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 <sys/ioctl.h>
  17 #include "qemu/error-report.h"
  18 #include "hw/sysbus.h"
  19 #include "sysemu/kvm.h"
  20 #include "migration/qemu-file.h"
  21 #include "hw/s390x/s390_flic.h"
  22 #include "hw/s390x/adapter.h"
  23 #include "trace.h"
  24
  25 #define FLIC_SAVE_INITIAL_SIZE getpagesize()
  26 #define FLIC_FAILED (-1UL)
  27 #define FLIC_SAVEVM_VERSION 1
  28
  29 typedef struct KVMS390FLICState {
  30     S390FLICState parent_obj;
  31
  32     uint32_t fd;
  33     bool clear_io_supported;
  34 } KVMS390FLICState;
  35
  36 DeviceState *s390_flic_kvm_create(void)
  37 {
  38     DeviceState *dev = NULL;
  39
  40     if (kvm_enabled()) {
  41         dev = qdev_create(NULL, TYPE_KVM_S390_FLIC);
  42         object_property_add_child(qdev_get_machine(), TYPE_KVM_S390_FLIC,
  43                                   OBJECT(dev), NULL);
  44     }
  45     return dev;
  46 }
  47
  48 /**
  49  * flic_get_all_irqs - store all pending irqs in buffer
  50  * @buf: pointer to buffer which is passed to kernel
  51  * @len: length of buffer
  52  * @flic: pointer to flic device state
  53  *
  54  * Returns: -ENOMEM if buffer is too small,
  55  * -EINVAL if attr.group is invalid,
  56  * -EFAULT if copying to userspace failed,
  57  * on success return number of stored interrupts
  58  */
  59 static int flic_get_all_irqs(KVMS390FLICState *flic,
  60                              void *buf, int len)
  61 {
  62     struct kvm_device_attr attr = {
  63         .group = KVM_DEV_FLIC_GET_ALL_IRQS,
  64         .addr = (uint64_t) buf,
  65         .attr = len,
  66     };
  67     int rc;
  68
  69     rc = ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr);
  70
  71     return rc == -1 ? -errno : rc;
  72 }
  73
  74 static void flic_enable_pfault(KVMS390FLICState *flic)
  75 {
  76     struct kvm_device_attr attr = {
  77         .group = KVM_DEV_FLIC_APF_ENABLE,
  78     };
  79     int rc;
  80
  81     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
  82
  83     if (rc) {
  84         fprintf(stderr, "flic: couldn't enable pfault\n");
  85     }
  86 }
  87
  88 static void flic_disable_wait_pfault(KVMS390FLICState *flic)
  89 {
  90     struct kvm_device_attr attr = {
  91         .group = KVM_DEV_FLIC_APF_DISABLE_WAIT,
  92     };
  93     int rc;
  94
  95     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
  96
  97     if (rc) {
  98         fprintf(stderr, "flic: couldn't disable pfault\n");
  99     }
 100 }
 101
 102 /** flic_enqueue_irqs - returns 0 on success
 103  * @buf: pointer to buffer which is passed to kernel
 104  * @len: length of buffer
 105  * @flic: pointer to flic device state
 106  *
 107  * Returns: -EINVAL if attr.group is unknown
 108  */
 109 static int flic_enqueue_irqs(void *buf, uint64_t len,
 110                             KVMS390FLICState *flic)
 111 {
 112     int rc;
 113     struct kvm_device_attr attr = {
 114         .group = KVM_DEV_FLIC_ENQUEUE,
 115         .addr = (uint64_t) buf,
 116         .attr = len,
 117     };
 118
 119     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 120
 121     return rc ? -errno : 0;
 122 }
 123
 124 int kvm_s390_inject_flic(struct kvm_s390_irq *irq)
 125 {
 126     static KVMS390FLICState *flic;
 127
 128     if (unlikely(!flic)) {
 129         flic = KVM_S390_FLIC(s390_get_flic());
 130     }
 131     return flic_enqueue_irqs(irq, sizeof(*irq), flic);
 132 }
 133
 134 static int kvm_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
 135                            uint16_t subchannel_nr)
 136 {
 137     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 138     int rc;
 139     uint32_t sid = subchannel_id << 16 | subchannel_nr;
 140     struct kvm_device_attr attr = {
 141         .group = KVM_DEV_FLIC_CLEAR_IO_IRQ,
 142         .addr = (uint64_t) &sid,
 143         .attr = sizeof(sid),
 144     };
 145     if (unlikely(!flic->clear_io_supported)) {
 146         return -ENOSYS;
 147     }
 148     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 149     return rc ? -errno : 0;
 150 }
 151
 152 /**
 153  * __get_all_irqs - store all pending irqs in buffer
 154  * @flic: pointer to flic device state
 155  * @buf: pointer to pointer to a buffer
 156  * @len: length of buffer
 157  *
 158  * Returns: return value of flic_get_all_irqs
 159  * Note: Retry and increase buffer size until flic_get_all_irqs
 160  * either returns a value >= 0 or a negative error code.
