virtio.c revision 1.38
1 /* $NetBSD: virtio.c,v 1.38 2019/10/01 18:00:08 chs Exp $ */ 2 3 /* 4 * Copyright (c) 2010 Minoura Makoto. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: virtio.c,v 1.38 2019/10/01 18:00:08 chs Exp $"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/atomic.h> 35 #include <sys/bus.h> 36 #include <sys/device.h> 37 #include <sys/kmem.h> 38 #include <sys/module.h> 39 40 #define VIRTIO_PRIVATE 41 42 #include <dev/pci/virtioreg.h> /* XXX: move to non-pci */ 43 #include <dev/pci/virtiovar.h> /* XXX: move to non-pci */ 44 45 #define MINSEG_INDIRECT 2 /* use indirect if nsegs >= this value */ 46 47 static void virtio_init_vq(struct virtio_softc *, 48 struct virtqueue *, const bool); 49 50 void 51 virtio_set_status(struct virtio_softc *sc, int status) 52 { 53 sc->sc_ops->set_status(sc, status); 54 } 55 56 /* 57 * Reset the device. 58 */ 59 /* 60 * To reset the device to a known state, do following: 61 * virtio_reset(sc); // this will stop the device activity 62 * <dequeue finished requests>; // virtio_dequeue() still can be called 63 * <revoke pending requests in the vqs if any>; 64 * virtio_reinit_begin(sc); // dequeue prohibitted 65 * newfeatures = virtio_negotiate_features(sc, requestedfeatures); 66 * <some other initialization>; 67 * virtio_reinit_end(sc); // device activated; enqueue allowed 68 * Once attached, feature negotiation can only be allowed after virtio_reset. 69 */ 70 void 71 virtio_reset(struct virtio_softc *sc) 72 { 73 virtio_device_reset(sc); 74 } 75 76 void 77 virtio_reinit_start(struct virtio_softc *sc) 78 { 79 int i; 80 81 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_ACK); 82 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER); 83 for (i = 0; i < sc->sc_nvqs; i++) { 84 int n; 85 struct virtqueue *vq = &sc->sc_vqs[i]; 86 n = sc->sc_ops->read_queue_size(sc, vq->vq_index); 87 if (n == 0) /* vq disappeared */ 88 continue; 89 if (n != vq->vq_num) { 90 panic("%s: virtqueue size changed, vq index %d\n", 91 device_xname(sc->sc_dev), 92 vq->vq_index); 93 } 94 virtio_init_vq(sc, vq, true); 95 sc->sc_ops->setup_queue(sc, vq->vq_index, 96 vq->vq_dmamap->dm_segs[0].ds_addr / VIRTIO_PAGE_SIZE); 97 } 98 } 99 100 void 101 virtio_reinit_end(struct virtio_softc *sc) 102 { 103 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER_OK); 104 } 105 106 /* 107 * Feature negotiation. 108 */ 109 uint32_t 110 virtio_negotiate_features(struct virtio_softc *sc, uint32_t guest_features) 111 { 112 uint32_t r; 113 114 if (!(device_cfdata(sc->sc_dev)->cf_flags & 1) && 115 !(device_cfdata(sc->sc_child)->cf_flags & 1)) /* XXX */ 116 guest_features |= VIRTIO_F_RING_INDIRECT_DESC; 117 r = sc->sc_ops->neg_features(sc, guest_features); 118 sc->sc_features = r; 119 if (r & VIRTIO_F_RING_INDIRECT_DESC) 120 sc->sc_indirect = true; 121 else 122 sc->sc_indirect = false; 123 124 return r; 125 } 126 127 /* 128 * Device configuration registers. 