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 "sysemu/sysemu.h"
  20
  21 #include "hw/s390x/sclp.h"
  22 #include "hw/s390x/event-facility.h"
  23
  24 typedef struct SCLPEventsBus {
  25     BusState qbus;
  26 } SCLPEventsBus;
  27
  28 struct SCLPEventFacility {
  29     SysBusDevice parent_obj;
  30     SCLPEventsBus sbus;
  31     /* guest' receive mask */
  32     unsigned int receive_mask;
  33 };
  34
  35 /* return true if any child has event pending set */
  36 static bool event_pending(SCLPEventFacility *ef)
  37 {
  38     BusChild *kid;
  39     SCLPEvent *event;
  40     SCLPEventClass *event_class;
  41
  42     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  43         DeviceState *qdev = kid->child;
  44         event = DO_UPCAST(SCLPEvent, qdev, qdev);
  45         event_class = SCLP_EVENT_GET_CLASS(event);
  46         if (event->event_pending &&
  47             event_class->get_send_mask() & ef->receive_mask) {
  48             return true;
  49         }
  50     }
  51     return false;
  52 }
  53
  54 static unsigned int get_host_send_mask(SCLPEventFacility *ef)
  55 {
  56     unsigned int mask;
  57     BusChild *kid;
  58     SCLPEventClass *child;
  59
  60     mask = 0;
  61
  62     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  63         DeviceState *qdev = kid->child;
  64         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  65         mask |= child->get_send_mask();
  66     }
  67     return mask;
  68 }
  69
  70 static unsigned int get_host_receive_mask(SCLPEventFacility *ef)
  71 {
  72     unsigned int mask;
  73     BusChild *kid;
  74     SCLPEventClass *child;
  75
  76     mask = 0;
  77
  78     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  79         DeviceState *qdev = kid->child;
  80         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  81         mask |= child->get_receive_mask();
  82     }
  83     return mask;
  84 }
  85
  86 static uint16_t write_event_length_check(SCCB *sccb)
  87 {
  88     int slen;
  89     unsigned elen = 0;
  90     EventBufferHeader *event;
  91     WriteEventData *wed = (WriteEventData *) sccb;
  92
  93     event = (EventBufferHeader *) &wed->ebh;
  94     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
  95         elen = be16_to_cpu(event->length);
  96         if (elen < sizeof(*event) || elen > slen) {
  97             return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
  98         }
  99         event = (void *) event + elen;
 100     }
 101     if (slen) {
 102         return SCLP_RC_INCONSISTENT_LENGTHS;
 103     }
 104     return SCLP_RC_NORMAL_COMPLETION;
 105 }
 106
 107 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
 108                                        EventBufferHeader *event_buf, SCCB *sccb)
 109 {
 110     uint16_t rc;
 111     BusChild *kid;
 112     SCLPEvent *event;
 113     SCLPEventClass *ec;
 114
 115     rc = SCLP_RC_INVALID_FUNCTION;
 116
 117     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 118         DeviceState *qdev = kid->child;
 119         event = (SCLPEvent *) qdev;
 120         ec = SCLP_EVENT_GET_CLASS(event);
 121
 122         if (ec->write_event_data &&
 123             ec->can_handle_event(event_buf->type)) {
 124             rc = ec->write_event_data(event, event_buf);
 125             break;
 126         }
 127     }
 128     return rc;
 129 }
 130
 131 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
 132 {
 133     uint16_t rc;
 134     int slen;
 135     unsigned elen = 0;
 136     EventBufferHeader *event_buf;
 137     WriteEventData *wed = (WriteEventData *) sccb;
 138
 139     event_buf = &wed->ebh;
 140     rc = SCLP_RC_NORMAL_COMPLETION;
 141
 142     /* loop over all contained event buffers */
 143     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
 144         elen = be16_to_cpu(event_buf->length);
 145
 146         /* in case of a previous error mark all trailing buffers
 147          * as not accepted */
 148         if (rc != SCLP_RC_NORMAL_COMPLETION) {
 149             event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 150         } else {
 151             rc = handle_write_event_buf(ef, event_buf, sccb);
 152         }
 153         event_buf = (void *) event_buf + elen;
 154     }
 155     return rc;
 156 }
 157
 158 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
 159 {
 160     if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
 161         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 162         goto out;
 163     }
 164     if (be16_to_cpu(sccb->h.length) < 8) {
 165         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 166         goto out;
 167     }
 168     /* first do a sanity check of the write events */
