include/linux/vdpa.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_VDPA_H
   3 #define _LINUX_VDPA_H
   4
   5 #include <linux/kernel.h>
   6 #include <linux/device.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/vhost_iotlb.h>
   9
  10 /**
  11  * struct vdpa_calllback - vDPA callback definition.
  12  * @callback: interrupt callback function
  13  * @private: the data passed to the callback function
  14  */
  15 struct vdpa_callback {
  16         irqreturn_t (*callback)(void *data);
  17         void *private;
  18 };
  19
  20 /**
  21  * struct vdpa_notification_area - vDPA notification area
  22  * @addr: base address of the notification area
  23  * @size: size of the notification area
  24  */
  25 struct vdpa_notification_area {
  26         resource_size_t addr;
  27         resource_size_t size;
  28 };
  29
  30 /**
  31  * struct vdpa_vq_state_split - vDPA split virtqueue state
  32  * @avail_index: available index
  33  */
  34 struct vdpa_vq_state_split {
  35         u16     avail_index;
  36 };
  37
  38 /**
  39  * struct vdpa_vq_state_packed - vDPA packed virtqueue state
  40  * @last_avail_counter: last driver ring wrap counter observed by device
  41  * @last_avail_idx: device available index
  42  * @last_used_counter: device ring wrap counter
  43  * @last_used_idx: used index
  44  */
  45 struct vdpa_vq_state_packed {
  46         u16     last_avail_counter:1;
  47         u16     last_avail_idx:15;
  48         u16     last_used_counter:1;
  49         u16     last_used_idx:15;
  50 };
  51
  52 struct vdpa_vq_state {
  53      union {
  54           struct vdpa_vq_state_split split;
  55           struct vdpa_vq_state_packed packed;
  56      };
  57 };
  58
  59 struct vdpa_mgmt_dev;
  60
  61 /**
  62  * struct vdpa_device - representation of a vDPA device
  63  * @dev: underlying device
  64  * @dma_dev: the actual device that is performing DMA
  65  * @config: the configuration ops for this device.
  66  * @index: device index
  67  * @features_valid: were features initialized? for legacy guests
  68  * @nvqs: maximum number of supported virtqueues
  69  * @mdev: management device pointer; caller must setup when registering device as part
  70  *        of dev_add() mgmtdev ops callback before invoking _vdpa_register_device().
  71  */
  72 struct vdpa_device {
  73         struct device dev;
  74         struct device *dma_dev;
  75         const struct vdpa_config_ops *config;
  76         unsigned int index;
  77         bool features_valid;
  78         int nvqs;
  79         struct vdpa_mgmt_dev *mdev;
  80 };
  81
  82 /**
  83  * struct vdpa_iova_range - the IOVA range support by the device
  84  * @first: start of the IOVA range
  85  * @last: end of the IOVA range
  86  */
  87 struct vdpa_iova_range {
  88         u64 first;
  89         u64 last;
  90 };
  91
  92 /**
  93  * struct vdpa_config_ops - operations for configuring a vDPA device.
  94  * Note: vDPA device drivers are required to implement all of the
  95  * operations unless it is mentioned to be optional in the following
  96  * list.
