drivers/s390/cio/vfio_ccw_ops.c

   1 /*
   2  * Physical device callbacks for vfio_ccw
   3  *
   4  * Copyright IBM Corp. 2017
   5  *
   6  * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
   7  *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
   8  */
   9
  10 #include <linux/vfio.h>
  11 #include <linux/mdev.h>
  12
  13 #include "vfio_ccw_private.h"
  14
  15 static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
  16 {
  17         struct vfio_ccw_private *private;
  18         struct subchannel *sch;
  19         int ret;
  20
  21         private = dev_get_drvdata(mdev_parent_dev(mdev));
  22         sch = private->sch;
  23         /*
  24          * TODO:
  25          * In the cureent stage, some things like "no I/O running" and "no
  26          * interrupt pending" are clear, but we are not sure what other state
  27          * we need to care about.
  28          * There are still a lot more instructions need to be handled. We
  29          * should come back here later.
  30          */
  31         ret = vfio_ccw_sch_quiesce(sch);
  32         if (ret)
  33                 return ret;
  34
  35         ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
  36         if (!ret)
  37                 private->state = VFIO_CCW_STATE_IDLE;
  38
  39         return ret;
  40 }
  41
  42 static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
  43                                   unsigned long action,
  44                                   void *data)
  45 {
  46         struct vfio_ccw_private *private =
  47                 container_of(nb, struct vfio_ccw_private, nb);
  48
  49         /*
  50          * Vendor drivers MUST unpin pages in response to an
  51          * invalidation.
  52          */
  53         if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
  54                 struct vfio_iommu_type1_dma_unmap *unmap = data;
  55
  56                 if (!cp_iova_pinned(&private->cp, unmap->iova))
  57                         return NOTIFY_OK;
  58
  59                 if (vfio_ccw_mdev_reset(private->mdev))
  60                         return NOTIFY_BAD;
  61
  62                 cp_free(&private->cp);
  63                 return NOTIFY_OK;
  64         }
  65
  66         return NOTIFY_DONE;
  67 }
  68
  69 static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
  70 {
  71         return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
  72 }
  73 static MDEV_TYPE_ATTR_RO(name);
  74
  75 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
  76                                char *buf)
  77 {
  78         return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
  79 }
  80 static MDEV_TYPE_ATTR_RO(device_api);
  81
  82 static ssize_t available_instances_show(struct kobject *kobj,
  83                                         struct device *dev, char *buf)
  84 {
  85         struct vfio_ccw_private *private = dev_get_drvdata(dev);
  86
  87         return sprintf(buf, "%d\n", atomic_read(&private->avail));
  88 }
  89 static MDEV_TYPE_ATTR_RO(available_instances);
  90
  91 static struct attribute *mdev_types_attrs[] = {
  92         &mdev_type_attr_name.attr,
  93         &mdev_type_attr_device_api.attr,
  94         &mdev_type_attr_available_instances.attr,
  95         NULL,
  96 };
  97
  98 static struct attribute_group mdev_type_group = {
  99         .name  = "io",
 100         .attrs = mdev_types_attrs,
 101 };
 102
 103 static struct attribute_group *mdev_type_groups[] = {
 104         &mdev_type_group,
 105         NULL,
 106 };
 107
 108 static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
 109 {
 110         struct vfio_ccw_private *private =
 111                 dev_get_drvdata(mdev_parent_dev(mdev));
 112
 113         if (private->state == VFIO_CCW_STATE_NOT_OPER)
 114                 return -ENODEV;
 115
 116         if (atomic_dec_if_positive(&private->avail) < 0)
 117                 return -EPERM;
 118
 119         private->mdev = mdev;
 120         private->state = VFIO_CCW_STATE_IDLE;
 121
 122         return 0;
 123 }
 124
 125 static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
 126 {
 127         struct vfio_ccw_private *private =
 128                 dev_get_drvdata(mdev_parent_dev(mdev));
 129
 130         if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
 131             (private->state != VFIO_CCW_STATE_STANDBY)) {
 132                 if (!vfio_ccw_mdev_reset(mdev))
 133                         private->state = VFIO_CCW_STATE_STANDBY;
 134                 /* The state will be NOT_OPER on error. */
 135         }
 136
 137         private->mdev = NULL;
 138         atomic_inc(&private->avail);
 139
 140         return 0;
 141 }
 142
 143 static int vfio_ccw_mdev_open(struct mdev_device *mdev)
 144 {
 145         struct vfio_ccw_private *private =
 146                 dev_get_drvdata(mdev_parent_dev(mdev));
 147         unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
 148
