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