1 /*- 2 * Copyright (c) 2016 Akshay Jaggi <jaggi@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * gntdev.c 27 * 28 * Interface to /dev/xen/gntdev. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/uio.h> 38 #include <sys/bus.h> 39 #include <sys/malloc.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/mutex.h> 43 #include <sys/rwlock.h> 44 #include <sys/selinfo.h> 45 #include <sys/poll.h> 46 #include <sys/conf.h> 47 #include <sys/fcntl.h> 48 #include <sys/ioccom.h> 49 #include <sys/rman.h> 50 #include <sys/tree.h> 51 #include <sys/module.h> 52 #include <sys/proc.h> 53 #include <sys/bitset.h> 54 #include <sys/queue.h> 55 #include <sys/mman.h> 56 #include <sys/syslog.h> 57 #include <sys/taskqueue.h> 58 59 #include <vm/vm.h> 60 #include <vm/vm_param.h> 61 #include <vm/vm_extern.h> 62 #include <vm/vm_kern.h> 63 #include <vm/vm_page.h> 64 #include <vm/vm_map.h> 65 #include <vm/vm_object.h> 66 #include <vm/vm_pager.h> 67 68 #include <machine/md_var.h> 69 70 #include <xen/xen-os.h> 71 #include <xen/hypervisor.h> 72 #include <xen/error.h> 73 #include <xen/xen_intr.h> 74 #include <xen/gnttab.h> 75 #include <xen/gntdev.h> 76 77 MALLOC_DEFINE(M_GNTDEV, "gntdev", "Xen grant-table user-space device"); 78 79 #define MAX_OFFSET_COUNT ((0xffffffffffffffffull >> PAGE_SHIFT) + 1) 80 81 static d_open_t gntdev_open; 82 static d_ioctl_t gntdev_ioctl; 83 static d_mmap_single_t gntdev_mmap_single; 84 85 static struct cdevsw gntdev_devsw = { 86 .d_version = D_VERSION, 87 .d_open = gntdev_open, 88 .d_ioctl = gntdev_ioctl, 89 .d_mmap_single = gntdev_mmap_single, 90 .d_name = "gntdev", 91 }; 92 93 static device_t gntdev_dev = NULL; 94 95 struct gntdev_gref; 96 struct gntdev_gmap; 97 STAILQ_HEAD(gref_list_head, gntdev_gref); 98 STAILQ_HEAD(gmap_list_head, gntdev_gmap); 99 RB_HEAD(gref_tree_head, gntdev_gref); 100 RB_HEAD(gmap_tree_head, gntdev_gmap); 101 102 struct file_offset_struct { 103 RB_ENTRY(file_offset_struct) next; 104 uint64_t file_offset; 105 uint64_t count; 106 }; 107 108 static int 109 offset_cmp(struct file_offset_struct *f1, struct file_offset_struct *f2) 110 { 111 return (f1->file_offset - f2->file_offset); 112 } 113 114 RB_HEAD(file_offset_head, file_offset_struct); 115 RB_GENERATE_STATIC(file_offset_head, file_offset_struct, next, offset_cmp); 116 117 struct per_user_data { 118 struct mtx user_data_lock; 119 struct gref_tree_head gref_tree; 120 struct gmap_tree_head gmap_tree; 121 struct file_offset_head file_offset; 122 }; 123 124 /* 125 * Get offset into the file which will be used while mmapping the 126 * appropriate pages by the userspace program. 127 */ 128 static int 129 get_file_offset(struct per_user_data *priv_user, uint32_t count, 130 uint64_t *file_offset) 131 { 132 struct file_offset_struct *offset, *offset_tmp; 133 134 if (count == 0) 135 return (EINVAL); 136 mtx_lock(&priv_user->user_data_lock); 137 RB_FOREACH_SAFE(offset, file_offset_head, &priv_user->file_offset, 138 offset_tmp) { 139 if (offset->count >= count) { 140 offset->count -= count; 141 *file_offset = offset->file_offset + offset->count * 142 PAGE_SIZE; 143 if (offset->count == 0) { 144 RB_REMOVE(file_offset_head, 145 &priv_user->file_offset, offset); 146 free(offset, M_GNTDEV); 147 } 148 mtx_unlock(&priv_user->user_data_lock); 149 return (0); 150 } 151 } 152 mtx_unlock(&priv_user->user_data_lock); 153 154 return (ENOSPC); 155 } 156 157 static void 158 put_file_offset(struct per_user_data *priv_user, uint32_t count, 159 uint64_t file_offset) 160 { 161 struct file_offset_struct *offset, *offset_nxt, *offset_prv; 162 163 offset = malloc(sizeof(*offset), M_GNTDEV, M_WAITOK | M_ZERO); 164 offset->file_offset = file_offset; 165 offset->count = count; 166 167 mtx_lock(&priv_user->user_data_lock); 168 RB_INSERT(file_offset_head, &priv_user->file_offset, offset); 169 offset_nxt = RB_NEXT(file_offset_head, &priv_user->file_offset, offset); 170 offset_prv = RB_PREV(file_offset_head, &priv_user->file_offset, offset); 171 if (offset_nxt != NULL && 172 offset_nxt->file_offset == offset->file_offset + offset->count * 173 PAGE_SIZE) { 174 offset->count += offset_nxt->count; 175 RB_REMOVE(file_offset_head, &priv_user->file_offset, 176 offset_nxt); 177 free(offset_nxt, M_GNTDEV); 178 } 179 if (offset_prv != NULL && 180 offset->file_offset == offset_prv->file_offset + offset_prv->count * 181 PAGE_SIZE) { 182 offset_prv->count += offset->count; 183 RB_REMOVE(file_offset_head, &priv_user->file_offset, offset); 184 free(offset, M_GNTDEV); 185 } 186 mtx_unlock(&priv_user->user_data_lock); 187 } 188 189 static int gntdev_gmap_pg_ctor(void *handle, vm_ooffset_t size, 190 vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred, u_short *color); 191 static void gntdev_gmap_pg_dtor(void *handle); 192 static int gntdev_gmap_pg_fault(vm_object_t object, vm_ooffset_t offset, 193 int prot, vm_page_t *mres); 194 195 static struct cdev_pager_ops gntdev_gmap_pg_ops = { 196 .cdev_pg_fault = gntdev_gmap_pg_fault, 197 .cdev_pg_ctor = gntdev_gmap_pg_ctor, 198 .cdev_pg_dtor = gntdev_gmap_pg_dtor, 199 }; 200 201 struct cleanup_data_struct { 202 struct mtx to_kill_grefs_mtx; 203 struct mtx to_kill_gmaps_mtx; 204 struct gref_list_head to_kill_grefs; 205 struct gmap_list_head to_kill_gmaps; 206 }; 207 208 static struct cleanup_data_struct cleanup_data = { 209 .to_kill_grefs = STAILQ_HEAD_INITIALIZER(cleanup_data.to_kill_grefs), 210 .to_kill_gmaps = STAILQ_HEAD_INITIALIZER(cleanup_data.to_kill_gmaps), 211 }; 212 MTX_SYSINIT(to_kill_grefs_mtx, &cleanup_data.to_kill_grefs_mtx, 213 "gntdev to_kill_grefs mutex", MTX_DEF); 214 MTX_SYSINIT(to_kill_gmaps_mtx, &cleanup_data.to_kill_gmaps_mtx, 215 "gntdev to_kill_gmaps mutex", MTX_DEF); 216 217 static void cleanup_function(void *arg, __unused int pending); 218 static struct task cleanup_task = TASK_INITIALIZER(0, cleanup_function, 219 &cleanup_data); 220 221 struct notify_data { 222 uint64_t index; 223 uint32_t action; 224 uint32_t event_channel_port; 225 xen_intr_handle_t notify_evtchn_handle; 226 }; 227 228 static void notify(struct notify_data *notify, vm_page_t page); 229 230 /*-------------------- Grant Allocation Methods -----------------------------*/ 231 232 struct gntdev_gref { 233 union gref_next_union { 234 STAILQ_ENTRY(gntdev_gref) list; 235 RB_ENTRY(gntdev_gref) tree; 236 } gref_next; 237 uint64_t file_index; 238 grant_ref_t gref_id; 239 vm_page_t page; 240 struct notify_data *notify; 241 }; 242 243 static int 244 gref_cmp(struct gntdev_gref *g1, struct gntdev_gref *g2) 245 { 246 return (g1->file_index - g2->file_index); 247 } 248 249 RB_GENERATE_STATIC(gref_tree_head, gntdev_gref, gref_next.tree, gref_cmp); 250 251 /* 252 * Traverse over the device-list of to-be-deleted grants allocated, and 253 * if all accesses, both local mmaps and foreign maps, to them have ended, 254 * destroy them. 255 */ 256 static void 257 gref_list_dtor(struct cleanup_data_struct *cleanup_data) 258 { 259 struct gref_list_head tmp_grefs; 260 struct gntdev_gref *gref, *gref_tmp, *gref_previous; 261 262 STAILQ_INIT(&tmp_grefs); 263 mtx_lock(&cleanup_data->to_kill_grefs_mtx); 264 STAILQ_SWAP(&cleanup_data->to_kill_grefs, &tmp_grefs, gntdev_gref); 265 mtx_unlock(&cleanup_data->to_kill_grefs_mtx); 266 267 gref_previous = NULL; 268 STAILQ_FOREACH_SAFE(gref, &tmp_grefs, gref_next.list, gref_tmp) { 269 if (gref->page && gref->page->object == NULL) { 270 if (gref->notify) { 271 notify(gref->notify, gref->page); 272 } 273 if (gref->gref_id != GRANT_REF_INVALID) { 274 if (gnttab_query_foreign_access(gref->gref_id)) 275 continue; 276 if (gnttab_end_foreign_access_ref(gref->gref_id) 277 == 0) 278 continue; 279 gnttab_free_grant_reference(gref->gref_id); 280 } 281 vm_page_unwire_noq(gref->page); 282 vm_page_free(gref->page); 283 gref->page = NULL; 284 } 285 if (gref->page == NULL) { 286 if (gref_previous == NULL) 287 STAILQ_REMOVE_HEAD(&tmp_grefs, gref_next.list); 288 else 289 STAILQ_REMOVE_AFTER(&tmp_grefs, gref_previous, 290 gref_next.list); 291 if (gref->notify) 292 free(gref->notify, M_GNTDEV); 293 free(gref, M_GNTDEV); 294 } 295 else 296 gref_previous = gref; 297 } 298 299 if (!STAILQ_EMPTY(&tmp_grefs)) { 300 mtx_lock(&cleanup_data->to_kill_grefs_mtx); 301 STAILQ_CONCAT(&cleanup_data->to_kill_grefs, &tmp_grefs); 302 mtx_unlock(&cleanup_data->to_kill_grefs_mtx); 303 } 304 } 305 306 /* 307 * Find count number of contiguous allocated grants for a given userspace 308 * program by file-offset (index). 309 */ 310 static struct gntdev_gref* 311 gntdev_find_grefs(struct per_user_data *priv_user, 312 uint64_t index, uint32_t count) 313 { 314 struct gntdev_gref find_gref, *gref, *gref_start = NULL; 315 316 find_gref.file_index = index; 317 318 mtx_lock(&priv_user->user_data_lock); 319 gref_start = RB_FIND(gref_tree_head, &priv_user->gref_tree, &find_gref); 320 for (gref = gref_start; gref != NULL && count > 0; gref = 321 RB_NEXT(gref_tree_head, &priv_user->gref_tree, gref)) { 322 if (index != gref->file_index) 323 break; 324 index += PAGE_SIZE; 325 count--; 326 } 327 mtx_unlock(&priv_user->user_data_lock); 328 329 if (count) 330 return (NULL); 331 return (gref_start); 332 } 333 334 /* 335 * IOCTL_GNTDEV_ALLOC_GREF 336 * Allocate required number of wired pages for the request, grant foreign 337 * access to the physical frames for these pages, and add details about 338 * this allocation to the per user private data, so that these pages can 339 * be mmapped by the userspace program. 