1 /* Copyright (C) 2009 Red Hat, Inc. 2 * Copyright (C) 2006 Rusty Russell IBM Corporation 3 * 4 * Author: Michael S. Tsirkin <mst@redhat.com> 5 * 6 * Inspiration, some code, and most witty comments come from 7 * Documentation/lguest/lguest.c, by Rusty Russell 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. 10 * 11 * Generic code for virtio server in host kernel. 12 */ 13 14 #include <linux/eventfd.h> 15 #include <linux/vhost.h> 16 #include <linux/virtio_net.h> 17 #include <linux/mm.h> 18 #include <linux/mmu_context.h> 19 #include <linux/miscdevice.h> 20 #include <linux/mutex.h> 21 #include <linux/rcupdate.h> 22 #include <linux/poll.h> 23 #include <linux/file.h> 24 #include <linux/highmem.h> 25 #include <linux/slab.h> 26 #include <linux/kthread.h> 27 #include <linux/cgroup.h> 28 29 #include <linux/net.h> 30 #include <linux/if_packet.h> 31 #include <linux/if_arp.h> 32 33 #include "vhost.h" 34 35 enum { 36 VHOST_MEMORY_MAX_NREGIONS = 64, 37 VHOST_MEMORY_F_LOG = 0x1, 38 }; 39 40 static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, 41 poll_table *pt) 42 { 43 struct vhost_poll *poll; 44 poll = container_of(pt, struct vhost_poll, table); 45 46 poll->wqh = wqh; 47 add_wait_queue(wqh, &poll->wait); 48 } 49 50 static int vhost_poll_wakeup(wait_queue_t *wait, unsigned mode, int sync, 51 void *key) 52 { 53 struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); 54 55 if (!((unsigned long)key & poll->mask)) 56 return 0; 57 58 vhost_poll_queue(poll); 59 return 0; 60 } 61 62 static void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) 63 { 64 INIT_LIST_HEAD(&work->node); 65 work->fn = fn; 66 init_waitqueue_head(&work->done); 67 work->flushing = 0; 68 work->queue_seq = work->done_seq = 0; 69 } 70 71 /* Init poll structure */ 72 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, 73 unsigned long mask, struct vhost_dev *dev) 74 { 75 init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); 76 init_poll_funcptr(&poll->table, vhost_poll_func); 77 poll->mask = mask; 78 poll->dev = dev; 79 80 vhost_work_init(&poll->work, fn); 81 } 82 83 /* Start polling a file. We add ourselves to file's wait queue. The caller must 84 * keep a reference to a file until after vhost_poll_stop is called. */ 85 void vhost_poll_start(struct vhost_poll *poll, struct file *file) 86 { 87 unsigned long mask; 88 mask = file->f_op->poll(file, &poll->table); 89 if (mask) 90 vhost_poll_wakeup(&poll->wait, 0, 0, (void *)mask); 91 } 92 93 /* Stop polling a file. After this function returns, it becomes safe to drop the 94 * file reference. You must also flush afterwards. */ 95 void vhost_poll_stop(struct vhost_poll *poll) 96 { 97 remove_wait_queue(poll->wqh, &poll->wait); 98 } 99 100 static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work, 101 unsigned seq) 102 { 103 int left; 104 spin_lock_irq(&dev->work_lock); 105 left = seq - work->done_seq; 106 spin_unlock_irq(&dev->work_lock); 107 return left <= 0; 108 } 109 110 static void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) 111 { 112 unsigned seq; 113 int flushing; 114 115 spin_lock_irq(&dev->work_lock); 116 seq = work->queue_seq; 117 work->flushing++; 118 spin_unlock_irq(&dev->work_lock); 119 wait_event(work->done, vhost_work_seq_done(dev, work, seq)); 120 spin_lock_irq(&dev->work_lock); 121 flushing = --work->flushing; 122 spin_unlock_irq(&dev->work_lock); 123 BUG_ON(flushing < 0); 124 } 125 126 /* Flush any work that has been scheduled. When calling this, don't hold any 127 * locks that are also used by the callback. */ 128 void vhost_poll_flush(struct vhost_poll *poll) 129 { 130 vhost_work_flush(poll->dev, &poll->work); 131 } 132 133 static inline void vhost_work_queue(struct vhost_dev *dev, 134 struct vhost_work *work) 135 { 136 unsigned long flags; 137 138 spin_lock_irqsave(&dev->work_lock, flags); 139 if (list_empty(&work->node)) { 140 list_add_tail(&work->node, &dev->work_list); 141 work->queue_seq++; 142 wake_up_process(dev->worker); 143 } 144 spin_unlock_irqrestore(&dev->work_lock, flags); 145 } 146 147 void vhost_poll_queue(struct vhost_poll *poll) 148 { 149 vhost_work_queue(poll->dev, &poll->work); 150 } 151 152 static void vhost_vq_reset(struct vhost_dev *dev, 153 struct vhost_virtqueue *vq) 154 { 155 vq->num = 1; 156 vq->desc = NULL; 157 vq->avail = NULL; 158 vq->used = NULL; 159 vq->last_avail_idx = 0; 160 vq->avail_idx = 0; 161 vq->last_used_idx = 0; 162 vq->used_flags = 0; 163 vq->log_used = false; 164 vq->log_addr = -1ull; 165 vq->vhost_hlen = 0; 166 vq->sock_hlen = 0; 167 vq->private_data = NULL; 168 vq->log_base = NULL; 169 vq->error_ctx = NULL; 170 vq->error = NULL; 171 vq->kick = NULL; 172 vq->call_ctx = NULL; 173 vq->call = NULL; 174 vq->log_ctx = NULL; 175 } 176 177 static int vhost_worker(void *data) 178 { 179 struct vhost_dev *dev = data; 180 struct vhost_work *work = NULL; 181 unsigned uninitialized_var(seq); 182 183 