1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * VIRTIO based driver for vDPA device 4 * 5 * Copyright (c) 2020, Red Hat. All rights reserved. 6 * Author: Jason Wang <jasowang@redhat.com> 7 * 8 */ 9 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/device.h> 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/uuid.h> 16 #include <linux/group_cpus.h> 17 #include <linux/virtio.h> 18 #include <linux/vdpa.h> 19 #include <linux/virtio_config.h> 20 #include <linux/virtio_ring.h> 21 22 #define MOD_VERSION "0.1" 23 #define MOD_AUTHOR "Jason Wang <jasowang@redhat.com>" 24 #define MOD_DESC "vDPA bus driver for virtio devices" 25 #define MOD_LICENSE "GPL v2" 26 27 struct virtio_vdpa_device { 28 struct virtio_device vdev; 29 struct vdpa_device *vdpa; 30 u64 features; 31 32 /* The lock to protect virtqueue list */ 33 spinlock_t lock; 34 /* List of virtio_vdpa_vq_info */ 35 struct list_head virtqueues; 36 }; 37 38 struct virtio_vdpa_vq_info { 39 /* the actual virtqueue */ 40 struct virtqueue *vq; 41 42 /* the list node for the virtqueues list */ 43 struct list_head node; 44 }; 45 46 static inline struct virtio_vdpa_device * 47 to_virtio_vdpa_device(struct virtio_device *dev) 48 { 49 return container_of(dev, struct virtio_vdpa_device, vdev); 50 } 51 52 static struct vdpa_device *vd_get_vdpa(struct virtio_device *vdev) 53 { 54 return to_virtio_vdpa_device(vdev)->vdpa; 55 } 56 57 static void virtio_vdpa_get(struct virtio_device *vdev, unsigned int offset, 58 void *buf, unsigned int len) 59 { 60 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 61 62 vdpa_get_config(vdpa, offset, buf, len); 63 } 64 65 static void virtio_vdpa_set(struct virtio_device *vdev, unsigned int offset, 66 const void *buf, unsigned int len) 67 { 68 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 69 70 vdpa_set_config(vdpa, offset, buf, len); 71 } 72 73 static u32 virtio_vdpa_generation(struct virtio_device *vdev) 74 { 75 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 76 const struct vdpa_config_ops *ops = vdpa->config; 77 78 if (ops->get_generation) 79 return ops->get_generation(vdpa); 80 81 return 0; 82 } 83 84 static u8 virtio_vdpa_get_status(struct virtio_device *vdev) 85 { 86 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 87 const struct vdpa_config_ops *ops = vdpa->config; 88 89 return ops->get_status(vdpa); 90 } 91 92 static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status) 93 { 94 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 95 96 return vdpa_set_status(vdpa, status); 97 } 98 99 static void virtio_vdpa_reset(struct virtio_device *vdev) 100 { 101 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 102 103 vdpa_reset(vdpa); 104 } 105 106 static bool virtio_vdpa_notify(struct virtqueue *vq) 107 { 108 struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev); 109 const struct vdpa_config_ops *ops = vdpa->config; 110 111 ops->kick_vq(vdpa, vq->index); 112 113 return true; 114 } 115 116 static bool virtio_vdpa_notify_with_data(struct virtqueue *vq) 117 { 118 struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev); 119 const struct vdpa_config_ops *ops = vdpa->config; 120 u32 data = vring_notification_data(vq); 121 122 ops->kick_vq_with_data(vdpa, data); 123 124 return true; 125 } 126 127 static irqreturn_t virtio_vdpa_config_cb(void *private) 128 { 129 struct virtio_vdpa_device *vd_dev = private; 130 131 virtio_config_changed(&vd_dev->vdev); 132 133 return IRQ_HANDLED; 134 } 135 136 static irqreturn_t virtio_vdpa_virtqueue_cb(void *private) 137 { 138 struct virtio_vdpa_vq_info *info = private; 139 140 return vring_interrupt(0, info->vq); 141 } 142 143 static struct virtqueue * 144 virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, 145 void (*callback)(struct virtqueue *vq), 146 const char *name, bool ctx) 147 { 148 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 149 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 150 struct device *dma_dev; 151 const struct vdpa_config_ops *ops = vdpa->config; 152 struct virtio_vdpa_vq_info *info; 153 bool (*notify)(struct virtqueue *vq) = virtio_vdpa_notify; 154 struct vdpa_callback cb; 155 struct virtqueue *vq; 156 u64 desc_addr, driver_addr, device_addr; 157 /* Assume split virtqueue, switch to packed if necessary */ 158 struct vdpa_vq_state state = {0}; 159 unsigned long flags; 160 u32 align, max_num, min_num = 1; 161 bool may_reduce_num = true; 162 int err; 163 164 if (!name) 165 return NULL; 166 167 if (index >= vdpa->nvqs) 168 return ERR_PTR(-ENOENT); 169 170 /* We cannot accept VIRTIO_F_NOTIFICATION_DATA without kick_vq_with_data */ 171 if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA)) { 172 if (ops->kick_vq_with_data) 173 notify = virtio_vdpa_notify_with_data; 174 else 175 __virtio_clear_bit(vdev, VIRTIO_F_NOTIFICATION_DATA); 176 } 177 178 /* Queue shouldn't already be set up. */ 179 if (ops->get_vq_ready(vdpa, index)) 180 return ERR_PTR(-ENOENT); 181 182 /* Allocate and fill out our active queue description */ 183 info = kmalloc(sizeof(*info), GFP_KERNEL); 184 if (!info) 185 return ERR_PTR(-ENOMEM); 186 187 max_num = ops->get_vq_num_max(vdpa); 188 if (max_num == 0) { 189 err = -ENOENT; 190 goto error_new_virtqueue; 191 } 192 193 if (ops->get_vq_num_min) 194 min_num = ops->get_vq_num_min(vdpa); 195 196 may_reduce_num = (max_num == min_num) ? false : true; 197 198 /* Create the vring */ 199 align = ops->get_vq_align(vdpa); 200 201 if (ops->get_vq_dma_dev) 202 dma_dev = ops->get_vq_dma_dev(vdpa, index); 203 else 204 dma_dev = vdpa_get_dma_dev(vdpa); 205 vq = vring_create_virtqueue_dma(index, max_num, align, vdev, 206 true, may_reduce_num, ctx, 207 notify, callback, name, dma_dev); 208 if (!vq) { 209 err = -ENOMEM; 210 goto error_new_virtqueue; 211 } 212 213 vq->num_max = max_num; 214 215 /* Setup virtqueue callback */ 216 cb.callback = callback ? virtio_vdpa_virtqueue_cb : NULL; 217 cb.private = info; 218 cb.trigger = NULL; 219 ops->set_vq_cb(vdpa, index, &cb); 220 ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq)); 221 222 desc_addr = virtqueue_get_desc_addr(vq); 223 driver_addr = virtqueue_get_avail_addr(vq); 224 device_addr = virtqueue_get_used_addr(vq); 225 226 if (ops->set_vq_address(vdpa, index, 227 desc_addr, driver_addr, 228 device_addr)) { 229 err = -EINVAL; 230 goto err_vq; 231 } 232 233 /* reset virtqueue state index */ 234 if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 235 struct vdpa_vq_state_packed *s = &state.packed; 236 237 s->last_avail_counter = 1; 238 s->last_avail_idx = 0; 239 s->last_used_counter = 1; 240 s->last_used_idx = 0; 241 } 242 err = ops->set_vq_state(vdpa, index, &state); 243 if (err) 244 goto err_vq; 245 246 ops->set_vq_ready(vdpa, index, 1); 247 248 vq->priv = info; 249 info->vq = vq; 250 251 spin_lock_irqsave(&vd_dev->lock, flags); 252 list_add(&info->node, &vd_dev->virtqueues); 253 spin_unlock_irqrestore(&vd_dev->lock, flags); 254 255 return vq; 256 257 err_vq: 258 vring_del_virtqueue(vq); 259 error_new_virtqueue: 260 ops->set_vq_ready(vdpa, index, 0); 261 /* VDPA driver should make sure vq is stopeed here */ 262 WARN_ON(ops->get_vq_ready(vdpa, index)); 263 kfree(info); 264 return ERR_PTR(err); 265 } 266 267 static void virtio_vdpa_del_vq(struct virtqueue *vq) 268 { 269 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev); 270 struct vdpa_device *vdpa = vd_dev->vdpa; 271 const struct vdpa_config_ops *ops = vdpa->config; 272 struct virtio_vdpa_vq_info *info = vq->priv; 273 unsigned int