hw/intc/s390_flic_kvm.c

   1 /*
   2  * QEMU S390x KVM floating interrupt controller (flic)
   3  *
   4  * Copyright 2014 IBM Corp.
   5  * Author(s): Jens Freimann <jfrei@linux.vnet.ibm.com>
   6  *            Cornelia Huck <cornelia.huck@de.ibm.com>
   7  *
   8  * This work is licensed under the terms of the GNU GPL, version 2 or (at
   9  * your option) any later version. See the COPYING file in the top-level
  10  * directory.
  11  */
  12
  13 #include "qemu/osdep.h"
  14 #include "qemu-common.h"
  15 #include "cpu.h"
  16 #include "kvm_s390x.h"
  17 #include <sys/ioctl.h>
  18 #include "qemu/error-report.h"
  19 #include "qapi/error.h"
  20 #include "hw/sysbus.h"
  21 #include "sysemu/kvm.h"
  22 #include "hw/s390x/s390_flic.h"
  23 #include "hw/s390x/adapter.h"
  24 #include "hw/s390x/css.h"
  25 #include "trace.h"
  26
  27 #define FLIC_SAVE_INITIAL_SIZE getpagesize()
  28 #define FLIC_FAILED (-1UL)
  29 #define FLIC_SAVEVM_VERSION 1
  30
  31 typedef struct KVMS390FLICState {
  32     S390FLICState parent_obj;
  33
  34     uint32_t fd;
  35     bool clear_io_supported;
  36 } KVMS390FLICState;
  37
  38 DeviceState *s390_flic_kvm_create(void)
  39 {
  40     DeviceState *dev = NULL;
  41
  42     if (kvm_enabled()) {
  43         dev = qdev_create(NULL, TYPE_KVM_S390_FLIC);
  44         object_property_add_child(qdev_get_machine(), TYPE_KVM_S390_FLIC,
  45                                   OBJECT(dev), NULL);
  46     }
  47     return dev;
  48 }
  49
  50 /**
  51  * flic_get_all_irqs - store all pending irqs in buffer
  52  * @buf: pointer to buffer which is passed to kernel
  53  * @len: length of buffer
  54  * @flic: pointer to flic device state
  55  *
  56  * Returns: -ENOMEM if buffer is too small,
  57  * -EINVAL if attr.group is invalid,
  58  * -EFAULT if copying to userspace failed,
  59  * on success return number of stored interrupts
  60  */
  61 static int flic_get_all_irqs(KVMS390FLICState *flic,
  62                              void *buf, int len)
  63 {
  64     struct kvm_device_attr attr = {
  65         .group = KVM_DEV_FLIC_GET_ALL_IRQS,
  66         .addr = (uint64_t) buf,
  67         .attr = len,
  68     };
  69     int rc;
  70
  71     rc = ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr);
  72
  73     return rc == -1 ? -errno : rc;
  74 }
  75
  76 static void flic_enable_pfault(KVMS390FLICState *flic)
  77 {
  78     struct kvm_device_attr attr = {
  79         .group = KVM_DEV_FLIC_APF_ENABLE,
  80     };
  81     int rc;
  82
  83     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
  84
  85     if (rc) {
  86         fprintf(stderr, "flic: couldn't enable pfault\n");
  87     }
  88 }
  89
  90 static void flic_disable_wait_pfault(KVMS390FLICState *flic)
  91 {
  92     struct kvm_device_attr attr = {
  93         .group = KVM_DEV_FLIC_APF_DISABLE_WAIT,
  94     };
  95     int rc;
  96
  97     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
  98
  99     if (rc) {
 100         fprintf(stderr, "flic: couldn't disable pfault\n");
 101     }
 102 }
 103
