hw/s390x/event-facility.c

   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 "sysemu/sysemu.h"
  21
  22 #include "hw/s390x/sclp.h"
  23 #include "hw/s390x/event-facility.h"
  24
  25 typedef struct SCLPEventsBus {
  26     BusState qbus;
  27 } SCLPEventsBus;
  28
  29 struct SCLPEventFacility {
  30     SysBusDevice parent_obj;
  31     SCLPEventsBus sbus;
  32     /* guest's receive mask */
  33     sccb_mask_t receive_mask;
  34     /*
  35      * when false, we keep the same broken, backwards compatible behaviour as
  36      * before, allowing only masks of size exactly 4; when true, we implement
  37      * the architecture correctly, allowing all valid mask sizes. Needed for
  38      * migration toward older versions.
  39      */
  40     bool allow_all_mask_sizes;
  41     /* length of the receive mask */
  42     uint16_t mask_length;
  43 };
  44
  45 /* return true if any child has event pending set */
  46 static bool event_pending(SCLPEventFacility *ef)
  47 {
  48     BusChild *kid;
  49     SCLPEvent *event;
  50     SCLPEventClass *event_class;
  51
  52     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  53         DeviceState *qdev = kid->child;
  54         event = DO_UPCAST(SCLPEvent, qdev, qdev);
  55         event_class = SCLP_EVENT_GET_CLASS(event);
  56         if (event->event_pending &&
  57             event_class->get_send_mask() & ef->receive_mask) {
  58             return true;
  59         }
  60     }
  61     return false;
  62 }
  63
  64 static sccb_mask_t get_host_send_mask(SCLPEventFacility *ef)
  65 {
  66     sccb_mask_t mask;
  67     BusChild *kid;
  68     SCLPEventClass *child;
  69
  70     mask = 0;
  71
  72     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  73         DeviceState *qdev = kid->child;
  74         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  75         mask |= child->get_send_mask();
  76     }
  77     return mask;
  78 }
  79
  80 static sccb_mask_t get_host_receive_mask(SCLPEventFacility *ef)
  81 {
  82     sccb_mask_t mask;
  83     BusChild *kid;
  84     SCLPEventClass *child;
  85
  86     mask = 0;
  87
  88     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  89         DeviceState *qdev = kid->child;
  90         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  91         mask |= child->get_receive_mask();
  92     }
  93     return mask;
  94 }
  95
  96 static uint16_t write_event_length_check(SCCB *sccb)
  97 {
  98     int slen;
  99     unsigned elen = 0;
 100     EventBufferHeader *event;
 101     WriteEventData *wed = (WriteEventData *) sccb;
 102
 103     event = (EventBufferHeader *) &wed->ebh;
 104     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
 105         elen = be16_to_cpu(event->length);
 106         if (elen < sizeof(*event) || elen > slen) {
 107             return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
 108         }
 109         event = (void *) event + elen;
 110     }
 111     if (slen) {
 112         return SCLP_RC_INCONSISTENT_LENGTHS;
 113     }
 114     return SCLP_RC_NORMAL_COMPLETION;
 115 }
 116
 117 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
 118                                        EventBufferHeader *event_buf, SCCB *sccb)
 119 {
 120     uint16_t rc;
 121     BusChild *kid;
 122     SCLPEvent *event;
 123     SCLPEventClass *ec;
 124
 125     rc = SCLP_RC_INVALID_FUNCTION;
 126
 127     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 128         DeviceState *qdev = kid->child;
 129         event = (SCLPEvent *) qdev;
 130         ec = SCLP_EVENT_GET_CLASS(event);
 131
 132         if (ec->write_event_data &&
 133             ec->can_handle_event(event_buf->type)) {
 134             rc = ec->write_event_data(event, event_buf);
 135             break;
 136         }
 137     }
 138     return rc;
 139 }
 140
 141 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
 142 {
 143     uint16_t rc;
 144     int slen;
 145     unsigned elen = 0;
 146     EventBufferHeader *event_buf;
 147     WriteEventData *wed = (WriteEventData *) sccb;
 148
 149     event_buf = &wed->ebh;
 150     rc = SCLP_RC_NORMAL_COMPLETION;
 151
 152     /* loop over all contained event buffers */
 153     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
 154         elen = be16_to_cpu(event_buf->length);
 155
 156         /* in case of a previous error mark all trailing buffers
 157          * as not accepted */
 158         if (rc != SCLP_RC_NORMAL_COMPLETION) {
 159             event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 160         } else {
 161             rc = handle_write_event_buf(ef, event_buf, sccb);
 162         }
 163         event_buf = (void *) event_buf + elen;
 164     }
 165     return rc;
