1 /* 2 * s390 storage key device 3 * 4 * Copyright 2015 IBM Corp. 5 * Author(s): Jason J. Herne <jjherne@linux.vnet.ibm.com> 6 * 7 * This work is licensed under the terms of the GNU GPL, version 2 or (at 8 * your option) any later version. See the COPYING file in the top-level 9 * directory. 10 */ 11 12 #include "qemu/osdep.h" 13 #include "qemu/units.h" 14 #include "hw/boards.h" 15 #include "hw/qdev-properties.h" 16 #include "hw/s390x/storage-keys.h" 17 #include "qapi/error.h" 18 #include "qapi/qapi-commands-misc-target.h" 19 #include "qapi/qmp/qdict.h" 20 #include "qemu/error-report.h" 21 #include "sysemu/memory_mapping.h" 22 #include "exec/address-spaces.h" 23 #include "sysemu/kvm.h" 24 #include "migration/qemu-file-types.h" 25 #include "migration/register.h" 26 27 #define S390_SKEYS_BUFFER_SIZE (128 * KiB) /* Room for 128k storage keys */ 28 #define S390_SKEYS_SAVE_FLAG_EOS 0x01 29 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02 30 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04 31 32 S390SKeysState *s390_get_skeys_device(void) 33 { 34 S390SKeysState *ss; 35 36 ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL)); 37 assert(ss); 38 return ss; 39 } 40 41 void s390_skeys_init(void) 42 { 43 Object *obj; 44 45 if (kvm_enabled()) { 46 obj = object_new(TYPE_KVM_S390_SKEYS); 47 } else { 48 obj = object_new(TYPE_QEMU_S390_SKEYS); 49 } 50 object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS, 51 obj); 52 object_unref(obj); 53 54 qdev_realize(DEVICE(obj), NULL, &error_fatal); 55 } 56 57 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn, 58 uint64_t count, Error **errp) 59 { 60 uint64_t curpage = startgfn; 61 uint64_t maxpage = curpage + count - 1; 62 63 for (; curpage <= maxpage; curpage++) { 64 uint8_t acc = (*keys & 0xF0) >> 4; 65 int fp = (*keys & 0x08); 66 int ref = (*keys & 0x04); 67 int ch = (*keys & 0x02); 68 int res = (*keys & 0x01); 69 70 fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d," 71 " ch=%d, reserved=%d\n", 72 curpage, *keys, acc, fp, ref, ch, res); 73 keys++; 74 } 75 } 76 77 void hmp_info_skeys(Monitor *mon, const QDict *qdict) 78 { 79 S390SKeysState *ss = s390_get_skeys_device(); 80 S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss); 81 uint64_t addr = qdict_get_int(qdict, "addr"); 82 uint8_t key; 83 int r; 84 85 /* Quick check to see if guest is using storage keys*/ 86 if (!skeyclass->skeys_are_enabled(ss)) { 87 monitor_printf(mon, "Error: This guest is not using storage keys\n"); 88 return; 89 } 90 91 if (!address_space_access_valid(&address_space_memory, 92 addr & TARGET_PAGE_MASK, TARGET_PAGE_SIZE, 93 false, MEMTXATTRS_UNSPECIFIED)) { 94 monitor_printf(mon, "Error: The given address is not valid\n"); 95 return; 96 } 97 98 r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key); 99 if (r < 0) { 100 monitor_printf(mon, "Error: %s\n", strerror(-r)); 101 return; 102 } 103 104 monitor_printf(mon, " key: 0x%X\n", key); 105 } 106 107 void hmp_dump_skeys(Monitor *mon, const QDict *qdict) 108 { 109 const char *filename = qdict_get_str(qdict, "filename"); 110 Error *err = NULL; 111 112 qmp_dump_skeys(filename, &err); 113 if (err) { 114 error_report_err(err); 115 } 116 } 117 118 void qmp_dump_skeys(const char *filename, Error **errp) 119 { 120 S390SKeysState *ss = s390_get_skeys_device(); 121 S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss); 122 GuestPhysBlockList guest_phys_blocks; 123 GuestPhysBlock *block; 124 uint64_t