 161  * -ENOMEM is an exception, which means the buffer is too small
 162  * and we should try again. Other negative error codes can be
 163  * -EFAULT and -EINVAL which we ignore at this point
 164  */
 165 static int __get_all_irqs(KVMS390FLICState *flic,
 166                           void **buf, int len)
 167 {
 168     int r;
 169
 170     do {
 171         /* returns -ENOMEM if buffer is too small and number
 172          * of queued interrupts on success */
 173         r = flic_get_all_irqs(flic, *buf, len);
 174         if (r >= 0) {
 175             break;
 176         }
 177         len *= 2;
 178         *buf = g_try_realloc(*buf, len);
 179         if (!buf) {
 180             return -ENOMEM;
 181         }
 182     } while (r == -ENOMEM && len <= KVM_S390_FLIC_MAX_BUFFER);
 183
 184     return r;
 185 }
 186
 187 static int kvm_s390_register_io_adapter(S390FLICState *fs, uint32_t id,
 188                                         uint8_t isc, bool swap,
 189                                         bool is_maskable)
 190 {
 191     struct kvm_s390_io_adapter adapter = {
 192         .id = id,
 193         .isc = isc,
 194         .maskable = is_maskable,
 195         .swap = swap,
 196     };
 197     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 198     int r, ret;
 199     struct kvm_device_attr attr = {
 200         .group = KVM_DEV_FLIC_ADAPTER_REGISTER,
 201         .addr = (uint64_t)&adapter,
 202     };
 203
 204     if (!kvm_check_extension(kvm_state, KVM_CAP_IRQ_ROUTING)) {
 205         /* nothing to do */
 206         return 0;
 207     }
 208
 209     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 210
 211     ret = r ? -errno : 0;
 212     return ret;
 213 }
 214
 215 static int kvm_s390_io_adapter_map(S390FLICState *fs, uint32_t id,
 216                                    uint64_t map_addr, bool do_map)
 217 {
 218     struct kvm_s390_io_adapter_req req = {
 219         .id = id,
 220         .type = do_map ? KVM_S390_IO_ADAPTER_MAP : KVM_S390_IO_ADAPTER_UNMAP,
 221         .addr = map_addr,
 222     };
 223     struct kvm_device_attr attr = {
 224         .group = KVM_DEV_FLIC_ADAPTER_MODIFY,
 225         .addr = (uint64_t)&req,
 226     };
 227     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
 228     int r;
 229
 230     if (!kvm_check_extension(kvm_state, KVM_CAP_IRQ_ROUTING)) {
 231         /* nothing to do */
 232         return 0;
 233     }
 234
 235     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 236     return r ? -errno : 0;
 237 }
 238
 239 static int kvm_s390_add_adapter_routes(S390FLICState *fs,
 240                                        AdapterRoutes *routes)
 241 {
 242     int ret, i;
 243     uint64_t ind_offset = routes->adapter.ind_offset;
 244
 245     for (i = 0; i < routes->num_routes; i++) {
 246         ret = kvm_irqchip_add_adapter_route(kvm_state, &routes->adapter);
 247         if (ret < 0) {
 248             goto out_undo;
 249         }
 250         routes->gsi[i] = ret;
 251         routes->adapter.ind_offset++;
 252     }
 253     kvm_irqchip_commit_routes(kvm_state);
 254
 255     /* Restore passed-in structure to original state. */
 256     routes->adapter.ind_offset = ind_offset;
 257     return 0;
 258 out_undo:
 259     while (--i >= 0) {