 166 }
 167
 168 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
 169 {
 170     if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
 171         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 172         goto out;
 173     }
 174     if (be16_to_cpu(sccb->h.length) < 8) {
 175         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 176         goto out;
 177     }
 178     /* first do a sanity check of the write events */
 179     sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
 180
 181     /* if no early error, then execute */
 182     if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
 183         sccb->h.response_code =
 184                 cpu_to_be16(handle_sccb_write_events(ef, sccb));
 185     }
 186
 187 out:
 188     return;
 189 }
 190
 191 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
 192                                         sccb_mask_t mask)
 193 {
 194     uint16_t rc;
 195     int slen;
 196     unsigned elen;
 197     BusChild *kid;
 198     SCLPEvent *event;
 199     SCLPEventClass *ec;
 200     EventBufferHeader *event_buf;
 201     ReadEventData *red = (ReadEventData *) sccb;
 202
 203     event_buf = &red->ebh;
 204     event_buf->length = 0;
 205     slen = sizeof(sccb->data);
 206
 207     rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
 208
 209     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 210         DeviceState *qdev = kid->child;
 211         event = (SCLPEvent *) qdev;
 212         ec = SCLP_EVENT_GET_CLASS(event);
 213
 214         if (mask & ec->get_send_mask()) {
 215             if (ec->read_event_data(event, event_buf, &slen)) {
 216                 elen = be16_to_cpu(event_buf->length);
 217                 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
 218                 rc = SCLP_RC_NORMAL_COMPLETION;
 219             }
 220         }
 221     }
 222
 223     if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
 224         /* architecture suggests to reset variable-length-response bit */
 225         sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
 226         /* with a new length value */
 227         sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
 228     }
 229     return rc;
 230 }
 231
 232 /* copy up to src_len bytes and fill the rest of dst with zeroes */
 233 static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len,
 234                       uint16_t src_len)
 235 {
 236     int i;
 237
 238     for (i = 0; i < dst_len; i++) {
 239         dst[i] = i < src_len ? src[i] : 0;
 240     }
 241 }
 242
 243 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
 244 {
 245     sccb_mask_t sclp_active_selection_mask;
 246     sccb_mask_t sclp_cp_receive_mask;
 247
 248     ReadEventData *red = (ReadEventData *) sccb;
 249
 250     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
 251         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 252         goto out;
 253     }
 254
 255     sclp_cp_receive_mask = ef->receive_mask;
 256
 257     /* get active selection mask */
 258     switch (sccb->h.function_code) {
 259     case SCLP_UNCONDITIONAL_READ:
 260         sclp_active_selection_mask = sclp_cp_receive_mask;
 261         break;
 262     case SCLP_SELECTIVE_READ:
 263         copy_mask((uint8_t *)&sclp_active_selection_mask, (uint8_t *)&red->mask,
 264                   sizeof(sclp_active_selection_mask), ef->mask_length);
 265         sclp_active_selection_mask = be32_to_cpu(sclp_active_selection_mask);
 266         if (!sclp_cp_receive_mask ||
 267             (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
 268             sccb->h.response_code =
 269                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
 270             goto out;
 271         }
 272         break;
 273     default:
 274         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 275         goto out;
 276     }
 277     sccb->h.response_code = cpu_to_be16(
 278             handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
 279
 280 out:
 281     return;
 282 }
 283
 284 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
 285 {
 286     WriteEventMask *we_mask = (WriteEventMask *) sccb;
 287     uint16_t mask_length = be16_to_cpu(we_mask->mask_length);
 288     sccb_mask_t tmp_mask;
 289
 290     if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX) ||
 291         ((mask_length != 4) && !ef->allow_all_mask_sizes)) {
 292         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
 293         goto out;
 294     }
 295
 296     /*
 297      * Note: We currently only support masks up to 4 byte length;
 298      *       the remainder is filled up with zeroes. Linux uses
 299      *       a 4 byte mask length.