129 */ 130 uint8_t 131 virtio_read_device_config_1(struct virtio_softc *sc, int index) 132 { 133 return sc->sc_ops->read_dev_cfg_1(sc, index); 134 } 135 136 uint16_t 137 virtio_read_device_config_2(struct virtio_softc *sc, int index) 138 { 139 return sc->sc_ops->read_dev_cfg_2(sc, index); 140 } 141 142 uint32_t 143 virtio_read_device_config_4(struct virtio_softc *sc, int index) 144 { 145 return sc->sc_ops->read_dev_cfg_4(sc, index); 146 } 147 148 uint64_t 149 virtio_read_device_config_8(struct virtio_softc *sc, int index) 150 { 151 return sc->sc_ops->read_dev_cfg_8(sc, index); 152 } 153 154 void 155 virtio_write_device_config_1(struct virtio_softc *sc, 156 int index, uint8_t value) 157 { 158 return sc->sc_ops->write_dev_cfg_1(sc, index, value); 159 } 160 161 void 162 virtio_write_device_config_2(struct virtio_softc *sc, 163 int index, uint16_t value) 164 { 165 return sc->sc_ops->write_dev_cfg_2(sc, index, value); 166 } 167 168 void 169 virtio_write_device_config_4(struct virtio_softc *sc, 170 int index, uint32_t value) 171 { 172 return sc->sc_ops->write_dev_cfg_4(sc, index, value); 173 } 174 175 void 176 virtio_write_device_config_8(struct virtio_softc *sc, 177 int index, uint64_t value) 178 { 179 return sc->sc_ops->write_dev_cfg_8(sc, index, value); 180 } 181 182 /* 183 * Interrupt handler. 184 */ 185 static void 186 virtio_soft_intr(void *arg) 187 { 188 struct virtio_softc *sc = arg; 189 190 KASSERT(sc->sc_intrhand != NULL); 191 192 (sc->sc_intrhand)(sc); 193 } 194 195 /* 196 * dmamap sync operations for a virtqueue. 197 */ 198 static inline void 199 vq_sync_descs(struct virtio_softc *sc, struct virtqueue *vq, int ops) 200 { 201 /* availoffset == sizeof(vring_desc)*vq_num */ 202 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap, 0, vq->vq_availoffset, 203 ops); 204 } 205 206 static inline void 207 vq_sync_aring(struct virtio_softc *sc, struct virtqueue *vq, int ops) 208 { 209 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap, 210 vq->vq_availoffset, 211 offsetof(struct vring_avail, ring) 212 + vq->vq_num * sizeof(uint16_t), 213 ops); 214 } 215 216 static inline void 217 vq_sync_uring(struct virtio_softc *sc, struct virtqueue *vq, int ops) 218 { 219 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap, 220 vq->vq_usedoffset, 221 offsetof(struct vring_used, ring) 222 + vq->vq_num * sizeof(struct vring_used_elem), 223 ops); 224 } 225 226 static inline void 227 vq_sync_indirect(struct virtio_softc *sc, struct virtqueue *vq, int slot, 228 int ops) 229 { 230 int offset = vq->vq_indirectoffset 231 + sizeof(struct vring_desc) * vq->vq_maxnsegs * slot; 232 233 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap, 234 offset, sizeof(struct vring_desc) * vq->vq_maxnsegs, 235 ops); 236 } 237 238 static void 239 virtio_vq_soft_intr(void *arg) 240 { 241 struct virtqueue *vq = arg; 242 243 KASSERT(vq->vq_intrhand != NULL); 244 245 (vq->vq_intrhand)(vq); 246 } 247 248 static int 249 virtio_vq_softint_establish(struct virtio_softc *sc) 250 { 251 struct virtqueue *vq; 252 int qid; 253 u_int flags; 254 255 flags = SOFTINT_NET; 256 if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE) 257 flags |= SOFTINT_MPSAFE; 258 259 for (qid = 0; qid < sc->sc_nvqs; qid++) { 260 vq = &sc->sc_vqs[qid]; 261 vq->vq_soft_ih = 262 softint_establish(flags, virtio_vq_soft_intr, vq); 263 if (vq->vq_soft_ih == NULL) 264 return -1; 265 } 266 267 return 0; 268 } 269 270 static void 271 virtio_vq_softint_disestablish(struct virtio_softc *sc) 272 { 273 struct virtqueue *vq; 274 int qid; 275 276 for (qid = 0; qid < sc->sc_nvqs; qid++) { 277 vq = &sc->sc_vqs[qid]; 278 if (vq->vq_soft_ih == NULL) 279 continue; 280 281 softint_disestablish(vq->vq_soft_ih); 282 vq->vq_soft_ih = NULL; 283 } 284 } 285 286 /* 287 * Can be used as sc_intrhand. 