  97  *
  98  * @set_vq_address:             Set the address of virtqueue
  99  *                              @vdev: vdpa device
 100  *                              @idx: virtqueue index
 101  *                              @desc_area: address of desc area
 102  *                              @driver_area: address of driver area
 103  *                              @device_area: address of device area
 104  *                              Returns integer: success (0) or error (< 0)
 105  * @set_vq_num:                 Set the size of virtqueue
 106  *                              @vdev: vdpa device
 107  *                              @idx: virtqueue index
 108  *                              @num: the size of virtqueue
 109  * @kick_vq:                    Kick the virtqueue
 110  *                              @vdev: vdpa device
 111  *                              @idx: virtqueue index
 112  * @set_vq_cb:                  Set the interrupt callback function for
 113  *                              a virtqueue
 114  *                              @vdev: vdpa device
 115  *                              @idx: virtqueue index
 116  *                              @cb: virtio-vdev interrupt callback structure
 117  * @set_vq_ready:               Set ready status for a virtqueue
 118  *                              @vdev: vdpa device
 119  *                              @idx: virtqueue index
 120  *                              @ready: ready (true) not ready(false)
 121  * @get_vq_ready:               Get ready status for a virtqueue
 122  *                              @vdev: vdpa device
 123  *                              @idx: virtqueue index
 124  *                              Returns boolean: ready (true) or not (false)
 125  * @set_vq_state:               Set the state for a virtqueue
 126  *                              @vdev: vdpa device
 127  *                              @idx: virtqueue index
 128  *                              @state: pointer to set virtqueue state (last_avail_idx)
 129  *                              Returns integer: success (0) or error (< 0)
 130  * @get_vq_state:               Get the state for a virtqueue
 131  *                              @vdev: vdpa device
 132  *                              @idx: virtqueue index
 133  *                              @state: pointer to returned state (last_avail_idx)
 134  * @get_vq_notification:        Get the notification area for a virtqueue
 135  *                              @vdev: vdpa device
 136  *                              @idx: virtqueue index
 137  *                              Returns the notifcation area
 138  * @get_vq_irq:                 Get the irq number of a virtqueue (optional,
 139  *                              but must implemented if require vq irq offloading)
 140  *                              @vdev: vdpa device
 141  *                              @idx: virtqueue index
 142  *                              Returns int: irq number of a virtqueue,
 143  *                              negative number if no irq assigned.
 144  * @get_vq_align:               Get the virtqueue align requirement
 145  *                              for the device
 146  *                              @vdev: vdpa device
 147  *                              Returns virtqueue algin requirement
 148  * @get_features:               Get virtio features supported by the device
 149  *                              @vdev: vdpa device
 150  *                              Returns the virtio features support by the
 151  *                              device
 152  * @set_features:               Set virtio features supported by the driver
 153  *                              @vdev: vdpa device
 154  *                              @features: feature support by the driver
 155  *                              Returns integer: success (0) or error (< 0)
 156  * @set_config_cb:              Set the config interrupt callback
 157  *                              @vdev: vdpa device
 158  *                              @cb: virtio-vdev interrupt callback structure
 159  * @get_vq_num_max:             Get the max size of virtqueue
 160  *                              @vdev: vdpa device
 161  *                              Returns u16: max size of virtqueue
 162  * @get_device_id:              Get virtio device id
 163  *                              @vdev: vdpa device
 164  *                              Returns u32: virtio device id
 165  * @get_vendor_id:              Get id for the vendor that provides this device
 166  *                              @vdev: vdpa device
 167  *                              Returns u32: virtio vendor id
 168  * @get_status:                 Get the device status
 169  *                              @vdev: vdpa device
 170  *                              Returns u8: virtio device status
 171  * @set_status:                 Set the device status
 172  *                              @vdev: vdpa device
 173  *                              @status: virtio device status
 174  * @get_config_size:            Get the size of the configuration space
 175  *                              @vdev: vdpa device
 176  *                              Returns size_t: configuration size
 177  * @get_config:                 Read from device specific configuration space
 178  *                              @vdev: vdpa device
 179  *                              @offset: offset from the beginning of
 180  *                              configuration space
 181  *                              @buf: buffer used to read to
 182  *                              @len: the length to read from
 183  *                              configuration space
 184  * @set_config:                 Write to device specific configuration space
 185  *                              @vdev: vdpa device
 186  *                              @offset: offset from the beginning of
 187  *                              configuration space
 188  *                              @buf: buffer used to write from
 189  *                              @len: the length to write to
 190  *                              configuration space
 191  * @get_generation:             Get device config generation (optional)
 192  *                              @vdev: vdpa device
 193  *                              Returns u32: device generation
 194  * @get_iova_range:             Get supported iova range (optional)
 195  *                              @vdev: vdpa device
 196  *                              Returns the iova range supported by
 197  *                              the device.
 198  * @set_map:                    Set device memory mapping (optional)
 199  *                              Needed for device that using device
 200  *                              specific DMA translation (on-chip IOMMU)
 201  *                              @vdev: vdpa device
 202  *                              @iotlb: vhost memory mapping to be
 203  *                              used by the vDPA
 204  *                              Returns integer: success (0) or error (< 0)
 205  * @dma_map:                    Map an area of PA to IOVA (optional)
 206  *                              Needed for device that using device
 207  *                              specific DMA translation (on-chip IOMMU)
 208  *                              and preferring incremental map.
