hw/vfio/ccw.c

   1 /*
   2  * vfio based subchannel assignment support
   3  *
   4  * Copyright 2017 IBM Corp.
   5  * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
   6  *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
   7  *            Pierre Morel <pmorel@linux.vnet.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or(at
  10  * your option) any version. See the COPYING file in the top-level
  11  * directory.
  12  */
  13
  14 #include <linux/vfio.h>
  15 #include <linux/vfio_ccw.h>
  16 #include <sys/ioctl.h>
  17
  18 #include "qemu/osdep.h"
  19 #include "qapi/error.h"
  20 #include "hw/sysbus.h"
  21 #include "hw/vfio/vfio.h"
  22 #include "hw/vfio/vfio-common.h"
  23 #include "hw/s390x/s390-ccw.h"
  24 #include "hw/s390x/ccw-device.h"
  25 #include "qemu/error-report.h"
  26
  27 #define TYPE_VFIO_CCW "vfio-ccw"
  28 typedef struct VFIOCCWDevice {
  29     S390CCWDevice cdev;
  30     VFIODevice vdev;
  31     uint64_t io_region_size;
  32     uint64_t io_region_offset;
  33     struct ccw_io_region *io_region;
  34     EventNotifier io_notifier;
  35 } VFIOCCWDevice;
  36
  37 static void vfio_ccw_compute_needs_reset(VFIODevice *vdev)
  38 {
  39     vdev->needs_reset = false;
  40 }
  41
  42 /*
  43  * We don't need vfio_hot_reset_multi and vfio_eoi operations for
  44  * vfio_ccw device now.
  45  */
  46 struct VFIODeviceOps vfio_ccw_ops = {
  47     .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset,
  48 };
  49
  50 static IOInstEnding vfio_ccw_handle_request(SubchDev *sch)
  51 {
  52     S390CCWDevice *cdev = sch->driver_data;
  53     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
  54     struct ccw_io_region *region = vcdev->io_region;
  55     int ret;
  56
  57     QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB));
  58     QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW));
  59     QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB));
  60
  61     memset(region, 0, sizeof(*region));
  62
  63     memcpy(region->orb_area, &sch->orb, sizeof(ORB));
  64     memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW));
  65
  66 again:
  67     ret = pwrite(vcdev->vdev.fd, region,
  68                  vcdev->io_region_size, vcdev->io_region_offset);
  69     if (ret != vcdev->io_region_size) {
  70         if (errno == EAGAIN) {
  71             goto again;
  72         }
  73         error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
  74         ret = -errno;
  75     } else {
  76         ret = region->ret_code;
  77     }
  78     switch (ret) {
  79     case 0:
  80         return IOINST_CC_EXPECTED;
  81     case -EBUSY:
  82         return IOINST_CC_BUSY;
  83     case -ENODEV:
  84     case -EACCES:
  85         return IOINST_CC_NOT_OPERATIONAL;
  86     case -EFAULT:
  87     default:
  88         sch_gen_unit_exception(sch);
  89         css_inject_io_interrupt(sch);
  90         return IOINST_CC_EXPECTED;
  91     }
  92 }
  93
  94 static void vfio_ccw_reset(DeviceState *dev)
  95 {
  96     CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
  97     S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
  98     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
  99
 100     ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
 101 }
 102
 103 static void vfio_ccw_io_notifier_handler(void *opaque)
 104 {
 105     VFIOCCWDevice *vcdev = opaque;
 106     struct ccw_io_region *region = vcdev->io_region;
 107     S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev);
 108     CcwDevice *ccw_dev = CCW_DEVICE(cdev);
 109     SubchDev *sch = ccw_dev->sch;
 110     SCSW *s = &sch->curr_status.scsw;
 111     PMCW *p = &sch->curr_status.pmcw;
 112     IRB irb;
 113     int size;
 114
 115     if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
 116         return;
 117     }
 118
 119     size = pread(vcdev->vdev.fd, region, vcdev->io_region_size,
