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14#include <linux/eventfd.h>
15#include <linux/vhost.h>
16#include <linux/uio.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/poll.h>
22#include <linux/file.h>
23#include <linux/highmem.h>
24#include <linux/slab.h>
25#include <linux/vmalloc.h>
26#include <linux/kthread.h>
27#include <linux/cgroup.h>
28#include <linux/module.h>
29#include <linux/sort.h>
30#include <linux/sched/mm.h>
31#include <linux/sched/signal.h>
32#include <linux/interval_tree_generic.h>
33
34#include "vhost.h"
35
36static ushort max_mem_regions = 64;
37module_param(max_mem_regions, ushort, 0444);
38MODULE_PARM_DESC(max_mem_regions,
39 "Maximum number of memory regions in memory map. (default: 64)");
40static int max_iotlb_entries = 2048;
41module_param(max_iotlb_entries, int, 0444);
42MODULE_PARM_DESC(max_iotlb_entries,
43 "Maximum number of iotlb entries. (default: 2048)");
44
45enum {
46 VHOST_MEMORY_F_LOG = 0x1,
47};
48
49#define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num])
50#define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num])
51
52INTERVAL_TREE_DEFINE(struct vhost_umem_node,
53 rb, __u64, __subtree_last,
54 START, LAST, static inline, vhost_umem_interval_tree);
55
56#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
57static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)
58{
59 vq->user_be = !virtio_legacy_is_little_endian();
60}
61
62static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq)
63{
64 vq->user_be = true;
65}
66
67static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq)
68{
69 vq->user_be = false;
70}
71
72static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp)
73{
74 struct vhost_vring_state s;
75
76 if (vq->private_data)
77 return -EBUSY;
78
79 if (copy_from_user(&s, argp, sizeof(s)))
80 return -EFAULT;
81
82 if (s.num != VHOST_VRING_LITTLE_ENDIAN &&
83 s.num != VHOST_VRING_BIG_ENDIAN)
84 return -EINVAL;
85
86 if (s.num == VHOST_VRING_BIG_ENDIAN)
87 vhost_enable_cross_endian_big(vq);
88 else
89 vhost_enable_cross_endian_little(vq);
90
91 return 0;
92}
93
94static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx,
95 int __user *argp)
96{
97 struct vhost_vring_state s = {
98 .index = idx,
99 .num = vq->user_be
100 };
101
102 if (copy_to_user(argp, &s, sizeof(s)))
103 return -EFAULT;
104
105 return 0;
106}
107
108static void vhost_init_is_le(struct vhost_virtqueue *vq)
109{
110
111
112
113
114
115 vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be;
116}
117#else
118static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)
119{
120}
121
122static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp)
123{
124 return -ENOIOCTLCMD;
125}
126
127static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx,
128 int __user *argp)
129{
130 return -ENOIOCTLCMD;
131}
132
133static void vhost_init_is_le(struct vhost_virtqueue *vq)
134{
135 vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1)
136 || virtio_legacy_is_little_endian();
137}
138#endif
139
140static void vhost_reset_is_le(struct vhost_virtqueue *vq)
141{
142 vhost_init_is_le(vq);
143}
144
145struct vhost_flush_struct {
146 struct vhost_work work;
147 struct completion wait_event;
148};
149
150static void vhost_flush_work(struct vhost_work *work)
151{
152 struct vhost_flush_struct *s;
153
154 s = container_of(work, struct vhost_flush_struct, work);
155 complete(&s->wait_event);
156}
157
158static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
159 poll_table *pt)
160{
161 struct vhost_poll *poll;
162
163 poll = container_of(pt, struct vhost_poll, table);
164 poll->wqh = wqh;
165 add_wait_queue(wqh, &poll->wait);
166}
167
168static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync,
169 void *key)
170{
171 struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait);