340 */ 341 static int 342 gntdev_alloc_gref(struct ioctl_gntdev_alloc_gref *arg) 343 { 344 uint32_t i; 345 int error, readonly; 346 uint64_t file_offset; 347 struct gntdev_gref *grefs; 348 struct per_user_data *priv_user; 349 350 readonly = !(arg->flags & GNTDEV_ALLOC_FLAG_WRITABLE); 351 352 error = devfs_get_cdevpriv((void**) &priv_user); 353 if (error != 0) 354 return (EINVAL); 355 356 /* Cleanup grefs and free pages. */ 357 taskqueue_enqueue(taskqueue_thread, &cleanup_task); 358 359 /* Get file offset for this request. */ 360 error = get_file_offset(priv_user, arg->count, &file_offset); 361 if (error != 0) 362 return (error); 363 364 /* Allocate grefs. */ 365 grefs = malloc(sizeof(*grefs) * arg->count, M_GNTDEV, M_WAITOK); 366 367 for (i = 0; i < arg->count; i++) { 368 grefs[i].file_index = file_offset + i * PAGE_SIZE; 369 grefs[i].gref_id = GRANT_REF_INVALID; 370 grefs[i].notify = NULL; 371 grefs[i].page = vm_page_alloc_noobj(VM_ALLOC_WIRED | 372 VM_ALLOC_ZERO); 373 if (grefs[i].page == NULL) { 374 log(LOG_ERR, "Page allocation failed."); 375 error = ENOMEM; 376 break; 377 } 378 grefs[i].page->valid = VM_PAGE_BITS_ALL; 379 380 error = gnttab_grant_foreign_access(arg->domid, 381 (VM_PAGE_TO_PHYS(grefs[i].page) >> PAGE_SHIFT), 382 readonly, &grefs[i].gref_id); 383 if (error != 0) { 384 log(LOG_ERR, "Grant Table Hypercall failed."); 385 break; 386 } 387 } 388 389 if (error != 0) { 390 /* 391 * If target domain maps the gref (by guessing the gref-id), 392 * then we can't clean it up yet and we have to leave the 393 * page in place so as to not leak our memory to that domain. 394 * Add it to a global list to be cleaned up later. 395 */ 396 mtx_lock(&cleanup_data.to_kill_grefs_mtx); 397 for (i = 0; i < arg->count; i++) 398 STAILQ_INSERT_TAIL(&cleanup_data.to_kill_grefs, 399 &grefs[i], gref_next.list); 400 mtx_unlock(&cleanup_data.to_kill_grefs_mtx); 401 402 taskqueue_enqueue(taskqueue_thread, &cleanup_task); 403 404 return (error); 405 } 406 407 /* Copy the output values. */ 408 arg->index = file_offset; 409 for (i = 0; i < arg->count; i++) 410 suword32(&arg->gref_ids[i], grefs[i].gref_id); 411 412 /* Modify the per user private data. */ 413 mtx_lock(&priv_user->user_data_lock); 414 for (i = 0; i < arg->count; i++) 415 RB_INSERT(gref_tree_head, &priv_user->gref_tree, &grefs[i]); 416 mtx_unlock(&priv_user->user_data_lock); 417 418 return (error); 419 } 420 421 /* 422 * IOCTL_GNTDEV_DEALLOC_GREF 423 * Remove grant allocation information from the per user private data, so 424 * that it can't be mmapped anymore by the userspace program, and add it 425 * to the to-be-deleted grants global device-list. 426 */ 427 static int 428 gntdev_dealloc_gref(struct ioctl_gntdev_dealloc_gref *arg) 429 { 430 int error; 431 uint32_t count; 432 struct gntdev_gref *gref, *gref_tmp; 433 struct per_user_data *priv_user; 434 435 error = devfs_get_cdevpriv((void**) &priv_user); 436 if (error != 0) 437 return (EINVAL); 438 439 gref = gntdev_find_grefs(priv_user, arg->index, arg->count); 440 if (gref == NULL) { 441 log(LOG_ERR, "Can't find requested grant-refs."); 442 return (EINVAL); 443 } 444 445 /* Remove the grefs from user private data. */ 446 count = arg->count; 447 mtx_lock(&priv_user->user_data_lock); 448 mtx_lock(&cleanup_data.to_kill_grefs_mtx); 449 for (; gref != NULL && count > 0; gref = gref_tmp) { 450 gref_tmp = RB_NEXT(gref_tree_head, &priv_user->gref_tree, gref); 451 RB_REMOVE(gref_tree_head, &priv_user->gref_tree, gref); 452 STAILQ_INSERT_TAIL(&cleanup_data.to_kill_grefs, gref, 453 gref_next.list); 454 count--; 455 } 456 mtx_unlock(&cleanup_data.to_kill_grefs_mtx); 457 mtx_unlock(&priv_user->user_data_lock); 458 459 taskqueue_enqueue(taskqueue_thread, &cleanup_task); 460 put_file_offset(priv_user, arg->count, arg->index); 461 462 return (0); 463 } 464 465 /*-------------------- Grant Mapping Methods --------------------------------*/ 466 467 struct gntdev_gmap_map { 468 vm_object_t mem; 469 struct resource *pseudo_phys_res; 470 int pseudo_phys_res_id; 471 vm_paddr_t phys_base_addr; 472 }; 473 474 struct gntdev_gmap { 475 union gmap_next_union { 476 STAILQ_ENTRY(gntdev_gmap) list; 477 RB_ENTRY(gntdev_gmap) tree; 478 } gmap_next; 479 uint64_t file_index; 480 uint32_t count; 481 struct gnttab_map_grant_ref *grant_map_ops; 482 struct gntdev_gmap_map *map; 483 struct notify_data *notify; 484 }; 485 486 static int 487 gmap_cmp(struct gntdev_gmap *g1, struct gntdev_gmap *g2) 488 { 489 return (g1->file_index - g2->file_index); 490 } 491 492 RB_GENERATE_STATIC(gmap_tree_head, gntdev_gmap, gmap_next.tree, gmap_cmp); 493 494 /* 495 * Traverse over the device-list of to-be-deleted grant mappings, and if 496 * the region is no longer mmapped by anyone, free the memory used to 497 * store information about the mapping. 