use_mm(dev->mm); 184 185 for (;;) { 186 /* mb paired w/ kthread_stop */ 187 set_current_state(TASK_INTERRUPTIBLE); 188 189 spin_lock_irq(&dev->work_lock); 190 if (work) { 191 work->done_seq = seq; 192 if (work->flushing) 193 wake_up_all(&work->done); 194 } 195 196 if (kthread_should_stop()) { 197 spin_unlock_irq(&dev->work_lock); 198 __set_current_state(TASK_RUNNING); 199 break; 200 } 201 if (!list_empty(&dev->work_list)) { 202 work = list_first_entry(&dev->work_list, 203 struct vhost_work, node); 204 list_del_init(&work->node); 205 seq = work->queue_seq; 206 } else 207 work = NULL; 208 spin_unlock_irq(&dev->work_lock); 209 210 if (work) { 211 __set_current_state(TASK_RUNNING); 212 work->fn(work); 213 } else 214 schedule(); 215 216 } 217 unuse_mm(dev->mm); 218 return 0; 219 } 220 221 /* Helper to allocate iovec buffers for all vqs. */ 222 static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) 223 { 224 int i; 225 for (i = 0; i < dev->nvqs; ++i) { 226 dev->vqs[i].indirect = kmalloc(sizeof *dev->vqs[i].indirect * 227 UIO_MAXIOV, GFP_KERNEL); 228 dev->vqs[i].log = kmalloc(sizeof *dev->vqs[i].log * UIO_MAXIOV, 229 GFP_KERNEL); 230 dev->vqs[i].heads = kmalloc(sizeof *dev->vqs[i].heads * 231 UIO_MAXIOV, GFP_KERNEL); 232 233 if (!dev->vqs[i].indirect || !dev->vqs[i].log || 234 !dev->vqs[i].heads) 235 goto err_nomem; 236 } 237 return 0; 238 err_nomem: 239 for (; i >= 0; --i) { 240 kfree(dev->vqs[i].indirect); 241 kfree(dev->vqs[i].log); 242 kfree(dev->vqs[i].heads); 243 } 244 return -ENOMEM; 245 } 246 247 static void vhost_dev_free_iovecs(struct vhost_dev *dev) 248 { 249 int i; 250 for (i = 0; i < dev->nvqs; ++i) { 251 kfree(dev->vqs[i].indirect); 252 dev->vqs[i].indirect = NULL; 253 kfree(dev->vqs[i].log); 254 dev->vqs[i].log = NULL; 255 kfree(dev->vqs[i].heads); 256 dev->vqs[i].heads = NULL; 257 } 258 } 259 260 long vhost_dev_init(struct vhost_dev *dev, 261 struct vhost_virtqueue *vqs, int nvqs) 262 { 263 int i; 264 265 dev->vqs = vqs; 266 dev->nvqs = nvqs; 267 mutex_init(&dev->mutex); 268 dev->log_ctx = NULL; 269 dev->log_file = NULL; 270 dev->memory = NULL; 271 dev->mm = NULL; 272 spin_lock_init(&dev->work_lock); 273 INIT_LIST_HEAD(&dev->work_list); 274 dev->worker = NULL; 275 276 for (i = 0; i < dev->nvqs; ++i) { 277 dev->vqs[i].log = NULL; 278 dev->vqs[i].indirect = NULL; 279 dev->vqs[i].heads = NULL; 280 dev->vqs[i].dev = dev; 281 mutex_init(&dev->vqs[i].mutex); 282 vhost_vq_reset(dev, dev->vqs + i); 283 if (dev->vqs[i].handle_kick) 284 vhost_poll_init(&dev->vqs[i].poll, 285 dev->vqs[i].handle_kick, POLLIN, dev); 286 } 287 288 return 0; 289 } 290 291 /* Caller should have device mutex */ 292 long vhost_dev_check_owner(struct vhost_dev *dev) 293 { 294 /* Are you the owner? If not, I don't think you mean to do that */ 295 return dev->mm == current->mm ? 0 : -EPERM; 296 } 297 298 struct vhost_attach_cgroups_struct { 299 struct vhost_work work; 300 struct task_struct *owner; 301 int ret; 302 }; 303 304 static void vhost_attach_cgroups_work(struct vhost_work *work) 305 { 306 struct vhost_attach_cgroups_struct *s; 307 s = container_of(work, struct vhost_attach_cgroups_struct, work); 308 s->ret = cgroup_attach_task_all(s->owner, current); 309 } 310 311 static int vhost_attach_cgroups(struct vhost_dev *dev) 312 { 313 struct vhost_attach_cgroups_struct attach; 314 attach.owner = current; 315 vhost_work_init(&attach.work, vhost_attach_cgroups_work); 316 vhost_work_queue(dev, &attach.work); 317 vhost_work_flush(dev, &attach.work); 318 return attach.ret; 319 } 320 321 /* Caller should have device mutex */ 322 static long vhost_dev_set_owner(struct vhost_dev *dev) 323 { 324 struct task_struct *worker; 325 int err; 326 /* Is there an owner already? */ 327 if (dev->mm) { 328 err = -EBUSY; 329 goto err_mm; 330 } 331 /* No owner, become one */ 332 dev->mm = get_task_mm(current); 333 worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); 334 if (IS_ERR(worker)) { 335 err = PTR_ERR(worker); 336 goto err_worker; 337 } 338 339 dev->worker = worker; 340 wake_up_process(worker); /* avoid contributing to loadavg */ 341 342 err = vhost_attach_cgroups(dev); 343 if (err) 344 goto err_cgroup; 345 346 err = vhost_dev_alloc_iovecs(dev); 347 if (err) 348 goto err_cgroup; 349 350 return 0; 351 err_cgroup: 352 kthread_stop(worker); 353 dev->worker = NULL; 354 err_worker: 355 if (dev->mm) 356 mmput(dev->mm); 357 dev->mm = NULL; 358 err_mm: 359 return err; 360 } 361 362 /* Caller should have device mutex */ 363 long vhost_dev_reset_owner(struct vhost_dev *dev) 364 { 365 struct vhost_memory *memory; 366 367 /* Restore memory to default empty mapping. */ 368 memory = kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL); 369 if (!memory) 370 return -ENOMEM; 371 372 vhost_dev_cleanup(dev); 373 374 memory->nregions = 0; 375 RCU_INIT_POINTER(dev->memory, memory); 376 return 0; 377 } 378 379 /* Caller should have