index = vq->index; 274 unsigned long flags; 275 276 spin_lock_irqsave(&vd_dev->lock, flags); 277 list_del(&info->node); 278 spin_unlock_irqrestore(&vd_dev->lock, flags); 279 280 /* Select and deactivate the queue (best effort) */ 281 ops->set_vq_ready(vdpa, index, 0); 282 283 vring_del_virtqueue(vq); 284 285 kfree(info); 286 } 287 288 static void virtio_vdpa_del_vqs(struct virtio_device *vdev) 289 { 290 struct virtqueue *vq, *n; 291 292 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 293 virtio_vdpa_del_vq(vq); 294 } 295 296 static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs) 297 { 298 affd->nr_sets = 1; 299 affd->set_size[0] = affvecs; 300 } 301 302 static struct cpumask * 303 create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd) 304 { 305 unsigned int affvecs = 0, curvec, usedvecs, i; 306 struct cpumask *masks = NULL; 307 308 if (nvecs > affd->pre_vectors + affd->post_vectors) 309 affvecs = nvecs - affd->pre_vectors - affd->post_vectors; 310 311 if (!affd->calc_sets) 312 affd->calc_sets = default_calc_sets; 313 314 affd->calc_sets(affd, affvecs); 315 316 if (!affvecs) 317 return NULL; 318 319 masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL); 320 if (!masks) 321 return NULL; 322 323 /* Fill out vectors at the beginning that don't need affinity */ 324 for (curvec = 0; curvec < affd->pre_vectors; curvec++) 325 cpumask_setall(&masks[curvec]); 326 327 for (i = 0, usedvecs = 0; i < affd->nr_sets; i++) { 328 unsigned int this_vecs = affd->set_size[i]; 329 int j; 330 struct cpumask *result = group_cpus_evenly(this_vecs); 331 332 if (!result) { 333 kfree(masks); 334 return NULL; 335 } 336 337 for (j = 0; j < this_vecs; j++) 338 cpumask_copy(&masks[curvec + j], &result[j]); 339 kfree(result); 340 341 curvec += this_vecs; 342 usedvecs += this_vecs; 343 } 344 345 /* Fill out vectors at the end that don't need affinity */ 346 if (usedvecs >= affvecs) 347 curvec = affd->pre_vectors + affvecs; 348 else 349 curvec = affd->pre_vectors + usedvecs; 350 for (; curvec < nvecs; curvec++) 351 cpumask_setall(&masks[curvec]); 352 353 return masks; 354 } 355 356 static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 357 struct virtqueue *vqs[], 358 vq_callback_t *callbacks[], 359 const char * const names[], 360 const bool *ctx, 361 struct irq_affinity *desc) 362 { 363 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 364 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 365 const struct vdpa_config_ops *ops = vdpa->config; 366 struct irq_affinity default_affd = { 0 }; 367 struct cpumask *masks; 368 struct vdpa_callback cb; 369 bool has_affinity = desc && ops->set_vq_affinity; 370 int i, err, queue_idx = 0; 371 372 if (has_affinity) { 373 masks = create_affinity_masks(nvqs, desc ? desc : &default_affd); 374 if (!masks) 375 return -ENOMEM; 376 } 377 378 for (i = 0; i < nvqs; ++i) { 379 if (!names[i]) { 380 vqs[i] = NULL; 381 continue; 382 } 383 384 vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++, 385 callbacks[i], names[i], ctx ? 386 ctx[i] : false); 387 if (IS_ERR(vqs[i])) { 388 err = PTR_ERR(vqs[i]); 389 goto err_setup_vq; 390 } 391 392 if (has_affinity) 393 ops->set_vq_affinity(vdpa, i, &masks[i]); 394 } 395 396 cb.callback = virtio_vdpa_config_cb; 397 cb.private = vd_dev; 398 ops->set_config_cb(vdpa, &cb); 399 if (has_affinity) 400 kfree(masks); 401 402 return 0; 403 404 err_setup_vq: 405 virtio_vdpa_del_vqs(vdev); 406 if (has_affinity) 407 kfree(masks); 408 return err; 409 } 410 411 static u64 virtio_vdpa_get_features(struct virtio_device *vdev) 412 { 413 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 414 const struct vdpa_config_ops *ops = vdpa->config; 415 416 return ops->get_device_features(vdpa); 417 } 418 419 static int