288 */ 289 /* 290 * Scan vq, bus_dmamap_sync for the vqs (not for the payload), 291 * and calls (*vq_done)() if some entries are consumed. 292 */ 293 static int 294 virtio_vq_intr_common(struct virtqueue *vq) 295 { 296 struct virtio_softc *sc = vq->vq_owner; 297 int r = 0; 298 299 if (vq->vq_queued) { 300 vq->vq_queued = 0; 301 vq_sync_aring(sc, vq, BUS_DMASYNC_POSTWRITE); 302 } 303 vq_sync_uring(sc, vq, BUS_DMASYNC_POSTREAD); 304 membar_consumer(); 305 if (vq->vq_used_idx != vq->vq_used->idx) { 306 if (vq->vq_done) 307 r |= (vq->vq_done)(vq); 308 } 309 310 return r; 311 } 312 313 int 314 virtio_vq_intr(struct virtio_softc *sc) 315 { 316 struct virtqueue *vq; 317 int i, r = 0; 318 319 for (i = 0; i < sc->sc_nvqs; i++) { 320 vq = &sc->sc_vqs[i]; 321 r |= virtio_vq_intr_common(vq); 322 } 323 324 return r; 325 } 326 327 static int 328 virtio_vq_mq_intr(struct virtqueue *vq) 329 { 330 331 return virtio_vq_intr_common(vq); 332 } 333 334 /* 335 * Start/stop vq interrupt. No guarantee. 336 */ 337 void 338 virtio_stop_vq_intr(struct virtio_softc *sc, struct virtqueue *vq) 339 { 340 vq->vq_avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; 341 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE); 342 vq->vq_queued++; 343 } 344 345 void 346 virtio_start_vq_intr(struct virtio_softc *sc, struct virtqueue *vq) 347 { 348 vq->vq_avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT; 349 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE); 350 vq->vq_queued++; 351 } 352 353 /* 354 * Initialize vq structure. 355 */ 356 static void 357 virtio_init_vq(struct virtio_softc *sc, struct virtqueue *vq, 358 const bool reinit) 359 { 360 int i, j; 361 int vq_size = vq->vq_num; 362 363 memset(vq->vq_vaddr, 0, vq->vq_bytesize); 364 365 /* build the indirect descriptor chain */ 366 if (vq->vq_indirect != NULL) { 367 struct vring_desc *vd; 368 369 for (i = 0; i < vq_size; i++) { 370 vd = vq->vq_indirect; 371 vd += vq->vq_maxnsegs * i; 372 for (j = 0; j < vq->vq_maxnsegs-1; j++) { 373 vd[j].next = j + 1; 374 } 375 } 376 } 377 378 /* free slot management */ 379 SIMPLEQ_INIT(&vq->vq_freelist); 380 for (i = 0; i < vq_size; i++) { 381 SIMPLEQ_INSERT_TAIL(&vq->vq_freelist, 382 &vq->vq_entries[i], qe_list); 383 vq->vq_entries[i].qe_index = i; 384 } 385 if (!reinit) 386 mutex_init(&vq->vq_freelist_lock, MUTEX_SPIN, sc->sc_ipl); 387 388 /* enqueue/dequeue status */ 389 vq->vq_avail_idx = 0; 390 vq->vq_used_idx = 0; 391 vq->vq_queued = 0; 392 if (!reinit) { 393 mutex_init(&vq->vq_aring_lock, MUTEX_SPIN, sc->sc_ipl); 394 mutex_init(&vq->vq_uring_lock, MUTEX_SPIN, sc->sc_ipl); 395 } 396 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE); 397 vq_sync_uring(sc, vq, BUS_DMASYNC_PREREAD); 398 vq->vq_queued++; 399 } 400 401 /* 402 * Allocate/free a vq. 403 */ 404 int 405 virtio_alloc_vq(struct virtio_softc *sc, struct virtqueue *vq, int index, 406 int maxsegsize, int maxnsegs, const char *name) 407 { 408 int vq_size, allocsize1, allocsize2, allocsize3, allocsize = 0; 409 int rsegs, r; 410 #define VIRTQUEUE_ALIGN(n) (((n)+(VIRTIO_PAGE_SIZE-1))& \ 411 ~(VIRTIO_PAGE_SIZE-1)) 412 413 /* Make sure callers allocate vqs in order */ 414 KASSERT(sc->sc_nvqs == index); 415 416 memset(vq, 0, sizeof(*vq)); 417 418 vq_size = sc->sc_ops->read_queue_size(sc, index); 419 if (vq_size == 0) { 420 aprint_error_dev(sc->sc_dev, 421 "virtqueue not