 260         kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
 261         routes->gsi[i] = -1;
 262     }
 263     routes->adapter.ind_offset = ind_offset;
 264     return ret;
 265 }
 266
 267 static void kvm_s390_release_adapter_routes(S390FLICState *fs,
 268                                             AdapterRoutes *routes)
 269 {
 270     int i;
 271
 272     for (i = 0; i < routes->num_routes; i++) {
 273         if (routes->gsi[i] >= 0) {
 274             kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
 275             routes->gsi[i] = -1;
 276         }
 277     }
 278 }
 279
 280 /**
 281  * kvm_flic_save - Save pending floating interrupts
 282  * @f: QEMUFile containing migration state
 283  * @opaque: pointer to flic device state
 284  *
 285  * Note: Pass buf and len to kernel. Start with one page and
 286  * increase until buffer is sufficient or maxium size is
 287  * reached
 288  */
 289 static void kvm_flic_save(QEMUFile *f, void *opaque)
 290 {
 291     KVMS390FLICState *flic = opaque;
 292     int len = FLIC_SAVE_INITIAL_SIZE;
 293     void *buf;
 294     int count;
 295
 296     flic_disable_wait_pfault((struct KVMS390FLICState *) opaque);
 297
 298     buf = g_try_malloc0(len);
 299     if (!buf) {
 300         /* Storing FLIC_FAILED into the count field here will cause the
 301          * target system to fail when attempting to load irqs from the
 302          * migration state */
 303         error_report("flic: couldn't allocate memory");
 304         qemu_put_be64(f, FLIC_FAILED);
 305         return;
 306     }
 307
 308     count = __get_all_irqs(flic, &buf, len);
 309     if (count < 0) {
 310         error_report("flic: couldn't retrieve irqs from kernel, rc %d",
 311                      count);
 312         /* Storing FLIC_FAILED into the count field here will cause the
 313          * target system to fail when attempting to load irqs from the
 314          * migration state */
 315         qemu_put_be64(f, FLIC_FAILED);
 316     } else {
 317         qemu_put_be64(f, count);
 318         qemu_put_buffer(f, (uint8_t *) buf,
 319                         count * sizeof(struct kvm_s390_irq));
 320     }
 321     g_free(buf);
 322 }
 323
 324 /**
 325  * kvm_flic_load - Load pending floating interrupts
 326  * @f: QEMUFile containing migration state
 327  * @opaque: pointer to flic device state
 328  * @version_id: version id for migration
 329  *
 330  * Returns: value of flic_enqueue_irqs, -EINVAL on error
 331  * Note: Do nothing when no interrupts where stored
 332  * in QEMUFile
 333  */
 334 static int kvm_flic_load(QEMUFile *f, void *opaque, int version_id)
 335 {
 336     uint64_t len = 0;
 337     uint64_t count = 0;
 338     void *buf = NULL;
 339     int r = 0;
 340
 341     if (version_id != FLIC_SAVEVM_VERSION) {
 342         r = -EINVAL;
 343         goto out;
 344     }
 345
 346     flic_enable_pfault((struct KVMS390FLICState *) opaque);
 347
 348     count = qemu_get_be64(f);
 349     len = count * sizeof(struct kvm_s390_irq);
 350     if (count == FLIC_FAILED) {
 351         r = -EINVAL;
 352         goto out;
 353     }
 354     if (count == 0) {
 355         r = 0;
 356         goto out;
 357     }
 358     buf = g_try_malloc0(len);
 359     if (!buf) {
 360         r = -ENOMEM;
 361         goto out;