172
173 if (!(key_to_poll(key) & poll->mask))
174 return 0;
175
176 vhost_poll_queue(poll);
177 return 0;
178}
179
180void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn)
181{
182 clear_bit(VHOST_WORK_QUEUED, &work->flags);
183 work->fn = fn;
184}
185EXPORT_SYMBOL_GPL(vhost_work_init);
186
187
188void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
189 __poll_t mask, struct vhost_dev *dev)
190{
191 init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup);
192 init_poll_funcptr(&poll->table, vhost_poll_func);
193 poll->mask = mask;
194 poll->dev = dev;
195 poll->wqh = NULL;
196
197 vhost_work_init(&poll->work, fn);
198}
199EXPORT_SYMBOL_GPL(vhost_poll_init);
200
201
202
203int vhost_poll_start(struct vhost_poll *poll, struct file *file)
204{
205 __poll_t mask;
206 int ret = 0;
207
208 if (poll->wqh)
209 return 0;
210
211 mask = file->f_op->poll(file, &poll->table);
212 if (mask)
213 vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask));
214 if (mask & EPOLLERR) {
215 vhost_poll_stop(poll);
216 ret = -EINVAL;
217 }
218
219 return ret;
220}
221EXPORT_SYMBOL_GPL(vhost_poll_start);
222
223
224
225void vhost_poll_stop(struct vhost_poll *poll)
226{
227 if (poll->wqh) {
228 remove_wait_queue(poll->wqh, &poll->wait);
229 poll->wqh = NULL;
230 }
231}
232EXPORT_SYMBOL_GPL(vhost_poll_stop);
233
234void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
235{
236 struct vhost_flush_struct flush;
237
238 if (dev->worker) {
239 init_completion(&flush.wait_event);
240 vhost_work_init(&flush.work, vhost_flush_work);
241
242 vhost_work_queue(dev, &flush.work);
243 wait_for_completion(&flush.wait_event);
244 }
245}
246EXPORT_SYMBOL_GPL(vhost_work_flush);
247
248
249
250void vhost_poll_flush(struct vhost_poll *poll)
251{
252 vhost_work_flush(poll->dev, &poll->work);
253}
254EXPORT_SYMBOL_GPL(vhost_poll_flush);
255
256void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
257{
258 if (!dev->worker)
259 return;
260
261 if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
262
263
264
265
266 llist_add(&work->node, &dev->work_list);
267 wake_up_process(dev->worker);
268 }
269}
270EXPORT_SYMBOL_GPL(vhost_work_queue);
271
272
273bool vhost_has_work(struct vhost_dev *dev)
274{
275 return !llist_empty(&dev->work_list);
276}
277EXPORT_SYMBOL_GPL(vhost_has_work);
278
279void vhost_poll_queue(struct vhost_poll *poll)
280{
281 vhost_work_queue(poll->dev, &poll->work);
282}
283EXPORT_SYMBOL_GPL(vhost_poll_queue);
284
285static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq)
286{
287 int j;
288
289 for (j = 0; j < VHOST_NUM_ADDRS; j++)
290 vq->meta_iotlb[j] = NULL;
291}
292
293static void vhost_vq_meta_reset(struct vhost_dev *d)
294{
295 int i;
296
297 for (i = 0; i < d->nvqs; ++i)
298 __vhost_vq_meta_reset(d->vqs[i]);
299}
300
301static void vhost_vq_reset(struct vhost_dev *dev,
302 struct vhost_virtqueue *vq)
303{
304 vq->num = 1;
305 vq->desc = NULL;
306 vq->avail = NULL;
307 vq->used = NULL;
308 vq->last_avail_idx = 0;
309 vq->avail_idx = 0;
310 vq->last_used_idx = 0;
311 vq->signalled_used = 0;
312 vq->signalled_used_valid = false;
313 vq->used_flags = 0;
314 vq->log_used = false;
315 vq->log_addr = -1ull;
316 vq->private_data = NULL;
317 vq->acked_features = 0;
318 vq->log_base = NULL;
319 vq->error_ctx = NULL;
320 vq->kick = NULL;
321 vq->call_ctx = NULL;
322 vq->log_ctx = NULL;
323 vhost_reset_is_le(vq);
324 vhost_disable_cross_endian(vq);
325 vq->busyloop_timeout = 0;
326 vq->umem = NULL;
327 vq->iotlb = NULL;
328 __vhost_vq_meta_reset(vq);
329}
330
331static int vhost_worker(void *data)
332{
333 struct vhost_dev *dev = data;
334 struct vhost_work *work, *work_next;
335 struct llist_node *node;
336 mm_segment_t oldfs = get_fs();
337
338 set_fs(USER_DS);
339 use_mm(dev->mm);