exist, index %d for %s\n", 422 index, name); 423 goto err; 424 } 425 /* allocsize1: descriptor table + avail ring + pad */ 426 allocsize1 = VIRTQUEUE_ALIGN(sizeof(struct vring_desc)*vq_size 427 + sizeof(uint16_t)*(2+vq_size)); 428 /* allocsize2: used ring + pad */ 429 allocsize2 = VIRTQUEUE_ALIGN(sizeof(uint16_t)*2 430 + sizeof(struct vring_used_elem)*vq_size); 431 /* allocsize3: indirect table */ 432 if (sc->sc_indirect && maxnsegs >= MINSEG_INDIRECT) 433 allocsize3 = sizeof(struct vring_desc) * maxnsegs * vq_size; 434 else 435 allocsize3 = 0; 436 allocsize = allocsize1 + allocsize2 + allocsize3; 437 438 /* alloc and map the memory */ 439 r = bus_dmamem_alloc(sc->sc_dmat, allocsize, VIRTIO_PAGE_SIZE, 0, 440 &vq->vq_segs[0], 1, &rsegs, BUS_DMA_NOWAIT); 441 if (r != 0) { 442 aprint_error_dev(sc->sc_dev, 443 "virtqueue %d for %s allocation failed, " 444 "error code %d\n", index, name, r); 445 goto err; 446 } 447 r = bus_dmamem_map(sc->sc_dmat, &vq->vq_segs[0], 1, allocsize, 448 &vq->vq_vaddr, BUS_DMA_NOWAIT); 449 if (r != 0) { 450 aprint_error_dev(sc->sc_dev, 451 "virtqueue %d for %s map failed, " 452 "error code %d\n", index, name, r); 453 goto err; 454 } 455 r = bus_dmamap_create(sc->sc_dmat, allocsize, 1, allocsize, 0, 456 BUS_DMA_NOWAIT, &vq->vq_dmamap); 457 if (r != 0) { 458 aprint_error_dev(sc->sc_dev, 459 "virtqueue %d for %s dmamap creation failed, " 460 "error code %d\n", index, name, r); 461 goto err; 462 } 463 r = bus_dmamap_load(sc->sc_dmat, vq->vq_dmamap, 464 vq->vq_vaddr, allocsize, NULL, BUS_DMA_NOWAIT); 465 if (r != 0) { 466 aprint_error_dev(sc->sc_dev, 467 "virtqueue %d for %s dmamap load failed, " 468 "error code %d\n", index, name, r); 469 goto err; 470 } 471 472 /* set the vq address */ 473 sc->sc_ops->setup_queue(sc, index, 474 vq->vq_dmamap->dm_segs[0].ds_addr / VIRTIO_PAGE_SIZE); 475 476 /* remember addresses and offsets for later use */ 477 vq->vq_owner = sc; 478 vq->vq_intrhand = virtio_vq_mq_intr; 479 vq->vq_num = vq_size; 480 vq->vq_index = index; 481 vq->vq_desc = vq->vq_vaddr; 482 vq->vq_availoffset = sizeof(struct vring_desc)*vq_size; 483 vq->vq_avail = (void*)(((char*)vq->vq_desc) + vq->vq_availoffset); 484 vq->vq_usedoffset = allocsize1; 485 vq->vq_used = (void*)(((char*)vq->vq_desc) + vq->vq_usedoffset); 486 if (allocsize3 > 0) { 487 vq->vq_indirectoffset = allocsize1 + allocsize2; 488 vq->vq_indirect = (void*)(((char*)vq->vq_desc) 489 + vq->vq_indirectoffset); 490 } 491 vq->vq_bytesize = allocsize; 492 vq->vq_maxsegsize = maxsegsize; 493 vq->vq_maxnsegs = maxnsegs; 494 495 /* free slot management */ 496 vq->vq_entries = kmem_zalloc(sizeof(struct vq_entry)*vq_size, 497 KM_SLEEP); 498 virtio_init_vq(sc, vq, false); 499 500 aprint_verbose_dev(sc->sc_dev, 501 "allocated %u byte for virtqueue %d for %s, " 502 "size %d\n", allocsize, index, name, vq_size); 503 if (allocsize3 > 0) 504 aprint_verbose_dev(sc->sc_dev, 505 "using %d byte (%d entries) " 506 "indirect descriptors\n", 507 allocsize3, maxnsegs * vq_size); 508 509 sc->sc_nvqs++; 510 511 return 0; 512 513 err: 514 sc->sc_ops->setup_queue(sc, index, 0); 515 if (vq->vq_dmamap) 516 bus_dmamap_destroy(sc->sc_dmat, vq->vq_dmamap); 517 if (vq->vq_vaddr) 518 bus_dmamem_unmap(sc->sc_dmat, vq->vq_vaddr, allocsize); 519 if (vq->vq_segs[0].ds_addr) 520 bus_dmamem_free(sc->sc_dmat, &vq->vq_segs[0], 1); 521 memset(vq, 0, sizeof(*vq)); 