 120                  vcdev->io_region_offset);
 121     if (size == -1) {
 122         switch (errno) {
 123         case ENODEV:
 124             /* Generate a deferred cc 3 condition. */
 125             s->flags |= SCSW_FLAGS_MASK_CC;
 126             s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
 127             s->ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
 128             goto read_err;
 129         case EFAULT:
 130             /* Memory problem, generate channel data check. */
 131             s->ctrl &= ~SCSW_ACTL_START_PEND;
 132             s->cstat = SCSW_CSTAT_DATA_CHECK;
 133             s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
 134             s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
 135                        SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
 136             goto read_err;
 137         default:
 138             /* Error, generate channel program check. */
 139             s->ctrl &= ~SCSW_ACTL_START_PEND;
 140             s->cstat = SCSW_CSTAT_PROG_CHECK;
 141             s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
 142             s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
 143                        SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
 144             goto read_err;
 145         }
 146     } else if (size != vcdev->io_region_size) {
 147         /* Information transfer error, generate channel-control check. */
 148         s->ctrl &= ~SCSW_ACTL_START_PEND;
 149         s->cstat = SCSW_CSTAT_CHN_CTRL_CHK;
 150         s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
 151         s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
 152                    SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
 153         goto read_err;
 154     }
 155
 156     memcpy(&irb, region->irb_area, sizeof(IRB));
 157
 158     /* Update control block via irb. */
 159     copy_scsw_to_guest(s, &irb.scsw);
 160
 161     /* If a uint check is pending, copy sense data. */
 162     if ((s->dstat & SCSW_DSTAT_UNIT_CHECK) &&
 163         (p->chars & PMCW_CHARS_MASK_CSENSE)) {
 164         memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw));
 165     }
 166
 167 read_err:
 168     css_inject_io_interrupt(sch);
 169 }
 170
 171 static void vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error **errp)
 172 {
 173     VFIODevice *vdev = &vcdev->vdev;
 174     struct vfio_irq_info *irq_info;
 175     struct vfio_irq_set *irq_set;
 176     size_t argsz;
 177     int32_t *pfd;
 178
 179     if (vdev->num_irqs < VFIO_CCW_IO_IRQ_INDEX + 1) {
 180         error_setg(errp, "vfio: unexpected number of io irqs %u",
 181                    vdev->num_irqs);
 182         return;
 183     }
 184
 185     argsz = sizeof(*irq_info);
 186     irq_info = g_malloc0(argsz);
 187     irq_info->index = VFIO_CCW_IO_IRQ_INDEX;
 188     irq_info->argsz = argsz;
 189     if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
 190               irq_info) < 0 || irq_info->count < 1) {
 191         error_setg_errno(errp, errno, "vfio: Error getting irq info");
 192         goto out_free_info;
 193     }
 194
 195     if (event_notifier_init(&vcdev->io_notifier, 0)) {
 196         error_setg_errno(errp, errno,
 197                          "vfio: Unable to init event notifier for IO");
 198         goto out_free_info;
 199     }
 200
 201     argsz = sizeof(*irq_set) + sizeof(*pfd);
 202     irq_set = g_malloc0(argsz);
 203     irq_set->argsz = argsz;
 204     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
 205                      VFIO_IRQ_SET_ACTION_TRIGGER;
 206     irq_set->index = VFIO_CCW_IO_IRQ_INDEX;
 207     irq_set->start = 0;
 208     irq_set->count = 1;
 209     pfd = (int32_t *) &irq_set->data;
 210
 211     *pfd = event_notifier_get_fd(&vcdev->io_notifier);