pages, gfn; 125 Error *lerr = NULL; 126 uint8_t *buf; 127 int ret; 128 int fd; 129 FILE *f; 130 131 /* Quick check to see if guest is using storage keys*/ 132 if (!skeyclass->skeys_are_enabled(ss)) { 133 error_setg(errp, "This guest is not using storage keys - " 134 "nothing to dump"); 135 return; 136 } 137 138 fd = qemu_open_old(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600); 139 if (fd < 0) { 140 error_setg_file_open(errp, errno, filename); 141 return; 142 } 143 f = fdopen(fd, "wb"); 144 if (!f) { 145 close(fd); 146 error_setg_file_open(errp, errno, filename); 147 return; 148 } 149 150 buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE); 151 if (!buf) { 152 error_setg(errp, "Could not allocate memory"); 153 goto out; 154 } 155 156 assert(qemu_mutex_iothread_locked()); 157 guest_phys_blocks_init(&guest_phys_blocks); 158 guest_phys_blocks_append(&guest_phys_blocks); 159 160 QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) { 161 assert(QEMU_IS_ALIGNED(block->target_start, TARGET_PAGE_SIZE)); 162 assert(QEMU_IS_ALIGNED(block->target_end, TARGET_PAGE_SIZE)); 163 164 gfn = block->target_start / TARGET_PAGE_SIZE; 165 pages = (block->target_end - block->target_start) / TARGET_PAGE_SIZE; 166 167 while (pages) { 168 const uint64_t cur_pages = MIN(pages, S390_SKEYS_BUFFER_SIZE); 169 170 ret = skeyclass->get_skeys(ss, gfn, cur_pages, buf); 171 if (ret < 0) { 172 error_setg_errno(errp, -ret, "get_keys error"); 173 goto out_free; 174 } 175 176 /* write keys to stream */ 177 write_keys(f, buf, gfn, cur_pages, &lerr); 178 if (lerr) { 179 goto out_free; 180 } 181 182 gfn += cur_pages; 183 pages -= cur_pages; 184 } 185 } 186 187 out_free: 188 guest_phys_blocks_free(&guest_phys_blocks); 189 error_propagate(errp, lerr); 190 g_free(buf); 191 out: 192 fclose(f); 193 } 194 195 static bool qemu_s390_skeys_are_enabled(S390SKeysState *ss) 196 { 197 QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(ss); 198 199 /* Lockless check is sufficient. */ 200 return !!skeys->keydata; 201 } 202 203 static bool qemu_s390_enable_skeys(S390SKeysState *ss) 204 { 205 QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(ss); 206 static gsize initialized; 207 208 if (likely(skeys->keydata)) { 209 return true; 210 } 211 212 /* 213 * TODO: Modern Linux doesn't use storage keys unless running KVM guests 214 * that use storage keys. Therefore, we keep it simple for now. 215 * 216 * 1) We should initialize to "referenced+changed" for an initial 217 * over-indication. Let's avoid touching megabytes of data for now and 218 * assume that any sane user will issue a storage key instruction before 219 * actually relying on this data. 220 * 2) Relying on ram_size and allocating a big array is ugly. We should 221 * allocate and manage storage key data per RAMBlock or optimally using 222 * some sparse data structure. 223 * 3) We only ever have a single S390SKeysState, so relying on 224 * g_once_init_enter() is good enough. 