498 */ 499 static void 500 gmap_list_dtor(struct cleanup_data_struct *cleanup_data) 501 { 502 struct gmap_list_head tmp_gmaps; 503 struct gntdev_gmap *gmap, *gmap_tmp, *gmap_previous; 504 505 STAILQ_INIT(&tmp_gmaps); 506 mtx_lock(&cleanup_data->to_kill_gmaps_mtx); 507 STAILQ_SWAP(&cleanup_data->to_kill_gmaps, &tmp_gmaps, gntdev_gmap); 508 mtx_unlock(&cleanup_data->to_kill_gmaps_mtx); 509 510 gmap_previous = NULL; 511 STAILQ_FOREACH_SAFE(gmap, &tmp_gmaps, gmap_next.list, gmap_tmp) { 512 if (gmap->map == NULL) { 513 if (gmap_previous == NULL) 514 STAILQ_REMOVE_HEAD(&tmp_gmaps, gmap_next.list); 515 else 516 STAILQ_REMOVE_AFTER(&tmp_gmaps, gmap_previous, 517 gmap_next.list); 518 519 if (gmap->notify) 520 free(gmap->notify, M_GNTDEV); 521 free(gmap->grant_map_ops, M_GNTDEV); 522 free(gmap, M_GNTDEV); 523 } 524 else 525 gmap_previous = gmap; 526 } 527 528 if (!STAILQ_EMPTY(&tmp_gmaps)) { 529 mtx_lock(&cleanup_data->to_kill_gmaps_mtx); 530 STAILQ_CONCAT(&cleanup_data->to_kill_gmaps, &tmp_gmaps); 531 mtx_unlock(&cleanup_data->to_kill_gmaps_mtx); 532 } 533 } 534 535 /* 536 * Find mapped grants for a given userspace program, by file-offset (index) 537 * and count, as supplied during the map-ioctl. 538 */ 539 static struct gntdev_gmap* 540 gntdev_find_gmap(struct per_user_data *priv_user, 541 uint64_t index, uint32_t count) 542 { 543 struct gntdev_gmap find_gmap, *gmap; 544 545 find_gmap.file_index = index; 546 547 mtx_lock(&priv_user->user_data_lock); 548 gmap = RB_FIND(gmap_tree_head, &priv_user->gmap_tree, &find_gmap); 549 mtx_unlock(&priv_user->user_data_lock); 550 551 if (gmap != NULL && gmap->count == count) 552 return (gmap); 553 return (NULL); 554 } 555 556 /* 557 * Remove the pages from the mgtdevice pager, call the unmap hypercall, 558 * free the xenmem resource. This function is called during the 559 * destruction of the mgtdevice pager, which happens when all mmaps to 560 * it have been removed, and the unmap-ioctl has been performed. 561 */ 562 static int 563 notify_unmap_cleanup(struct gntdev_gmap *gmap) 564 { 565 uint32_t i; 566 int error, count; 567 vm_page_t m; 568 struct gnttab_unmap_grant_ref *unmap_ops; 569 570 unmap_ops = malloc(sizeof(struct gnttab_unmap_grant_ref) * gmap->count, 571 M_GNTDEV, M_WAITOK); 572 573 /* Enumerate freeable maps. */ 574 count = 0; 575 for (i = 0; i < gmap->count; i++) { 576 if (gmap->grant_map_ops[i].handle != -1) { 577 unmap_ops[count].handle = gmap->grant_map_ops[i].handle; 578 unmap_ops[count].host_addr = 579 gmap->grant_map_ops[i].host_addr; 580 unmap_ops[count].dev_bus_addr = 0; 581 count++; 582 } 583 } 584 585 /* Perform notification. */ 586 if (count > 0 && gmap->notify) { 587 vm_page_t page; 588 uint64_t page_offset; 589 590 page_offset = gmap->notify->index - gmap->file_index; 591 page = PHYS_TO_VM_PAGE(gmap->map->phys_base_addr + page_offset); 592 notify(gmap->notify, page); 593 } 594 595 /* Free the pages. */ 596 VM_OBJECT_WLOCK(gmap->map->mem); 597 retry: 598 for (i = 0; i < gmap->count; i++) { 599 m = vm_page_lookup(gmap->map->mem, i); 600 if (m == NULL) 601 continue; 602 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) 603 goto retry; 604 cdev_pager_free_page(gmap->map->mem, m); 605 } 606 VM_OBJECT_WUNLOCK(gmap->map->mem); 607 608 /* Perform unmap hypercall. */ 609 error = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, 610 unmap_ops, count); 611 612 for (i = 0; i < gmap->count; i++) { 613 gmap->grant_map_ops[i].handle = -1; 614 gmap->grant_map_ops[i].host_addr = 0; 615 } 616 617 if (gmap->map) { 618 error = xenmem_free(gntdev_dev, gmap->map->pseudo_phys_res_id, 619 gmap->map->pseudo_phys_res); 620 KASSERT(error == 0, 621 ("Unable to release memory resource: %d", error)); 622 623 free(gmap->map, M_GNTDEV); 624 gmap->map = NULL; 625 } 626 627 free(unmap_ops, M_GNTDEV); 628 629 return (error); 630 } 631 632 /* 633 * IOCTL_GNTDEV_MAP_GRANT_REF 634 * Populate structures for mapping the grant reference in the per user 635 * private data. Actual resource allocation and map hypercall is performed 636 * during the mmap. 637 */ 638 static int 639 gntdev_map_grant_ref(struct ioctl_gntdev_map_grant_ref *arg) 640 { 641 uint32_t i; 642 int error; 643 struct gntdev_gmap *gmap; 644 struct per_user_data *priv_user; 645 646 error = devfs_get_cdevpriv((void**) &priv_user); 647 if (error != 0) 648 return (EINVAL); 649 650 gmap = malloc(sizeof(*gmap), M_GNTDEV, M_WAITOK | M_ZERO); 651 gmap->count = arg->count; 652 gmap->grant_map_ops = 653 malloc(sizeof(struct gnttab_map_grant_ref) * arg->count, 654 M_GNTDEV, M_WAITOK | M_ZERO); 655 656 for (i = 0; i < arg->count; i++) { 657 struct ioctl_gntdev_grant_ref ref; 658 659 error = copyin(&arg->refs[i], &ref, sizeof(ref)); 660 if (error != 0) { 661 free(gmap->grant_map_ops, M_GNTDEV); 662 free(gmap, M_GNTDEV); 663 return (error); 664 } 665 gmap->grant_map_ops[i].dom = ref.domid; 666 gmap->grant_map_ops[i].ref = ref.ref; 667 gmap->grant_map_ops[i].handle = -1; 668 gmap->grant_map_ops[i].flags = GNTMAP_host_map; 669 } 670 671 error = get_file_offset(priv_user, arg->count, &gmap->file_index); 672 if (error != 0) { 673 free(gmap->grant_map_ops, M_GNTDEV); 674 free(gmap, M_GNTDEV); 675 return (error); 676 } 677 678 mtx_lock(&priv_user->user_data_lock); 679 RB_INSERT(gmap_tree_head, &priv_user->gmap_tree, gmap); 680 mtx_unlock(&priv_user->user_data_lock); 681 682 arg->index = gmap->file_index; 683 684 return (error); 685 } 686 687 /* 688 * IOCTL_GNTDEV_UNMAP_GRANT_REF 689 * Remove the map information from the per user private data and add it 690 * to the global device-list of mappings to be deleted. A reference to 691 * the mgtdevice pager is also decreased, the reason for which is 692 * explained in mmap_gmap(). 693 */ 694 static int 695 gntdev_unmap_grant_ref(struct ioctl_gntdev_unmap_grant_ref *arg) 696 { 697 int error; 698 struct gntdev_gmap *gmap; 699 struct per_user_data *priv_user; 700 701 error = devfs_get_cdevpriv((void**) &priv_user); 702 if (error != 0) 703 return (EINVAL); 704 705 gmap = gntdev_find_gmap(priv_user, arg->index, arg->count); 706 if (gmap == NULL) { 707 log(LOG_ERR, "Can't find requested grant-map."); 708 return (EINVAL); 709 } 710 711 mtx_lock(&priv_user->user_data_lock); 712 mtx_lock(&cleanup_data.to_kill_gmaps_mtx); 713 RB_REMOVE(gmap_tree_head, &priv_user->gmap_tree, gmap); 714 STAILQ_INSERT_TAIL(&cleanup_data.to_kill_gmaps, gmap, gmap_next.list); 715 mtx_unlock(&cleanup_data.to_kill_gmaps_mtx); 716 mtx_unlock(&priv_user->user_data_lock); 717 718 if (gmap->map) 719 vm_object_deallocate(gmap->map->mem); 720 721 taskqueue_enqueue(taskqueue_thread, &cleanup_task); 722 put_file_offset(priv_user, arg->count, arg->index); 723 724 return (0); 725 } 726 727 /* 728 * IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR 729 * Get file-offset and count for a given mapping, from the virtual address 730 * where the mapping is mmapped. 731 * Please note, this only works for grants mapped by this domain, and not 732 * grants allocated. Count doesn't make much sense in reference to grants 733 * allocated. Also, because this function is present in the linux gntdev 734 * device, but not in the linux gntalloc one, most userspace code only use 735 * it for mapped grants. 736 */ 737 static int 738 gntdev_get_offset_for_vaddr(struct ioctl_gntdev_get_offset_for_vaddr *arg, 739 struct thread *td) 740 { 741 int error; 742 vm_map_t map; 743 vm_map_entry_t entry; 744 vm_object_t mem; 745 vm_pindex_t pindex; 746 vm_prot_t prot; 747 boolean_t wired; 748 struct gntdev_gmap *gmap; 749 int rc; 750 751 map = &td->td_proc->p_vmspace->vm_map; 752 error = vm_map_lookup(&map, arg->vaddr, VM_PROT_NONE, &entry, 753 &mem, &pindex, &prot, &wired); 754 if (error != KERN_SUCCESS) 755 return (EINVAL); 756 757 if ((mem->type != OBJT_MGTDEVICE) || 758 (mem->un_pager.devp.ops != &gntdev_gmap_pg_ops)) { 759 rc = EINVAL; 760 goto out; 761 } 762 763 gmap = mem->handle; 764 if (gmap == NULL || 765 (entry->end - entry->start) != (gmap->count * PAGE_SIZE)) { 766 rc = EINVAL; 767 goto out; 768 } 769 770 arg->count = gmap->count; 771 arg->offset = gmap->file_index; 772 rc = 0; 773 774 out: 775 vm_map_lookup_done(map, entry); 776 return (rc); 777 } 778 779 /*-------------------- Grant Mapping Pager ----------------------------------*/ 780 781 static int 782 gntdev_gmap_pg_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 783 vm_ooffset_t foff, struct ucred *cred, u_short *color) 784 { 785 786 return (0); 787 } 788 789 static void 790 gntdev_gmap_pg_dtor(void *handle) 791 { 792 793 notify_unmap_cleanup((struct gntdev_gmap *)handle); 794 } 795 796 static int 797 gntdev_gmap_pg_fault(vm_object_t object, vm_ooffset_t offset, int prot, 798 vm_page_t *mres) 799 { 800 struct gntdev_gmap *gmap = object->handle; 801 vm_pindex_t pidx, ridx; 802 vm_page_t page; 803 vm_ooffset_t relative_offset; 804 805 if (gmap->map == NULL) 806 return (VM_PAGER_FAIL); 807 808 relative_offset = offset - gmap->file_index; 809 810 pidx = OFF_TO_IDX(offset); 811 ridx = OFF_TO_IDX(relative_offset); 812 if (ridx >= gmap->count || 813 gmap->grant_map_ops[ridx].status != GNTST_okay) 814 return (VM_PAGER_FAIL); 815 816 page = PHYS_TO_VM_PAGE(gmap->map->phys_base_addr + relative_offset); 817 if (page == NULL) 818 return (VM_PAGER_FAIL); 819 820 KASSERT((page->flags & PG_FICTITIOUS) != 0, 821 ("not fictitious %p", page)); 822 KASSERT(vm_page_wired(page), ("page %p is not wired", page)); 823 KASSERT(!vm_page_busied(page), ("page %p is busy", page)); 824 825 vm_page_busy_acquire(page, 0); 826 vm_page_valid(page); 827 if (*mres != NULL) 828 vm_page_replace(page, object, pidx, *mres); 829 else 830 vm_page_insert(page, object, pidx); 831 *mres = page; 832 return (VM_PAGER_OK); 833 } 834 835 /*------------------ Grant Table Methods ------------------------------------*/ 836 837 static void 838 notify(struct notify_data *notify, vm_page_t page) 839 { 840 if (notify->action & UNMAP_NOTIFY_CLEAR_BYTE) { 841 uint8_t *mem; 842 uint64_t offset; 843 844 offset = notify->index & PAGE_MASK; 845 mem = (uint8_t *)pmap_quick_enter_page(page); 846 mem[offset] = 0; 847 pmap_quick_remove_page((vm_offset_t)mem); 848 } 849 if (notify->action & UNMAP_NOTIFY_SEND_EVENT) { 850 xen_intr_signal(notify->notify_evtchn_handle); 851 xen_intr_unbind(¬ify->notify_evtchn_handle); 852 } 853 notify->action = 0; 854 } 855 856 /* 857 * Helper to copy new arguments from the notify ioctl into 858 * the existing notify data. 859 */ 860 static int 861 copy_notify_helper(struct notify_data *destination, 862 struct ioctl_gntdev_unmap_notify *source) 863 { 864 xen_intr_handle_t handlep = NULL; 865 866 /* 867 * "Get" before "Put"ting previous reference, as we might be 868 * holding the last reference to the event channel port. 869 */ 870 if (source->action & UNMAP_NOTIFY_SEND_EVENT) 871 if (xen_intr_get_evtchn_from_port(source->event_channel_port, 872 &handlep) != 0) 873 return (EINVAL); 874 875 if (destination->action & UNMAP_NOTIFY_SEND_EVENT) 876 xen_intr_unbind(&destination->notify_evtchn_handle); 877 878 destination->action = source->action; 879 destination->event_channel_port = source->event_channel_port; 880 destination->index = source->index; 881 destination->notify_evtchn_handle = handlep; 882 883 return (0); 884 } 885 886 /* 887 * IOCTL_GNTDEV_SET_UNMAP_NOTIFY 888 * Set unmap notification inside the appropriate grant. It sends a 889 * notification when the grant is completely munmapped by this domain 890 * and ready for destruction. 891 */ 892 static int 893 gntdev_set_unmap_notify(struct ioctl_gntdev_unmap_notify *arg) 894 { 895 int error; 896 uint64_t index; 897 struct per_user_data *priv_user; 898 struct gntdev_gref *gref = NULL; 899 struct gntdev_gmap *gmap; 900 901 error = devfs_get_cdevpriv((void**) &priv_user); 902 if (error != 0) 903 return (EINVAL); 904 905 if (arg->action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) 906 return (EINVAL); 907 908 index = arg->index & ~PAGE_MASK; 909 gref = gntdev_find_grefs(priv_user, index, 1); 910 if (gref) { 911 if (gref->notify == NULL) 912 gref->notify = malloc(sizeof(*arg), M_GNTDEV, 913 M_WAITOK | M_ZERO); 914 return (copy_notify_helper(gref->notify, arg)); 915 } 916 917 error = EINVAL; 918 mtx_lock(&priv_user->user_data_lock); 919 RB_FOREACH(gmap, gmap_tree_head, &priv_user->gmap_tree) { 920 if (arg->index >= gmap->file_index && 921 arg->index < gmap->file_index + gmap->count * PAGE_SIZE) { 922 if (gmap->notify == NULL) 923 gmap->notify = malloc(sizeof(*arg), M_GNTDEV, 924 M_WAITOK | M_ZERO); 925 error = copy_notify_helper(gmap->notify, arg); 926 break; 927 } 928 } 929 mtx_unlock(&priv_user->user_data_lock); 930 931 return (error); 932 } 933 934 /*------------------ Gntdev Char Device Methods -----------------------------*/ 935 936 static void 937 cleanup_function(void *arg, __unused int pending) 938 { 939 940 gref_list_dtor((struct cleanup_data_struct *) arg); 941 gmap_list_dtor((struct cleanup_data_struct *) arg); 942 } 943 944 static void 945 per_user_data_dtor(void *arg) 946 { 947 struct gntdev_gref *gref, *gref_tmp; 948 struct gntdev_gmap *gmap, *gmap_tmp; 949 struct file_offset_struct *offset, *offset_tmp; 950 struct per_user_data *priv_user; 951 952 priv_user = (struct per_user_data *) arg; 953 954 mtx_lock(&priv_user->user_data_lock); 955 956 mtx_lock(&cleanup_data.to_kill_grefs_mtx); 957 RB_FOREACH_SAFE(gref, gref_tree_head, &priv_user->gref_tree, gref_tmp) { 958 RB_REMOVE(gref_tree_head, &priv_user->gref_tree, gref); 959 STAILQ_INSERT_TAIL(&cleanup_data.to_kill_grefs, gref, 960 gref_next.list); 961 } 962 mtx_unlock(&cleanup_data.to_kill_grefs_mtx); 963 964 mtx_lock(&cleanup_data.to_kill_gmaps_mtx); 965 RB_FOREACH_SAFE(gmap, gmap_tree_head, &priv_user->gmap_tree, gmap_tmp) { 966 