340
341 for (;;) {
342
343 set_current_state(TASK_INTERRUPTIBLE);
344
345 if (kthread_should_stop()) {
346 __set_current_state(TASK_RUNNING);
347 break;
348 }
349
350 node = llist_del_all(&dev->work_list);
351 if (!node)
352 schedule();
353
354 node = llist_reverse_order(node);
355
356 smp_wmb();
357 llist_for_each_entry_safe(work, work_next, node, node) {
358 clear_bit(VHOST_WORK_QUEUED, &work->flags);
359 __set_current_state(TASK_RUNNING);
360 work->fn(work);
361 if (need_resched())
362 schedule();
363 }
364 }
365 unuse_mm(dev->mm);
366 set_fs(oldfs);
367 return 0;
368}
369
370static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
371{
372 kfree(vq->indirect);
373 vq->indirect = NULL;
374 kfree(vq->log);
375 vq->log = NULL;
376 kfree(vq->heads);
377 vq->heads = NULL;
378}
379
380
381static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
382{
383 struct vhost_virtqueue *vq;
384 int i;
385
386 for (i = 0; i < dev->nvqs; ++i) {
387 vq = dev->vqs[i];
388 vq->indirect = kmalloc(sizeof *vq->indirect * UIO_MAXIOV,
389 GFP_KERNEL);
390 vq->log = kmalloc(sizeof *vq->log * UIO_MAXIOV, GFP_KERNEL);
391 vq->heads = kmalloc(sizeof *vq->heads * UIO_MAXIOV, GFP_KERNEL);
392 if (!vq->indirect || !vq->log || !vq->heads)
393 goto err_nomem;
394 }
395 return 0;
396
397err_nomem:
398 for (; i >= 0; --i)
399 vhost_vq_free_iovecs(dev->vqs[i]);
400 return -ENOMEM;
401}
402
403static void vhost_dev_free_iovecs(struct vhost_dev *dev)
404{
405 int i;
406
407 for (i = 0; i < dev->nvqs; ++i)
408 vhost_vq_free_iovecs(dev->vqs[i]);
409}
410
411void vhost_dev_init(struct vhost_dev *dev,
412 struct vhost_virtqueue **vqs, int nvqs)
413{
414 struct vhost_virtqueue *vq;
415 int i;
416
417 dev->vqs = vqs;
418 dev->nvqs = nvqs;
419 mutex_init(&dev->mutex);
420 dev->log_ctx = NULL;
421 dev->umem = NULL;
422 dev->iotlb = NULL;
423 dev->mm = NULL;
424 dev->worker = NULL;
425 init_llist_head(&dev->work_list);
426 init_waitqueue_head(&dev->wait);
427 INIT_LIST_HEAD(&dev->read_list);
428 INIT_LIST_HEAD(&dev->pending_list);
429 spin_lock_init(&dev->iotlb_lock);
430
431
432 for (i = 0; i < dev->nvqs; ++i) {
433 vq = dev->vqs[i];
434 vq->log = NULL;
435 vq->indirect = NULL;
436 vq->heads = NULL;
437 vq->dev = dev;
438 mutex_init(&vq->mutex);
439 vhost_vq_reset(dev, vq);
440 if (vq->handle_kick)
441 vhost_poll_init(&vq->poll, vq->handle_kick,
442 EPOLLIN, dev);
443 }
444}
445EXPORT_SYMBOL_GPL(vhost_dev_init);
446
447
448long vhost_dev_check_owner(struct vhost_dev *dev)
449{
450
451 return dev->mm == current->mm ? 0 : -EPERM;
452}
453EXPORT_SYMBOL_GPL(vhost_dev_check_owner);
454
455struct vhost_attach_cgroups_struct {
456 struct vhost_work work;
457 struct task_struct *owner;
458 int ret;
459};
460
461static void vhost_attach_cgroups_work(struct vhost_work *work)
462{
463 struct vhost_attach_cgroups_struct *s;
464
465 s = container_of(work, struct vhost_attach_cgroups_struct, work);
466 s->ret = cgroup_attach_task_all(s->owner, current);
467}
468
469static int vhost_attach_cgroups(struct vhost_dev *dev)
470{
471 struct vhost_attach_cgroups_struct attach;
472
473 attach.owner = current;
474 vhost_work_init(&attach.work, vhost_attach_cgroups_work);
475 vhost_work_queue(dev, &attach.work);
476 vhost_work_flush(dev, &attach.work);
477 return attach.ret;
478}
479
480
481bool vhost_dev_has_owner(struct vhost_dev *dev)
482{
483 return dev->mm;
484}
485EXPORT_SYMBOL_GPL(vhost_dev_has_owner);
486
487
488long vhost_dev_set_owner(struct vhost_dev *dev)
489{
490 struct task_struct *worker;
491 int err;
492
493
494 if (vhost_dev_has_owner(dev)) {
495 err = -EBUSY;
496 goto err_mm;
497 }
498
499
500 dev->mm = get_task_mm(current);
501 worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid);
502 if (IS_ERR(worker)) {
503 err = PTR_ERR(worker);
504 goto err_worker;