522 523 return -1; 524 } 525 526 int 527 virtio_free_vq(struct virtio_softc *sc, struct virtqueue *vq) 528 { 529 struct vq_entry *qe; 530 int i = 0; 531 532 /* device must be already deactivated */ 533 /* confirm the vq is empty */ 534 SIMPLEQ_FOREACH(qe, &vq->vq_freelist, qe_list) { 535 i++; 536 } 537 if (i != vq->vq_num) { 538 printf("%s: freeing non-empty vq, index %d\n", 539 device_xname(sc->sc_dev), vq->vq_index); 540 return EBUSY; 541 } 542 543 /* tell device that there's no virtqueue any longer */ 544 sc->sc_ops->setup_queue(sc, vq->vq_index, 0); 545 546 kmem_free(vq->vq_entries, sizeof(*vq->vq_entries) * vq->vq_num); 547 bus_dmamap_unload(sc->sc_dmat, vq->vq_dmamap); 548 bus_dmamap_destroy(sc->sc_dmat, vq->vq_dmamap); 549 bus_dmamem_unmap(sc->sc_dmat, vq->vq_vaddr, vq->vq_bytesize); 550 bus_dmamem_free(sc->sc_dmat, &vq->vq_segs[0], 1); 551 mutex_destroy(&vq->vq_freelist_lock); 552 mutex_destroy(&vq->vq_uring_lock); 553 mutex_destroy(&vq->vq_aring_lock); 554 memset(vq, 0, sizeof(*vq)); 555 556 sc->sc_nvqs--; 557 558 return 0; 559 } 560 561 /* 562 * Free descriptor management. 563 */ 564 static struct vq_entry * 565 vq_alloc_entry(struct virtqueue *vq) 566 { 567 struct vq_entry *qe; 568 569 mutex_enter(&vq->vq_freelist_lock); 570 if (SIMPLEQ_EMPTY(&vq->vq_freelist)) { 571 mutex_exit(&vq->vq_freelist_lock); 572 return NULL; 573 } 574 qe = SIMPLEQ_FIRST(&vq->vq_freelist); 575 SIMPLEQ_REMOVE_HEAD(&vq->vq_freelist, qe_list); 576 mutex_exit(&vq->vq_freelist_lock); 577 578 return qe; 579 } 580 581 static void 582 vq_free_entry(struct virtqueue *vq, struct vq_entry *qe) 583 { 584 mutex_enter(&vq->vq_freelist_lock); 585 SIMPLEQ_INSERT_TAIL(&vq->vq_freelist, qe, qe_list); 586 mutex_exit(&vq->vq_freelist_lock); 587 588 return; 589 } 590 591 /* 592 * Enqueue several dmamaps as a single request. 593 */ 594 /* 595 * Typical usage: 596 * <queue size> number of followings are stored in arrays 597 * - command blocks (in dmamem) should be pre-allocated and mapped 598 * - dmamaps for command blocks should be pre-allocated and loaded 599 * - dmamaps for payload should be pre-allocated 600 * r = virtio_enqueue_prep(sc, vq, &slot); // allocate a slot 601 * if (r) // currently 0 or EAGAIN 602 * return r; 603 * r = bus_dmamap_load(dmat, dmamap_payload[slot], data, count, ..); 604 * if (r) { 605 * virtio_enqueue_abort(sc, vq, slot); 606 * return r; 607 * } 608 * r = virtio_enqueue_reserve(sc, vq, slot, 609 * dmamap_payload[slot]->dm_nsegs+1); 610 * // ^ +1 for command 611 * if (r) { // currently 0 or EAGAIN 612 * bus_dmamap_unload(dmat, dmamap_payload[slot]); 613 * return r; // do not call abort() 614 * } 615 * <setup and prepare commands> 616 * bus_dmamap_sync(dmat, dmamap_cmd[slot],... BUS_DMASYNC_PREWRITE); 617 * bus_dmamap_sync(dmat, dmamap_payload[slot],...); 618 * virtio_enqueue(sc, vq, slot, dmamap_cmd[slot], false); 619 * virtio_enqueue(sc, vq, slot, dmamap_payload[slot], iswrite); 620 * virtio_enqueue_commit(sc, vq, slot, true); 621 */ 622 623 /* 624 * enqueue_prep: allocate a slot number 625 */ 626 int 627 virtio_enqueue_prep(struct virtio_softc *sc, struct virtqueue *vq, int *slotp) 628 { 629 struct vq_entry *qe1; 630 631 KASSERT(slotp != NULL); 632 633 qe1 = vq_alloc_entry(vq); 634 if (qe1 == NULL) 635 return EAGAIN; 636 /* next slot is not allocated yet */ 637 qe1->qe_next = -1; 638 *slotp = qe1->qe_index; 639 640 return 0; 641 } 642 643 /* 644 * enqueue_reserve: allocate remaining slots and build the descriptor chain. 