 300      */
 301
 302     /* keep track of the guest's capability masks */
 303     copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length),
 304               sizeof(tmp_mask), mask_length);
 305     ef->receive_mask = be32_to_cpu(tmp_mask);
 306
 307     /* return the SCLP's capability masks to the guest */
 308     tmp_mask = cpu_to_be32(get_host_receive_mask(ef));
 309     copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
 310               mask_length, sizeof(tmp_mask));
 311     tmp_mask = cpu_to_be32(get_host_send_mask(ef));
 312     copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
 313               mask_length, sizeof(tmp_mask));
 314
 315     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
 316     ef->mask_length = mask_length;
 317
 318 out:
 319     return;
 320 }
 321
 322 /* qemu object creation and initialization functions */
 323
 324 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
 325
 326 static void sclp_events_bus_realize(BusState *bus, Error **errp)
 327 {
 328     BusChild *kid;
 329
 330     /* TODO: recursive realization has to be done in common code */
 331     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 332         DeviceState *dev = kid->child;
 333
 334         object_property_set_bool(OBJECT(dev), true, "realized", errp);
 335         if (*errp) {
 336             return;
 337         }
 338     }
 339 }
 340
 341 static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
 342 {
 343     BusClass *bc = BUS_CLASS(klass);
 344
 345     bc->realize = sclp_events_bus_realize;
 346 }
 347
 348 static const TypeInfo sclp_events_bus_info = {
 349     .name = TYPE_SCLP_EVENTS_BUS,
 350     .parent = TYPE_BUS,
 351     .class_init = sclp_events_bus_class_init,
 352 };
 353
 354 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
 355 {
 356     switch (code & SCLP_CMD_CODE_MASK) {
 357     case SCLP_CMD_READ_EVENT_DATA:
 358         read_event_data(ef, sccb);
 359         break;
 360     case SCLP_CMD_WRITE_EVENT_DATA:
 361         write_event_data(ef, sccb);
 362         break;
 363     case SCLP_CMD_WRITE_EVENT_MASK:
 364         write_event_mask(ef, sccb);
 365         break;
 366     default:
 367         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
 368         break;
 369     }
 370 }
 371
 372 static bool vmstate_event_facility_mask_length_needed(void *opaque)
 373 {
 374     SCLPEventFacility *ef = opaque;
 375
 376     return ef->allow_all_mask_sizes;
 377 }
 378
 379 static const VMStateDescription vmstate_event_facility_mask_length = {
 380     .name = "vmstate-event-facility/mask_length",
 381     .version_id = 0,
 382     .minimum_version_id = 0,
 383     .needed = vmstate_event_facility_mask_length_needed,
 384     .fields = (VMStateField[]) {
 385         VMSTATE_UINT16(mask_length, SCLPEventFacility),
 386         VMSTATE_END_OF_LIST()
 387      }
 388 };
 389
 390 static const VMStateDescription vmstate_event_facility = {
 391     .name = "vmstate-event-facility",
 392     .version_id = 0,
 393     .minimum_version_id = 0,
 394     .fields = (VMStateField[]) {
 395         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
 396         VMSTATE_END_OF_LIST()
 397      },
 398     .subsections = (const VMStateDescription * []) {
 399         &vmstate_event_facility_mask_length,
 400         NULL
 401      }
 402 };
 403
 404 static void sclp_event_set_allow_all_mask_sizes(Object *obj, bool value,
 405                                                        Error **errp)
 406 {
 407     SCLPEventFacility *ef = (SCLPEventFacility *)obj;
 408
 409     ef->allow_all_mask_sizes = value;
 410 }
 411