 104 /** flic_enqueue_irqs - returns 0 on success
 105  * @buf: pointer to buffer which is passed to kernel
 106  * @len: length of buffer
 107  * @flic: pointer to flic device state
 108  *
 109  * Returns: -EINVAL if attr.group is unknown
 110  */
 111 static int flic_enqueue_irqs(void *buf, uint64_t len,
 112                             KVMS390FLICState *flic)
 113 {
 114     int rc;
 115     struct kvm_device_attr attr = {
 116         .group = KVM_DEV_FLIC_ENQUEUE,
 117         .addr = (uint64_t) buf,
 118         .attr = len,
 119     };
 120
 121     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 122
 123     return rc ? -errno : 0;
 124 }
 125
 126 int kvm_s390_inject_flic(struct kvm_s390_irq *irq)
 127 {
 128     static KVMS390FLICState *flic;
 129
 130     if (unlikely(!flic)) {
 131         flic = KVM_S390_FLIC(s390_get_flic());
 132     }
 133     return flic_enqueue_irqs(irq, sizeof(*irq), flic);
 134 }
 135
 136 static int kvm_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
 137                            uint16_t subchannel_nr)
 138 {
 139     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 140     int rc;
 141     uint32_t sid = subchannel_id << 16 | subchannel_nr;
 142     struct kvm_device_attr attr = {
 143         .group = KVM_DEV_FLIC_CLEAR_IO_IRQ,
 144         .addr = (uint64_t) &sid,
 145         .attr = sizeof(sid),
 146     };
 147     if (unlikely(!flic->clear_io_supported)) {
 148         return -ENOSYS;
 149     }
 150     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 151     return rc ? -errno : 0;
 152 }
 153
 154 static int kvm_s390_modify_ais_mode(S390FLICState *fs, uint8_t isc,
 155                                     uint16_t mode)
 156 {
 157     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 158     struct kvm_s390_ais_req req = {
 159         .isc = isc,
 160         .mode = mode,
 161     };
 162     struct kvm_device_attr attr = {
 163         .group = KVM_DEV_FLIC_AISM,
 164         .addr = (uint64_t)&req,
 165     };
 166
 167     if (!fs->ais_supported) {
 168         return -ENOSYS;
 169     }
 170
 171     return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
 172 }
 173
 174 static int kvm_s390_inject_airq(S390FLICState *fs, uint8_t type,
 175                                 uint8_t isc, uint8_t flags)
 176 {
 177     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 178     uint32_t id = css_get_adapter_id(type, isc);
 179     struct kvm_device_attr attr = {
 180         .group = KVM_DEV_FLIC_AIRQ_INJECT,
 181         .attr = id,
 182     };
 183
 184     if (!fs->ais_supported) {
 185         return -ENOSYS;
 186     }
 187
 188     return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
 189 }
 190
 191 /**
 192  * __get_all_irqs - store all pending irqs in buffer
 193  * @flic: pointer to flic device state
 194  * @buf: pointer to pointer to a buffer
 195  * @len: length of buffer
 196  *
 197  * Returns: return value of flic_get_all_irqs
 198  * Note: Retry and increase buffer size until flic_get_all_irqs
 199  * either returns a value >= 0 or a negative error code.
