drivers/s390/cio/vfio_ccw_ops.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Physical device callbacks for vfio_ccw
   4  *
   5  * Copyright IBM Corp. 2017
   6  *
   7  * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
   8  *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
   9  */
  10
  11 #include <linux/vfio.h>
  12 #include <linux/mdev.h>
  13
  14 #include "vfio_ccw_private.h"
  15
  16 static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
  17 {
  18         struct vfio_ccw_private *private;
  19         struct subchannel *sch;
  20         int ret;
  21
  22         private = dev_get_drvdata(mdev_parent_dev(mdev));
  23         sch = private->sch;
  24         /*
  25          * TODO:
  26          * In the cureent stage, some things like "no I/O running" and "no
  27          * interrupt pending" are clear, but we are not sure what other state
  28          * we need to care about.
  29          * There are still a lot more instructions need to be handled. We
  30          * should come back here later.
  31          */
  32         ret = vfio_ccw_sch_quiesce(sch);
  33         if (ret)
  34                 return ret;
  35
  36         ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
  37         if (!ret)
  38                 private->state = VFIO_CCW_STATE_IDLE;
  39
  40         return ret;
  41 }
  42
  43 static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
  44                                   unsigned long action,
  45                                   void *data)
  46 {
  47         struct vfio_ccw_private *private =
  48                 container_of(nb, struct vfio_ccw_private, nb);
  49
  50         /*
  51          * Vendor drivers MUST unpin pages in response to an
  52          * invalidation.
  53          */
  54         if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
  55                 struct vfio_iommu_type1_dma_unmap *unmap = data;
  56
  57                 if (!cp_iova_pinned(&private->cp, unmap->iova))
  58                         return NOTIFY_OK;
  59
  60                 if (vfio_ccw_mdev_reset(private->mdev))
  61                         return NOTIFY_BAD;
  62
  63                 cp_free(&private->cp);
  64                 return NOTIFY_OK;
  65         }
  66
  67         return NOTIFY_DONE;
  68 }
  69
  70 static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
  71 {
  72         return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
  73 }
  74 static MDEV_TYPE_ATTR_RO(name);
  75
  76 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
  77                                char *buf)
  78 {
  79         return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
  80 }
  81 static MDEV_TYPE_ATTR_RO(device_api);
  82
  83 static ssize_t available_instances_show(struct kobject *kobj,
  84                                         struct device *dev, char *buf)
  85 {
  86         struct vfio_ccw_private *private = dev_get_drvdata(dev);
  87
  88         return sprintf(buf, "%d\n", atomic_read(&private->avail));
  89 }
  90 static MDEV_TYPE_ATTR_RO(available_instances);
  91
  92 static struct attribute *mdev_types_attrs[] = {
  93         &mdev_type_attr_name.attr,
  94         &mdev_type_attr_device_api.attr,
  95         &mdev_type_attr_available_instances.attr,
  96         NULL,
  97 };
  98
  99 static struct attribute_group mdev_type_group = {
 100         .name  = "io",
 101         .attrs = mdev_types_attrs,
 102 };
 103
 104 static struct attribute_group *mdev_type_groups[] = {
 105         &mdev_type_group,
 106         NULL,
 107 };
 108
 109 static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
 110 {
 111         struct vfio_ccw_private *private =
 112                 dev_get_drvdata(mdev_parent_dev(mdev));
 113
 114         if (private->state == VFIO_CCW_STATE_NOT_OPER)
 115                 return -ENODEV;
 116
 117         if (atomic_dec_if_positive(&private->avail) < 0)
 118                 return -EPERM;
 119
 120         private->mdev = mdev;
 121         private->state = VFIO_CCW_STATE_IDLE;
 122
 123         return 0;
 124 }
 125
 126 static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
 127 {
 128         struct vfio_ccw_private *private =
 129                 dev_get_drvdata(mdev_parent_dev(mdev));
 130
 131         if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
 132             (private->state != VFIO_CCW_STATE_STANDBY)) {
 133                 if (!vfio_ccw_mdev_reset(mdev))
 134                         private->state = VFIO_CCW_STATE_STANDBY;
 135                 /* The state will be NOT_OPER on error. */
 136         }
 137
 138         private->mdev = NULL;
 139         atomic_inc(&private->avail);
 140
 141         return 0;
 142 }
 143
 144 static int vfio_ccw_mdev_open(struct mdev_device *mdev)
 145 {
 146         struct vfio_ccw_private *private =
 147                 dev_get_drvdata(mdev_parent_dev(mdev));
 148         unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