 169     sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
 170
 171     /* if no early error, then execute */
 172     if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
 173         sccb->h.response_code =
 174                 cpu_to_be16(handle_sccb_write_events(ef, sccb));
 175     }
 176
 177 out:
 178     return;
 179 }
 180
 181 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
 182                                         unsigned int mask)
 183 {
 184     uint16_t rc;
 185     int slen;
 186     unsigned elen;
 187     BusChild *kid;
 188     SCLPEvent *event;
 189     SCLPEventClass *ec;
 190     EventBufferHeader *event_buf;
 191     ReadEventData *red = (ReadEventData *) sccb;
 192
 193     event_buf = &red->ebh;
 194     event_buf->length = 0;
 195     slen = sizeof(sccb->data);
 196
 197     rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
 198
 199     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 200         DeviceState *qdev = kid->child;
 201         event = (SCLPEvent *) qdev;
 202         ec = SCLP_EVENT_GET_CLASS(event);
 203
 204         if (mask & ec->get_send_mask()) {
 205             if (ec->read_event_data(event, event_buf, &slen)) {
 206                 elen = be16_to_cpu(event_buf->length);
 207                 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
 208                 rc = SCLP_RC_NORMAL_COMPLETION;
 209             }
 210         }
 211     }
 212
 213     if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
 214         /* architecture suggests to reset variable-length-response bit */
 215         sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
 216         /* with a new length value */
 217         sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
 218     }
 219     return rc;
 220 }
 221
 222 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
 223 {
 224     unsigned int sclp_active_selection_mask;
 225     unsigned int sclp_cp_receive_mask;
 226
 227     ReadEventData *red = (ReadEventData *) sccb;
 228
 229     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
 230         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 231         goto out;
 232     }
 233
 234     sclp_cp_receive_mask = ef->receive_mask;
 235
 236     /* get active selection mask */
 237     switch (sccb->h.function_code) {
 238     case SCLP_UNCONDITIONAL_READ:
 239         sclp_active_selection_mask = sclp_cp_receive_mask;
 240         break;
 241     case SCLP_SELECTIVE_READ:
 242         sclp_active_selection_mask = be32_to_cpu(red->mask);
 243         if (!sclp_cp_receive_mask ||
 244             (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
 245             sccb->h.response_code =
 246                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
 247             goto out;
 248         }
 249         break;
 250     default:
 251         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 252         goto out;
 253     }
 254     sccb->h.response_code = cpu_to_be16(
 255             handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
 256
 257 out:
 258     return;
 259 }
 260
 261 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
 262 {
 263     WriteEventMask *we_mask = (WriteEventMask *) sccb;
 264
 265     /* Attention: We assume that Linux uses 4-byte masks, what it actually
 266        does. Architecture allows for masks of variable size, though */
 267     if (be16_to_cpu(we_mask->mask_length) != 4) {
 268         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
 269         goto out;
 270     }
 271
 272     /* keep track of the guest's capability masks */
 273     ef->receive_mask = be32_to_cpu(we_mask->cp_receive_mask);
 274
 275     /* return the SCLP's capability masks to the guest */
 276     we_mask->send_mask = cpu_to_be32(get_host_send_mask(ef));
 277     we_mask->receive_mask = cpu_to_be32(get_host_receive_mask(ef));
 278
 279     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
 280
 281 out:
 282     return;
 283 }
 284
 285 /* qemu object creation and initialization functions */
 286
 287 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
 288
 289 static void sclp_events_bus_realize(BusState *bus, Error **errp)
 290 {
 291     BusChild *kid;
 292
 293     /* TODO: recursive realization has to be done in common code */
 294     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 295         DeviceState *dev = kid->child;
 296
 297         object_property_set_bool(OBJECT(dev), true, "realized", errp);
 298         if (*errp) {
 299             return;
 300         }
 301     }
 302 }
 303
 304 static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
 305 {
 306     BusClass *bc = BUS_CLASS(klass);
