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_sch_quiesce(private->sch))
 134                         private->state = VFIO_CCW_STATE_STANDBY;
 135                 /* The state will be NOT_OPER on error. */
 136         }
 137
 138         cp_free(&private->cp);
 139         private->mdev = NULL;
 140         atomic_inc(&private->avail);
 141
 142         return 0;
 143 }
 144
 145 static int vfio_ccw_mdev_open(struct mdev_device *mdev)
 146 {
 147         struct vfio_ccw_private *private =
 148                 dev_get_drvdata(mdev_parent_dev(mdev));
 149         unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
 150
 151         private->nb.notifier_call = vfio_ccw_mdev_notifier;
 152
 153         return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 154                                       &events, &private->nb);
 155 }
 156
 157 static void vfio_ccw_mdev_release(struct mdev_device *mdev)
 158 {
 159         struct vfio_ccw_private *private =
 160                 dev_get_drvdata(mdev_parent_dev(mdev));
 161
 162         if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
 163             (private->state != VFIO_CCW_STATE_STANDBY)) {
 164                 if (!vfio_ccw_mdev_reset(mdev))
 165                         private->state = VFIO_CCW_STATE_STANDBY;
 166                 /* The state will be NOT_OPER on error. */
 167         }
 168
 169         cp_free(&private->cp);
 170         vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 171                                  &private->nb);
 172 }
 173
 174 static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
 175                                   char __user *buf,
 176                                   size_t count,
 177                                   loff_t *ppos)
 178 {
 179         struct vfio_ccw_private *private;
 180         struct ccw_io_region *region;
 181
 182         if (*ppos + count > sizeof(*region))
 183                 return -EINVAL;
 184
 185         private = dev_get_drvdata(mdev_parent_dev(mdev));
 186         region = private->io_region;
 187         if (copy_to_user(buf, (void *)region + *ppos, count))
 188                 return -EFAULT;
 189
 190         return count;
 191 }
 192
 193 static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
 194                                    const char __user *buf,
 195                                    size_t count,
 196                                    loff_t *ppos)
 197 {
 198         struct vfio_ccw_private *private;
 199         struct ccw_io_region *region;
 200
 201         if (*ppos + count > sizeof(*region))
 202                 return -EINVAL;
 203
 204         private = dev_get_drvdata(mdev_parent_dev(mdev));
 205         if (private->state != VFIO_CCW_STATE_IDLE)
 206                 return -EACCES;
 207
 208         region = private->io_region;
 209         if (copy_from_user((void *)region + *ppos, buf, count))
 210                 return -EFAULT;
 211
 212         vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
 213         if (region->ret_code != 0) {
 214                 private->state = VFIO_CCW_STATE_IDLE;
 215                 return region->ret_code;
 216         }
 217
 218         return count;
 219 }
 220
 221 static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
 222 {
 223         info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
 224         info->num_regions = VFIO_CCW_NUM_REGIONS;
 225         info->num_irqs = VFIO_CCW_NUM_IRQS;
 226
 227         return 0;
 228 }
 229
 230 static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
 231                                          u16 *cap_type_id,
 232                                          void **cap_type)
 233 {
 234         switch (info->index) {
 235         case VFIO_CCW_CONFIG_REGION_INDEX:
 236                 info->offset = 0;
 237                 info->size = sizeof(struct ccw_io_region);
 238                 info->flags = VFIO_REGION_INFO_FLAG_READ
 239                               | VFIO_REGION_INFO_FLAG_WRITE;
 240                 return 0;
 241         default:
 242                 return -EINVAL;
 243         }
 244 }
 245
 246 static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
 247 {
 248         if (info->index != VFIO_CCW_IO_IRQ_INDEX)
 249                 return -EINVAL;
 250
 251         info->count = 1;
 252         info->flags = VFIO_IRQ_INFO_EVENTFD;
 253
 254         return 0;
 255 }
 256
 257 static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
 258                                   uint32_t flags,
 259                                   void __user *data)
 260 {
 261         struct vfio_ccw_private *private;
 262         struct eventfd_ctx **ctx;
 263
 264         if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
 265                 return -EINVAL;
 266
 267         private = dev_get_drvdata(mdev_parent_dev(mdev));
 268         ctx = &private->io_trigger;
 269
 270         switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
 271         case VFIO_IRQ_SET_DATA_NONE:
 272         {
 273                 if (*ctx)
 274                         eventfd_signal(*ctx, 1);
 275                 return 0;
 276         }
 277         case VFIO_IRQ_SET_DATA_BOOL:
 278         {
 279                 uint8_t trigger;
 280
 281                 if (get_user(trigger, (uint8_t __user *)data))
 282                         return -EFAULT;
 283
 284                 if (trigger && *ctx)
 285                         eventfd_signal(*ctx, 1);
