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