505 }
506
507 dev->worker = worker;
508 wake_up_process(worker);
509
510 err = vhost_attach_cgroups(dev);
511 if (err)
512 goto err_cgroup;
513
514 err = vhost_dev_alloc_iovecs(dev);
515 if (err)
516 goto err_cgroup;
517
518 return 0;
519err_cgroup:
520 kthread_stop(worker);
521 dev->worker = NULL;
522err_worker:
523 if (dev->mm)
524 mmput(dev->mm);
525 dev->mm = NULL;
526err_mm:
527 return err;
528}
529EXPORT_SYMBOL_GPL(vhost_dev_set_owner);
530
531struct vhost_umem *vhost_dev_reset_owner_prepare(void)
532{
533 return kvzalloc(sizeof(struct vhost_umem), GFP_KERNEL);
534}
535EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare);
536
537
538void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_umem *umem)
539{
540 int i;
541
542 vhost_dev_cleanup(dev);
543
544
545 INIT_LIST_HEAD(&umem->umem_list);
546 dev->umem = umem;
547
548
549
550 for (i = 0; i < dev->nvqs; ++i)
551 dev->vqs[i]->umem = umem;
552}
553EXPORT_SYMBOL_GPL(vhost_dev_reset_owner);
554
555void vhost_dev_stop(struct vhost_dev *dev)
556{
557 int i;
558
559 for (i = 0; i < dev->nvqs; ++i) {
560 if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) {
561 vhost_poll_stop(&dev->vqs[i]->poll);
562 vhost_poll_flush(&dev->vqs[i]->poll);
563 }
564 }
565}
566EXPORT_SYMBOL_GPL(vhost_dev_stop);
567
568static void vhost_umem_free(struct vhost_umem *umem,
569 struct vhost_umem_node *node)
570{
571 vhost_umem_interval_tree_remove(node, &umem->umem_tree);
572 list_del(&node->link);
573 kfree(node);
574 umem->numem--;
575}
576
577static void vhost_umem_clean(struct vhost_umem *umem)
578{
579 struct vhost_umem_node *node, *tmp;
580
581 if (!umem)
582 return;
583
584 list_for_each_entry_safe(node, tmp, &umem->umem_list, link)
585 vhost_umem_free(umem, node);
586
587 kvfree(umem);
588}
589
590static void vhost_clear_msg(struct vhost_dev *dev)
591{
592 struct vhost_msg_node *node, *n;
593
594 spin_lock(&dev->iotlb_lock);
595
596 list_for_each_entry_safe(node, n, &dev->read_list, node) {
597 list_del(&node->node);
598 kfree(node);
599 }
600
601 list_for_each_entry_safe(node, n, &dev->pending_list, node) {
602 list_del(&node->node);
603 kfree(node);
604 }
605
606 spin_unlock(&dev->iotlb_lock);
607}
608
609void vhost_dev_cleanup(struct vhost_dev *dev)
610{
611 int i;
612
613 for (i = 0; i < dev->nvqs; ++i) {
614 if (dev->vqs[i]->error_ctx)
615 eventfd_ctx_put(dev->vqs[i]->error_ctx);
616 if (dev->vqs[i]->kick)
617 fput(dev->vqs[i]->kick);
618 if (dev->vqs[i]->call_ctx)
619 eventfd_ctx_put(dev->vqs[i]->call_ctx);
620 vhost_vq_reset(dev, dev->vqs[i]);
621 }
622 vhost_dev_free_iovecs(dev);
623 if (dev->log_ctx)
624 eventfd_ctx_put(dev->log_ctx);
625 dev->log_ctx = NULL;
626
627 vhost_umem_clean(dev->umem);
628 dev->umem = NULL;
629 vhost_umem_clean(dev->iotlb);
630 dev->iotlb = NULL;
631 vhost_clear_msg(dev);
632 wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM);
633 WARN_ON(!llist_empty(&dev->work_list));
634 if (dev->worker) {
635 kthread_stop(dev->worker);
636 dev->worker = NULL;
637 }
638 if (dev->mm)
639 mmput(dev->mm);
640 dev->mm = NULL;
641}
642EXPORT_SYMBOL_GPL(vhost_dev_cleanup);
643
644static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
645{
646 u64 a = addr / VHOST_PAGE_SIZE / 8;
647
648
649 if (a > ULONG_MAX - (unsigned long)log_base ||
650 a + (unsigned long)log_base > ULONG_MAX)
651 return false;
652
653 return access_ok(VERIFY_WRITE, log_base + a,
654 (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8);
655}
656
657static bool vhost_overflow(u64 uaddr, u64 size)
658{
659
660 return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size;
661}
662
663
664static bool vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem,
665 int log_all)
666{
667 struct vhost_umem_node *node;
668
669 if (!umem)
670 return false;
671