RB_REMOVE(gmap_tree_head, &priv_user->gmap_tree, gmap); 967 STAILQ_INSERT_TAIL(&cleanup_data.to_kill_gmaps, gmap, 968 gmap_next.list); 969 if (gmap->map) 970 vm_object_deallocate(gmap->map->mem); 971 } 972 mtx_unlock(&cleanup_data.to_kill_gmaps_mtx); 973 974 RB_FOREACH_SAFE(offset, file_offset_head, &priv_user->file_offset, 975 offset_tmp) { 976 RB_REMOVE(file_offset_head, &priv_user->file_offset, offset); 977 free(offset, M_GNTDEV); 978 } 979 980 mtx_unlock(&priv_user->user_data_lock); 981 982 taskqueue_enqueue(taskqueue_thread, &cleanup_task); 983 984 mtx_destroy(&priv_user->user_data_lock); 985 free(priv_user, M_GNTDEV); 986 } 987 988 static int 989 gntdev_open(struct cdev *dev, int flag, int otyp, struct thread *td) 990 { 991 int error; 992 struct per_user_data *priv_user; 993 struct file_offset_struct *offset; 994 995 priv_user = malloc(sizeof(*priv_user), M_GNTDEV, M_WAITOK | M_ZERO); 996 RB_INIT(&priv_user->gref_tree); 997 RB_INIT(&priv_user->gmap_tree); 998 RB_INIT(&priv_user->file_offset); 999 offset = malloc(sizeof(*offset), M_GNTDEV, M_WAITOK | M_ZERO); 1000 offset->file_offset = 0; 1001 offset->count = MAX_OFFSET_COUNT; 1002 RB_INSERT(file_offset_head, &priv_user->file_offset, offset); 1003 mtx_init(&priv_user->user_data_lock, 1004 "per user data mutex", NULL, MTX_DEF); 1005 1006 error = devfs_set_cdevpriv(priv_user, per_user_data_dtor); 1007 if (error != 0) 1008 per_user_data_dtor(priv_user); 1009 1010 return (error); 1011 } 1012 1013 static int 1014 gntdev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, 1015 int fflag, struct thread *td) 1016 { 1017 int error; 1018 1019 switch (cmd) { 1020 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: 1021 error = gntdev_set_unmap_notify( 1022 (struct ioctl_gntdev_unmap_notify*) data); 1023 break; 1024 case IOCTL_GNTDEV_ALLOC_GREF: 1025 error = gntdev_alloc_gref( 1026 (struct ioctl_gntdev_alloc_gref*) data); 1027 break; 1028 case IOCTL_GNTDEV_DEALLOC_GREF: 1029 error = gntdev_dealloc_gref( 1030 (struct ioctl_gntdev_dealloc_gref*) data); 1031 break; 1032 case IOCTL_GNTDEV_MAP_GRANT_REF: 1033 error = gntdev_map_grant_ref( 1034 (struct ioctl_gntdev_map_grant_ref*) data); 1035 break; 1036 case IOCTL_GNTDEV_UNMAP_GRANT_REF: 1037 error = gntdev_unmap_grant_ref( 1038 (struct ioctl_gntdev_unmap_grant_ref*) data); 1039 break; 1040 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: 1041 error = gntdev_get_offset_for_vaddr( 1042 (struct ioctl_gntdev_get_offset_for_vaddr*) data, td); 1043 break; 1044 default: 1045 error = ENOSYS; 1046 break; 1047 } 1048 1049 return (error); 1050 } 1051 1052 /* 1053 * MMAP an allocated grant into user memory. 1054 * Please note, that the grants must not already be mmapped, otherwise 1055 * this function will fail. 1056 */ 1057 static int 1058 mmap_gref(struct per_user_data *priv_user, struct gntdev_gref *gref_start, 1059 uint32_t count, vm_size_t size, struct vm_object **object) 1060 { 1061 vm_object_t mem_obj; 1062 struct gntdev_gref *gref; 1063 1064 mem_obj = vm_pager_allocate(OBJT_PHYS, NULL, size, VM_PROT_ALL, 0, 1065 curthread->td_ucred); 1066 if (mem_obj == NULL) 1067 return (ENOMEM); 1068 1069 mtx_lock(&priv_user->user_data_lock); 1070 VM_OBJECT_WLOCK(mem_obj); 1071 for (gref = gref_start; gref != NULL && count > 0; gref = 1072 RB_NEXT(gref_tree_head, &priv_user->gref_tree, gref)) { 1073 if (gref->page->object) 1074 break; 1075 1076 vm_page_insert(gref->page, mem_obj, 1077 OFF_TO_IDX(gref->file_index)); 1078 1079 count--; 1080 } 1081 VM_OBJECT_WUNLOCK(mem_obj); 1082 mtx_unlock(&priv_user->user_data_lock); 1083 1084 if (count) { 1085 vm_object_deallocate(mem_obj); 1086 return (EINVAL); 1087 } 1088 1089 *object = mem_obj; 1090 1091 return (0); 1092 1093 } 1094 1095 /* 1096 * MMAP a mapped grant into user memory. 1097 */ 1098 static int 1099 mmap_gmap(struct per_user_data *priv_user, struct gntdev_gmap *gmap_start, 1100 vm_ooffset_t *offset, vm_size_t size, struct vm_object **object, int nprot) 1101 { 1102 uint32_t i; 1103 int error; 1104 1105 /* 1106 * The grant map hypercall might already be done. 1107 * If that is the case, increase a reference to the 1108 * vm object and return the already allocated object. 