qemu/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 "sysemu/sysemu.h"
  19
  20 #include "hw/s390x/sclp.h"
  21 #include "hw/s390x/event-facility.h"
  22
  23 typedef struct SCLPEventsBus {
  24     BusState qbus;
  25 } SCLPEventsBus;
  26
  27 struct SCLPEventFacility {
  28     SysBusDevice parent_obj;
  29     SCLPEventsBus sbus;
  30     /* guest' receive mask */
  31     unsigned int receive_mask;
  32 };
  33
  34 static SCLPEvent cpu_hotplug;
  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         if (!(sclp_cp_receive_mask & be32_to_cpu(red->mask))) {
 244             sccb->h.response_code =
 245                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
 246             goto out;
 247         }
 248         sclp_active_selection_mask = be32_to_cpu(red->mask);
 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_class_init(ObjectClass *klass, void *data)
 290 {
 291 }
 292
 293 static const TypeInfo sclp_events_bus_info = {
 294     .name = TYPE_SCLP_EVENTS_BUS,
 295     .parent = TYPE_BUS,
 296     .class_init = sclp_events_bus_class_init,
 297 };
 298
 299 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
 300 {
 301     switch (code & SCLP_CMD_CODE_MASK) {
 302     case SCLP_CMD_READ_EVENT_DATA:
 303         read_event_data(ef, sccb);
 304         break;
 305     case SCLP_CMD_WRITE_EVENT_DATA:
 306         write_event_data(ef, sccb);
 307         break;
 308     case SCLP_CMD_WRITE_EVENT_MASK:
 309         write_event_mask(ef, sccb);
 310         break;
 311     default:
 312         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
 313         break;
 314     }
 315 }
 316
 317 static const VMStateDescription vmstate_event_facility = {
 318     .name = "vmstate-event-facility",
 319     .version_id = 0,
 320     .minimum_version_id = 0,
 321     .fields = (VMStateField[]) {
 322         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
 323         VMSTATE_END_OF_LIST()
 324      }
 325 };
 326
 327 static int init_event_facility(SCLPEventFacility *event_facility)
 328 {
 329     DeviceState *sdev = DEVICE(event_facility);
 330     DeviceState *quiesce;
 331
 332     /* Spawn a new bus for SCLP events */
 333     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
 334                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
 335
 336     quiesce = qdev_create(&event_facility->sbus.qbus, "sclpquiesce");
 337     if (!quiesce) {
 338         return -1;
 339     }
 340     qdev_init_nofail(quiesce);
 341
 342     object_initialize(&cpu_hotplug, sizeof(cpu_hotplug), TYPE_SCLP_CPU_HOTPLUG);
 343     qdev_set_parent_bus(DEVICE(&cpu_hotplug), BUS(&event_facility->sbus));
 344     object_property_set_bool(OBJECT(&cpu_hotplug), true, "realized", NULL);
 345
 346     return 0;
 347 }
 348
 349 static void reset_event_facility(DeviceState *dev)
 350 {
 351     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
 352
 353     sdev->receive_mask = 0;
 354 }
 355
 356 static void init_event_facility_class(ObjectClass *klass, void *data)
 357 {
 358     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
 359     DeviceClass *dc = DEVICE_CLASS(sbdc);
 360     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
 361
 362     dc->reset = reset_event_facility;
 363     dc->vmsd = &vmstate_event_facility;
 364     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 365     k->init = init_event_facility;
 366     k->command_handler = command_handler;
 367     k->event_pending = event_pending;
 368 }
 369
 370 static const TypeInfo sclp_event_facility_info = {
 371     .name          = TYPE_SCLP_EVENT_FACILITY,
 372     .parent        = TYPE_SYS_BUS_DEVICE,
 373     .instance_size = sizeof(SCLPEventFacility),
 374     .class_init    = init_event_facility_class,
 375     .class_size    = sizeof(SCLPEventFacilityClass),
 376 };
 377
 378 static void event_realize(DeviceState *qdev, Error **errp)
 379 {
 380     SCLPEvent *event = SCLP_EVENT(qdev);
 381     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 382
 383     if (child->init) {
 384         int rc = child->init(event);
 385         if (rc < 0) {
 386             error_setg(errp, "SCLP event initialization failed.");
 387             return;
 388         }
 389     }
 390 }
 391
 392 static void event_unrealize(DeviceState *qdev, Error **errp)
 393 {
 394     SCLPEvent *event = SCLP_EVENT(qdev);
 395     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 396     if (child->exit) {
 397         int rc = child->exit(event);
 398         if (rc < 0) {
 399             error_setg(errp, "SCLP event exit failed.");
 400             return;
 401         }
 402     }
 403 }
 404
 405 static void event_class_init(ObjectClass *klass, void *data)
 406 {
 407     DeviceClass *dc = DEVICE_CLASS(klass);
 408
 409     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
 410     dc->realize = event_realize;
 411     dc->unrealize = event_unrealize;
 412 }
 413
 414 static const TypeInfo sclp_event_type_info = {
 415     .name = TYPE_SCLP_EVENT,
 416     .parent = TYPE_DEVICE,
 417     .instance_size = sizeof(SCLPEvent),
 418     .class_init = event_class_init,
 419     .class_size = sizeof(SCLPEventClass),
 420     .abstract = true,
 421 };
 422
 423 static void register_types(void)
 424 {
 425     type_register_static(&sclp_events_bus_info);
 426     type_register_static(&sclp_event_facility_info);
 427     type_register_static(&sclp_event_type_info);
 428 }
 429
 430 type_init(register_types)