672 list_for_each_entry(node, &umem->umem_list, link) {
673 unsigned long a = node->userspace_addr;
674
675 if (vhost_overflow(node->userspace_addr, node->size))
676 return false;
677
678
679 if (!access_ok(VERIFY_WRITE, (void __user *)a,
680 node->size))
681 return false;
682 else if (log_all && !log_access_ok(log_base,
683 node->start,
684 node->size))
685 return false;
686 }
687 return true;
688}
689
690static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq,
691 u64 addr, unsigned int size,
692 int type)
693{
694 const struct vhost_umem_node *node = vq->meta_iotlb[type];
695
696 if (!node)
697 return NULL;
698
699 return (void *)(uintptr_t)(node->userspace_addr + addr - node->start);
700}
701
702
703
704static bool memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem,
705 int log_all)
706{
707 int i;
708
709 for (i = 0; i < d->nvqs; ++i) {
710 bool ok;
711 bool log;
712
713 mutex_lock(&d->vqs[i]->mutex);
714 log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL);
715
716 if (d->vqs[i]->private_data)
717 ok = vq_memory_access_ok(d->vqs[i]->log_base,
718 umem, log);
719 else
720 ok = true;
721 mutex_unlock(&d->vqs[i]->mutex);
722 if (!ok)
723 return false;
724 }
725 return true;
726}
727
728static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
729 struct iovec iov[], int iov_size, int access);
730
731static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to,
732 const void *from, unsigned size)
733{
734 int ret;
735
736 if (!vq->iotlb)
737 return __copy_to_user(to, from, size);
738 else {
739
740
741
742
743
744 struct iov_iter t;
745 void __user *uaddr = vhost_vq_meta_fetch(vq,
746 (u64)(uintptr_t)to, size,
747 VHOST_ADDR_USED);
748
749 if (uaddr)
750 return __copy_to_user(uaddr, from, size);
751
752 ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov,
753 ARRAY_SIZE(vq->iotlb_iov),
754 VHOST_ACCESS_WO);
755 if (ret < 0)
756 goto out;
757 iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size);
758 ret = copy_to_iter(from, size, &t);
759 if (ret == size)
760 ret = 0;
761 }
762out:
763 return ret;
764}
765
766static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to,
767 void __user *from, unsigned size)
768{
769 int ret;
770
771 if (!vq->iotlb)
772 return __copy_from_user(to, from, size);
773 else {
774
775
776
777
778
779 void __user *uaddr = vhost_vq_meta_fetch(vq,
780 (u64)(uintptr_t)from, size,
781 VHOST_ADDR_DESC);
782 struct iov_iter f;
783
784 if (uaddr)
785 return __copy_from_user(to, uaddr, size);
786
787 ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov,
788 ARRAY_SIZE(vq->iotlb_iov),
789 VHOST_ACCESS_RO);
790 if (ret < 0) {
791 vq_err(vq, "IOTLB translation failure: uaddr "
792 "%p size 0x%llx\n", from,
793 (unsigned long long) size);
794 goto out;
795 }
796 iov_iter_init(&f, READ, vq->iotlb_iov, ret, size);
797 ret = copy_from_iter(to, size, &f);
798 if (ret == size)
799 ret = 0;
800 }
801
802out:
803 return ret;
804}
805
806static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq,
807 void __user *addr, unsigned int size,
808 int type)
809{
810 int ret;
811
812 ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov,
813 ARRAY_SIZE(vq->iotlb_iov),
814 VHOST_ACCESS_RO);
815 if (ret < 0) {
816 vq_err(vq, "IOTLB translation failure: uaddr "
817 "%p size 0x%llx\n", addr,
818 (unsigned long long) size);
819 return NULL;
820 }
821
822 if (ret != 1 || vq->iotlb_iov[0].iov_len != size) {
823 vq_err(vq, "Non atomic userspace memory access: uaddr "
824 "%p size 0x%llx\n", addr,
825 (unsigned long long) size);
826 return NULL;
827 }
828
829 return vq->iotlb_iov[0].iov_base;
830}
831
832
833
834
835
836
837static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq,
838 void *addr, unsigned int size,
839 int type)
840{
841 void __user *uaddr = vhost_vq_meta_fetch(vq,