1109 */ 1110 if (gmap_start->map) { 1111 vm_object_reference(gmap_start->map->mem); 1112 *object = gmap_start->map->mem; 1113 return (0); 1114 } 1115 1116 gmap_start->map = malloc(sizeof(*(gmap_start->map)), M_GNTDEV, 1117 M_WAITOK | M_ZERO); 1118 1119 /* Allocate the xen pseudo physical memory resource. */ 1120 gmap_start->map->pseudo_phys_res_id = 0; 1121 gmap_start->map->pseudo_phys_res = xenmem_alloc(gntdev_dev, 1122 &gmap_start->map->pseudo_phys_res_id, size); 1123 if (gmap_start->map->pseudo_phys_res == NULL) { 1124 free(gmap_start->map, M_GNTDEV); 1125 gmap_start->map = NULL; 1126 return (ENOMEM); 1127 } 1128 gmap_start->map->phys_base_addr = 1129 rman_get_start(gmap_start->map->pseudo_phys_res); 1130 1131 /* Allocate the mgtdevice pager. */ 1132 gmap_start->map->mem = cdev_pager_allocate(gmap_start, OBJT_MGTDEVICE, 1133 &gntdev_gmap_pg_ops, size, nprot, *offset, NULL); 1134 if (gmap_start->map->mem == NULL) { 1135 xenmem_free(gntdev_dev, gmap_start->map->pseudo_phys_res_id, 1136 gmap_start->map->pseudo_phys_res); 1137 free(gmap_start->map, M_GNTDEV); 1138 gmap_start->map = NULL; 1139 return (ENOMEM); 1140 } 1141 1142 for (i = 0; i < gmap_start->count; i++) { 1143 gmap_start->grant_map_ops[i].host_addr = 1144 gmap_start->map->phys_base_addr + i * PAGE_SIZE; 1145 1146 if ((nprot & PROT_WRITE) == 0) 1147 gmap_start->grant_map_ops[i].flags |= GNTMAP_readonly; 1148 } 1149 /* Make the MAP hypercall. */ 1150 error = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, 1151 gmap_start->grant_map_ops, gmap_start->count); 1152 if (error != 0) { 1153 /* 1154 * Deallocate pager. 1155 * Pager deallocation will automatically take care of 1156 * xenmem deallocation, etc. 1157 */ 1158 vm_object_deallocate(gmap_start->map->mem); 1159 1160 return (EINVAL); 1161 } 1162 1163 /* Retry EAGAIN maps. */ 1164 for (i = 0; i < gmap_start->count; i++) { 1165 int delay = 1; 1166 while (delay < 256 && 1167 gmap_start->grant_map_ops[i].status == GNTST_eagain) { 1168 HYPERVISOR_grant_table_op( GNTTABOP_map_grant_ref, 1169 &gmap_start->grant_map_ops[i], 1); 1170 pause(("gntmap"), delay * SBT_1MS); 1171 delay++; 1172 } 1173 if (gmap_start->grant_map_ops[i].status == GNTST_eagain) 1174 gmap_start->grant_map_ops[i].status = GNTST_bad_page; 1175 1176 if (gmap_start->grant_map_ops[i].status != GNTST_okay) { 1177 /* 1178 * Deallocate pager. 1179 * Pager deallocation will automatically take care of 1180 * xenmem deallocation, notification, unmap hypercall, 1181 * etc. 1182 */ 1183 vm_object_deallocate(gmap_start->map->mem); 1184 1185 return (EINVAL); 1186 } 1187 } 1188 1189 /* 1190 * Add a reference to the vm object. We do not want 1191 * the vm object to be deleted when all the mmaps are 1192 * unmapped, because it may be re-mmapped. Instead, 1193 * we want the object to be deleted, when along with 1194 * munmaps, we have also processed the unmap-ioctl. 1195 */ 1196 vm_object_reference(gmap_start->map->mem); 1197 1198 *object = gmap_start->map->mem; 1199 1200 return (0); 1201 } 1202 1203 static int 1204 gntdev_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t size, 1205 struct vm_object **object, int nprot) 1206 { 1207 int error; 1208 uint32_t count; 1209 struct gntdev_gref *gref_start; 1210 struct gntdev_gmap *gmap_start; 1211 struct per_user_data *priv_user; 1212 1213 error = devfs_get_cdevpriv((void**) &priv_user); 1214 if (error != 0) 1215 return (EINVAL); 1216 1217 count = OFF_TO_IDX(size); 1218 1219 gref_start = gntdev_find_grefs(priv_user, *offset, count); 1220 if (gref_start) { 1221 error = mmap_gref(priv_user, gref_start, count, size, object); 1222 return (error); 1223 } 1224 1225 gmap_start = gntdev_find_gmap(priv_user, *offset, count); 1226 if (gmap_start) { 1227 error = mmap_gmap(priv_user, gmap_start, offset, size, object, 1228 nprot); 1229 return (error); 1230 } 1231 1232 return (EINVAL); 1233 } 1234 1235 /*------------------ Private Device Attachment Functions --------------------*/ 1236 static void 1237 gntdev_identify(driver_t *driver, device_t parent) 1238 { 1239 1240 KASSERT((xen_domain()), 1241 ("Trying to attach gntdev device on non Xen domain")); 1242 1243 if (BUS_ADD_CHILD(parent, 0, "gntdev", 0) == NULL) 1244 panic("unable to attach gntdev user-space device"); 1245 } 1246 1247 static int 1248 gntdev_probe(device_t dev) 1249 { 1250 1251 gntdev_dev = dev; 1252 device_set_desc(dev, "Xen grant-table user-space device"); 1253 return (BUS_PROBE_NOWILDCARD); 1254 } 1255 1256 static int 1257 gntdev_attach(device_t dev) 1258 { 1259 1260 make_dev_credf(MAKEDEV_ETERNAL, &gntdev_devsw, 0, NULL, UID_ROOT, 1261 GID_WHEEL, 0600, "xen/gntdev"); 1262 return (0); 1263 } 1264 1265 /*-------------------- Private Device Attachment Data -----------------------*/ 1266 static device_method_t gntdev_methods[] = { 1267 DEVMETHOD(device_identify, gntdev_identify), 1268 DEVMETHOD(device_probe, gntdev_probe), 1269 DEVMETHOD(device_attach, gntdev_attach), 1270 DEVMETHOD_END 1271 }; 1272 1273 static driver_t gntdev_driver = { 1274 "gntdev", 1275 gntdev_methods, 1276 0, 1277 }; 1278 1279 DRIVER_MODULE(gntdev, xenpv, gntdev_driver, 0, 0); 1280 MODULE_DEPEND(gntdev, xenpv, 1, 1, 1); 1281