 149         private->nb.notifier_call = vfio_ccw_mdev_notifier;
 150
 151         return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 152                                       &events, &private->nb);
 153 }
 154
 155 static void vfio_ccw_mdev_release(struct mdev_device *mdev)
 156 {
 157         struct vfio_ccw_private *private =
 158                 dev_get_drvdata(mdev_parent_dev(mdev));
 159
 160         vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 161                                  &private->nb);
 162 }
 163
 164 static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
 165                                   char __user *buf,
 166                                   size_t count,
 167                                   loff_t *ppos)
 168 {
 169         struct vfio_ccw_private *private;
 170         struct ccw_io_region *region;
 171
 172         if (*ppos + count > sizeof(*region))
 173                 return -EINVAL;
 174
 175         private = dev_get_drvdata(mdev_parent_dev(mdev));
 176         region = &private->io_region;
 177         if (copy_to_user(buf, (void *)region + *ppos, count))
 178                 return -EFAULT;
 179
 180         return count;
 181 }
 182
 183 static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
 184                                    const char __user *buf,
 185                                    size_t count,
 186                                    loff_t *ppos)
 187 {
 188         struct vfio_ccw_private *private;
 189         struct ccw_io_region *region;
 190
 191         if (*ppos + count > sizeof(*region))
 192                 return -EINVAL;
 193
 194         private = dev_get_drvdata(mdev_parent_dev(mdev));
 195         if (private->state != VFIO_CCW_STATE_IDLE)
 196                 return -EACCES;
 197
 198         region = &private->io_region;
 199         if (copy_from_user((void *)region + *ppos, buf, count))
 200                 return -EFAULT;
 201
 202         vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
 203         if (region->ret_code != 0) {
 204                 private->state = VFIO_CCW_STATE_IDLE;
 205                 return region->ret_code;
 206         }
 207
 208         return count;
 209 }
 210
 211 static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
 212 {
 213         info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
 214         info->num_regions = VFIO_CCW_NUM_REGIONS;
 215         info->num_irqs = VFIO_CCW_NUM_IRQS;
 216
 217         return 0;
 218 }
 219
 220 static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
 221                                          u16 *cap_type_id,
 222                                          void **cap_type)
 223 {
 224         switch (info->index) {
 225         case VFIO_CCW_CONFIG_REGION_INDEX:
 226                 info->offset = 0;
 227                 info->size = sizeof(struct ccw_io_region);
 228                 info->flags = VFIO_REGION_INFO_FLAG_READ
 229                               | VFIO_REGION_INFO_FLAG_WRITE;
 230                 return 0;
 231         default:
 232                 return -EINVAL;
 233         }
 234 }
 235
 236 static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
 237 {
 238         if (info->index != VFIO_CCW_IO_IRQ_INDEX)
 239                 return -EINVAL;
 240
 241         info->count = 1;
 242         info->flags = VFIO_IRQ_INFO_EVENTFD;
 243
 244         return 0;
 245 }
 246
 247 static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
 248                                   uint32_t flags,
 249                                   void __user *data)
 250 {
 251         struct vfio_ccw_private *private;
 252         struct eventfd_ctx **ctx;
 253
 254         if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
 255                 return -EINVAL;
 256
 257         private = dev_get_drvdata(mdev_parent_dev(mdev));
 258         ctx = &private->io_trigger;
 259
 260         switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
 261         case VFIO_IRQ_SET_DATA_NONE:
 262         {
 263                 if (*ctx)
 264                         eventfd_signal(*ctx, 1);
 265                 return 0;
 266         }
 267         case VFIO_IRQ_SET_DATA_BOOL:
 268         {
 269                 uint8_t trigger;
 270
 271                 if (get_user(trigger, (uint8_t __user *)data))
 272                         return -EFAULT;
 273
 274                 if (trigger && *ctx)
 275                         eventfd_signal(*ctx, 1);
 276                 return 0;
 277         }
 278         case VFIO_IRQ_SET_DATA_EVENTFD:
 279         {
 280                 int32_t fd;
 281
 282                 if (get_user(fd, (int32_t __user *)data))
 283                         return -EFAULT;
 284
 285                 if (fd == -1) {
 286                         if (*ctx)
 287                                 eventfd_ctx_put(*ctx);
 288                         *ctx = NULL;
 289                 } else if (fd >= 0) {