virtio_vdpa_finalize_features(struct virtio_device *vdev) 420 { 421 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 422 423 /* Give virtio_ring a chance to accept features. */ 424 vring_transport_features(vdev); 425 426 return vdpa_set_features(vdpa, vdev->features); 427 } 428 429 static const char *virtio_vdpa_bus_name(struct virtio_device *vdev) 430 { 431 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 432 struct vdpa_device *vdpa = vd_dev->vdpa; 433 434 return dev_name(&vdpa->dev); 435 } 436 437 static int virtio_vdpa_set_vq_affinity(struct virtqueue *vq, 438 const struct cpumask *cpu_mask) 439 { 440 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev); 441 struct vdpa_device *vdpa = vd_dev->vdpa; 442 const struct vdpa_config_ops *ops = vdpa->config; 443 unsigned int index = vq->index; 444 445 if (ops->set_vq_affinity) 446 return ops->set_vq_affinity(vdpa, index, cpu_mask); 447 448 return 0; 449 } 450 451 static const struct cpumask * 452 virtio_vdpa_get_vq_affinity(struct virtio_device *vdev, int index) 453 { 454 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 455 const struct vdpa_config_ops *ops = vdpa->config; 456 457 if (ops->get_vq_affinity) 458 return ops->get_vq_affinity(vdpa, index); 459 460 return NULL; 461 } 462 463 static const struct virtio_config_ops virtio_vdpa_config_ops = { 464 .get = virtio_vdpa_get, 465 .set = virtio_vdpa_set, 466 .generation = virtio_vdpa_generation, 467 .get_status = virtio_vdpa_get_status, 468 .set_status = virtio_vdpa_set_status, 469 .reset = virtio_vdpa_reset, 470 .find_vqs = virtio_vdpa_find_vqs, 471 .del_vqs = virtio_vdpa_del_vqs, 472 .get_features = virtio_vdpa_get_features, 473 .finalize_features = virtio_vdpa_finalize_features, 474 .bus_name = virtio_vdpa_bus_name, 475 .set_vq_affinity = virtio_vdpa_set_vq_affinity, 476 .get_vq_affinity = virtio_vdpa_get_vq_affinity, 477 }; 478 479 static void virtio_vdpa_release_dev(struct device *_d) 480 { 481 struct virtio_device *vdev = 482 container_of(_d, struct virtio_device, dev); 483 struct virtio_vdpa_device *vd_dev = 484 container_of(vdev, struct virtio_vdpa_device, vdev); 485 486 kfree(vd_dev); 487 } 488 489 static int virtio_vdpa_probe(struct vdpa_device *vdpa) 490 { 491 const struct vdpa_config_ops *ops = vdpa->config; 492 struct virtio_vdpa_device *vd_dev, *reg_dev = NULL; 493 int ret = -EINVAL; 494 495 vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL); 496 if (!vd_dev) 497 return -ENOMEM; 498 499 vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa); 500 vd_dev->vdev.dev.release = virtio_vdpa_release_dev; 501 vd_dev->vdev.config = &virtio_vdpa_config_ops; 502 vd_dev->vdpa = vdpa; 503 INIT_LIST_HEAD(&vd_dev->virtqueues); 504 spin_lock_init(&vd_dev->lock); 505 506 vd_dev->vdev.id.device = ops->get_device_id(vdpa); 507 if (vd_dev->vdev.id.device == 0) 508 goto err; 509 510 vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa); 511 ret = register_virtio_device(&vd_dev->vdev); 512 reg_dev = vd_dev; 513 if (ret) 514 goto err; 515 516 vdpa_set_drvdata(vdpa, vd_dev); 517 518 return 0; 519 520 err: 521 if (reg_dev) 522 put_device(&vd_dev->vdev.dev); 523 else 524 kfree(vd_dev); 525 return ret; 526 } 527 528 static void virtio_vdpa_remove(struct vdpa_device *vdpa) 529 { 530 struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa); 531 532 unregister_virtio_device(&vd_dev->vdev); 533 } 534 535 static struct vdpa_driver virtio_vdpa_driver = { 536 .driver = { 537 .name = "virtio_vdpa", 538 }, 539 .probe = virtio_vdpa_probe, 540 .remove = virtio_vdpa_remove, 541 }; 542 543 module_vdpa_driver(virtio_vdpa_driver); 544 545 MODULE_VERSION(MOD_VERSION); 546 MODULE_LICENSE(MOD_LICENSE); 547 MODULE_AUTHOR(MOD_AUTHOR); 548 MODULE_DESCRIPTION(MOD_DESC); 549