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 "monitor/monitor.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 SCLPEvent cpu_hotplug;
  36
  37 /* return true if any child has event pending set */
  38 static bool event_pending(SCLPEventFacility *ef)
  39 {
  40     BusChild *kid;
  41     SCLPEvent *event;
  42     SCLPEventClass *event_class;
  43
  44     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  45         DeviceState *qdev = kid->child;
  46         event = DO_UPCAST(SCLPEvent, qdev, qdev);
  47         event_class = SCLP_EVENT_GET_CLASS(event);
  48         if (event->event_pending &&
  49             event_class->get_send_mask() & ef->receive_mask) {
  50             return true;
  51         }
  52     }
  53     return false;
  54 }
  55
  56 static unsigned int get_host_send_mask(SCLPEventFacility *ef)
  57 {
  58     unsigned int mask;
  59     BusChild *kid;
  60     SCLPEventClass *child;
  61
  62     mask = 0;
  63
  64     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  65         DeviceState *qdev = kid->child;
  66         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  67         mask |= child->get_send_mask();
  68     }
  69     return mask;
  70 }
  71
  72 static unsigned int get_host_receive_mask(SCLPEventFacility *ef)
  73 {
  74     unsigned int mask;
  75     BusChild *kid;
  76     SCLPEventClass *child;
  77
  78     mask = 0;
  79
  80     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  81         DeviceState *qdev = kid->child;
  82         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  83         mask |= child->get_receive_mask();
  84     }
  85     return mask;
  86 }
  87
  88 static uint16_t write_event_length_check(SCCB *sccb)
  89 {
  90     int slen;
  91     unsigned elen = 0;
  92     EventBufferHeader *event;
  93     WriteEventData *wed = (WriteEventData *) sccb;
  94
  95     event = (EventBufferHeader *) &wed->ebh;
  96     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
  97         elen = be16_to_cpu(event->length);
  98         if (elen < sizeof(*event) || elen > slen) {
  99             return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
 100         }
 101         event = (void *) event + elen;
 102     }
 103     if (slen) {
 104         return SCLP_RC_INCONSISTENT_LENGTHS;
 105     }
 106     return SCLP_RC_NORMAL_COMPLETION;
 107 }
 108
 109 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
 110                                        EventBufferHeader *event_buf, SCCB *sccb)
 111 {
 112     uint16_t rc;
 113     BusChild *kid;
 114     SCLPEvent *event;
 115     SCLPEventClass *ec;
 116
 117     rc = SCLP_RC_INVALID_FUNCTION;
 118
 119     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 120         DeviceState *qdev = kid->child;
 121         event = (SCLPEvent *) qdev;
 122         ec = SCLP_EVENT_GET_CLASS(event);
 123
 124         if (ec->write_event_data &&
 125             ec->can_handle_event(event_buf->type)) {
 126             rc = ec->write_event_data(event, event_buf);
 127             break;
 128         }
 129     }
 130     return rc;
 131 }
 132
 133 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
 134 {
 135     uint16_t rc;
 136     int slen;
 137     unsigned elen = 0;
 138     EventBufferHeader *event_buf;
 139     WriteEventData *wed = (WriteEventData *) sccb;
 140
 141     event_buf = &wed->ebh;
 142     rc = SCLP_RC_NORMAL_COMPLETION;
 143
 144     /* loop over all contained event buffers */
 145     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
 146         elen = be16_to_cpu(event_buf->length);
 147
 148         /* in case of a previous error mark all trailing buffers
 149          * as not accepted */
 150         if (rc != SCLP_RC_NORMAL_COMPLETION) {
 151             event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 152         } else {
 153             rc = handle_write_event_buf(ef, event_buf, sccb);
 154         }
 155         event_buf = (void *) event_buf + elen;
 156     }
 157     return rc;
 158 }
 159
 160 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
 161 {
 162     if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
 163         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 164         goto out;
 165     }
 166     if (be16_to_cpu(sccb->h.length) < 8) {
