(event), 298 event_get_offset(event), 299 event_get_starting_index(event), 300 event_get_lpar(event), 301 res, 302 success_expected); 303 } 304 305 static int h_24x7_event_init(struct perf_event *event) 306 { 307 struct hv_perf_caps caps; 308 unsigned domain; 309 unsigned long hret; 310 u64 ct; 311 312 /* Not our event */ 313 if (event->attr.type != event->pmu->type) 314 return -ENOENT; 315 316 /* Unused areas must be 0 */ 317 if (event_get_reserved1(event) || 318 event_get_reserved2(event) || 319 event_get_reserved3(event)) { 320 pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n", 321 event->attr.config, 322 event_get_reserved1(event), 323 event->attr.config1, 324 event_get_reserved2(event), 325 event->attr.config2, 326 event_get_reserved3(event)); 327 return -EINVAL; 328 } 329 330 /* unsupported modes and filters */ 331 if (event->attr.exclude_user || 332 event->attr.exclude_kernel || 333 event->attr.exclude_hv || 334 event->attr.exclude_idle || 335 event->attr.exclude_host || 336 event->attr.exclude_guest) 337 return -EINVAL; 338 339 /* no branch sampling */ 340 if (has_branch_stack(event)) 341 return -EOPNOTSUPP; 342 343 /* offset must be 8 byte aligned */ 344 if (event_get_offset(event) % 8) { 345 pr_devel("bad alignment\n"); 346 return -EINVAL; 347 } 348 349 /* Domains above 6 are invalid */ 350 domain = event_get_domain(event); 351 if (domain > 6) { 352 pr_devel("invalid domain %d\n", domain); 353 return -EINVAL; 354 } 355 356 hret = hv_perf_caps_get(&caps); 357 if (hret) { 358 pr_devel("could not get capabilities: rc=%ld\n", hret); 359 return -EIO; 360 } 361 362 /* PHYSICAL domains & other lpars require extra capabilities */ 363 if (!caps.collect_privileged && (is_physical_domain(domain) || 364 (event_get_lpar(event) != event_get_lpar_max()))) { 365 pr_devel("hv permisions disallow: is_physical_domain:%d, lpar=0x%llx\n", 366 is_physical_domain(domain), 367 event_get_lpar(event)); 368 return -EACCES; 369 } 370 371 /* see if the event complains */ 372 if (event_24x7_request(event, &ct, false)) { 373 pr_devel("test hcall failed\n"); 374 return -EIO; 375 } 376 377 return 0; 378 } 379 380 static u64 h_24x7_get_value(struct perf_event *event) 381 { 382 unsigned long ret; 383 u64 ct; 384 ret = event_24x7_request(event, &ct, true); 385 if (ret) 386 /* We checked this in event init, shouldn't fail here... */ 387 return 0; 388 389 return ct; 390 } 391 392 static void h_24x7_event_update(struct perf_event *event) 393 { 394 s64 prev; 395 u64 now; 396 now = h_24x7_get_value(event); 397 prev = local64_xchg(&event->hw.prev_count, now); 398 local64_add(now - prev, &event->count); 399 } 400 401 static void h_24x7_event_start(struct perf_event *event, int flags) 402 { 403 if (flags & PERF_EF_RELOAD) 404 local64_set(&event->hw.prev_count, h_24x7_get_value(event)); 405 } 406 407 static void h_24x7_event_stop(struct perf_event *event, int flags) 408 { 409 h_24x7_event_update(event); 410 } 411 412 static int h_24x7_event_add(struct perf_event *event, int flags) 413 { 414 if (flags & PERF_EF_START) 415 h_24x7_event_start(event, flags); 416 417 return 0; 418 } 419 420 static struct pmu h_24x7_pmu = { 421 .task_ctx_nr = perf_invalid_context, 422 423 .name = "hv_24x7", 424 .attr_groups = attr_groups, 425 .event_init = h_24x7_event_init, 426 .add = h_24x7_event_add, 427 .del = h_24x7_event_stop, 428 .start = h_24x7_event_start, 429 .stop = h_24x7_event_stop, 430 .read = h_24x7_event_update, 431 }; 432 433 static int hv_24x7_init(void) 434 { 435 int r; 436 unsigned long hret; 437 struct hv_perf_caps caps; 438 439 if (!firmware_has_feature(FW_FEATURE_LPAR)) { 440 pr_debug("not a virtualized system, not enabling\n"); 441 return -ENODEV; 442 } 443 444 hret = hv_perf_caps_get(&caps); 445 if (hret) { 446 pr_debug("could not obtain capabilities, not enabling, rc=%ld\n", 447 hret); 448 return -ENODEV; 449 } 450 451 hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL); 452 if (!hv_page_cache) 453 return -ENOMEM; 454 455 /* sampling not supported */ 456 h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; 457 458 r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1); 459 if (r) 460 return r; 461 462 return 0; 463 } 464 465 device_initcall(hv_24x7_init); 466