225 */ 226 if (g_once_init_enter(&initialized)) { 227 MachineState *machine = MACHINE(qdev_get_machine()); 228 229 skeys->key_count = machine->ram_size / TARGET_PAGE_SIZE; 230 skeys->keydata = g_malloc0(skeys->key_count); 231 g_once_init_leave(&initialized, 1); 232 } 233 return false; 234 } 235 236 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn, 237 uint64_t count, uint8_t *keys) 238 { 239 QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss); 240 int i; 241 242 /* Check for uint64 overflow and access beyond end of key data */ 243 if (unlikely(!skeydev->keydata || start_gfn + count > skeydev->key_count || 244 start_gfn + count < count)) { 245 error_report("Error: Setting storage keys for pages with unallocated " 246 "storage key memory: gfn=%" PRIx64 " count=%" PRId64, 247 start_gfn, count); 248 return -EINVAL; 249 } 250 251 for (i = 0; i < count; i++) { 252 skeydev->keydata[start_gfn + i] = keys[i]; 253 } 254 return 0; 255 } 256 257 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn, 258 uint64_t count, uint8_t *keys) 259 { 260 QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss); 261 int i; 262 263 /* Check for uint64 overflow and access beyond end of key data */ 264 if (unlikely(!skeydev->keydata || start_gfn + count > skeydev->key_count || 265 start_gfn + count < count)) { 266 error_report("Error: Getting storage keys for pages with unallocated " 267 "storage key memory: gfn=%" PRIx64 " count=%" PRId64, 268 start_gfn, count); 269 return -EINVAL; 270 } 271 272 for (i = 0; i < count; i++) { 273 keys[i] = skeydev->keydata[start_gfn + i]; 274 } 275 return 0; 276 } 277 278 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data) 279 { 280 S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc); 281 DeviceClass *dc = DEVICE_CLASS(oc); 282 283 skeyclass->skeys_are_enabled = qemu_s390_skeys_are_enabled; 284 skeyclass->enable_skeys = qemu_s390_enable_skeys; 285 skeyclass->get_skeys = qemu_s390_skeys_get; 286 skeyclass->set_skeys = qemu_s390_skeys_set; 287 288 /* Reason: Internal device (only one skeys device for the whole memory) */ 289 dc->user_creatable = false; 290 } 291 292 static const TypeInfo qemu_s390_skeys_info = { 293 .name = TYPE_QEMU_S390_SKEYS, 294 .parent = TYPE_S390_SKEYS, 295 .instance_size = sizeof(QEMUS390SKeysState), 296 .class_init = qemu_s390_skeys_class_init, 297 .class_size = sizeof(S390SKeysClass), 298 }; 299 300 static void s390_storage_keys_save(QEMUFile *f, void *opaque) 301 { 302 S390SKeysState *ss = S390_SKEYS(opaque); 303 S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss); 304 GuestPhysBlockList guest_phys_blocks; 305 GuestPhysBlock *block; 306 uint64_t pages, gfn; 307 int error = 0; 308 uint8_t *buf; 309 310 if (!skeyclass->skeys_are_enabled(ss)) { 311 goto end_stream; 312 } 313 314 buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE); 315 if (!buf) { 316 error_report("storage key save could not allocate memory"); 317 goto end_stream; 318 } 319 320 guest_phys_blocks_init(&guest_phys_blocks); 321 guest_phys_blocks_append(&guest_phys_blocks); 322 323 /* Send each contiguous physical memory range separately. */ 324 QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) { 325 assert(QEMU_IS_ALIGNED(block->target_start, TARGET_PAGE_SIZE)); 326 assert(QEMU_IS_ALIGNED(block->target_end, TARGET_PAGE_SIZE)); 327 328 gfn = block->target_start / TARGET_PAGE_SIZE; 329 pages = (block->target_end - block->target_start) / TARGET_PAGE_SIZE; 330 qemu_put_be64(f, block->target_start | S390_SKEYS_SAVE_FLAG_SKEYS); 331 qemu_put_be64(f, pages); 332 333 while (pages) { 334 const uint64_t cur_pages = MIN(pages, S390_SKEYS_BUFFER_SIZE); 335 336 if (!error) { 337 error = skeyclass->get_skeys(ss, gfn, cur_pages, buf); 338 if (error) { 339 /* 340 * Create a valid stream with all 0x00 and indicate 341 * S390_SKEYS_SAVE_FLAG_ERROR to the destination. 