 290                         struct eventfd_ctx *efdctx;
 291
 292                         efdctx = eventfd_ctx_fdget(fd);
 293                         if (IS_ERR(efdctx))
 294                                 return PTR_ERR(efdctx);
 295
 296                         if (*ctx)
 297                                 eventfd_ctx_put(*ctx);
 298
 299                         *ctx = efdctx;
 300                 } else
 301                         return -EINVAL;
 302
 303                 return 0;
 304         }
 305         default:
 306                 return -EINVAL;
 307         }
 308 }
 309
 310 static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
 311                                    unsigned int cmd,
 312                                    unsigned long arg)
 313 {
 314         int ret = 0;
 315         unsigned long minsz;
 316
 317         switch (cmd) {
 318         case VFIO_DEVICE_GET_INFO:
 319         {
 320                 struct vfio_device_info info;
 321
 322                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 323
 324                 if (copy_from_user(&info, (void __user *)arg, minsz))
 325                         return -EFAULT;
 326
 327                 if (info.argsz < minsz)
 328                         return -EINVAL;
 329
 330                 ret = vfio_ccw_mdev_get_device_info(&info);
 331                 if (ret)
 332                         return ret;
 333
 334                 return copy_to_user((void __user *)arg, &info, minsz);
 335         }
 336         case VFIO_DEVICE_GET_REGION_INFO:
 337         {
 338                 struct vfio_region_info info;
 339                 u16 cap_type_id = 0;
 340                 void *cap_type = NULL;
 341
 342                 minsz = offsetofend(struct vfio_region_info, offset);
 343
 344                 if (copy_from_user(&info, (void __user *)arg, minsz))
 345                         return -EFAULT;
 346
 347                 if (info.argsz < minsz)
 348                         return -EINVAL;
 349
 350                 ret = vfio_ccw_mdev_get_region_info(&info, &cap_type_id,
 351                                                     &cap_type);
 352                 if (ret)
 353                         return ret;
 354
 355                 return copy_to_user((void __user *)arg, &info, minsz);
 356         }
 357         case VFIO_DEVICE_GET_IRQ_INFO:
 358         {
 359                 struct vfio_irq_info info;
 360
 361                 minsz = offsetofend(struct vfio_irq_info, count);
 362
 363                 if (copy_from_user(&info, (void __user *)arg, minsz))
 364                         return -EFAULT;
 365
 366                 if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
 367                         return -EINVAL;
 368
 369                 ret = vfio_ccw_mdev_get_irq_info(&info);
 370                 if (ret)
 371                         return ret;
 372
 373                 if (info.count == -1)
 374                         return -EINVAL;
 375
 376                 return copy_to_user((void __user *)arg, &info, minsz);
 377         }
 378         case VFIO_DEVICE_SET_IRQS:
 379         {
 380                 struct vfio_irq_set hdr;
 381                 size_t data_size;
 382                 void __user *data;
 383
 384                 minsz = offsetofend(struct vfio_irq_set, count);
 385
 386                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 387                         return -EFAULT;
 388
 389                 ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
 390                                                          VFIO_CCW_NUM_IRQS,
 391                                                          &data_size);
 392                 if (ret)
 393                         return ret;
 394
 395                 data = (void __user *)(arg + minsz);
 396                 return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
 397         }
 398         case VFIO_DEVICE_RESET:
 399                 return vfio_ccw_mdev_reset(mdev);
 400         default:
 401                 return -ENOTTY;
 402         }
 403 }
 404
 405 static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
 406         .owner                  = THIS_MODULE,
 407         .supported_type_groups  = mdev_type_groups,
 408         .create                 = vfio_ccw_mdev_create,
 409         .remove                 = vfio_ccw_mdev_remove,
 410         .open                   = vfio_ccw_mdev_open,
 411         .release                = vfio_ccw_mdev_release,
 412         .read                   = vfio_ccw_mdev_read,
 413         .write                  = vfio_ccw_mdev_write,
 414         .ioctl                  = vfio_ccw_mdev_ioctl,
 415 };
 416
 417 int vfio_ccw_mdev_reg(struct subchannel *sch)
 418 {
 419         return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
 420 }
 421
 422 void vfio_ccw_mdev_unreg(struct subchannel *sch)
 423 {
 424         mdev_unregister_device(&sch->dev);
 425 }