842 (u64)(uintptr_t)addr, size, type);
843 if (uaddr)
844 return uaddr;
845
846 return __vhost_get_user_slow(vq, addr, size, type);
847}
848
849#define vhost_put_user(vq, x, ptr) \
850({ \
851 int ret = -EFAULT; \
852 if (!vq->iotlb) { \
853 ret = __put_user(x, ptr); \
854 } else { \
855 __typeof__(ptr) to = \
856 (__typeof__(ptr)) __vhost_get_user(vq, ptr, \
857 sizeof(*ptr), VHOST_ADDR_USED); \
858 if (to != NULL) \
859 ret = __put_user(x, to); \
860 else \
861 ret = -EFAULT; \
862 } \
863 ret; \
864})
865
866#define vhost_get_user(vq, x, ptr, type) \
867({ \
868 int ret; \
869 if (!vq->iotlb) { \
870 ret = __get_user(x, ptr); \
871 } else { \
872 __typeof__(ptr) from = \
873 (__typeof__(ptr)) __vhost_get_user(vq, ptr, \
874 sizeof(*ptr), \
875 type); \
876 if (from != NULL) \
877 ret = __get_user(x, from); \
878 else \
879 ret = -EFAULT; \
880 } \
881 ret; \
882})
883
884#define vhost_get_avail(vq, x, ptr) \
885 vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL)
886
887#define vhost_get_used(vq, x, ptr) \
888 vhost_get_user(vq, x, ptr, VHOST_ADDR_USED)
889
890static void vhost_dev_lock_vqs(struct vhost_dev *d)
891{
892 int i = 0;
893 for (i = 0; i < d->nvqs; ++i)
894 mutex_lock_nested(&d->vqs[i]->mutex, i);
895}
896
897static void vhost_dev_unlock_vqs(struct vhost_dev *d)
898{
899 int i = 0;
900 for (i = 0; i < d->nvqs; ++i)
901 mutex_unlock(&d->vqs[i]->mutex);
902}
903
904static int vhost_new_umem_range(struct vhost_umem *umem,
905 u64 start, u64 size, u64 end,
906 u64 userspace_addr, int perm)
907{
908 struct vhost_umem_node *tmp, *node = kmalloc(sizeof(*node), GFP_ATOMIC);
909
910 if (!node)
911 return -ENOMEM;
912
913 if (umem->numem == max_iotlb_entries) {
914 tmp = list_first_entry(&umem->umem_list, typeof(*tmp), link);
915 vhost_umem_free(umem, tmp);
916 }
917
918 node->start = start;
919 node->size = size;
920 node->last = end;
921 node->userspace_addr = userspace_addr;
922 node->perm = perm;
923 INIT_LIST_HEAD(&node->link);
924 list_add_tail(&node->link, &umem->umem_list);
925 vhost_umem_interval_tree_insert(node, &umem->umem_tree);
926 umem->numem++;
927
928 return 0;
929}
930
931static void vhost_del_umem_range(struct vhost_umem *umem,
932 u64 start, u64 end)
933{
934 struct vhost_umem_node *node;
935
936 while ((node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
937 start, end)))
938 vhost_umem_free(umem, node);
939}
940
941static void vhost_iotlb_notify_vq(struct vhost_dev *d,
942 struct vhost_iotlb_msg *msg)
943{
944 struct vhost_msg_node *node, *n;
945
946 spin_lock(&d->iotlb_lock);
947
948 list_for_each_entry_safe(node, n, &d->pending_list, node) {
949 struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb;
950 if (msg->iova <= vq_msg->iova &&
951 msg->iova + msg->size - 1 > vq_msg->iova &&
952 vq_msg->type == VHOST_IOTLB_MISS) {
953 vhost_poll_queue(&node->vq->poll);
954 list_del(&node->node);
955 kfree(node);
956 }
957 }
958
959 spin_unlock(&d->iotlb_lock);
960}
961
962static bool umem_access_ok(u64 uaddr, u64 size, int access)
963{
964 unsigned long a = uaddr;
965
966
967 if (vhost_overflow(uaddr, size))
968 return false;
969
970 if ((access & VHOST_ACCESS_RO) &&
971 !access_ok(VERIFY_READ, (void __user *)a, size))
972 return false;
973 if ((access & VHOST_ACCESS_WO) &&
974 !access_ok(VERIFY_WRITE, (void __user *)a, size))
975 return false;
976 return true;
977}
978
979static int vhost_process_iotlb_msg(struct vhost_dev *dev,
980 struct vhost_iotlb_msg *msg)
981{
982 int ret = 0;
983
984 mutex_lock(&dev->mutex);
985 vhost_dev_lock_vqs(dev);
986 switch (msg->type) {
987 case VHOST_IOTLB_UPDATE:
988 if (!dev->iotlb) {
989 ret = -EFAULT;
990 break;
991 }
992 if (!umem_access_ok(msg->uaddr, msg->size, msg->perm)) {
993 ret = -EFAULT;
994 break;
995 }
996 vhost_vq_meta_reset(dev);