 212     qemu_set_fd_handler(*pfd, vfio_ccw_io_notifier_handler, NULL, vcdev);
 213     if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
 214         error_setg(errp, "vfio: Failed to set up io notification");
 215         qemu_set_fd_handler(*pfd, NULL, NULL, vcdev);
 216         event_notifier_cleanup(&vcdev->io_notifier);
 217     }
 218
 219     g_free(irq_set);
 220
 221 out_free_info:
 222     g_free(irq_info);
 223 }
 224
 225 static void vfio_ccw_unregister_io_notifier(VFIOCCWDevice *vcdev)
 226 {
 227     struct vfio_irq_set *irq_set;
 228     size_t argsz;
 229     int32_t *pfd;
 230
 231     argsz = sizeof(*irq_set) + sizeof(*pfd);
 232     irq_set = g_malloc0(argsz);
 233     irq_set->argsz = argsz;
 234     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
 235                      VFIO_IRQ_SET_ACTION_TRIGGER;
 236     irq_set->index = VFIO_CCW_IO_IRQ_INDEX;
 237     irq_set->start = 0;
 238     irq_set->count = 1;
 239     pfd = (int32_t *) &irq_set->data;
 240     *pfd = -1;
 241
 242     if (ioctl(vcdev->vdev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
 243         error_report("vfio: Failed to de-assign device io fd: %m");
 244     }
 245
 246     qemu_set_fd_handler(event_notifier_get_fd(&vcdev->io_notifier),
 247                         NULL, NULL, vcdev);
 248     event_notifier_cleanup(&vcdev->io_notifier);
 249
 250     g_free(irq_set);
 251 }
 252
 253 static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
 254 {
 255     VFIODevice *vdev = &vcdev->vdev;
 256     struct vfio_region_info *info;
 257     int ret;
 258
 259     /* Sanity check device */
 260     if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) {
 261         error_setg(errp, "vfio: Um, this isn't a vfio-ccw device");
 262         return;
 263     }
 264
 265     if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) {
 266         error_setg(errp, "vfio: Unexpected number of the I/O region %u",
 267                    vdev->num_regions);
 268         return;
 269     }
 270
 271     ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info);
 272     if (ret) {
 273         error_setg_errno(errp, -ret, "vfio: Error getting config info");
 274         return;
 275     }
 276
 277     vcdev->io_region_size = info->size;
 278     if (sizeof(*vcdev->io_region) != vcdev->io_region_size) {
 279         error_setg(errp, "vfio: Unexpected size of the I/O region");
 280         g_free(info);
 281         return;
 282     }
 283
 284     vcdev->io_region_offset = info->offset;
 285     vcdev->io_region = g_malloc0(info->size);
 286
 287     g_free(info);
 288 }
 289
 290 static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
 291 {
 292     g_free(vcdev->io_region);
 293 }
 294
 295 static void vfio_put_device(VFIOCCWDevice *vcdev)
 296 {
 297     g_free(vcdev->vdev.name);
 298     vfio_put_base_device(&vcdev->vdev);
 299 }
 300
 301 static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp)
 302 {
 303     char *tmp, group_path[PATH_MAX];
 304     ssize_t len;
 305     int groupid;
 306
 307     tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group",
 308                           cdev->hostid.cssid, cdev->hostid.ssid,
 309                           cdev->hostid.devid, cdev->mdevid);
 310     len = readlink(tmp, group_path, sizeof(group_path));
 311     g_free(tmp);
 312
 313     if (len <= 0 || len >= sizeof(group_path)) {
 314         error_setg(errp, "vfio: no iommu_group found");
 315         return NULL;
 316     }
 317
 318     group_path[len] = 0;
 319
 320     if (sscanf(basename(group_path), "%d", &groupid) != 1) {
 321         error_setg(errp, "vfio: failed to read %s", group_path);
 322         return NULL;
 323     }
 324
 325     return vfio_get_group(groupid, &address_space_memory, errp);
 326 }
 327
 328 static void vfio_ccw_realize(DeviceState *dev, Error **errp)
 329 {
 330     VFIODevice *vbasedev;
 331     VFIOGroup *group;