 286                 return 0;
 287         }
 288         case VFIO_IRQ_SET_DATA_EVENTFD:
 289         {
 290                 int32_t fd;
 291
 292                 if (get_user(fd, (int32_t __user *)data))
 293                         return -EFAULT;
 294
 295                 if (fd == -1) {
 296                         if (*ctx)
 297                                 eventfd_ctx_put(*ctx);
 298                         *ctx = NULL;
 299                 } else if (fd >= 0) {
 300                         struct eventfd_ctx *efdctx;
 301
 302                         efdctx = eventfd_ctx_fdget(fd);
 303                         if (IS_ERR(efdctx))
 304                                 return PTR_ERR(efdctx);
 305
 306                         if (*ctx)
 307                                 eventfd_ctx_put(*ctx);
 308
 309                         *ctx = efdctx;
 310                 } else
 311                         return -EINVAL;
 312
 313                 return 0;
 314         }
 315         default:
 316                 return -EINVAL;
 317         }
 318 }
 319
 320 static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
 321                                    unsigned int cmd,
 322                                    unsigned long arg)
 323 {
 324         int ret = 0;
 325         unsigned long minsz;
 326
 327         switch (cmd) {
 328         case VFIO_DEVICE_GET_INFO:
 329         {
 330                 struct vfio_device_info info;
 331
 332                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 333
 334                 if (copy_from_user(&info, (void __user *)arg, minsz))
 335                         return -EFAULT;
 336
 337                 if (info.argsz < minsz)
 338                         return -EINVAL;
 339
 340                 ret = vfio_ccw_mdev_get_device_info(&info);
 341                 if (ret)
 342                         return ret;
 343
 344                 return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
 345         }
 346         case VFIO_DEVICE_GET_REGION_INFO:
 347         {
 348                 struct vfio_region_info info;
 349                 u16 cap_type_id = 0;
 350                 void *cap_type = NULL;
 351
 352                 minsz = offsetofend(struct vfio_region_info, offset);
 353
 354                 if (copy_from_user(&info, (void __user *)arg, minsz))
 355                         return -EFAULT;
 356
 357                 if (info.argsz < minsz)
 358                         return -EINVAL;
 359
 360                 ret = vfio_ccw_mdev_get_region_info(&info, &cap_type_id,
 361                                                     &cap_type);
 362                 if (ret)
 363                         return ret;
 364
 365                 return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
 366         }
 367         case VFIO_DEVICE_GET_IRQ_INFO:
 368         {
 369                 struct vfio_irq_info info;
 370
 371                 minsz = offsetofend(struct vfio_irq_info, count);
 372
 373                 if (copy_from_user(&info, (void __user *)arg, minsz))
 374                         return -EFAULT;
 375
 376                 if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
 377                         return -EINVAL;
 378
 379                 ret = vfio_ccw_mdev_get_irq_info(&info);
 380                 if (ret)
 381                         return ret;
 382
 383                 if (info.count == -1)
 384                         return -EINVAL;
 385
 386                 return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
 387         }
 388         case VFIO_DEVICE_SET_IRQS:
 389         {
 390                 struct vfio_irq_set hdr;
 391                 size_t data_size;
 392                 void __user *data;
 393
 394                 minsz = offsetofend(struct vfio_irq_set, count);
 395
 396                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 397                         return -EFAULT;
 398
 399                 ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
 400                                                          VFIO_CCW_NUM_IRQS,
 401                                                          &data_size);
 402                 if (ret)
 403                         return ret;
 404
 405                 data = (void __user *)(arg + minsz);
 406                 return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
 407         }
 408         case VFIO_DEVICE_RESET:
 409                 return vfio_ccw_mdev_reset(mdev);
 410         default:
 411                 return -ENOTTY;
 412         }
 413 }
 414
 415 static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
 416         .owner                  = THIS_MODULE,
 417         .supported_type_groups  = mdev_type_groups,
 418         .create                 = vfio_ccw_mdev_create,
 419         .remove                 = vfio_ccw_mdev_remove,
 420         .open                   = vfio_ccw_mdev_open,
 421         .release                = vfio_ccw_mdev_release,
 422         .read                   = vfio_ccw_mdev_read,
 423         .write                  = vfio_ccw_mdev_write,
 424         .ioctl                  = vfio_ccw_mdev_ioctl,
 425 };
 426
 427 int vfio_ccw_mdev_reg(struct subchannel *sch)
 428 {
 429         return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
 430 }
 431
 432 void vfio_ccw_mdev_unreg(struct subchannel *sch)
 433 {
 434         mdev_unregister_device(&sch->dev);
 435 }