997 if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size,
998 msg->iova + msg->size - 1,
999 msg->uaddr, msg->perm)) {
1000 ret = -ENOMEM;
1001 break;
1002 }
1003 vhost_iotlb_notify_vq(dev, msg);
1004 break;
1005 case VHOST_IOTLB_INVALIDATE:
1006 if (!dev->iotlb) {
1007 ret = -EFAULT;
1008 break;
1009 }
1010 vhost_vq_meta_reset(dev);
1011 vhost_del_umem_range(dev->iotlb, msg->iova,
1012 msg->iova + msg->size - 1);
1013 break;
1014 default:
1015 ret = -EINVAL;
1016 break;
1017 }
1018
1019 vhost_dev_unlock_vqs(dev);
1020 mutex_unlock(&dev->mutex);
1021
1022 return ret;
1023}
1024ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
1025 struct iov_iter *from)
1026{
1027 struct vhost_msg_node node;
1028 unsigned size = sizeof(struct vhost_msg);
1029 size_t ret;
1030 int err;
1031
1032 if (iov_iter_count(from) < size)
1033 return 0;
1034 ret = copy_from_iter(&node.msg, size, from);
1035 if (ret != size)
1036 goto done;
1037
1038 switch (node.msg.type) {
1039 case VHOST_IOTLB_MSG:
1040 err = vhost_process_iotlb_msg(dev, &node.msg.iotlb);
1041 if (err)
1042 ret = err;
1043 break;
1044 default:
1045 ret = -EINVAL;
1046 break;
1047 }
1048
1049done:
1050 return ret;
1051}
1052EXPORT_SYMBOL(vhost_chr_write_iter);
1053
1054__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
1055 poll_table *wait)
1056{
1057 __poll_t mask = 0;
1058
1059 poll_wait(file, &dev->wait, wait);
1060
1061 if (!list_empty(&dev->read_list))
1062 mask |= EPOLLIN | EPOLLRDNORM;
1063
1064 return mask;
1065}
1066EXPORT_SYMBOL(vhost_chr_poll);
1067
1068ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
1069 int noblock)
1070{
1071 DEFINE_WAIT(wait);
1072 struct vhost_msg_node *node;
1073 ssize_t ret = 0;
1074 unsigned size = sizeof(struct vhost_msg);
1075
1076 if (iov_iter_count(to) < size)
1077 return 0;
1078
1079 while (1) {
1080 if (!noblock)
1081 prepare_to_wait(&dev->wait, &wait,
1082 TASK_INTERRUPTIBLE);
1083
1084 node = vhost_dequeue_msg(dev, &dev->read_list);
1085 if (node)
1086 break;
1087 if (noblock) {
1088 ret = -EAGAIN;
1089 break;
1090 }
1091 if (signal_pending(current)) {
1092 ret = -ERESTARTSYS;
1093 break;
1094 }
1095 if (!dev->iotlb) {
1096 ret = -EBADFD;
1097 break;
1098 }
1099
1100 schedule();
1101 }
1102
1103 if (!noblock)
1104 finish_wait(&dev->wait, &wait);
1105
1106 if (node) {
1107 ret = copy_to_iter(&node->msg, size, to);
1108
1109 if (ret != size || node->msg.type != VHOST_IOTLB_MISS) {
1110 kfree(node);
1111 return ret;
1112 }
1113
1114 vhost_enqueue_msg(dev, &dev->pending_list, node);
1115 }
1116
1117 return ret;
1118}
1119EXPORT_SYMBOL_GPL(vhost_chr_read_iter);
1120
1121static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access)
1122{
1123 struct vhost_dev *dev = vq->dev;
1124 struct vhost_msg_node *node;
1125 struct vhost_iotlb_msg *msg;
1126
1127 node = vhost_new_msg(vq, VHOST_IOTLB_MISS);
1128 if (!node)
1129 return -ENOMEM;
1130
1131 msg = &node->msg.iotlb;
1132 msg->type = VHOST_IOTLB_MISS;
1133 msg->iova = iova;
1134 msg->perm = access;
1135
1136 vhost_enqueue_msg(dev, &dev->read_list, node);
1137
1138 return 0;
1139}
1140
1141static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
1142 struct vring_desc __user *desc,
1143 struct vring_avail __user *avail,
1144 struct vring_used __user *used)
1145
1146{
1147 size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
1148
1149 return access_ok(VERIFY_READ, desc, num * sizeof *desc) &&
1150 access_ok(VERIFY_READ, avail,
1151 sizeof *avail + num * sizeof *avail->ring + s) &&
1152 access_ok(VERIFY_WRITE, used,
1153 sizeof *used + num * sizeof *used->ring + s);
1154}
1155
1156static void vhost_vq_meta_update(struct vhost_virtqueue *vq,
1157 const struct vhost_umem_node *node,
1158 int type)
1159{
1160 int access = (type == VHOST_ADDR_USED) ?