 200  * -ENOMEM is an exception, which means the buffer is too small
 201  * and we should try again. Other negative error codes can be
 202  * -EFAULT and -EINVAL which we ignore at this point
 203  */
 204 static int __get_all_irqs(KVMS390FLICState *flic,
 205                           void **buf, int len)
 206 {
 207     int r;
 208
 209     do {
 210         /* returns -ENOMEM if buffer is too small and number
 211          * of queued interrupts on success */
 212         r = flic_get_all_irqs(flic, *buf, len);
 213         if (r >= 0) {
 214             break;
 215         }
 216         len *= 2;
 217         *buf = g_try_realloc(*buf, len);
 218         if (!buf) {
 219             return -ENOMEM;
 220         }
 221     } while (r == -ENOMEM && len <= KVM_S390_FLIC_MAX_BUFFER);
 222
 223     return r;
 224 }
 225
 226 static int kvm_s390_register_io_adapter(S390FLICState *fs, uint32_t id,
 227                                         uint8_t isc, bool swap,
 228                                         bool is_maskable, uint8_t flags)
 229 {
 230     struct kvm_s390_io_adapter adapter = {
 231         .id = id,
 232         .isc = isc,
 233         .maskable = is_maskable,
 234         .swap = swap,
 235         .flags = flags,
 236     };
 237     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 238     int r;
 239     struct kvm_device_attr attr = {
 240         .group = KVM_DEV_FLIC_ADAPTER_REGISTER,
 241         .addr = (uint64_t)&adapter,
 242     };
 243
 244     if (!kvm_gsi_routing_enabled()) {
 245         /* nothing to do */
 246         return 0;
 247     }
 248
 249     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 250
 251     return r ? -errno : 0;
 252 }
 253
 254 static int kvm_s390_io_adapter_map(S390FLICState *fs, uint32_t id,
 255                                    uint64_t map_addr, bool do_map)
 256 {
 257     struct kvm_s390_io_adapter_req req = {
 258         .id = id,
 259         .type = do_map ? KVM_S390_IO_ADAPTER_MAP : KVM_S390_IO_ADAPTER_UNMAP,
 260         .addr = map_addr,
 261     };
 262     struct kvm_device_attr attr = {
 263         .group = KVM_DEV_FLIC_ADAPTER_MODIFY,
 264         .addr = (uint64_t)&req,
 265     };
 266     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 267     int r;
 268
 269     if (!kvm_gsi_routing_enabled()) {
 270         /* nothing to do */
 271         return 0;
 272     }
 273
 274     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 275     return r ? -errno : 0;
 276 }
 277
 278 static int kvm_s390_add_adapter_routes(S390FLICState *fs,
 279                                        AdapterRoutes *routes)
 280 {
 281     int ret, i;
 282     uint64_t ind_offset = routes->adapter.ind_offset;
 283
 284     for (i = 0; i < routes->num_routes; i++) {
 285         ret = kvm_irqchip_add_adapter_route(kvm_state, &routes->adapter);
 286         if (ret < 0) {
 287             goto out_undo;
 288         }
 289         routes->gsi[i] = ret;
 290         routes->adapter.ind_offset++;
 291     }
 292     kvm_irqchip_commit_routes(kvm_state);
 293
 294     /* Restore passed-in structure to original state. */
 295     routes->adapter.ind_offset = ind_offset;
 296     return 0;
 297 out_undo:
 298     while (--i >= 0) {
 299         kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
 300         routes->gsi[i] = -1;
 301     }
 302     routes->adapter.ind_offset = ind_offset;
 303     return ret;
 304 }
 305
 306 static void kvm_s390_release_adapter_routes(S390FLICState *fs,
 307                                             AdapterRoutes *routes)
 308 {
 309     int i;
 310
 311     for (i = 0; i < routes->num_routes; i++) {
 312         if (routes->gsi[i] >= 0) {
 313             kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
 314             routes->gsi[i] = -1;
 315         }
 316     }
 317 }
 318
 319 /**
 320  * kvm_flic_save - Save pending floating interrupts
 321  * @f: QEMUFile containing migration state
 322  * @opaque: pointer to flic device state
 323  * @size: ignored
 324  *
 325  * Note: Pass buf and len to kernel. Start with one page and
 326  * increase until buffer is sufficient or maxium size is
 327  * reached
 328  */