device mutex */ 380 void vhost_dev_cleanup(struct vhost_dev *dev) 381 { 382 int i; 383 for (i = 0; i < dev->nvqs; ++i) { 384 if (dev->vqs[i].kick && dev->vqs[i].handle_kick) { 385 vhost_poll_stop(&dev->vqs[i].poll); 386 vhost_poll_flush(&dev->vqs[i].poll); 387 } 388 if (dev->vqs[i].error_ctx) 389 eventfd_ctx_put(dev->vqs[i].error_ctx); 390 if (dev->vqs[i].error) 391 fput(dev->vqs[i].error); 392 if (dev->vqs[i].kick) 393 fput(dev->vqs[i].kick); 394 if (dev->vqs[i].call_ctx) 395 eventfd_ctx_put(dev->vqs[i].call_ctx); 396 if (dev->vqs[i].call) 397 fput(dev->vqs[i].call); 398 vhost_vq_reset(dev, dev->vqs + i); 399 } 400 vhost_dev_free_iovecs(dev); 401 if (dev->log_ctx) 402 eventfd_ctx_put(dev->log_ctx); 403 dev->log_ctx = NULL; 404 if (dev->log_file) 405 fput(dev->log_file); 406 dev->log_file = NULL; 407 /* No one will access memory at this point */ 408 kfree(rcu_dereference_protected(dev->memory, 409 lockdep_is_held(&dev->mutex))); 410 RCU_INIT_POINTER(dev->memory, NULL); 411 WARN_ON(!list_empty(&dev->work_list)); 412 if (dev->worker) { 413 kthread_stop(dev->worker); 414 dev->worker = NULL; 415 } 416 if (dev->mm) 417 mmput(dev->mm); 418 dev->mm = NULL; 419 } 420 421 static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) 422 { 423 u64 a = addr / VHOST_PAGE_SIZE / 8; 424 /* Make sure 64 bit math will not overflow. */ 425 if (a > ULONG_MAX - (unsigned long)log_base || 426 a + (unsigned long)log_base > ULONG_MAX) 427 return 0; 428 429 return access_ok(VERIFY_WRITE, log_base + a, 430 (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); 431 } 432 433 /* Caller should have vq mutex and device mutex. */ 434 static int vq_memory_access_ok(void __user *log_base, struct vhost_memory *mem, 435 int log_all) 436 { 437 int i; 438 439 if (!mem) 440 return 0; 441 442 for (i = 0; i < mem->nregions; ++i) { 443 struct vhost_memory_region *m = mem->regions + i; 444 unsigned long a = m->userspace_addr; 445 if (m->memory_size > ULONG_MAX) 446 return 0; 447 else if (!access_ok(VERIFY_WRITE, (void __user *)a, 448 m->memory_size)) 449 return 0; 450 else if (log_all && !log_access_ok(log_base, 451 m->guest_phys_addr, 452 m->memory_size)) 453 return 0; 454 } 455 return 1; 456 } 457 458 /* Can we switch to this memory table? */ 459 /* Caller should have device mutex but not vq mutex */ 460 static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem, 461 int log_all) 462 { 463 int i; 464 for (i = 0; i < d->nvqs; ++i) { 465 int ok; 466 mutex_lock(&d->vqs[i].mutex); 467 /* If ring is inactive, will check when it's enabled. */ 468 if (d->vqs[i].private_data) 469 ok = vq_memory_access_ok(d->vqs[i].log_base, mem, 470 log_all); 471 else 472 ok = 1; 473 mutex_unlock(&d->vqs[i].mutex); 474 if (!ok) 475 return 0; 476 } 477 return 1; 478 } 479 480 static int vq_access_ok(unsigned int num, 481 struct vring_desc __user *desc, 482 struct vring_avail __user *avail, 483 struct vring_used __user *used) 484 { 485 return access_ok(VERIFY_READ, desc, num * sizeof *desc) && 486 access_ok(VERIFY_READ, avail, 487 sizeof *avail + num * sizeof *avail->ring) && 488 access_ok(VERIFY_WRITE, used, 489 sizeof *used + num * sizeof *used->ring); 490 } 491 492 /* Can we log writes? */ 493 /* Caller should have device mutex but not vq mutex */ 494 int vhost_log_access_ok(struct vhost_dev *dev) 495 { 496 struct vhost_memory *mp; 497 498 mp = rcu_dereference_protected(dev->memory, 499 lockdep_is_held(&dev->mutex)); 500 return memory_access_ok(dev, mp, 1); 501 } 502 503 /* Verify access for write logging. */ 504 /* Caller should have vq mutex and device mutex */ 505 static int vq_log_access_ok(struct vhost_virtqueue *vq, void __user *log_base) 506 { 507 struct vhost_memory *mp; 508 509 mp = rcu_dereference_protected(vq->dev->memory, 510 lockdep_is_held(&vq->mutex)); 511 return vq_memory_access_ok(log_base, mp, 512 vhost_has_feature(vq->dev, VHOST_F_LOG_ALL)) && 513 (!vq->log_used || log_access_ok(log_base, vq->log_addr, 514 sizeof *vq->used + 515 vq->num * sizeof *vq->used->ring)); 516 } 517 518 /* Can we start vq? */ 519 /* Caller should have vq mutex and device mutex */ 520 int vhost_vq_access_ok(struct vhost_virtqueue *vq) 521 { 522 return vq_access_ok(vq->num, vq->desc, vq->avail, vq->used) && 523 vq_log_access_ok(vq, vq->log_base); 524 } 525 526 static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) 527 { 528 struct vhost_memory mem, *newmem, *oldmem; 529 unsigned long size = offsetof(struct vhost_memory, regions); 530 if (copy_from_user(&mem, m, size)) 531 return -EFAULT; 532 if (mem.padding) 533 return -EOPNOTSUPP; 534 if (mem.nregions > VHOST_MEMORY_MAX_NREGIONS) 535 return -E2BIG; 536 newmem = kmalloc(size + mem.nregions * sizeof *m->regions, GFP_KERNEL); 537 if (!newmem) 538 return -ENOMEM; 539 540 memcpy(newmem, &mem, size); 541 if (copy_from_user(newmem->regions, m->regions, 542 mem.nregions * sizeof *m->regions)) { 543 