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