645 */ 646 int 647 virtio_enqueue_reserve(struct virtio_softc *sc, struct virtqueue *vq, 648 int slot, int nsegs) 649 { 650 int indirect; 651 struct vq_entry *qe1 = &vq->vq_entries[slot]; 652 653 KASSERT(qe1->qe_next == -1); 654 KASSERT(1 <= nsegs && nsegs <= vq->vq_num); 655 656 if ((vq->vq_indirect != NULL) && 657 (nsegs >= MINSEG_INDIRECT) && 658 (nsegs <= vq->vq_maxnsegs)) 659 indirect = 1; 660 else 661 indirect = 0; 662 qe1->qe_indirect = indirect; 663 664 if (indirect) { 665 struct vring_desc *vd; 666 int i; 667 668 vd = &vq->vq_desc[qe1->qe_index]; 669 vd->addr = vq->vq_dmamap->dm_segs[0].ds_addr 670 + vq->vq_indirectoffset; 671 vd->addr += sizeof(struct vring_desc) 672 * vq->vq_maxnsegs * qe1->qe_index; 673 vd->len = sizeof(struct vring_desc) * nsegs; 674 vd->flags = VRING_DESC_F_INDIRECT; 675 676 vd = vq->vq_indirect; 677 vd += vq->vq_maxnsegs * qe1->qe_index; 678 qe1->qe_desc_base = vd; 679 680 for (i = 0; i < nsegs-1; i++) { 681 vd[i].flags = VRING_DESC_F_NEXT; 682 } 683 vd[i].flags = 0; 684 qe1->qe_next = 0; 685 686 return 0; 687 } else { 688 struct vring_desc *vd; 689 struct vq_entry *qe; 690 int i, s; 691 692 vd = &vq->vq_desc[0]; 693 qe1->qe_desc_base = vd; 694 qe1->qe_next = qe1->qe_index; 695 s = slot; 696 for (i = 0; i < nsegs - 1; i++) { 697 qe = vq_alloc_entry(vq); 698 if (qe == NULL) { 699 vd[s].flags = 0; 700 virtio_enqueue_abort(sc, vq, slot); 701 return EAGAIN; 702 } 703 vd[s].flags = VRING_DESC_F_NEXT; 704 vd[s].next = qe->qe_index; 705 s = qe->qe_index; 706 } 707 vd[s].flags = 0; 708 709 return 0; 710 } 711 } 712 713 /* 714 * enqueue: enqueue a single dmamap. 715 */ 716 int 717 virtio_enqueue(struct virtio_softc *sc, struct virtqueue *vq, int slot, 718 bus_dmamap_t dmamap, bool write) 719 { 720 struct vq_entry *qe1 = &vq->vq_entries[slot]; 721 struct vring_desc *vd = qe1->qe_desc_base; 722 int i; 723 int s = qe1->qe_next; 724 725 KASSERT(s >= 0); 726 KASSERT(dmamap->dm_nsegs > 0); 727 728 for (i = 0; i < dmamap->dm_nsegs; i++) { 729 vd[s].addr = dmamap->dm_segs[i].ds_addr; 730 vd[s].len = dmamap->dm_segs[i].ds_len; 731 if (!write) 732 vd[s].flags |= VRING_DESC_F_WRITE; 733 s = vd[s].next; 734 } 735 qe1->qe_next = s; 736 737 return 0; 738 } 739 740 int 741 virtio_enqueue_p(struct virtio_softc *sc, struct virtqueue *vq, int slot, 742 bus_dmamap_t dmamap, bus_addr_t start, bus_size_t len, 743 bool write) 744 { 745 struct vq_entry *qe1 = &vq->vq_entries[slot]; 746 struct vring_desc *vd = qe1->qe_desc_base; 747 int s = qe1->qe_next; 748 749 KASSERT(s >= 0); 750 KASSERT(dmamap->dm_nsegs == 1); /* XXX */ 751 KASSERT((dmamap->dm_segs[0].ds_len > start) && 752 (dmamap->dm_segs[0].ds_len >= start + len)); 753 754 vd[s].addr = dmamap->dm_segs[0].ds_addr + start; 755 vd[s].len = len; 756 if (!write) 757 vd[s].flags |= VRING_DESC_F_WRITE; 758 qe1->qe_next = vd[s].next; 759 760 return 0; 761 } 762 763 /* 764 * enqueue_commit: add it to the aring. 