342 */ 343 error_report("S390_GET_KEYS error %d", error); 344 memset(buf, 0, S390_SKEYS_BUFFER_SIZE); 345 } 346 } 347 348 qemu_put_buffer(f, buf, cur_pages); 349 gfn += cur_pages; 350 pages -= cur_pages; 351 } 352 353 if (error) { 354 break; 355 } 356 } 357 358 guest_phys_blocks_free(&guest_phys_blocks); 359 g_free(buf); 360 end_stream: 361 if (error) { 362 qemu_put_be64(f, S390_SKEYS_SAVE_FLAG_ERROR); 363 } else { 364 qemu_put_be64(f, S390_SKEYS_SAVE_FLAG_EOS); 365 } 366 } 367 368 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id) 369 { 370 S390SKeysState *ss = S390_SKEYS(opaque); 371 S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss); 372 int ret = 0; 373 374 /* 375 * Make sure to lazy-enable if required to be done explicitly. No need to 376 * flush any TLB as the VM is not running yet. 377 */ 378 if (skeyclass->enable_skeys) { 379 skeyclass->enable_skeys(ss); 380 } 381 382 while (!ret) { 383 ram_addr_t addr; 384 int flags; 385 386 addr = qemu_get_be64(f); 387 flags = addr & ~TARGET_PAGE_MASK; 388 addr &= TARGET_PAGE_MASK; 389 390 switch (flags) { 391 case S390_SKEYS_SAVE_FLAG_SKEYS: { 392 const uint64_t total_count = qemu_get_be64(f); 393 uint64_t handled_count = 0, cur_count; 394 uint64_t cur_gfn = addr / TARGET_PAGE_SIZE; 395 uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE); 396 397 if (!buf) { 398 error_report("storage key load could not allocate memory"); 399 ret = -ENOMEM; 400 break; 401 } 402 403 while (handled_count < total_count) { 404 cur_count = MIN(total_count - handled_count, 405 S390_SKEYS_BUFFER_SIZE); 406 qemu_get_buffer(f, buf, cur_count); 407 408 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf); 409 if (ret < 0) { 410 error_report("S390_SET_KEYS error %d", ret); 411 break; 412 } 413 handled_count += cur_count; 414 cur_gfn += cur_count; 415 } 416 g_free(buf); 417 break; 418 } 419 case S390_SKEYS_SAVE_FLAG_ERROR: { 420 error_report("Storage key data is incomplete"); 421 ret = -EINVAL; 422 break; 423 } 424 case S390_SKEYS_SAVE_FLAG_EOS: 425 /* normal exit */ 426 return 0; 427 default: 428 error_report("Unexpected storage key flag data: %#x", flags); 429 ret = -EINVAL; 430 } 431 } 432 433 return ret; 434 } 435 436 static SaveVMHandlers savevm_s390_storage_keys = { 437 .save_state = s390_storage_keys_save, 438 .load_state = s390_storage_keys_load, 439 }; 440 441 static void s390_skeys_realize(DeviceState *dev, Error **errp) 442 { 443 S390SKeysState *ss = S390_SKEYS(dev); 444 445 if (ss->migration_enabled) { 446 register_savevm_live(TYPE_S390_SKEYS, 0, 1, 447 &savevm_s390_storage_keys, ss); 448 } 449 } 450 451 static Property s390_skeys_props[] = { 452 DEFINE_PROP_BOOL("migration-enabled", S390SKeysState, migration_enabled, true), 453 DEFINE_PROP_END_OF_LIST(), 454 }; 455 456 static void s390_skeys_class_init(ObjectClass *oc, void *data) 457 { 458 DeviceClass *dc = DEVICE_CLASS(oc); 459 460 dc->hotpluggable = false; 461 dc->realize = s390_skeys_realize; 462 device_class_set_props(dc, s390_skeys_props); 463 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 464 } 465 466 static const TypeInfo s390_skeys_info = { 467 .name = TYPE_S390_SKEYS, 468 .parent = TYPE_DEVICE, 469 .instance_size = sizeof(S390SKeysState), 470 .class_init = s390_skeys_class_init, 471 .class_size = sizeof(S390SKeysClass), 472 .abstract = true, 473 }; 474 475 static void qemu_s390_skeys_register_types(void) 476 { 477 type_register_static(&s390_skeys_info); 478 type_register_static(&qemu_s390_skeys_info); 479 } 480 481 type_init(qemu_s390_skeys_register_types) 482