 332     CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
 333     S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
 334     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
 335     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
 336     Error *err = NULL;
 337
 338     /* Call the class init function for subchannel. */
 339     if (cdc->realize) {
 340         cdc->realize(cdev, vcdev->vdev.sysfsdev, &err);
 341         if (err) {
 342             goto out_err_propagate;
 343         }
 344     }
 345
 346     group = vfio_ccw_get_group(cdev, &err);
 347     if (!group) {
 348         goto out_group_err;
 349     }
 350
 351     vcdev->vdev.ops = &vfio_ccw_ops;
 352     vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW;
 353     vcdev->vdev.name = g_strdup_printf("%x.%x.%04x", cdev->hostid.cssid,
 354                                        cdev->hostid.ssid, cdev->hostid.devid);
 355     vcdev->vdev.dev = dev;
 356     QLIST_FOREACH(vbasedev, &group->device_list, next) {
 357         if (strcmp(vbasedev->name, vcdev->vdev.name) == 0) {
 358             error_setg(&err, "vfio: subchannel %s has already been attached",
 359                        vcdev->vdev.name);
 360             goto out_device_err;
 361         }
 362     }
 363
 364     if (vfio_get_device(group, cdev->mdevid, &vcdev->vdev, &err)) {
 365         goto out_device_err;
 366     }
 367
 368     vfio_ccw_get_region(vcdev, &err);
 369     if (err) {
 370         goto out_region_err;
 371     }
 372
 373     vfio_ccw_register_io_notifier(vcdev, &err);
 374     if (err) {
 375         goto out_notifier_err;
 376     }
 377
 378     return;
 379
 380 out_notifier_err:
 381     vfio_ccw_put_region(vcdev);
 382 out_region_err:
 383     vfio_put_device(vcdev);
 384 out_device_err:
 385     vfio_put_group(group);
 386 out_group_err:
 387     if (cdc->unrealize) {
 388         cdc->unrealize(cdev, NULL);
 389     }
 390 out_err_propagate:
 391     error_propagate(errp, err);
 392 }
 393
 394 static void vfio_ccw_unrealize(DeviceState *dev, Error **errp)
 395 {
 396     CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
 397     S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
 398     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
 399     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
 400     VFIOGroup *group = vcdev->vdev.group;
 401
 402     vfio_ccw_unregister_io_notifier(vcdev);
 403     vfio_ccw_put_region(vcdev);
 404     vfio_put_device(vcdev);
 405     vfio_put_group(group);
 406
 407     if (cdc->unrealize) {
 408         cdc->unrealize(cdev, errp);
 409     }
 410 }
 411
 412 static Property vfio_ccw_properties[] = {
 413     DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev),
 414     DEFINE_PROP_END_OF_LIST(),
 415 };
 416
 417 static const VMStateDescription vfio_ccw_vmstate = {
 418     .name = TYPE_VFIO_CCW,
 419     .unmigratable = 1,
 420 };
 421
 422 static void vfio_ccw_class_init(ObjectClass *klass, void *data)
 423 {
 424     DeviceClass *dc = DEVICE_CLASS(klass);
 425     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
 426
 427     dc->props = vfio_ccw_properties;
 428     dc->vmsd = &vfio_ccw_vmstate;
 429     dc->desc = "VFIO-based subchannel assignment";
 430     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 431     dc->realize = vfio_ccw_realize;
 432     dc->unrealize = vfio_ccw_unrealize;
 433     dc->reset = vfio_ccw_reset;
 434
 435     cdc->handle_request = vfio_ccw_handle_request;
 436 }
 437
 438 static const TypeInfo vfio_ccw_info = {
 439     .name = TYPE_VFIO_CCW,
 440     .parent = TYPE_S390_CCW,
 441     .instance_size = sizeof(VFIOCCWDevice),
 442     .class_init = vfio_ccw_class_init,
 443 };
 444
 445 static void register_vfio_ccw_type(void)
 446 {
 447     type_register_static(&vfio_ccw_info);
 448 }
 449
 450 type_init(register_vfio_ccw_type)