1 /* 2 * SCLP 3 * Event Facility 4 * handles SCLP event types 5 * - Signal Quiesce - system power down 6 * - ASCII Console Data - VT220 read and write 7 * 8 * Copyright IBM, Corp. 2012 9 * 10 * Authors: 11 * Heinz Graalfs <graalfs@de.ibm.com> 12 * 13 * This work is licensed under the terms of the GNU GPL, version 2 or (at your 14 * option) any later version. See the COPYING file in the top-level directory. 15 * 16 */ 17 18 #include "qemu/osdep.h" 19 #include "qapi/error.h" 20 #include "qemu/module.h" 21 22 #include "hw/s390x/sclp.h" 23 #include "migration/vmstate.h" 24 #include "hw/s390x/event-facility.h" 25 26 typedef struct SCLPEventsBus { 27 BusState qbus; 28 } SCLPEventsBus; 29 30 /* we need to save 32 bit chunks for compatibility */ 31 #ifdef HOST_WORDS_BIGENDIAN 32 #define RECV_MASK_LOWER 1 33 #define RECV_MASK_UPPER 0 34 #else /* little endian host */ 35 #define RECV_MASK_LOWER 0 36 #define RECV_MASK_UPPER 1 37 #endif 38 39 struct SCLPEventFacility { 40 SysBusDevice parent_obj; 41 SCLPEventsBus sbus; 42 SCLPEvent quiesce, cpu_hotplug; 43 /* guest's receive mask */ 44 union { 45 uint32_t receive_mask_pieces[2]; 46 sccb_mask_t receive_mask; 47 }; 48 /* 49 * when false, we keep the same broken, backwards compatible behaviour as 50 * before, allowing only masks of size exactly 4; when true, we implement 51 * the architecture correctly, allowing all valid mask sizes. Needed for 52 * migration toward older versions. 53 */ 54 bool allow_all_mask_sizes; 55 /* length of the receive mask */ 56 uint16_t mask_length; 57 }; 58 59 /* return true if any child has event pending set */ 60 static bool event_pending(SCLPEventFacility *ef) 61 { 62 BusChild *kid; 63 SCLPEvent *event; 64 SCLPEventClass *event_class; 65 66 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) { 67 DeviceState *qdev = kid->child; 68 event = DO_UPCAST(SCLPEvent, qdev, qdev); 69 event_class = SCLP_EVENT_GET_CLASS(event); 70 if (event->event_pending && 71 event_class->get_send_mask() & ef->receive_mask) { 72 return true; 73 } 74 } 75 return false; 76 } 77 78 static sccb_mask_t get_host_send_mask(SCLPEventFacility *ef) 79 { 80 sccb_mask_t mask; 81 BusChild *kid; 82 SCLPEventClass *child; 83 84 mask = 0; 85 86 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) { 87 DeviceState *qdev = kid->child; 88 child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev); 89 mask |= child->get_send_mask(); 90 } 91 return mask; 92 } 93 94 static sccb_mask_t get_host_receive_mask(SCLPEventFacility *ef) 95 { 96 sccb_mask_t mask; 97 BusChild *kid; 98 SCLPEventClass *child; 99 100 mask = 0; 101 102 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) { 103 DeviceState *qdev = kid->child; 104 child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev); 105 mask |= child->get_receive_mask(); 106 } 107 return mask; 108 } 109 110 static uint16_t write_event_length_check(SCCB *sccb) 111 { 112 int slen; 113 unsigned elen = 0; 114 EventBufferHeader *event; 115 WriteEventData *wed = (WriteEventData *) sccb; 116 117 event = (EventBufferHeader *) &wed->ebh; 118 for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) { 119 elen = be16_to_cpu(event->length); 120 if (elen < sizeof(*event) || elen > slen) { 121 return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR; 122 } 123 event = (void *) event + elen; 124 } 125 if (slen) { 126 return SCLP_RC_INCONSISTENT_LENGTHS; 127 } 128 return SCLP_RC_NORMAL_COMPLETION; 129 } 130 131 static uint16_t handle_write_event_buf(SCLPEventFacility *ef, 132 EventBufferHeader *event_buf, SCCB *sccb) 133 { 134 uint16_t rc; 135 BusChild *kid; 136 SCLPEvent *event; 137 SCLPEventClass *ec; 138 139 rc = SCLP_RC_INVALID_FUNCTION; 140 141 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) { 142 DeviceState *qdev = kid->child; 143 event = (SCLPEvent *) qdev; 144 ec = SCLP_EVENT_GET_CLASS(event); 145 146 if (ec->write_event_data && 147 ec->can_handle_event(event_buf->type)) { 