765 */ 766 int 767 virtio_enqueue_commit(struct virtio_softc *sc, struct virtqueue *vq, int slot, 768 bool notifynow) 769 { 770 struct vq_entry *qe1; 771 772 if (slot < 0) { 773 mutex_enter(&vq->vq_aring_lock); 774 goto notify; 775 } 776 vq_sync_descs(sc, vq, BUS_DMASYNC_PREWRITE); 777 qe1 = &vq->vq_entries[slot]; 778 if (qe1->qe_indirect) 779 vq_sync_indirect(sc, vq, slot, BUS_DMASYNC_PREWRITE); 780 mutex_enter(&vq->vq_aring_lock); 781 vq->vq_avail->ring[(vq->vq_avail_idx++) % vq->vq_num] = slot; 782 783 notify: 784 if (notifynow) { 785 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE); 786 vq_sync_uring(sc, vq, BUS_DMASYNC_PREREAD); 787 membar_producer(); 788 vq->vq_avail->idx = vq->vq_avail_idx; 789 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE); 790 membar_producer(); 791 vq->vq_queued++; 792 vq_sync_uring(sc, vq, BUS_DMASYNC_POSTREAD); 793 membar_consumer(); 794 if (!(vq->vq_used->flags & VRING_USED_F_NO_NOTIFY)) 795 sc->sc_ops->kick(sc, vq->vq_index); 796 } 797 mutex_exit(&vq->vq_aring_lock); 798 799 return 0; 800 } 801 802 /* 803 * enqueue_abort: rollback. 804 */ 805 int 806 virtio_enqueue_abort(struct virtio_softc *sc, struct virtqueue *vq, int slot) 807 { 808 struct vq_entry *qe = &vq->vq_entries[slot]; 809 struct vring_desc *vd; 810 int s; 811 812 if (qe->qe_next < 0) { 813 vq_free_entry(vq, qe); 814 return 0; 815 } 816 817 s = slot; 818 vd = &vq->vq_desc[0]; 819 while (vd[s].flags & VRING_DESC_F_NEXT) { 820 s = vd[s].next; 821 vq_free_entry(vq, qe); 822 qe = &vq->vq_entries[s]; 823 } 824 vq_free_entry(vq, qe); 825 return 0; 826 } 827 828 /* 829 * Dequeue a request. 830 */ 831 /* 832 * dequeue: dequeue a request from uring; dmamap_sync for uring is 833 * already done in the interrupt handler. 834 */ 835 int 836 virtio_dequeue(struct virtio_softc *sc, struct virtqueue *vq, 837 int *slotp, int *lenp) 838 { 839 uint16_t slot, usedidx; 840 struct vq_entry *qe; 841 842 if (vq->vq_used_idx == vq->vq_used->idx) 843 return ENOENT; 844 mutex_enter(&vq->vq_uring_lock); 845 usedidx = vq->vq_used_idx++; 846 mutex_exit(&vq->vq_uring_lock); 847 usedidx %= vq->vq_num; 848 slot = vq->vq_used->ring[usedidx].id; 849 qe = &vq->vq_entries[slot]; 850 851 if (qe->qe_indirect) 852 vq_sync_indirect(sc, vq, slot, BUS_DMASYNC_POSTWRITE); 853 854 if (slotp) 855 *slotp = slot; 856 if (lenp) 857 *lenp = vq->vq_used->ring[usedidx].len; 858 859 return 0; 860 } 861 862 /* 863 * dequeue_commit: complete dequeue; the slot is recycled for future use. 864 * if you forget to call this the slot will be leaked. 865 */ 866 int 867 virtio_dequeue_commit(struct virtio_softc *sc, struct virtqueue *vq, int slot) 868 { 869 struct vq_entry *qe = &vq->vq_entries[slot]; 870 struct vring_desc *vd = &vq->vq_desc[0]; 871 int s = slot; 872 873 while (vd[s].flags & VRING_DESC_F_NEXT) { 874 s = vd[s].next; 875 vq_free_entry(vq, qe); 876 qe = &vq->vq_entries[s]; 877 } 878 vq_free_entry(vq, qe); 879 880 return 0; 881 } 882 883 /* 884 * Attach a child, fill all the members. 885 */ 886 void 887 virtio_child_attach_start(struct virtio_softc *sc, device_t child, int ipl, 888 struct virtqueue *vqs, 889 virtio_callback config_change, 890 virtio_callback intr_hand, 891 int req_flags, int req_features, const char *feat_bits) 892 { 893 char buf[256]; 894 int features; 895 896 sc->sc_child = child; 897 sc->sc_ipl = ipl; 898 sc->sc_vqs = vqs; 899 sc->sc_config_change = config_change; 900 sc->sc_intrhand = intr_hand; 901 sc->sc_flags = req_flags; 902 903 features = virtio_negotiate_features(sc, req_features); 904 snprintb(buf, sizeof(buf), feat_bits, features); 905 aprint_normal(": Features: %s\n", buf); 906 aprint_naive("\n"); 907 } 908 909 void 