 307
 308     bc->realize = sclp_events_bus_realize;
 309 }
 310
 311 static const TypeInfo sclp_events_bus_info = {
 312     .name = TYPE_SCLP_EVENTS_BUS,
 313     .parent = TYPE_BUS,
 314     .class_init = sclp_events_bus_class_init,
 315 };
 316
 317 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
 318 {
 319     switch (code & SCLP_CMD_CODE_MASK) {
 320     case SCLP_CMD_READ_EVENT_DATA:
 321         read_event_data(ef, sccb);
 322         break;
 323     case SCLP_CMD_WRITE_EVENT_DATA:
 324         write_event_data(ef, sccb);
 325         break;
 326     case SCLP_CMD_WRITE_EVENT_MASK:
 327         write_event_mask(ef, sccb);
 328         break;
 329     default:
 330         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
 331         break;
 332     }
 333 }
 334
 335 static const VMStateDescription vmstate_event_facility = {
 336     .name = "vmstate-event-facility",
 337     .version_id = 0,
 338     .minimum_version_id = 0,
 339     .fields = (VMStateField[]) {
 340         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
 341         VMSTATE_END_OF_LIST()
 342      }
 343 };
 344
 345 static void init_event_facility(Object *obj)
 346 {
 347     SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
 348     DeviceState *sdev = DEVICE(obj);
 349     Object *new;
 350
 351     /* Spawn a new bus for SCLP events */
 352     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
 353                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
 354
 355     new = object_new(TYPE_SCLP_QUIESCE);
 356     object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
 357     object_unref(new);
 358     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 359
 360     new = object_new(TYPE_SCLP_CPU_HOTPLUG);
 361     object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
 362     object_unref(new);
 363     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 364     /* the facility will automatically realize the devices via the bus */
 365 }
 366
 367 static void reset_event_facility(DeviceState *dev)
 368 {
 369     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
 370
 371     sdev->receive_mask = 0;
 372 }
 373
 374 static void init_event_facility_class(ObjectClass *klass, void *data)
 375 {
 376     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
 377     DeviceClass *dc = DEVICE_CLASS(sbdc);
 378     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
 379
 380     dc->reset = reset_event_facility;
 381     dc->vmsd = &vmstate_event_facility;
 382     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 383     k->command_handler = command_handler;
 384     k->event_pending = event_pending;
 385 }
 386
 387 static const TypeInfo sclp_event_facility_info = {
 388     .name          = TYPE_SCLP_EVENT_FACILITY,
 389     .parent        = TYPE_SYS_BUS_DEVICE,
 390     .instance_init = init_event_facility,
 391     .instance_size = sizeof(SCLPEventFacility),
 392     .class_init    = init_event_facility_class,
 393     .class_size    = sizeof(SCLPEventFacilityClass),
 394 };
 395
 396 static void event_realize(DeviceState *qdev, Error **errp)
 397 {
 398     SCLPEvent *event = SCLP_EVENT(qdev);
 399     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 400
 401     if (child->init) {
 402         int rc = child->init(event);
 403         if (rc < 0) {
 404             error_setg(errp, "SCLP event initialization failed.");
 405             return;
 406         }
 407     }
 408 }
 409
 410 static void event_unrealize(DeviceState *qdev, Error **errp)
 411 {
 412     SCLPEvent *event = SCLP_EVENT(qdev);
 413     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 414     if (child->exit) {
 415         int rc = child->exit(event);
 416         if (rc < 0) {
 417             error_setg(errp, "SCLP event exit failed.");
 418             return;
 419         }
 420     }
 421 }
 422
 423 static void event_class_init(ObjectClass *klass, void *data)
 424 {
 425     DeviceClass *dc = DEVICE_CLASS(klass);
 426
 427     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
 428     dc->realize = event_realize;
 429     dc->unrealize = event_unrealize;
 430 }
 431
 432 static const TypeInfo sclp_event_type_info = {
 433     .name = TYPE_SCLP_EVENT,
 434     .parent = TYPE_DEVICE,
 435     .instance_size = sizeof(SCLPEvent),
 436     .class_init = event_class_init,
 437     .class_size = sizeof(SCLPEventClass),
 438     .abstract = true,
 439 };
 440
 441 static void register_types(void)
 442 {
 443     type_register_static(&sclp_events_bus_info);
 444     type_register_static(&sclp_event_facility_info);
 445     type_register_static(&sclp_event_type_info);
 446 }
 447
 448 type_init(register_types)