kfree(newmem); 544 return -EFAULT; 545 } 546 547 if (!memory_access_ok(d, newmem, vhost_has_feature(d, VHOST_F_LOG_ALL))) { 548 kfree(newmem); 549 return -EFAULT; 550 } 551 oldmem = rcu_dereference_protected(d->memory, 552 lockdep_is_held(&d->mutex)); 553 rcu_assign_pointer(d->memory, newmem); 554 synchronize_rcu(); 555 kfree(oldmem); 556 return 0; 557 } 558 559 static int init_used(struct vhost_virtqueue *vq, 560 struct vring_used __user *used) 561 { 562 int r = put_user(vq->used_flags, &used->flags); 563 if (r) 564 return r; 565 return get_user(vq->last_used_idx, &used->idx); 566 } 567 568 static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp) 569 { 570 struct file *eventfp, *filep = NULL, 571 *pollstart = NULL, *pollstop = NULL; 572 struct eventfd_ctx *ctx = NULL; 573 u32 __user *idxp = argp; 574 struct vhost_virtqueue *vq; 575 struct vhost_vring_state s; 576 struct vhost_vring_file f; 577 struct vhost_vring_addr a; 578 u32 idx; 579 long r; 580 581 r = get_user(idx, idxp); 582 if (r < 0) 583 return r; 584 if (idx >= d->nvqs) 585 return -ENOBUFS; 586 587 vq = d->vqs + idx; 588 589 mutex_lock(&vq->mutex); 590 591 switch (ioctl) { 592 case VHOST_SET_VRING_NUM: 593 /* Resizing ring with an active backend? 594 * You don't want to do that. */ 595 if (vq->private_data) { 596 r = -EBUSY; 597 break; 598 } 599 if (copy_from_user(&s, argp, sizeof s)) { 600 r = -EFAULT; 601 break; 602 } 603 if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) { 604 r = -EINVAL; 605 break; 606 } 607 vq->num = s.num; 608 break; 609 case VHOST_SET_VRING_BASE: 610 /* Moving base with an active backend? 611 * You don't want to do that. */ 612 if (vq->private_data) { 613 r = -EBUSY; 614 break; 615 } 616 if (copy_from_user(&s, argp, sizeof s)) { 617 r = -EFAULT; 618 break; 619 } 620 if (s.num > 0xffff) { 621 r = -EINVAL; 622 break; 623 } 624 vq->last_avail_idx = s.num; 625 /* Forget the cached index value. */ 626 vq->avail_idx = vq->last_avail_idx; 627 break; 628 case VHOST_GET_VRING_BASE: 629 s.index = idx; 630 s.num = vq->last_avail_idx; 631 if (copy_to_user(argp, &s, sizeof s)) 632 r = -EFAULT; 633 break; 634 case VHOST_SET_VRING_ADDR: 635 if (copy_from_user(&a, argp, sizeof a)) { 636 r = -EFAULT; 637 break; 638 } 639 if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) { 640 r = -EOPNOTSUPP; 641 break; 642 } 643 /* For 32bit, verify that the top 32bits of the user 644 data are set to zero. */ 645 if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || 646 (u64)(unsigned long)a.used_user_addr != a.used_user_addr || 647 (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) { 648 r = -EFAULT; 649 break; 650 } 651 if ((a.avail_user_addr & (sizeof *vq->avail->ring - 1)) || 652 (a.used_user_addr & (sizeof *vq->used->ring - 1)) || 653 (a.log_guest_addr & (sizeof *vq->used->ring - 1))) { 654 r = -EINVAL; 655 break; 656 } 657 658 /* We only verify access here if backend is configured. 659 * If it is not, we don't as size might not have been setup. 660 * We will verify when backend is configured. */ 661 if (vq->private_data) { 662 if (!vq_access_ok(vq->num, 663 (void __user *)(unsigned long)a.desc_user_addr, 664 (void __user *)(unsigned long)a.avail_user_addr, 665 (void __user *)(unsigned long)a.used_user_addr)) { 666 r = -EINVAL; 667 break; 668 } 669 670 /* Also validate log access for used ring if enabled. */ 671 if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && 672 !log_access_ok(vq->log_base, a.log_guest_addr, 673 sizeof *vq->used + 674 vq->num * sizeof *vq->used->ring)) { 675 r = -EINVAL; 676 break; 677 } 678 } 679 680 r = init_used(vq, (struct vring_used __user *)(unsigned long) 681 a.used_user_addr); 682 if (r) 683 break; 684 vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); 685 vq->desc = (void __user *)(unsigned long)a.desc_user_addr; 686 vq->avail = (void __user *)(unsigned long)a.avail_user_addr; 687 vq->log_addr = a.log_guest_addr; 688 vq->used = (void __user *)(unsigned long)a.used_user_addr; 689 break; 690 case VHOST_SET_VRING_KICK: 691 if (copy_from_user(&f, argp, sizeof f)) { 692 r = -EFAULT; 693 break; 694 } 695 eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); 696 if (IS_ERR(eventfp)) { 697 r = PTR_ERR(eventfp); 698 break; 699 } 700 if (eventfp != vq->kick) { 701 pollstop = filep = vq->kick; 702 pollstart = vq->kick = eventfp; 703 } else 704 filep = eventfp; 705 break; 706 case VHOST_SET_VRING_CALL: 707 if (copy_from_user(&f, argp, sizeof f)) { 708 r = -EFAULT; 709 break; 710 } 711 eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); 712 if (IS_ERR(eventfp)) { 713 r = PTR_ERR(eventfp); 714 break; 715 } 716 if (eventfp != vq->call) { 717 filep = vq->call; 718 ctx = vq->call_ctx; 719 vq->call = eventfp; 720 vq->call_ctx = eventfp ? 