 329 static int kvm_flic_save(QEMUFile *f, void *opaque, size_t size,
 330                          VMStateField *field, QJSON *vmdesc)
 331 {
 332     KVMS390FLICState *flic = opaque;
 333     int len = FLIC_SAVE_INITIAL_SIZE;
 334     void *buf;
 335     int count;
 336     int r = 0;
 337
 338     flic_disable_wait_pfault((struct KVMS390FLICState *) opaque);
 339
 340     buf = g_try_malloc0(len);
 341     if (!buf) {
 342         /* Storing FLIC_FAILED into the count field here will cause the
 343          * target system to fail when attempting to load irqs from the
 344          * migration state */
 345         error_report("flic: couldn't allocate memory");
 346         qemu_put_be64(f, FLIC_FAILED);
 347         return -ENOMEM;
 348     }
 349
 350     count = __get_all_irqs(flic, &buf, len);
 351     if (count < 0) {
 352         error_report("flic: couldn't retrieve irqs from kernel, rc %d",
 353                      count);
 354         /* Storing FLIC_FAILED into the count field here will cause the
 355          * target system to fail when attempting to load irqs from the
 356          * migration state */
 357         qemu_put_be64(f, FLIC_FAILED);
 358         r = count;
 359     } else {
 360         qemu_put_be64(f, count);
 361         qemu_put_buffer(f, (uint8_t *) buf,
 362                         count * sizeof(struct kvm_s390_irq));
 363     }
 364     g_free(buf);
 365
 366     return r;
 367 }
 368
 369 /**
 370  * kvm_flic_load - Load pending floating interrupts
 371  * @f: QEMUFile containing migration state
 372  * @opaque: pointer to flic device state
 373  * @size: ignored
 374  *
 375  * Returns: value of flic_enqueue_irqs, -EINVAL on error
 376  * Note: Do nothing when no interrupts where stored
 377  * in QEMUFile
 378  */
 379 static int kvm_flic_load(QEMUFile *f, void *opaque, size_t size,
 380                          VMStateField *field)
 381 {
 382     uint64_t len = 0;
 383     uint64_t count = 0;
 384     void *buf = NULL;
 385     int r = 0;
 386
 387     flic_enable_pfault((struct KVMS390FLICState *) opaque);
 388
 389     count = qemu_get_be64(f);
 390     len = count * sizeof(struct kvm_s390_irq);
 391     if (count == FLIC_FAILED) {
 392         r = -EINVAL;
 393         goto out;
 394     }
 395     if (count == 0) {
 396         r = 0;
 397         goto out;
 398     }
 399     buf = g_try_malloc0(len);
 400     if (!buf) {
 401         r = -ENOMEM;
 402         goto out;
 403     }
 404
 405     if (qemu_get_buffer(f, (uint8_t *) buf, len) != len) {
 406         r = -EINVAL;
 407         goto out_free;
 408     }
 409     r = flic_enqueue_irqs(buf, len, (struct KVMS390FLICState *) opaque);
 410
 411 out_free:
 412     g_free(buf);
 413 out:
 414     return r;
 415 }
 416
 417 typedef struct KVMS390FLICStateMigTmp {
 418     KVMS390FLICState *parent;
 419     uint8_t simm;
 420     uint8_t nimm;
 421 } KVMS390FLICStateMigTmp;
 422
 423 static void kvm_flic_ais_pre_save(void *opaque)
 424 {
 425     KVMS390FLICStateMigTmp *tmp = opaque;
 426     KVMS390FLICState *flic = tmp->parent;
 427     struct kvm_s390_ais_all ais;
 428     struct kvm_device_attr attr = {
 429         .group = KVM_DEV_FLIC_AISM_ALL,
 430         .addr = (uint64_t)&ais,
 431         .attr = sizeof(ais),
 432     };
 433
 434     if (ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr)) {
 435         error_report("Failed to retrieve kvm flic ais states");
 436         return;
 437     }
 438
 439     tmp->simm = ais.simm;
 440     tmp->nimm = ais.nimm;
 441 }
 442
 443 static int kvm_flic_ais_post_load(void *opaque, int version_id)
 444 {
 445     KVMS390FLICStateMigTmp *tmp = opaque;
 446     KVMS390FLICState *flic = tmp->parent;
 447     struct kvm_s390_ais_all ais = {
 448         .simm = tmp->simm,
 449         .nimm = tmp->nimm,
 450     };
 451     struct kvm_device_attr attr = {
 452         .group = KVM_DEV_FLIC_AISM_ALL,
 453         .addr = (uint64_t)&ais,
 454     };
 455
 456     /* This can happen when the user mis-configures its guests in an
 457      * incompatible fashion or without a CPU model. For example using
 458      * qemu with -cpu host (which is not migration safe) and do a
 459      * migration from a host that has AIS to a host that has no AIS.