 412 static bool sclp_event_get_allow_all_mask_sizes(Object *obj, Error **e)
 413 {
 414     SCLPEventFacility *ef = (SCLPEventFacility *)obj;
 415
 416     return ef->allow_all_mask_sizes;
 417 }
 418
 419 static void init_event_facility(Object *obj)
 420 {
 421     SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
 422     DeviceState *sdev = DEVICE(obj);
 423     Object *new;
 424
 425     event_facility->mask_length = 4;
 426     event_facility->allow_all_mask_sizes = true;
 427     object_property_add_bool(obj, "allow_all_mask_sizes",
 428                              sclp_event_get_allow_all_mask_sizes,
 429                              sclp_event_set_allow_all_mask_sizes, NULL);
 430     /* Spawn a new bus for SCLP events */
 431     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
 432                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
 433
 434     new = object_new(TYPE_SCLP_QUIESCE);
 435     object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
 436     object_unref(new);
 437     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 438
 439     new = object_new(TYPE_SCLP_CPU_HOTPLUG);
 440     object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
 441     object_unref(new);
 442     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 443     /* the facility will automatically realize the devices via the bus */
 444 }
 445
 446 static void reset_event_facility(DeviceState *dev)
 447 {
 448     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
 449
 450     sdev->receive_mask = 0;
 451 }
 452
 453 static void init_event_facility_class(ObjectClass *klass, void *data)
 454 {
 455     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
 456     DeviceClass *dc = DEVICE_CLASS(sbdc);
 457     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
 458
 459     dc->reset = reset_event_facility;
 460     dc->vmsd = &vmstate_event_facility;
 461     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 462     k->command_handler = command_handler;
 463     k->event_pending = event_pending;
 464 }
 465
 466 static const TypeInfo sclp_event_facility_info = {
 467     .name          = TYPE_SCLP_EVENT_FACILITY,
 468     .parent        = TYPE_SYS_BUS_DEVICE,
 469     .instance_init = init_event_facility,
 470     .instance_size = sizeof(SCLPEventFacility),
 471     .class_init    = init_event_facility_class,
 472     .class_size    = sizeof(SCLPEventFacilityClass),
 473 };
 474
 475 static void event_realize(DeviceState *qdev, Error **errp)
 476 {
 477     SCLPEvent *event = SCLP_EVENT(qdev);
 478     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 479
 480     if (child->init) {
 481         int rc = child->init(event);
 482         if (rc < 0) {
 483             error_setg(errp, "SCLP event initialization failed.");
 484             return;
 485         }
 486     }
 487 }
 488
 489 static void event_class_init(ObjectClass *klass, void *data)
 490 {
 491     DeviceClass *dc = DEVICE_CLASS(klass);
 492
 493     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
 494     dc->realize = event_realize;
 495 }
 496
 497 static const TypeInfo sclp_event_type_info = {
 498     .name = TYPE_SCLP_EVENT,
 499     .parent = TYPE_DEVICE,
 500     .instance_size = sizeof(SCLPEvent),
 501     .class_init = event_class_init,
 502     .class_size = sizeof(SCLPEventClass),
 503     .abstract = true,
 504 };
 505
 506 static void register_types(void)
 507 {
 508     type_register_static(&sclp_events_bus_info);
 509     type_register_static(&sclp_event_facility_info);
 510     type_register_static(&sclp_event_type_info);
 511 }
 512
 513 type_init(register_types)