721 eventfd_ctx_fileget(eventfp) : NULL; 722 } else 723 filep = eventfp; 724 break; 725 case VHOST_SET_VRING_ERR: 726 if (copy_from_user(&f, argp, sizeof f)) { 727 r = -EFAULT; 728 break; 729 } 730 eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); 731 if (IS_ERR(eventfp)) { 732 r = PTR_ERR(eventfp); 733 break; 734 } 735 if (eventfp != vq->error) { 736 filep = vq->error; 737 vq->error = eventfp; 738 ctx = vq->error_ctx; 739 vq->error_ctx = eventfp ? 740 eventfd_ctx_fileget(eventfp) : NULL; 741 } else 742 filep = eventfp; 743 break; 744 default: 745 r = -ENOIOCTLCMD; 746 } 747 748 if (pollstop && vq->handle_kick) 749 vhost_poll_stop(&vq->poll); 750 751 if (ctx) 752 eventfd_ctx_put(ctx); 753 if (filep) 754 fput(filep); 755 756 if (pollstart && vq->handle_kick) 757 vhost_poll_start(&vq->poll, vq->kick); 758 759 mutex_unlock(&vq->mutex); 760 761 if (pollstop && vq->handle_kick) 762 vhost_poll_flush(&vq->poll); 763 return r; 764 } 765 766 /* Caller must have device mutex */ 767 long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, unsigned long arg) 768 { 769 void __user *argp = (void __user *)arg; 770 struct file *eventfp, *filep = NULL; 771 struct eventfd_ctx *ctx = NULL; 772 u64 p; 773 long r; 774 int i, fd; 775 776 /* If you are not the owner, you can become one */ 777 if (ioctl == VHOST_SET_OWNER) { 778 r = vhost_dev_set_owner(d); 779 goto done; 780 } 781 782 /* You must be the owner to do anything else */ 783 r = vhost_dev_check_owner(d); 784 if (r) 785 goto done; 786 787 switch (ioctl) { 788 case VHOST_SET_MEM_TABLE: 789 r = vhost_set_memory(d, argp); 790 break; 791 case VHOST_SET_LOG_BASE: 792 if (copy_from_user(&p, argp, sizeof p)) { 793 r = -EFAULT; 794 break; 795 } 796 if ((u64)(unsigned long)p != p) { 797 r = -EFAULT; 798 break; 799 } 800 for (i = 0; i < d->nvqs; ++i) { 801 struct vhost_virtqueue *vq; 802 void __user *base = (void __user *)(unsigned long)p; 803 vq = d->vqs + i; 804 mutex_lock(&vq->mutex); 805 /* If ring is inactive, will check when it's enabled. */ 806 if (vq->private_data && !vq_log_access_ok(vq, base)) 807 r = -EFAULT; 808 else 809 vq->log_base = base; 810 mutex_unlock(&vq->mutex); 811 } 812 break; 813 case VHOST_SET_LOG_FD: 814 r = get_user(fd, (int __user *)argp); 815 if (r < 0) 816 break; 817 eventfp = fd == -1 ? NULL : eventfd_fget(fd); 818 if (IS_ERR(eventfp)) { 819 r = PTR_ERR(eventfp); 820 break; 821 } 822 if (eventfp != d->log_file) { 823 filep = d->log_file; 824 ctx = d->log_ctx; 825 d->log_ctx = eventfp ? 826 eventfd_ctx_fileget(eventfp) : NULL; 827 } else 828 filep = eventfp; 829 for (i = 0; i < d->nvqs; ++i) { 830 mutex_lock(&d->vqs[i].mutex); 831 d->vqs[i].log_ctx = d->log_ctx; 832 mutex_unlock(&d->vqs[i].mutex); 833 } 834 if (ctx) 835 eventfd_ctx_put(ctx); 836 if (filep) 837 fput(filep); 838 break; 839 default: 840 r = vhost_set_vring(d, ioctl, argp); 841 break; 842 } 843 done: 844 return r; 845 } 846 847 static const struct vhost_memory_region *find_region(struct vhost_memory *mem, 848 __u64 addr, __u32 len) 849 { 850 struct vhost_memory_region *reg; 851 int i; 852 /* linear search is not brilliant, but we really have on the order of 6 853 * regions in practice */ 854 for (i = 0; i < mem->nregions; ++i) { 855 reg = mem->regions + i; 856 if (reg->guest_phys_addr <= addr && 857 reg->guest_phys_addr + reg->memory_size - 1 >= addr) 858 return reg; 859 } 860 return NULL; 861 } 862 863 /* TODO: This is really inefficient. We need something like get_user() 864 * (instruction directly accesses the data, with an exception table entry 865 * returning -EFAULT). See Documentation/x86/exception-tables.txt. 866 */ 867 static int set_bit_to_user(int nr, void __user *addr) 868 { 869 unsigned long log = (unsigned long)addr; 870 struct page *page; 871 void *base; 872 int bit = nr + (log % PAGE_SIZE) * 8; 873 int r; 874 r = get_user_pages_fast(log, 1, 1, &page); 875 if (r < 0) 876 return r; 877 BUG_ON(r != 1); 878 base = kmap_atomic(page, KM_USER0); 879 set_bit(bit, base); 880 kunmap_atomic(base, KM_USER0); 881 set_page_dirty_lock(page); 882 put_page(page); 883 return 0; 884 } 885 886 static int log_write(void __user *log_base, 887 u64 write_address, u64 write_length) 888 { 889 u64 write_page = write_address / VHOST_PAGE_SIZE; 890 int r; 891 if (!write_length) 892 return 0; 893 write_length += write_address % VHOST_PAGE_SIZE; 894 for (;;) { 895 u64 base = (u64)(unsigned long)log_base; 896 u64 log = base + write_page / 8; 897 int bit = write_page % 8; 898 if ((u64)(unsigned long)log != log) 899 return -EFAULT; 900 r = set_bit_to_user(bit, (void __user *)(unsigned long)log); 901 if (r < 0) 902 return r; 903 if (write_length <= VHOST_PAGE_SIZE) 904 break; 905 write_length -= VHOST_PAGE_SIZE; 906 write_page += 1; 907 } 908 return r; 909 } 910 911 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 912 unsigned int log_num, u64 len) 913 { 914 int i, r; 915 916 /* Make sure data written is seen before log. */ 917 smp_wmb(); 918 for (i = 0; i < log_num; ++i) { 919 u64 l = min(log[i].len, len); 