 460      * In that case the target system will reject the migration here.
 461      */
 462     if (!ais_needed(flic)) {
 463         return -ENOSYS;
 464     }
 465
 466     return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
 467 }
 468
 469 static const VMStateDescription kvm_s390_flic_ais_tmp = {
 470     .name = "s390-flic-ais-tmp",
 471     .pre_save = kvm_flic_ais_pre_save,
 472     .post_load = kvm_flic_ais_post_load,
 473     .fields = (VMStateField[]) {
 474         VMSTATE_UINT8(simm, KVMS390FLICStateMigTmp),
 475         VMSTATE_UINT8(nimm, KVMS390FLICStateMigTmp),
 476         VMSTATE_END_OF_LIST()
 477     }
 478 };
 479
 480 static const VMStateDescription kvm_s390_flic_vmstate_ais = {
 481     .name = "s390-flic/ais",
 482     .version_id = 1,
 483     .minimum_version_id = 1,
 484     .needed = ais_needed,
 485     .fields = (VMStateField[]) {
 486         VMSTATE_WITH_TMP(KVMS390FLICState, KVMS390FLICStateMigTmp,
 487                          kvm_s390_flic_ais_tmp),
 488         VMSTATE_END_OF_LIST()
 489     }
 490 };
 491
 492 static const VMStateDescription kvm_s390_flic_vmstate = {
 493     /* should have been like kvm-s390-flic,
 494      * can't change without breaking compat */
 495     .name = "s390-flic",
 496     .version_id = FLIC_SAVEVM_VERSION,
 497     .minimum_version_id = FLIC_SAVEVM_VERSION,
 498     .fields = (VMStateField[]) {
 499         {
 500             .name = "irqs",
 501             .info = &(const VMStateInfo) {
 502                 .name = "irqs",
 503                 .get = kvm_flic_load,
 504                 .put = kvm_flic_save,
 505             },
 506             .flags = VMS_SINGLE,
 507         },
 508         VMSTATE_END_OF_LIST()
 509     },
 510     .subsections = (const VMStateDescription * []) {
 511         &kvm_s390_flic_vmstate_ais,
 512         NULL
 513     }
 514 };
 515
 516 typedef struct KVMS390FLICStateClass {
 517     S390FLICStateClass parent_class;
 518     DeviceRealize parent_realize;
 519 } KVMS390FLICStateClass;
 520
 521 #define KVM_S390_FLIC_GET_CLASS(obj) \
 522     OBJECT_GET_CLASS(KVMS390FLICStateClass, (obj), TYPE_KVM_S390_FLIC)
 523
 524 #define KVM_S390_FLIC_CLASS(klass) \
 525     OBJECT_CLASS_CHECK(KVMS390FLICStateClass, (klass), TYPE_KVM_S390_FLIC)
 526
 527 static void kvm_s390_flic_realize(DeviceState *dev, Error **errp)
 528 {
 529     KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
 530     struct kvm_create_device cd = {0};
 531     struct kvm_device_attr test_attr = {0};
 532     int ret;
 533     Error *errp_local = NULL;
 534
 535     KVM_S390_FLIC_GET_CLASS(dev)->parent_realize(dev, &errp_local);
 536     if (errp_local) {
 537         goto fail;
 538     }
 539     flic_state->fd = -1;
 540     if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
 541         error_setg_errno(&errp_local, errno, "KVM is missing capability"
 542                          " KVM_CAP_DEVICE_CTRL");
 543         trace_flic_no_device_api(errno);