910 virtio_child_attach_set_vqs(struct virtio_softc *sc, 911 struct virtqueue *vqs, int nvq_pairs) 912 { 913 if (nvq_pairs > 1) 914 sc->sc_child_mq = true; 915 916 sc->sc_vqs = vqs; 917 } 918 919 int 920 virtio_child_attach_finish(struct virtio_softc *sc) 921 { 922 int r; 923 924 r = sc->sc_ops->setup_interrupts(sc); 925 if (r != 0) { 926 aprint_error_dev(sc->sc_dev, "failed to setup interrupts\n"); 927 goto fail; 928 } 929 930 KASSERT(sc->sc_soft_ih == NULL); 931 if (sc->sc_flags & VIRTIO_F_PCI_INTR_SOFTINT) { 932 u_int flags = SOFTINT_NET; 933 if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE) 934 flags |= SOFTINT_MPSAFE; 935 936 sc->sc_soft_ih = softint_establish(flags, virtio_soft_intr, sc); 937 if (sc->sc_soft_ih == NULL) { 938 sc->sc_ops->free_interrupts(sc); 939 aprint_error_dev(sc->sc_dev, 940 "failed to establish soft interrupt\n"); 941 goto fail; 942 } 943 944 if (sc->sc_child_mq) { 945 r = virtio_vq_softint_establish(sc); 946 aprint_error_dev(sc->sc_dev, 947 "failed to establish softint interrupt\n"); 948 goto fail; 949 } 950 } 951 952 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER_OK); 953 return 0; 954 955 fail: 956 if (sc->sc_soft_ih) { 957 softint_disestablish(sc->sc_soft_ih); 958 sc->sc_soft_ih = NULL; 959 } 960 961 virtio_vq_softint_disestablish(sc); 962 963 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_FAILED); 964 return 1; 965 } 966 967 void 968 virtio_child_detach(struct virtio_softc *sc) 969 { 970 sc->sc_child = NULL; 971 sc->sc_vqs = NULL; 972 973 virtio_device_reset(sc); 974 975 sc->sc_ops->free_interrupts(sc); 976 977 if (sc->sc_soft_ih) { 978 softint_disestablish(sc->sc_soft_ih); 979 sc->sc_soft_ih = NULL; 980 } 981 } 982 983 void 984 virtio_child_attach_failed(struct virtio_softc *sc) 985 { 986 virtio_child_detach(sc); 987 988 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_FAILED); 989 990 sc->sc_child = VIRTIO_CHILD_FAILED; 991 } 992 993 bus_dma_tag_t 994 virtio_dmat(struct virtio_softc *sc) 995 { 996 return sc->sc_dmat; 997 } 998 999 device_t 1000 virtio_child(struct virtio_softc *sc) 1001 { 1002 return sc->sc_child; 1003 } 1004 1005 int 1006 virtio_intrhand(struct virtio_softc *sc) 1007 { 1008 return (sc->sc_intrhand)(sc); 1009 } 1010 1011 uint32_t 1012 virtio_features(struct virtio_softc *sc) 1013 { 1014 return sc->sc_features; 1015 } 1016 1017 int 1018 virtiobusprint(void *aux, const char *pnp) 1019 { 1020 struct virtio_attach_args * const va = aux; 1021 1022 if (va->sc_childdevid == 0) 1023 return QUIET; /* No device present */ 1024 1025 if (pnp) 1026 aprint_normal("Device ID %d at %s", va->sc_childdevid, pnp); 1027 1028 return UNCONF; 1029 } 1030 1031 MODULE(MODULE_CLASS_DRIVER, virtio, NULL); 1032 1033 #ifdef _MODULE 1034 #include "ioconf.c" 1035 #endif 1036 1037 static int 1038 virtio_modcmd(modcmd_t cmd, void *opaque) 1039 { 1040 int error = 0; 1041 1042 #ifdef _MODULE 1043 switch (cmd) { 1044 case MODULE_CMD_INIT: 1045 error = config_init_component(cfdriver_ioconf_virtio, 1046 cfattach_ioconf_virtio, cfdata_ioconf_virtio); 1047 break; 1048 case MODULE_CMD_FINI: 1049 error = config_fini_component(cfdriver_ioconf_virtio, 1050 cfattach_ioconf_virtio, cfdata_ioconf_virtio); 1051 break; 1052 default: 1053 error = ENOTTY; 1054 break; 1055 } 1056 #endif 1057 1058 return error; 1059 } 1060
Indexes created Fri Sep 26 08:10:20 GMT 2025