920 r = log_write(vq->log_base, log[i].addr, l); 921 if (r < 0) 922 return r; 923 len -= l; 924 if (!len) { 925 if (vq->log_ctx) 926 eventfd_signal(vq->log_ctx, 1); 927 return 0; 928 } 929 } 930 /* Length written exceeds what we have stored. This is a bug. */ 931 BUG(); 932 return 0; 933 } 934 935 static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len, 936 struct iovec iov[], int iov_size) 937 { 938 const struct vhost_memory_region *reg; 939 struct vhost_memory *mem; 940 struct iovec *_iov; 941 u64 s = 0; 942 int ret = 0; 943 944 rcu_read_lock(); 945 946 mem = rcu_dereference(dev->memory); 947 while ((u64)len > s) { 948 u64 size; 949 if (unlikely(ret >= iov_size)) { 950 ret = -ENOBUFS; 951 break; 952 } 953 reg = find_region(mem, addr, len); 954 if (unlikely(!reg)) { 955 ret = -EFAULT; 956 break; 957 } 958 _iov = iov + ret; 959 size = reg->memory_size - addr + reg->guest_phys_addr; 960 _iov->iov_len = min((u64)len, size); 961 _iov->iov_base = (void __user *)(unsigned long) 962 (reg->userspace_addr + addr - reg->guest_phys_addr); 963 s += size; 964 addr += size; 965 ++ret; 966 } 967 968 rcu_read_unlock(); 969 return ret; 970 } 971 972 /* Each buffer in the virtqueues is actually a chain of descriptors. This 973 * function returns the next descriptor in the chain, 974 * or -1U if we're at the end. */ 975 static unsigned next_desc(struct vring_desc *desc) 976 { 977 unsigned int next; 978 979 /* If this descriptor says it doesn't chain, we're done. */ 980 if (!(desc->flags & VRING_DESC_F_NEXT)) 981 return -1U; 982 983 /* Check they're not leading us off end of descriptors. */ 984 next = desc->next; 985 /* Make sure compiler knows to grab that: we don't want it changing! */ 986 /* We will use the result as an index in an array, so most 987 * architectures only need a compiler barrier here. */ 988 read_barrier_depends(); 989 990 return next; 991 } 992 993 static int get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq, 994 struct iovec iov[], unsigned int iov_size, 995 unsigned int *out_num, unsigned int *in_num, 996 struct vhost_log *log, unsigned int *log_num, 997 struct vring_desc *indirect) 998 { 999 struct vring_desc desc; 1000 unsigned int i = 0, count, found = 0; 1001 int ret; 1002 1003 /* Sanity check */ 1004 if (unlikely(indirect->len % sizeof desc)) { 1005 vq_err(vq, "Invalid length in indirect descriptor: " 1006 "len 0x%llx not multiple of 0x%zx\n", 1007 (unsigned long long)indirect->len, 1008 sizeof desc); 1009 return -EINVAL; 1010 } 1011 1012 ret = translate_desc(dev, indirect->addr, indirect->len, vq->indirect, 1013 UIO_MAXIOV); 1014 if (unlikely(ret < 0)) { 1015 vq_err(vq, "Translation failure %d in indirect.\n", ret); 1016 return ret; 1017 } 1018 1019 /* We will use the result as an address to read from, so most 1020 * architectures only need a compiler barrier here. */ 1021 read_barrier_depends(); 1022 1023 count = indirect->len / sizeof desc; 1024 /* Buffers are chained via a 16 bit next field, so 1025 * we can have at most 2^16 of these. */ 1026 if (unlikely(count > USHRT_MAX + 1)) { 1027 vq_err(vq, "Indirect buffer length too big: %d\n", 1028 indirect->len); 1029 return -E2BIG; 1030 } 1031 1032 do { 1033 unsigned iov_count = *in_num + *out_num; 1034 if (unlikely(++found > count)) { 1035 vq_err(vq, "Loop detected: last one at %u " 1036 "indirect size %u\n", 1037 i, count); 1038 return -EINVAL; 1039 } 1040 if (unlikely(memcpy_fromiovec((unsigned char *)&desc, vq->indirect, 1041 sizeof desc))) { 1042 vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", 1043 i, (size_t)indirect->addr + i * sizeof desc); 1044 return -EINVAL; 1045 } 1046 if (unlikely(desc.flags & VRING_DESC_F_INDIRECT)) { 1047 vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", 1048 i, (size_t)indirect->addr + i * sizeof desc); 1049 return -EINVAL; 1050 } 1051 1052 ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count, 1053 iov_size - iov_count); 1054 if (unlikely(ret < 0)) { 1055 vq_err(vq, "Translation failure %d indirect idx %d\n", 1056 ret, i); 1057 return ret; 1058 } 1059 /* If this is an input descriptor, increment that count. */ 1060 if (desc.flags & VRING_DESC_F_WRITE) { 1061 *in_num += ret; 1062 if (unlikely(log)) { 1063 log[*log_num].addr = desc.addr; 1064 log[*log_num].len = desc.len; 1065 ++*log_num; 1066 } 1067 } else { 1068 /* If it's an output descriptor, they're all supposed 1069 * to come before any input descriptors. */ 1070 if (unlikely(*in_num)) { 1071 vq_err(vq, "Indirect descriptor " 1072 "has out after in: idx %d\n", i); 1073 return -EINVAL; 1074 } 1075 *out_num += ret; 1076 } 1077 } while ((i = next_desc(&desc)) != -1); 1078 return 0; 1079 } 1080 1081 /* This looks in the virtqueue and for the first available buffer, and converts 1082 * it to an iovec for convenient access. Since descriptors consist of some 1083 * number of output then some number of input