 167         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 168         goto out;
 169     }
 170     /* first do a sanity check of the write events */
 171     sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
 172
 173     /* if no early error, then execute */
 174     if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
 175         sccb->h.response_code =
 176                 cpu_to_be16(handle_sccb_write_events(ef, sccb));
 177     }
 178
 179 out:
 180     return;
 181 }
 182
 183 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
 184                                         unsigned int mask)
 185 {
 186     uint16_t rc;
 187     int slen;
 188     unsigned elen;
 189     BusChild *kid;
 190     SCLPEvent *event;
 191     SCLPEventClass *ec;
 192     EventBufferHeader *event_buf;
 193     ReadEventData *red = (ReadEventData *) sccb;
 194
 195     event_buf = &red->ebh;
 196     event_buf->length = 0;
 197     slen = sizeof(sccb->data);
 198
 199     rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
 200
 201     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 202         DeviceState *qdev = kid->child;
 203         event = (SCLPEvent *) qdev;
 204         ec = SCLP_EVENT_GET_CLASS(event);
 205
 206         if (mask & ec->get_send_mask()) {
 207             if (ec->read_event_data(event, event_buf, &slen)) {
 208                 elen = be16_to_cpu(event_buf->length);
 209                 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
 210                 rc = SCLP_RC_NORMAL_COMPLETION;
 211             }
 212         }
 213     }
 214
 215     if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
 216         /* architecture suggests to reset variable-length-response bit */
 217         sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
 218         /* with a new length value */
 219         sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
 220     }
 221     return rc;
 222 }
 223
 224 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
 225 {
 226     unsigned int sclp_active_selection_mask;
 227     unsigned int sclp_cp_receive_mask;
 228
 229     ReadEventData *red = (ReadEventData *) sccb;
 230
 231     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
 232         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 233         goto out;
 234     }
 235
 236     sclp_cp_receive_mask = ef->receive_mask;
 237
 238     /* get active selection mask */
 239     switch (sccb->h.function_code) {
 240     case SCLP_UNCONDITIONAL_READ:
 241         sclp_active_selection_mask = sclp_cp_receive_mask;
 242         break;
 243     case SCLP_SELECTIVE_READ:
 244         if (!(sclp_cp_receive_mask & be32_to_cpu(red->mask))) {
 245             sccb->h.response_code =
 246                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
 247             goto out;
 248         }
 249         sclp_active_selection_mask = be32_to_cpu(red->mask);
 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 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
 263 {
 264     WriteEventMask *we_mask = (WriteEventMask *) sccb;
 265
 266     /* Attention: We assume that Linux uses 4-byte masks, what it actually
 267        does. Architecture allows for masks of variable size, though */
 268     if (be16_to_cpu(we_mask->mask_length) != 4) {
 269         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
 270         goto out;
 271     }
 272
 273     /* keep track of the guest's capability masks */
 274     ef->receive_mask = be32_to_cpu(we_mask->cp_receive_mask);
 275
 276     /* return the SCLP's capability masks to the guest */
 277     we_mask->send_mask = cpu_to_be32(get_host_send_mask(ef));
 278     we_mask->receive_mask = cpu_to_be32(get_host_receive_mask(ef));
 279
 280     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
 281
 282 out:
 283     return;
 284 }
 285
 286 /* qemu object creation and initialization functions */
 287
 288 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
 289
 290 static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
 291 {
 292 }
 293
 294 static const TypeInfo sclp_events_bus_info = {
 295     .name = TYPE_SCLP_EVENTS_BUS,
 296     .parent = TYPE_BUS,
 297     .class_init = sclp_events_bus_class_init,
 298 };
 299
 300 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
 301 {
 302     switch (code & SCLP_CMD_CODE_MASK) {