 149
 150         private->nb.notifier_call = vfio_ccw_mdev_notifier;
 151
 152         return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 153                                       &events, &private->nb);
 154 }
 155
 156 static void vfio_ccw_mdev_release(struct mdev_device *mdev)
 157 {
 158         struct vfio_ccw_private *private =
 159                 dev_get_drvdata(mdev_parent_dev(mdev));
 160
 161         vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 162                                  &private->nb);
 163 }
 164
 165 static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
 166                                   char __user *buf,
 167                                   size_t count,
 168                                   loff_t *ppos)
 169 {
 170         struct vfio_ccw_private *private;
 171         struct ccw_io_region *region;
 172
 173         if (*ppos + count > sizeof(*region))
 174                 return -EINVAL;
 175
 176         private = dev_get_drvdata(mdev_parent_dev(mdev));
 177         region = &private->io_region;
 178         if (copy_to_user(buf, (void *)region + *ppos, count))
 179                 return -EFAULT;
 180
 181         return count;
 182 }
 183
 184 static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
 185                                    const char __user *buf,
 186                                    size_t count,
 187                                    loff_t *ppos)
 188 {
 189         struct vfio_ccw_private *private;
 190         struct ccw_io_region *region;
 191
 192         if (*ppos + count > sizeof(*region))
 193                 return -EINVAL;
 194
 195         private = dev_get_drvdata(mdev_parent_dev(mdev));
 196         if (private->state != VFIO_CCW_STATE_IDLE)
 197                 return -EACCES;
 198
 199         region = &private->io_region;
 200         if (copy_from_user((void *)region + *ppos, buf, count))
 201                 return -EFAULT;
 202
 203         vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
 204         if (region->ret_code != 0) {
 205                 private->state = VFIO_CCW_STATE_IDLE;
 206                 return region->ret_code;
 207         }
 208
 209         return count;
 210 }
 211
 212 static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
 213 {
 214         info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
 215         info->num_regions = VFIO_CCW_NUM_REGIONS;
 216         info->num_irqs = VFIO_CCW_NUM_IRQS;
 217
 218         return 0;
 219 }
 220
 221 static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
 222                                          u16 *cap_type_id,
 223                                          void **cap_type)
 224 {
 225         switch (info->index) {
 226         case VFIO_CCW_CONFIG_REGION_INDEX:
 227                 info->offset = 0;
 228                 info->size = sizeof(struct ccw_io_region);
 229                 info->flags = VFIO_REGION_INFO_FLAG_READ
 230                               | VFIO_REGION_INFO_FLAG_WRITE;
 231                 return 0;
 232         default:
 233                 return -EINVAL;
 234         }
 235 }
 236
 237 static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
 238 {
 239         if (info->index != VFIO_CCW_IO_IRQ_INDEX)
 240                 return -EINVAL;
 241
 242         info->count = 1;
 243         info->flags = VFIO_IRQ_INFO_EVENTFD;
 244
 245         return 0;
 246 }
 247
 248 static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
 249                                   uint32_t flags,
 250                                   void __user *data)
 251 {
 252         struct vfio_ccw_private *private;
 253         struct eventfd_ctx **ctx;
 254
 255         if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
 256                 return -EINVAL;
 257
 258         private = dev_get_drvdata(mdev_parent_dev(mdev));
 259         ctx = &private->io_trigger;
 260
 261         switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
 262         case VFIO_IRQ_SET_DATA_NONE:
 263         {
 264                 if (*ctx)
 265                         eventfd_signal(*ctx, 1);
 266                 return 0;
 267         }
 268         case VFIO_IRQ_SET_DATA_BOOL:
 269         {
 270                 uint8_t trigger;
 271
 272                 if (get_user(trigger, (uint8_t __user *)data))
 273                         return -EFAULT;
 274
 275                 if (trigger && *ctx)
 276                         eventfd_signal(*ctx, 1);
 277                 return 0;
 278         }
 279         case VFIO_IRQ_SET_DATA_EVENTFD:
 280         {
 281                 int32_t fd;
 282
 283                 if (get_user(fd, (int32_t __user *)data))
 284                         return -EFAULT;
 285
 286                 if (fd == -1) {
 287                         if (*ctx)
 288                                 eventfd_ctx_put(*ctx);
 289                         *ctx = NULL;
 290                 } else if (fd >= 0) {