 209  *                              @vdev: vdpa device
 210  *                              @iova: iova to be mapped
 211  *                              @size: size of the area
 212  *                              @pa: physical address for the map
 213  *                              @perm: device access permission (VHOST_MAP_XX)
 214  *                              Returns integer: success (0) or error (< 0)
 215  * @dma_unmap:                  Unmap an area of IOVA (optional but
 216  *                              must be implemented with dma_map)
 217  *                              Needed for device that using device
 218  *                              specific DMA translation (on-chip IOMMU)
 219  *                              and preferring incremental unmap.
 220  *                              @vdev: vdpa device
 221  *                              @iova: iova to be unmapped
 222  *                              @size: size of the area
 223  *                              Returns integer: success (0) or error (< 0)
 224  * @free:                       Free resources that belongs to vDPA (optional)
 225  *                              @vdev: vdpa device
 226  */
 227 struct vdpa_config_ops {
 228         /* Virtqueue ops */
 229         int (*set_vq_address)(struct vdpa_device *vdev,
 230                               u16 idx, u64 desc_area, u64 driver_area,
 231                               u64 device_area);
 232         void (*set_vq_num)(struct vdpa_device *vdev, u16 idx, u32 num);
 233         void (*kick_vq)(struct vdpa_device *vdev, u16 idx);
 234         void (*set_vq_cb)(struct vdpa_device *vdev, u16 idx,
 235                           struct vdpa_callback *cb);
 236         void (*set_vq_ready)(struct vdpa_device *vdev, u16 idx, bool ready);
 237         bool (*get_vq_ready)(struct vdpa_device *vdev, u16 idx);
 238         int (*set_vq_state)(struct vdpa_device *vdev, u16 idx,
 239                             const struct vdpa_vq_state *state);
 240         int (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
 241                             struct vdpa_vq_state *state);
 242         struct vdpa_notification_area
 243         (*get_vq_notification)(struct vdpa_device *vdev, u16 idx);
 244         /* vq irq is not expected to be changed once DRIVER_OK is set */
 245         int (*get_vq_irq)(struct vdpa_device *vdv, u16 idx);
 246
 247         /* Device ops */
 248         u32 (*get_vq_align)(struct vdpa_device *vdev);
 249         u64 (*get_features)(struct vdpa_device *vdev);
 250         int (*set_features)(struct vdpa_device *vdev, u64 features);
 251         void (*set_config_cb)(struct vdpa_device *vdev,
 252                               struct vdpa_callback *cb);
 253         u16 (*get_vq_num_max)(struct vdpa_device *vdev);
 254         u32 (*get_device_id)(struct vdpa_device *vdev);
 255         u32 (*get_vendor_id)(struct vdpa_device *vdev);
 256         u8 (*get_status)(struct vdpa_device *vdev);
 257         void (*set_status)(struct vdpa_device *vdev, u8 status);
 258         size_t (*get_config_size)(struct vdpa_device *vdev);
 259         void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
 260                            void *buf, unsigned int len);
 261         void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
 262                            const void *buf, unsigned int len);
 263         u32 (*get_generation)(struct vdpa_device *vdev);
 264         struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
 265
 266         /* DMA ops */
 267         int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
 268         int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
 269                        u64 pa, u32 perm);
 270         int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
 271
 272         /* Free device resources */
 273         void (*free)(struct vdpa_device *vdev);
 274 };
 275
 276 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
 277                                         const struct vdpa_config_ops *config,
 278                                         size_t size, const char *name);
 279
 280 /**
 281  * vdpa_alloc_device - allocate and initilaize a vDPA device
 282  *
 283  * @dev_struct: the type of the parent structure
 284  * @member: the name of struct vdpa_device within the @dev_struct
 285  * @parent: the parent device
 286  * @config: the bus operations that is supported by this device
 287  * @name: name of the vdpa device
 288  *
 289  * Return allocated data structure or ERR_PTR upon error
 290  */
 291 #define vdpa_alloc_device(dev_struct, member, parent, config, name)   \
 292                           container_of(__vdpa_alloc_device( \
 293                                        parent, config, \
 294                                        sizeof(dev_struct) + \
 295                                        BUILD_BUG_ON_ZERO(offsetof( \
 296                                        dev_struct, member)), name), \
 297                                        dev_struct, member)
 298
 299 int vdpa_register_device(struct vdpa_device *vdev, int nvqs);
 300 void vdpa_unregister_device(struct vdpa_device *vdev);
 301
 302 int _vdpa_register_device(struct vdpa_device *vdev, int nvqs);
 303 void _vdpa_unregister_device(struct vdpa_device *vdev);
 304
 305 /**
 306  * struct vdpa_driver - operations for a vDPA driver
 307  * @driver: underlying device driver
 308  * @probe: the function to call when a device is found.  Returns 0 or -errno.