descriptors, it's actually two 1084 * iovecs, but we pack them into one and note how many of each there were. 1085 * 1086 * This function returns the descriptor number found, or vq->num (which is 1087 * never a valid descriptor number) if none was found. A negative code is 1088 * returned on error. */ 1089 int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, 1090 struct iovec iov[], unsigned int iov_size, 1091 unsigned int *out_num, unsigned int *in_num, 1092 struct vhost_log *log, unsigned int *log_num) 1093 { 1094 struct vring_desc desc; 1095 unsigned int i, head, found = 0; 1096 u16 last_avail_idx; 1097 int ret; 1098 1099 /* Check it isn't doing very strange things with descriptor numbers. */ 1100 last_avail_idx = vq->last_avail_idx; 1101 if (unlikely(__get_user(vq->avail_idx, &vq->avail->idx))) { 1102 vq_err(vq, "Failed to access avail idx at %p\n", 1103 &vq->avail->idx); 1104 return -EFAULT; 1105 } 1106 1107 if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { 1108 vq_err(vq, "Guest moved used index from %u to %u", 1109 last_avail_idx, vq->avail_idx); 1110 return -EFAULT; 1111 } 1112 1113 /* If there's nothing new since last we looked, return invalid. */ 1114 if (vq->avail_idx == last_avail_idx) 1115 return vq->num; 1116 1117 /* Only get avail ring entries after they have been exposed by guest. */ 1118 smp_rmb(); 1119 1120 /* Grab the next descriptor number they're advertising, and increment 1121 * the index we've seen. */ 1122 if (unlikely(__get_user(head, 1123 &vq->avail->ring[last_avail_idx % vq->num]))) { 1124 vq_err(vq, "Failed to read head: idx %d address %p\n", 1125 last_avail_idx, 1126 &vq->avail->ring[last_avail_idx % vq->num]); 1127 return -EFAULT; 1128 } 1129 1130 /* If their number is silly, that's an error. */ 1131 if (unlikely(head >= vq->num)) { 1132 vq_err(vq, "Guest says index %u > %u is available", 1133 head, vq->num); 1134 return -EINVAL; 1135 } 1136 1137 /* When we start there are none of either input nor output. */ 1138 *out_num = *in_num = 0; 1139 if (unlikely(log)) 1140 *log_num = 0; 1141 1142 i = head; 1143 do { 1144 unsigned iov_count = *in_num + *out_num; 1145 if (unlikely(i >= vq->num)) { 1146 vq_err(vq, "Desc index is %u > %u, head = %u", 1147 i, vq->num, head); 1148 return -EINVAL; 1149 } 1150 if (unlikely(++found > vq->num)) { 1151 vq_err(vq, "Loop detected: last one at %u " 1152 "vq size %u head %u\n", 1153 i, vq->num, head); 1154 return -EINVAL; 1155 } 1156 ret = copy_from_user(&desc, vq->desc + i, sizeof desc); 1157 if (unlikely(ret)) { 1158 vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", 1159 i, vq->desc + i); 1160 return -EFAULT; 1161 } 1162 if (desc.flags & VRING_DESC_F_INDIRECT) { 1163 ret = get_indirect(dev, vq, iov, iov_size, 1164 out_num, in_num, 1165 log, log_num, &desc); 1166 if (unlikely(ret < 0)) { 1167 vq_err(vq, "Failure detected " 1168 "in indirect descriptor at idx %d\n", i); 1169 return ret; 1170 } 1171 continue; 1172 } 1173 1174 ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count, 1175 iov_size - iov_count); 1176 if (unlikely(ret < 0)) { 1177 vq_err(vq, "Translation failure %d descriptor idx %d\n", 1178 ret, i); 1179 return ret; 1180 } 1181 if (desc.flags & VRING_DESC_F_WRITE) { 1182 /* If this is an input descriptor, 1183 * increment that count. */ 1184 *in_num += ret; 1185 if (unlikely(log)) { 1186 log[*log_num].addr = desc.addr; 1187 log[*log_num].len = desc.len; 1188 ++*log_num; 1189 } 1190 } else { 1191 /* If it's an output descriptor, they're all supposed 1192 * to come before any input descriptors. */ 1193 if (unlikely(*in_num)) { 1194 vq_err(vq, "Descriptor has out after in: " 1195 "idx %d\n", i); 1196 return -EINVAL; 1197 } 1198 *out_num += ret; 1199 } 1200 } while ((i = next_desc(&desc)) != -1); 1201 1202 /* On success, increment avail index. */ 1203 vq->last_avail_idx++; 1204 return head; 1205 } 1206 1207 /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ 1208 void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) 1209 { 1210 vq->last_avail_idx -= n; 1211 } 1212 1213 /* After we've used one of their buffers, we tell them about it. We'll then 1214 * want to notify the guest, using eventfd. */ 1215 int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) 1216 { 1217 struct vring_used_elem __user *used; 1218 1219 /* The virtqueue contains a ring of used buffers. Get a pointer to the 1220 * next entry in that used ring. */ 1221 used = &vq->used->ring[vq->last_used_idx % vq->num]; 1222 if (__put_user(head, &used->id)) { 1223 vq_err(vq, "Failed to write used id"); 1224 return -EFAULT; 1225 } 1226 if (__put_user(len, &used->len)) { 1227 vq_err(vq, "Failed to write used len"); 1228 return -EFAULT; 1229 } 1230 /* Make sure buffer is written before we update index. */ 1231 smp_wmb(); 1232 if (__put_user(vq->last_used_idx + 1, &vq->used->idx)) { 1233 vq_err(vq, "Failed to increment used idx"); 