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' receive mask */
  33     unsigned int receive_mask;
  34 };
  35
  36 /* return true if any child has event pending set */
  37 static bool event_pending(SCLPEventFacility *ef)
  38 {
  39     BusChild *kid;
  40     SCLPEvent *event;
  41     SCLPEventClass *event_class;
  42
  43     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  44         DeviceState *qdev = kid->child;
  45         event = DO_UPCAST(SCLPEvent, qdev, qdev);
  46         event_class = SCLP_EVENT_GET_CLASS(event);
  47         if (event->event_pending &&
  48             event_class->get_send_mask() & ef->receive_mask) {
  49             return true;
  50         }
  51     }
  52     return false;
  53 }
  54
  55 static unsigned int get_host_send_mask(SCLPEventFacility *ef)
  56 {
  57     unsigned int mask;
  58     BusChild *kid;
  59     SCLPEventClass *child;
  60
  61     mask = 0;
  62
  63     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  64         DeviceState *qdev = kid->child;
  65         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  66         mask |= child->get_send_mask();
  67     }
  68     return mask;
  69 }
  70
  71 static unsigned int get_host_receive_mask(SCLPEventFacility *ef)
  72 {
  73     unsigned int mask;
  74     BusChild *kid;
  75     SCLPEventClass *child;
  76
  77     mask = 0;
  78
  79     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  80         DeviceState *qdev = kid->child;
  81         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  82         mask |= child->get_receive_mask();
  83     }
  84     return mask;
  85 }
  86
  87 static uint16_t write_event_length_check(SCCB *sccb)
  88 {
  89     int slen;
  90     unsigned elen = 0;
  91     EventBufferHeader *event;
  92     WriteEventData *wed = (WriteEventData *) sccb;
  93
  94     event = (EventBufferHeader *) &wed->ebh;
  95     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
  96         elen = be16_to_cpu(event->length);
  97         if (elen < sizeof(*event) || elen > slen) {
  98             return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
  99         }
 100         event = (void *) event + elen;
 101     }
 102     if (slen) {
 103         return SCLP_RC_INCONSISTENT_LENGTHS;
 104     }
 105     return SCLP_RC_NORMAL_COMPLETION;
 106 }
 107
 108 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
 109                                        EventBufferHeader *event_buf, SCCB *sccb)
 110 {
 111     uint16_t rc;
 112     BusChild *kid;
 113     SCLPEvent *event;
 114     SCLPEventClass *ec;
 115
 116     rc = SCLP_RC_INVALID_FUNCTION;
 117
 118     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 119         DeviceState *qdev = kid->child;
 120         event = (SCLPEvent *) qdev;
 121         ec = SCLP_EVENT_GET_CLASS(event);
 122
 123         if (ec->write_event_data &&
 124             ec->can_handle_event(event_buf->type)) {
 125             rc = ec->write_event_data(event, event_buf);
 126             break;
 127         }
 128     }
 129     return rc;
 130 }
 131
 132 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
 133 {
 134     uint16_t rc;
 135     int slen;
 136     unsigned elen = 0;
 137     EventBufferHeader *event_buf;
 138     WriteEventData *wed = (WriteEventData *) sccb;
 139
 140     event_buf = &wed->ebh;
 141     rc = SCLP_RC_NORMAL_COMPLETION;
 142
 143     /* loop over all contained event buffers */
 144     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
 145         elen = be16_to_cpu(event_buf->length);
 146
 147         /* in case of a previous error mark all trailing buffers
 148          * as not accepted */
 149         if (rc != SCLP_RC_NORMAL_COMPLETION) {
 150             event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 151         } else {
 152             rc = handle_write_event_buf(ef, event_buf, sccb);
 153         }
 154         event_buf = (void *) event_buf + elen;
 155     }
 156     return rc;
 157 }
 158
 159 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
 160 {
 161     if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
 162         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 163         goto out;
 164     }
 165     if (be16_to_cpu(sccb->h.length) < 8) {
 166         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 167         goto out;
 168     }
 169     /* first do a sanity check of the write events */
 170     sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
 171
 172     /* if no early error, then execute */
 173     if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
 174         sccb->h.response_code =
 175                 cpu_to_be16(handle_sccb_write_events(ef, sccb));
 176     }
 177
 178 out:
 179     return;
 180 }
 181
 182 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
 183                                         unsigned int mask)