 303     case SCLP_CMD_READ_EVENT_DATA:
 304         read_event_data(ef, sccb);
 305         break;
 306     case SCLP_CMD_WRITE_EVENT_DATA:
 307         write_event_data(ef, sccb);
 308         break;
 309     case SCLP_CMD_WRITE_EVENT_MASK:
 310         write_event_mask(ef, sccb);
 311         break;
 312     default:
 313         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
 314         break;
 315     }
 316 }
 317
 318 static const VMStateDescription vmstate_event_facility = {
 319     .name = "vmstate-event-facility",
 320     .version_id = 0,
 321     .minimum_version_id = 0,
 322     .minimum_version_id_old = 0,
 323     .fields      = (VMStateField[]) {
 324         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
 325         VMSTATE_END_OF_LIST()
 326      }
 327 };
 328
 329 static int init_event_facility(SCLPEventFacility *event_facility)
 330 {
 331     DeviceState *sdev = DEVICE(event_facility);
 332     DeviceState *quiesce;
 333
 334     /* Spawn a new bus for SCLP events */
 335     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
 336                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
 337     event_facility->sbus.qbus.allow_hotplug = 0;
 338
 339     quiesce = qdev_create(&event_facility->sbus.qbus, "sclpquiesce");
 340     if (!quiesce) {
 341         return -1;
 342     }
 343     qdev_init_nofail(quiesce);
 344
 345     object_initialize(&cpu_hotplug, sizeof(cpu_hotplug), TYPE_SCLP_CPU_HOTPLUG);
 346     qdev_set_parent_bus(DEVICE(&cpu_hotplug), BUS(&event_facility->sbus));
 347     object_property_set_bool(OBJECT(&cpu_hotplug), true, "realized", NULL);
 348
 349     return 0;
 350 }
 351
 352 static void reset_event_facility(DeviceState *dev)
 353 {
 354     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
 355
 356     sdev->receive_mask = 0;
 357 }
 358
 359 static void init_event_facility_class(ObjectClass *klass, void *data)
 360 {
 361     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
 362     DeviceClass *dc = DEVICE_CLASS(sbdc);
 363     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
 364
 365     dc->reset = reset_event_facility;
 366     dc->vmsd = &vmstate_event_facility;
 367     k->init = init_event_facility;
 368     k->command_handler = command_handler;
 369     k->event_pending = event_pending;
 370 }
 371
 372 static const TypeInfo sclp_event_facility_info = {
 373     .name          = TYPE_SCLP_EVENT_FACILITY,
 374     .parent        = TYPE_SYS_BUS_DEVICE,
 375     .instance_size = sizeof(SCLPEventFacility),
 376     .class_init    = init_event_facility_class,
 377     .class_size    = sizeof(SCLPEventFacilityClass),
 378 };
 379
 380 static void event_realize(DeviceState *qdev, Error **errp)
 381 {
 382     SCLPEvent *event = SCLP_EVENT(qdev);
 383     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 384
 385     if (child->init) {
 386         int rc = child->init(event);
 387         if (rc < 0) {
 388             error_setg(errp, "SCLP event initialization failed.");
 389             return;
 390         }
 391     }
 392 }
 393
 394 static void event_unrealize(DeviceState *qdev, Error **errp)
 395 {
 396     SCLPEvent *event = SCLP_EVENT(qdev);
 397     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 398     if (child->exit) {
 399         int rc = child->exit(event);
 400         if (rc < 0) {
 401             error_setg(errp, "SCLP event exit failed.");
 402             return;
 403         }
 404     }
 405 }
 406
 407 static void event_class_init(ObjectClass *klass, void *data)
 408 {
 409     DeviceClass *dc = DEVICE_CLASS(klass);
 410
 411     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
 412     dc->unplug = qdev_simple_unplug_cb;
 413     dc->realize = event_realize;
 414     dc->unrealize = event_unrealize;
 415 }
 416
 417 static const TypeInfo sclp_event_type_info = {
 418     .name = TYPE_SCLP_EVENT,
 419     .parent = TYPE_DEVICE,
 420     .instance_size = sizeof(SCLPEvent),
 421     .class_init = event_class_init,
 422     .class_size = sizeof(SCLPEventClass),
 423     .abstract = true,
 424 };
 425
 426 static void register_types(void)
 427 {
 428     type_register_static(&sclp_events_bus_info);
 429     type_register_static(&sclp_event_facility_info);
 430     type_register_static(&sclp_event_type_info);
 431 }
 432
 433 type_init(register_types)