1234 return -EFAULT; 1235 } 1236 if (unlikely(vq->log_used)) { 1237 /* Make sure data is seen before log. */ 1238 smp_wmb(); 1239 /* Log used ring entry write. */ 1240 log_write(vq->log_base, 1241 vq->log_addr + 1242 ((void __user *)used - (void __user *)vq->used), 1243 sizeof *used); 1244 /* Log used index update. */ 1245 log_write(vq->log_base, 1246 vq->log_addr + offsetof(struct vring_used, idx), 1247 sizeof vq->used->idx); 1248 if (vq->log_ctx) 1249 eventfd_signal(vq->log_ctx, 1); 1250 } 1251 vq->last_used_idx++; 1252 return 0; 1253 } 1254 1255 static int __vhost_add_used_n(struct vhost_virtqueue *vq, 1256 struct vring_used_elem *heads, 1257 unsigned count) 1258 { 1259 struct vring_used_elem __user *used; 1260 int start; 1261 1262 start = vq->last_used_idx % vq->num; 1263 used = vq->used->ring + start; 1264 if (__copy_to_user(used, heads, count * sizeof *used)) { 1265 vq_err(vq, "Failed to write used"); 1266 return -EFAULT; 1267 } 1268 if (unlikely(vq->log_used)) { 1269 /* Make sure data is seen before log. */ 1270 smp_wmb(); 1271 /* Log used ring entry write. */ 1272 log_write(vq->log_base, 1273 vq->log_addr + 1274 ((void __user *)used - (void __user *)vq->used), 1275 count * sizeof *used); 1276 } 1277 vq->last_used_idx += count; 1278 return 0; 1279 } 1280 1281 /* After we've used one of their buffers, we tell them about it. We'll then 1282 * want to notify the guest, using eventfd. */ 1283 int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, 1284 unsigned count) 1285 { 1286 int start, n, r; 1287 1288 start = vq->last_used_idx % vq->num; 1289 n = vq->num - start; 1290 if (n < count) { 1291 r = __vhost_add_used_n(vq, heads, n); 1292 if (r < 0) 1293 return r; 1294 heads += n; 1295 count -= n; 1296 } 1297 r = __vhost_add_used_n(vq, heads, count); 1298 1299 /* Make sure buffer is written before we update index. */ 1300 smp_wmb(); 1301 if (put_user(vq->last_used_idx, &vq->used->idx)) { 1302 vq_err(vq, "Failed to increment used idx"); 1303 return -EFAULT; 1304 } 1305 if (unlikely(vq->log_used)) { 1306 /* Log used index update. */ 1307 log_write(vq->log_base, 1308 vq->log_addr + offsetof(struct vring_used, idx), 1309 sizeof vq->used->idx); 1310 if (vq->log_ctx) 1311 eventfd_signal(vq->log_ctx, 1); 1312 } 1313 return r; 1314 } 1315 1316 /* This actually signals the guest, using eventfd. */ 1317 void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) 1318 { 1319 __u16 flags; 1320 /* Flush out used index updates. This is paired 1321 * with the barrier that the Guest executes when enabling 1322 * interrupts. */ 1323 smp_mb(); 1324 1325 if (__get_user(flags, &vq->avail->flags)) { 1326 vq_err(vq, "Failed to get flags"); 1327 return; 1328 } 1329 1330 /* If they don't want an interrupt, don't signal, unless empty. */ 1331 if ((flags & VRING_AVAIL_F_NO_INTERRUPT) && 1332 (vq->avail_idx != vq->last_avail_idx || 1333 !vhost_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY))) 1334 return; 1335 1336 /* Signal the Guest tell them we used something up. */ 1337 if (vq->call_ctx) 1338 eventfd_signal(vq->call_ctx, 1); 1339 } 1340 1341 /* And here's the combo meal deal. Supersize me! */ 1342 void vhost_add_used_and_signal(struct vhost_dev *dev, 1343 struct vhost_virtqueue *vq, 1344 unsigned int head, int len) 1345 { 1346 vhost_add_used(vq, head, len); 1347 vhost_signal(dev, vq); 1348 } 1349 1350 /* multi-buffer version of vhost_add_used_and_signal */ 1351 void vhost_add_used_and_signal_n(struct vhost_dev *dev, 1352 struct vhost_virtqueue *vq, 1353 struct vring_used_elem *heads, unsigned count) 1354 { 1355 vhost_add_used_n(vq, heads, count); 1356 vhost_signal(dev, vq); 1357 } 1358 1359 /* OK, now we need to know about added descriptors. */ 1360 bool vhost_enable_notify(struct vhost_virtqueue *vq) 1361 { 1362 u16 avail_idx; 1363 int r; 1364 if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) 1365 return false; 1366 vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; 1367 r = put_user(vq->used_flags, &vq->used->flags); 1368 if (r) { 1369 vq_err(vq, "Failed to enable notification at %p: %d\n", 1370 &vq->used->flags, r); 1371 return false; 1372 } 1373 /* They could have slipped one in as we were doing that: make 1374 * sure it's written, then check again. */ 1375 smp_mb(); 1376 r = __get_user(avail_idx, &vq->avail->idx); 1377 if (r) { 1378 vq_err(vq, "Failed to check avail idx at %p: %d\n", 1379 &vq->avail->idx, r); 1380 return false; 1381 } 1382 1383 return avail_idx != vq->avail_idx; 1384 } 1385 1386 /* We don't need to be notified again. */ 1387 void vhost_disable_notify(struct vhost_virtqueue *vq) 1388 { 1389 int r; 1390 if (vq->used_flags & VRING_USED_F_NO_NOTIFY) 1391 return; 1392 vq->used_flags |= VRING_USED_F_NO_NOTIFY; 1393 r = put_user(vq->used_flags, &vq->used->flags); 1394 if (r) 1395 vq_err(vq, "Failed to enable notification at %p: %d\n", 1396 &vq->used->flags, r); 1397 } 1398