 184 {
 185     uint16_t rc;
 186     int slen;
 187     unsigned elen;
 188     BusChild *kid;
 189     SCLPEvent *event;
 190     SCLPEventClass *ec;
 191     EventBufferHeader *event_buf;
 192     ReadEventData *red = (ReadEventData *) sccb;
 193
 194     event_buf = &red->ebh;
 195     event_buf->length = 0;
 196     slen = sizeof(sccb->data);
 197
 198     rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
 199
 200     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 201         DeviceState *qdev = kid->child;
 202         event = (SCLPEvent *) qdev;
 203         ec = SCLP_EVENT_GET_CLASS(event);
 204
 205         if (mask & ec->get_send_mask()) {
 206             if (ec->read_event_data(event, event_buf, &slen)) {
 207                 elen = be16_to_cpu(event_buf->length);
 208                 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
 209                 rc = SCLP_RC_NORMAL_COMPLETION;
 210             }
 211         }
 212     }
 213
 214     if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
 215         /* architecture suggests to reset variable-length-response bit */
 216         sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
 217         /* with a new length value */
 218         sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
 219     }
 220     return rc;
 221 }
 222
 223 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
 224 {
 225     unsigned int sclp_active_selection_mask;
 226     unsigned int sclp_cp_receive_mask;
 227
 228     ReadEventData *red = (ReadEventData *) sccb;
 229
 230     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
 231         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 232         goto out;
 233     }
 234
 235     sclp_cp_receive_mask = ef->receive_mask;
 236
 237     /* get active selection mask */
 238     switch (sccb->h.function_code) {
 239     case SCLP_UNCONDITIONAL_READ:
 240         sclp_active_selection_mask = sclp_cp_receive_mask;
 241         break;
 242     case SCLP_SELECTIVE_READ:
 243         sclp_active_selection_mask = be32_to_cpu(red->mask);
 244         if (!sclp_cp_receive_mask ||
 245             (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
 246             sccb->h.response_code =
 247                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
 248             goto out;
 249         }
 250         break;
 251     default:
 252         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 253         goto out;
 254     }
 255     sccb->h.response_code = cpu_to_be16(
 256             handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
 257
 258 out:
 259     return;
 260 }
 261
 262 /* copy up to dst_len bytes and fill the rest of dst with zeroes */
 263 static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len,
 264                       uint16_t src_len)
 265 {
 266     int i;
 267
 268     for (i = 0; i < dst_len; i++) {
 269         dst[i] = i < src_len ? src[i] : 0;
 270     }
 271 }
 272
 273 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
 274 {
 275     WriteEventMask *we_mask = (WriteEventMask *) sccb;
 276     uint16_t mask_length = be16_to_cpu(we_mask->mask_length);
 277     uint32_t tmp_mask;
 278
 279     if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX)) {
 280         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
 281         goto out;
 282     }
 283
 284     /*
 285      * Note: We currently only support masks up to 4 byte length;
 286      *       the remainder is filled up with zeroes. Linux uses
 287      *       a 4 byte mask length.
 288      */
 289
 290     /* keep track of the guest's capability masks */
 291     copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length),
 292               sizeof(tmp_mask), mask_length);
 293     ef->receive_mask = be32_to_cpu(tmp_mask);
 294
 295     /* return the SCLP's capability masks to the guest */
 296     tmp_mask = cpu_to_be32(get_host_send_mask(ef));
 297     copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
 298               mask_length, sizeof(tmp_mask));
 299     tmp_mask = cpu_to_be32(get_host_receive_mask(ef));
 300     copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
 301               mask_length, sizeof(tmp_mask));
 302
 303     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
 304
 305 out:
 306     return;
 307 }
 308
 309 /* qemu object creation and initialization functions */
 310
 311 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
 312
 313 static void sclp_events_bus_realize(BusState *bus, Error **errp)
 314 {
 315     BusChild *kid;
 316
 317     /* TODO: recursive realization has to be done in common code */
 318     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 319         DeviceState *dev = kid->child;
 320
 321         object_property_set_bool(OBJECT(dev), true, "realized", errp);
 322         if (*errp) {