 362     }
 363
 364     if (qemu_get_buffer(f, (uint8_t *) buf, len) != len) {
 365         r = -EINVAL;
 366         goto out_free;
 367     }
 368     r = flic_enqueue_irqs(buf, len, (struct KVMS390FLICState *) opaque);
 369
 370 out_free:
 371     g_free(buf);
 372 out:
 373     return r;
 374 }
 375
 376 static void kvm_s390_flic_realize(DeviceState *dev, Error **errp)
 377 {
 378     KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
 379     struct kvm_create_device cd = {0};
 380     struct kvm_device_attr test_attr = {0};
 381     int ret;
 382
 383     flic_state->fd = -1;
 384     if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
 385         trace_flic_no_device_api(errno);
 386         return;
 387     }
 388
 389     cd.type = KVM_DEV_TYPE_FLIC;
 390     ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
 391     if (ret < 0) {
 392         trace_flic_create_device(errno);
 393         return;
 394     }
 395     flic_state->fd = cd.fd;
 396
 397     /* Check clear_io_irq support */
 398     test_attr.group = KVM_DEV_FLIC_CLEAR_IO_IRQ;
 399     flic_state->clear_io_supported = !ioctl(flic_state->fd,
 400                                             KVM_HAS_DEVICE_ATTR, test_attr);
 401
 402     /* Register savevm handler for floating interrupts */
 403     register_savevm(NULL, "s390-flic", 0, 1, kvm_flic_save,
 404                     kvm_flic_load, (void *) flic_state);
 405 }
 406
 407 static void kvm_s390_flic_unrealize(DeviceState *dev, Error **errp)
 408 {
 409     KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
 410
 411     unregister_savevm(DEVICE(flic_state), "s390-flic", flic_state);
 412 }
 413
 414 static void kvm_s390_flic_reset(DeviceState *dev)
 415 {
 416     KVMS390FLICState *flic = KVM_S390_FLIC(dev);
 417     struct kvm_device_attr attr = {
 418         .group = KVM_DEV_FLIC_CLEAR_IRQS,
 419     };
 420     int rc = 0;
 421
 422     if (flic->fd == -1) {
 423         return;
 424     }
 425
 426     flic_disable_wait_pfault(flic);
 427
 428     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 429     if (rc) {
 430         trace_flic_reset_failed(errno);
 431     }
 432
 433     flic_enable_pfault(flic);
 434 }
 435
 436 static void kvm_s390_flic_class_init(ObjectClass *oc, void *data)
 437 {
 438     DeviceClass *dc = DEVICE_CLASS(oc);
 439     S390FLICStateClass *fsc = S390_FLIC_COMMON_CLASS(oc);
 440
 441     dc->realize = kvm_s390_flic_realize;
 442     dc->unrealize = kvm_s390_flic_unrealize;
 443     dc->reset = kvm_s390_flic_reset;
 444     fsc->register_io_adapter = kvm_s390_register_io_adapter;
 445     fsc->io_adapter_map = kvm_s390_io_adapter_map;
 446     fsc->add_adapter_routes = kvm_s390_add_adapter_routes;
 447     fsc->release_adapter_routes = kvm_s390_release_adapter_routes;
 448     fsc->clear_io_irq = kvm_s390_clear_io_flic;
 449 }
 450
 451 static const TypeInfo kvm_s390_flic_info = {
 452     .name          = TYPE_KVM_S390_FLIC,
 453     .parent        = TYPE_S390_FLIC_COMMON,
 454     .instance_size = sizeof(KVMS390FLICState),
 455     .class_init    = kvm_s390_flic_class_init,
 456 };
 457
 458 static void kvm_s390_flic_register_types(void)
 459 {
 460     type_register_static(&kvm_s390_flic_info);
 461 }
 462
 463 type_init(kvm_s390_flic_register_types)