148 rc = ec->write_event_data(event, event_buf); 149 break; 150 } 151 } 152 return rc; 153 } 154 155 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb) 156 { 157 uint16_t rc; 158 int slen; 159 unsigned elen = 0; 160 EventBufferHeader *event_buf; 161 WriteEventData *wed = (WriteEventData *) sccb; 162 163 event_buf = &wed->ebh; 164 rc = SCLP_RC_NORMAL_COMPLETION; 165 166 /* loop over all contained event buffers */ 167 for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) { 168 elen = be16_to_cpu(event_buf->length); 169 170 /* in case of a previous error mark all trailing buffers 171 * as not accepted */ 172 if (rc != SCLP_RC_NORMAL_COMPLETION) { 173 event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED); 174 } else { 175 rc = handle_write_event_buf(ef, event_buf, sccb); 176 } 177 event_buf = (void *) event_buf + elen; 178 } 179 return rc; 180 } 181 182 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb) 183 { 184 if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) { 185 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION); 186 return; 187 } 188 if (be16_to_cpu(sccb->h.length) < 8) { 189 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH); 190 return; 191 } 192 /* first do a sanity check of the write events */ 193 sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb)); 194 195 /* if no early error, then execute */ 196 if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) { 197 sccb->h.response_code = 198 cpu_to_be16(handle_sccb_write_events(ef, sccb)); 199 } 200 } 201 202 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb, 203 sccb_mask_t mask) 204 { 205 uint16_t rc; 206 int slen; 207 unsigned elen; 208 BusChild *kid; 209 SCLPEvent *event; 210 SCLPEventClass *ec; 211 EventBufferHeader *event_buf; 212 ReadEventData *red = (ReadEventData *) sccb; 213 214 event_buf = &red->ebh; 215 event_buf->length = 0; 216 slen = sccb_data_len(sccb); 217 218 rc = SCLP_RC_NO_EVENT_BUFFERS_STORED; 219 220 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) { 221 DeviceState *qdev = kid->child; 222 event = (SCLPEvent *) qdev; 223 ec = SCLP_EVENT_GET_CLASS(event); 224 225 if (mask & ec->get_send_mask()) { 226 if (ec->read_event_data(event, event_buf, &slen)) { 227 elen = be16_to_cpu(event_buf->length); 228 event_buf = (EventBufferHeader *) ((char *)event_buf + elen); 229 rc = SCLP_RC_NORMAL_COMPLETION; 230 } 231 } 232 } 233 234 if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) { 235 /* architecture suggests to reset variable-length-response bit */ 236 sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE; 237 /* with a new length value */ 238 sccb->h.length = cpu_to_be16(SCCB_SIZE - slen); 239 } 240 return rc; 241 } 242 243 /* copy up to src_len bytes and fill the rest of dst with zeroes */ 244 static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len, 245 uint16_t src_len) 246 { 247 int i; 248 249 for (i = 0; i < dst_len; i++) { 250 dst[i] = i < src_len ? src[i] : 0; 251 } 252 } 253 254 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb) 255 { 256 sccb_mask_t sclp_active_selection_mask; 257 sccb_mask_t sclp_cp_receive_mask; 258 259 ReadEventData *red = (ReadEventData *) sccb; 260 261 if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) { 262 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH); 263 return; 264 } 265 266 switch (sccb->h.function_code) { 267 case SCLP_UNCONDITIONAL_READ: 268 sccb->h.response_code = cpu_to_be16( 269 handle_sccb_read_events(ef, sccb, ef->receive_mask)); 270 break; 271 case SCLP_SELECTIVE_READ: 272 /* get active selection mask */ 273 sclp_cp_receive_mask = ef->receive_mask; 274 275 copy_mask((uint8_t *)&sclp_active_selection_mask, (uint8_t *)&red->mask, 276 sizeof(sclp_active_selection_mask), ef->mask_length); 277 sclp_active_selection_mask = be64_to_cpu(sclp_active_selection_mask); 278 if (!sclp_cp_receive_mask || 279 (sclp_active_selection_mask & ~sclp_cp_receive_mask)) { 280 sccb->h.response_code = 281 cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK); 282 } else { 283 sccb->h.response_code = cpu_to_be16( 284 handle_sccb_read_events(ef, sccb, sclp_active_selection_mask)); 285 } 286 break; 287 default: 288 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION); 289 } 290 } 291 292 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb) 293 { 294 WriteEventMask *we_mask = (WriteEventMask *) sccb; 295 uint16_t mask_length = be16_to_cpu(we_mask->mask_length); 296 sccb_mask_t tmp_mask; 297 298 if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX) || 299 ((mask_length != 4) && !ef->allow_all_mask_sizes)) { 300 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH); 301 return; 302 } 303 304 /* 305 * Note: We currently only support masks up to 8 byte length; 306 * the remainder is filled up with zeroes. Older Linux 307 * kernels use a 4 byte mask length, newer ones can use both 308 * 8 or 4 depending on what is available on the host. 309 */ 310 311 /* keep track of the guest's capability masks */ 312 copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length), 313 sizeof(tmp_mask), mask_length); 314 ef->receive_mask = be64_to_cpu(tmp_mask); 315 316 /* return the SCLP's capability masks to the guest */ 317 tmp_mask = cpu_to_be64(get_host_receive_mask(ef)); 318 copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask, 319 mask_length, sizeof(tmp_mask)); 320 tmp_mask = cpu_to_be64(get_host_send_mask(ef)); 321 copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask, 322 mask_length, sizeof(tmp_mask)); 323 324 sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION); 325 ef->mask_length = mask_length; 326 } 327 328 /* qemu object creation and initialization functions */ 329 330 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus" 331 332 static const TypeInfo sclp_events_bus_info = { 333 .name = TYPE_SCLP_EVENTS_BUS, 334 .parent = TYPE_BUS, 335 }; 336 337 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code) 338 { 339 switch (code & SCLP_CMD_CODE_MASK) { 340 case SCLP_CMD_READ_EVENT_DATA: 341 read_event_data(ef, sccb); 342 break; 343 case SCLP_CMD_WRITE_EVENT_DATA: 344 write_event_data(ef, sccb); 345 break; 346 case SCLP_CMD_WRITE_EVENT_MASK: 347 write_event_mask(ef, sccb); 348 break; 349 } 350 } 351 352 static bool vmstate_event_facility_mask64_needed(void *opaque) 353 { 354 SCLPEventFacility *ef = opaque; 355 356 return (ef->receive_mask & 0xFFFFFFFF) != 0; 357 } 358 359 static bool vmstate_event_facility_mask_length_needed(void *opaque) 360 { 361 SCLPEventFacility *ef = opaque; 362 363 return ef->allow_all_mask_sizes; 364 } 365 366 static const VMStateDescription vmstate_event_facility_mask64 = { 367 .name = "vmstate-event-facility/mask64", 368 .version_id = 0, 369 .minimum_version_id = 0, 370 .needed = vmstate_event_facility_mask64_needed, 371 .fields = (VMStateField[]) { 372 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_LOWER], SCLPEventFacility), 373 VMSTATE_END_OF_LIST() 374 } 375 }; 376 377 static const VMStateDescription vmstate_event_facility_mask_length = { 378 .name = "vmstate-event-facility/mask_length", 379 .version_id = 0, 380 .minimum_version_id = 0, 381 .needed = vmstate_event_facility_mask_length_needed, 382 .fields = (VMStateField[]) { 383 VMSTATE_UINT16(mask_length, SCLPEventFacility), 384 VMSTATE_END_OF_LIST() 385 } 386 }; 387 388 static const VMStateDescription vmstate_event_facility = { 389 .name = "vmstate-event-facility", 390 .version_id = 0, 391 .minimum_version_id = 0, 392 .fields = (VMStateField[]) { 393 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_UPPER], SCLPEventFacility), 394 VMSTATE_END_OF_LIST() 395 }, 396 .subsections = (const VMStateDescription * []) { 397 &vmstate_event_facility_mask64, 398 &vmstate_event_facility_mask_length, 399 NULL 400 } 401 }; 402 403 static void sclp_event_set_allow_all_mask_sizes(Object *obj, bool value, 404 Error **errp) 405 { 406 SCLPEventFacility *ef = (SCLPEventFacility *)obj; 407 408 ef->allow_all_mask_sizes = value; 409 } 410 411 static bool sclp_event_get_allow_all_mask_sizes(Object *obj, Error **errp) 412 { 413 SCLPEventFacility *ef = (SCLPEventFacility *)obj; 414 415 return ef->allow_all_mask_sizes; 416 } 417 418 static void init_event_facility(Object *obj) 419 { 420 SCLPEventFacility *event_facility = EVENT_FACILITY(obj); 421 DeviceState *sdev = DEVICE(obj); 422 423 event_facility->mask_length = 4; 424 event_facility->allow_all_mask_sizes = true; 425 object_property_add_bool(obj, "allow_all_mask_sizes", 426 sclp_event_get_allow_all_mask_sizes, 427 sclp_event_set_allow_all_mask_sizes); 428 429 /* Spawn a new bus for SCLP events */ 430 qbus_init(&event_facility->sbus, sizeof(event_facility->sbus), 431 TYPE_SCLP_EVENTS_BUS, sdev, NULL); 432 433 object_initialize_child(obj, TYPE_SCLP_QUIESCE, 434 &event_facility->quiesce, 435 TYPE_SCLP_QUIESCE); 436 437 object_initialize_child(obj, TYPE_SCLP_CPU_HOTPLUG, 438 &event_facility->cpu_hotplug, 439 TYPE_SCLP_CPU_HOTPLUG); 440 } 441 442 static void realize_event_facility(DeviceState *dev, Error **errp) 443 { 444 SCLPEventFacility *event_facility = EVENT_FACILITY(dev); 445 446 if (!qdev_realize(DEVICE(&event_facility->quiesce), 447 BUS(&event_facility->sbus), errp)) { 448 return; 449 } 450 if (!qdev_realize(DEVICE(&event_facility->cpu_hotplug), 451 BUS(&event_facility->sbus), errp)) { 452 qdev_unrealize(DEVICE(&event_facility->quiesce)); 453 return; 454 } 455 } 456 457 static void reset_event_facility(DeviceState *dev) 458 { 459 SCLPEventFacility *sdev = EVENT_FACILITY(dev); 460 461 sdev->receive_mask = 0; 462 } 463 464 static void init_event_facility_class(ObjectClass *klass, void *data) 465 { 466 SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass); 467 DeviceClass *dc = DEVICE_CLASS(sbdc); 468 SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc); 469 470 dc->realize = realize_event_facility; 471 dc->reset = reset_event_facility; 472 dc->vmsd = &vmstate_event_facility; 473 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 474 k->command_handler = command_handler; 475 k->event_pending = event_pending; 476 } 477 478 static const TypeInfo sclp_event_facility_info = { 479 .name = TYPE_SCLP_EVENT_FACILITY, 480 .parent = TYPE_SYS_BUS_DEVICE, 481 .instance_init = init_event_facility, 482 .instance_size = sizeof(SCLPEventFacility), 483 .class_init = init_event_facility_class, 484 .class_size = sizeof(SCLPEventFacilityClass), 485 }; 486 487 static void event_realize(DeviceState *qdev, Error **errp) 488 { 489 SCLPEvent *event = SCLP_EVENT(qdev); 490 SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event); 491 492 if (child->init) { 493 int rc = child->init(event); 494 if (rc < 0) { 495 error_setg(errp, "SCLP event initialization failed."); 496 return; 497 } 498 } 499 } 500 501 static void event_class_init(ObjectClass *klass, void *data) 502 { 503 DeviceClass *dc = DEVICE_CLASS(klass); 504 505 dc->bus_type = TYPE_SCLP_EVENTS_BUS; 506 dc->realize = event_realize; 507 } 508 509 static const TypeInfo sclp_event_type_info = { 510 .name = TYPE_SCLP_EVENT, 511 .parent = TYPE_DEVICE, 512 .instance_size = sizeof(SCLPEvent), 513 .class_init = event_class_init, 514 .class_size = sizeof(SCLPEventClass), 515 .abstract = true, 516 }; 517 518 static void register_types(void) 519 { 520 type_register_static(&sclp_events_bus_info); 521 type_register_static(&sclp_event_facility_info); 522 type_register_static(&sclp_event_type_info); 523 } 524 525 type_init(register_types) 526 527 BusState *sclp_get_event_facility_bus(void) 528 { 529 Object *busobj; 530 SCLPEventsBus *sbus; 531 532 busobj = object_resolve_path_type("", TYPE_SCLP_EVENTS_BUS, NULL); 533 sbus = OBJECT_CHECK(SCLPEventsBus, busobj, TYPE_SCLP_EVENTS_BUS); 534 if (!sbus) { 535 return NULL; 536 } 537 538 return &sbus->qbus; 539 } 540