 323             return;
 324         }
 325     }
 326 }
 327
 328 static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
 329 {
 330     BusClass *bc = BUS_CLASS(klass);
 331
 332     bc->realize = sclp_events_bus_realize;
 333 }
 334
 335 static const TypeInfo sclp_events_bus_info = {
 336     .name = TYPE_SCLP_EVENTS_BUS,
 337     .parent = TYPE_BUS,
 338     .class_init = sclp_events_bus_class_init,
 339 };
 340
 341 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
 342 {
 343     switch (code & SCLP_CMD_CODE_MASK) {
 344     case SCLP_CMD_READ_EVENT_DATA:
 345         read_event_data(ef, sccb);
 346         break;
 347     case SCLP_CMD_WRITE_EVENT_DATA:
 348         write_event_data(ef, sccb);
 349         break;
 350     case SCLP_CMD_WRITE_EVENT_MASK:
 351         write_event_mask(ef, sccb);
 352         break;
 353     default:
 354         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
 355         break;
 356     }
 357 }
 358
 359 static const VMStateDescription vmstate_event_facility = {
 360     .name = "vmstate-event-facility",
 361     .version_id = 0,
 362     .minimum_version_id = 0,
 363     .fields = (VMStateField[]) {
 364         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
 365         VMSTATE_END_OF_LIST()
 366      }
 367 };
 368
 369 static void init_event_facility(Object *obj)
 370 {
 371     SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
 372     DeviceState *sdev = DEVICE(obj);
 373     Object *new;
 374
 375     /* Spawn a new bus for SCLP events */
 376     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
 377                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
 378
 379     new = object_new(TYPE_SCLP_QUIESCE);
 380     object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
 381     object_unref(new);
 382     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 383
 384     new = object_new(TYPE_SCLP_CPU_HOTPLUG);
 385     object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
 386     object_unref(new);
 387     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 388     /* the facility will automatically realize the devices via the bus */
 389 }
 390
 391 static void reset_event_facility(DeviceState *dev)
 392 {
 393     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
 394
 395     sdev->receive_mask = 0;
 396 }
 397
 398 static void init_event_facility_class(ObjectClass *klass, void *data)
 399 {
 400     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
 401     DeviceClass *dc = DEVICE_CLASS(sbdc);
 402     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
 403
 404     dc->reset = reset_event_facility;
 405     dc->vmsd = &vmstate_event_facility;
 406     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 407     k->command_handler = command_handler;
 408     k->event_pending = event_pending;
 409 }
 410
 411 static const TypeInfo sclp_event_facility_info = {
 412     .name          = TYPE_SCLP_EVENT_FACILITY,
 413     .parent        = TYPE_SYS_BUS_DEVICE,
 414     .instance_init = init_event_facility,
 415     .instance_size = sizeof(SCLPEventFacility),
 416     .class_init    = init_event_facility_class,
 417     .class_size    = sizeof(SCLPEventFacilityClass),
 418 };
 419
 420 static void event_realize(DeviceState *qdev, Error **errp)
 421 {
 422     SCLPEvent *event = SCLP_EVENT(qdev);
 423     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 424
 425     if (child->init) {
 426         int rc = child->init(event);
 427         if (rc < 0) {
 428             error_setg(errp, "SCLP event initialization failed.");
 429             return;
 430         }
 431     }
 432 }
 433
 434 static void event_unrealize(DeviceState *qdev, Error **errp)
 435 {
 436     SCLPEvent *event = SCLP_EVENT(qdev);
 437     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 438     if (child->exit) {
 439         int rc = child->exit(event);
 440         if (rc < 0) {
 441             error_setg(errp, "SCLP event exit failed.");
 442             return;
 443         }
 444     }
 445 }
 446
 447 static void event_class_init(ObjectClass *klass, void *data)
 448 {
 449     DeviceClass *dc = DEVICE_CLASS(klass);
 450
 451     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
 452     dc->realize = event_realize;
 453     dc->unrealize = event_unrealize;
 454 }
 455
 456 static const TypeInfo sclp_event_type_info = {
 457     .name = TYPE_SCLP_EVENT,
 458     .parent = TYPE_DEVICE,
 459     .instance_size = sizeof(SCLPEvent),
 460     .class_init = event_class_init,
 461     .class_size = sizeof(SCLPEventClass),
 462     .abstract = true,
 463 };
 464
 465 static void register_types(void)
 466 {
 467     type_register_static(&sclp_events_bus_info);
 468     type_register_static(&sclp_event_facility_info);
 469     type_register_static(&sclp_event_type_info);
 470 }
 471
 472 type_init(register_types)