 309  * @remove: the function to call when a device is removed.
 310  */
 311 struct vdpa_driver {
 312         struct device_driver driver;
 313         int (*probe)(struct vdpa_device *vdev);
 314         void (*remove)(struct vdpa_device *vdev);
 315 };
 316
 317 #define vdpa_register_driver(drv) \
 318         __vdpa_register_driver(drv, THIS_MODULE)
 319 int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner);
 320 void vdpa_unregister_driver(struct vdpa_driver *drv);
 321
 322 #define module_vdpa_driver(__vdpa_driver) \
 323         module_driver(__vdpa_driver, vdpa_register_driver,      \
 324                       vdpa_unregister_driver)
 325
 326 static inline struct vdpa_driver *drv_to_vdpa(struct device_driver *driver)
 327 {
 328         return container_of(driver, struct vdpa_driver, driver);
 329 }
 330
 331 static inline struct vdpa_device *dev_to_vdpa(struct device *_dev)
 332 {
 333         return container_of(_dev, struct vdpa_device, dev);
 334 }
 335
 336 static inline void *vdpa_get_drvdata(const struct vdpa_device *vdev)
 337 {
 338         return dev_get_drvdata(&vdev->dev);
 339 }
 340
 341 static inline void vdpa_set_drvdata(struct vdpa_device *vdev, void *data)
 342 {
 343         dev_set_drvdata(&vdev->dev, data);
 344 }
 345
 346 static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
 347 {
 348         return vdev->dma_dev;
 349 }
 350
 351 static inline void vdpa_reset(struct vdpa_device *vdev)
 352 {
 353         const struct vdpa_config_ops *ops = vdev->config;
 354
 355         vdev->features_valid = false;
 356         ops->set_status(vdev, 0);
 357 }
 358
 359 static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
 360 {
 361         const struct vdpa_config_ops *ops = vdev->config;
 362
 363         vdev->features_valid = true;
 364         return ops->set_features(vdev, features);
 365 }
 366
 367
 368 static inline void vdpa_get_config(struct vdpa_device *vdev, unsigned offset,
 369                                    void *buf, unsigned int len)
 370 {
 371         const struct vdpa_config_ops *ops = vdev->config;
 372
 373         /*
 374          * Config accesses aren't supposed to trigger before features are set.
 375          * If it does happen we assume a legacy guest.
 376          */
 377         if (!vdev->features_valid)
 378                 vdpa_set_features(vdev, 0);
 379         ops->get_config(vdev, offset, buf, len);
 380 }
 381
 382 /**
 383  * struct vdpa_mgmtdev_ops - vdpa device ops
 384  * @dev_add: Add a vdpa device using alloc and register
 385  *           @mdev: parent device to use for device addition
 386  *           @name: name of the new vdpa device
 387  *           Driver need to add a new device using _vdpa_register_device()
 388  *           after fully initializing the vdpa device. Driver must return 0
 389  *           on success or appropriate error code.
 390  * @dev_del: Remove a vdpa device using unregister
 391  *           @mdev: parent device to use for device removal
 392  *           @dev: vdpa device to remove
 393  *           Driver need to remove the specified device by calling
 394  *           _vdpa_unregister_device().
 395  */
 396 struct vdpa_mgmtdev_ops {
 397         int (*dev_add)(struct vdpa_mgmt_dev *mdev, const char *name);
 398         void (*dev_del)(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev);
 399 };
 400
 401 struct vdpa_mgmt_dev {
 402         struct device *device;
 403         const struct vdpa_mgmtdev_ops *ops;
 404         const struct virtio_device_id *id_table; /* supported ids */
 405         struct list_head list;
 406 };
 407
 408 int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev);
 409 void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev);
 410
 411 #endif /* _LINUX_VDPA_H */