 544         goto fail;
 545     }
 546
 547     cd.type = KVM_DEV_TYPE_FLIC;
 548     ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
 549     if (ret < 0) {
 550         error_setg_errno(&errp_local, errno, "Creating the KVM device failed");
 551         trace_flic_create_device(errno);
 552         goto fail;
 553     }
 554     flic_state->fd = cd.fd;
 555
 556     /* Check clear_io_irq support */
 557     test_attr.group = KVM_DEV_FLIC_CLEAR_IO_IRQ;
 558     flic_state->clear_io_supported = !ioctl(flic_state->fd,
 559                                             KVM_HAS_DEVICE_ATTR, test_attr);
 560     return;
 561 fail:
 562     error_propagate(errp, errp_local);
 563 }
 564
 565 static void kvm_s390_flic_reset(DeviceState *dev)
 566 {
 567     KVMS390FLICState *flic = KVM_S390_FLIC(dev);
 568     S390FLICState *fs = S390_FLIC_COMMON(dev);
 569     struct kvm_device_attr attr = {
 570         .group = KVM_DEV_FLIC_CLEAR_IRQS,
 571     };
 572     int rc = 0;
 573     uint8_t isc;
 574
 575     if (flic->fd == -1) {
 576         return;
 577     }
 578
 579     flic_disable_wait_pfault(flic);
 580
 581     if (fs->ais_supported) {
 582         for (isc = 0; isc <= MAX_ISC; isc++) {
 583             rc = kvm_s390_modify_ais_mode(fs, isc, SIC_IRQ_MODE_ALL);
 584             if (rc) {
 585                 error_report("Failed to reset ais mode for isc %d: %s",
 586                              isc, strerror(-rc));
 587             }
 588         }
 589     }
 590
 591     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 592     if (rc) {
 593         trace_flic_reset_failed(errno);
 594     }
 595
 596     flic_enable_pfault(flic);
 597 }
 598
 599 static void kvm_s390_flic_class_init(ObjectClass *oc, void *data)
 600 {
 601     DeviceClass *dc = DEVICE_CLASS(oc);
 602     S390FLICStateClass *fsc = S390_FLIC_COMMON_CLASS(oc);
 603
 604     KVM_S390_FLIC_CLASS(oc)->parent_realize = dc->realize;
 605     dc->realize = kvm_s390_flic_realize;
 606     dc->vmsd = &kvm_s390_flic_vmstate;
 607     dc->reset = kvm_s390_flic_reset;
 608     fsc->register_io_adapter = kvm_s390_register_io_adapter;
 609     fsc->io_adapter_map = kvm_s390_io_adapter_map;
 610     fsc->add_adapter_routes = kvm_s390_add_adapter_routes;
 611     fsc->release_adapter_routes = kvm_s390_release_adapter_routes;
 612     fsc->clear_io_irq = kvm_s390_clear_io_flic;
 613     fsc->modify_ais_mode = kvm_s390_modify_ais_mode;
 614     fsc->inject_airq = kvm_s390_inject_airq;
 615 }
 616
 617 static const TypeInfo kvm_s390_flic_info = {
 618     .name          = TYPE_KVM_S390_FLIC,
 619     .parent        = TYPE_S390_FLIC_COMMON,
 620     .instance_size = sizeof(KVMS390FLICState),
 621     .class_size    = sizeof(KVMS390FLICStateClass),
 622     .class_init    = kvm_s390_flic_class_init,
 623 };
 624
 625 static void kvm_s390_flic_register_types(void)
 626 {
 627     type_register_static(&kvm_s390_flic_info);
 628 }
 629
 630 type_init(kvm_s390_flic_register_types)