 291                         struct eventfd_ctx *efdctx;
 292
 293                         efdctx = eventfd_ctx_fdget(fd);
 294                         if (IS_ERR(efdctx))
 295                                 return PTR_ERR(efdctx);
 296
 297                         if (*ctx)
 298                                 eventfd_ctx_put(*ctx);
 299
 300                         *ctx = efdctx;
 301                 } else
 302                         return -EINVAL;
 303
 304                 return 0;
 305         }
 306         default:
 307                 return -EINVAL;
 308         }
 309 }
 310
 311 static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
 312                                    unsigned int cmd,
 313                                    unsigned long arg)
 314 {
 315         int ret = 0;
 316         unsigned long minsz;
 317
 318         switch (cmd) {
 319         case VFIO_DEVICE_GET_INFO:
 320         {
 321                 struct vfio_device_info info;
 322
 323                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 324
 325                 if (copy_from_user(&info, (void __user *)arg, minsz))
 326                         return -EFAULT;
 327
 328                 if (info.argsz < minsz)
 329                         return -EINVAL;
 330
 331                 ret = vfio_ccw_mdev_get_device_info(&info);
 332                 if (ret)
 333                         return ret;
 334
 335                 return copy_to_user((void __user *)arg, &info, minsz);
 336         }
 337         case VFIO_DEVICE_GET_REGION_INFO:
 338         {
 339                 struct vfio_region_info info;
 340                 u16 cap_type_id = 0;
 341                 void *cap_type = NULL;
 342
 343                 minsz = offsetofend(struct vfio_region_info, offset);
 344
 345                 if (copy_from_user(&info, (void __user *)arg, minsz))
 346                         return -EFAULT;
 347
 348                 if (info.argsz < minsz)
 349                         return -EINVAL;
 350
 351                 ret = vfio_ccw_mdev_get_region_info(&info, &cap_type_id,
 352                                                     &cap_type);
 353                 if (ret)
 354                         return ret;
 355
 356                 return copy_to_user((void __user *)arg, &info, minsz);
 357         }
 358         case VFIO_DEVICE_GET_IRQ_INFO:
 359         {
 360                 struct vfio_irq_info info;
 361
 362                 minsz = offsetofend(struct vfio_irq_info, count);
 363
 364                 if (copy_from_user(&info, (void __user *)arg, minsz))
 365                         return -EFAULT;
 366
 367                 if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
 368                         return -EINVAL;
 369
 370                 ret = vfio_ccw_mdev_get_irq_info(&info);
 371                 if (ret)
 372                         return ret;
 373
 374                 if (info.count == -1)
 375                         return -EINVAL;
 376
 377                 return copy_to_user((void __user *)arg, &info, minsz);
 378         }
 379         case VFIO_DEVICE_SET_IRQS:
 380         {
 381                 struct vfio_irq_set hdr;
 382                 size_t data_size;
 383                 void __user *data;
 384
 385                 minsz = offsetofend(struct vfio_irq_set, count);
 386
 387                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 388                         return -EFAULT;
 389
 390                 ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
 391                                                          VFIO_CCW_NUM_IRQS,
 392                                                          &data_size);
 393                 if (ret)
 394                         return ret;
 395
 396                 data = (void __user *)(arg + minsz);
 397                 return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
 398         }
 399         case VFIO_DEVICE_RESET:
 400                 return vfio_ccw_mdev_reset(mdev);
 401         default:
 402                 return -ENOTTY;
 403         }
 404 }
 405
 406 static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
 407         .owner                  = THIS_MODULE,
 408         .supported_type_groups  = mdev_type_groups,
 409         .create                 = vfio_ccw_mdev_create,
 410         .remove                 = vfio_ccw_mdev_remove,
 411         .open                   = vfio_ccw_mdev_open,
 412         .release                = vfio_ccw_mdev_release,
 413         .read                   = vfio_ccw_mdev_read,
 414         .write                  = vfio_ccw_mdev_write,
 415         .ioctl                  = vfio_ccw_mdev_ioctl,
 416 };
 417
 418 int vfio_ccw_mdev_reg(struct subchannel *sch)
 419 {
 420         return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
 421 }
 422
 423 void vfio_ccw_mdev_unreg(struct subchannel *sch)
 424 {
 425         mdev_unregister_device(&sch->dev);
 426 }