1161 VHOST_ACCESS_WO : VHOST_ACCESS_RO;
1162
1163 if (likely(node->perm & access))
1164 vq->meta_iotlb[type] = node;
1165}
1166
1167static bool iotlb_access_ok(struct vhost_virtqueue *vq,
1168 int access, u64 addr, u64 len, int type)
1169{
1170 const struct vhost_umem_node *node;
1171 struct vhost_umem *umem = vq->iotlb;
1172 u64 s = 0, size, orig_addr = addr, last = addr + len - 1;
1173
1174 if (vhost_vq_meta_fetch(vq, addr, len, type))
1175 return true;
1176
1177 while (len > s) {
1178 node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
1179 addr,
1180 last);
1181 if (node == NULL || node->start > addr) {
1182 vhost_iotlb_miss(vq, addr, access);
1183 return false;
1184 } else if (!(node->perm & access)) {
1185
1186
1187
1188 return false;
1189 }
1190
1191 size = node->size - addr + node->start;
1192
1193 if (orig_addr == addr && size >= len)
1194 vhost_vq_meta_update(vq, node, type);
1195
1196 s += size;
1197 addr += size;
1198 }
1199
1200 return true;
1201}
1202
1203int vq_iotlb_prefetch(struct vhost_virtqueue *vq)
1204{
1205 size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
1206 unsigned int num = vq->num;
1207
1208 if (!vq->iotlb)
1209 return 1;
1210
1211 return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc,
1212 num * sizeof(*vq->desc), VHOST_ADDR_DESC) &&
1213 iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail,
1214 sizeof *vq->avail +
1215 num * sizeof(*vq->avail->ring) + s,
1216 VHOST_ADDR_AVAIL) &&
1217 iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->used,
1218 sizeof *vq->used +
1219 num * sizeof(*vq->used->ring) + s,
1220 VHOST_ADDR_USED);
1221}
1222EXPORT_SYMBOL_GPL(vq_iotlb_prefetch);
1223
1224
1225
1226bool vhost_log_access_ok(struct vhost_dev *dev)
1227{
1228 return memory_access_ok(dev, dev->umem, 1);
1229}
1230EXPORT_SYMBOL_GPL(vhost_log_access_ok);
1231
1232
1233
1234static bool vq_log_access_ok(struct vhost_virtqueue *vq,
1235 void __user *log_base)
1236{
1237 size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
1238
1239 return vq_memory_access_ok(log_base, vq->umem,
1240 vhost_has_feature(vq, VHOST_F_LOG_ALL)) &&
1241 (!vq->log_used || log_access_ok(log_base, vq->log_addr,
1242 sizeof *vq->used +
1243 vq->num * sizeof *vq->used->ring + s));
1244}
1245
1246
1247
1248bool vhost_vq_access_ok(struct vhost_virtqueue *vq)
1249{
1250 if (!vq_log_access_ok(vq, vq->log_base))
1251 return false;
1252
1253
1254 if (vq->iotlb)
1255 return true;
1256
1257 return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used);
1258}
1259EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
1260
1261static struct vhost_umem *vhost_umem_alloc(void)
1262{
1263 struct vhost_umem *umem = kvzalloc(sizeof(*umem), GFP_KERNEL);
1264
1265 if (!umem)
1266 return NULL;
1267
1268 umem->umem_tree = RB_ROOT_CACHED;
1269 umem->numem = 0;
1270 INIT_LIST_HEAD(&umem->umem_list);
1271
1272 return umem;
1273}
1274
1275static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
1276{
1277 struct vhost_memory mem, *newmem;
1278 struct vhost_memory_region *region;
1279 struct vhost_umem *newumem, *oldumem;
1280 unsigned long size = offsetof(struct vhost_memory, regions);
1281 int i;
1282
1283 if (copy_from_user(&mem, m, size))
1284 return -EFAULT;
1285 if (mem.padding)
1286 return -EOPNOTSUPP;
1287 if (mem.nregions > max_mem_regions)
1288 return -E2BIG;
1289 newmem = kvzalloc(size + mem.nregions * sizeof(*m->regions), GFP_KERNEL);
1290 if (!newmem)
1291 return -ENOMEM;
1292
1293 memcpy(newmem, &mem, size);
1294 if (copy_from_user(newmem->regions, m->regions,
1295 mem.nregions * sizeof *m->regions)) {
1296 kvfree(newmem);
1297 return -EFAULT;
1298 }
1299
1300 newumem = vhost_umem_alloc();
1301 if (!newumem) {
1302 kvfree(newmem);
1303 return -ENOMEM;
1304 }
1305
1306 for (region = newmem->regions;
1307 region < newmem->regions + mem.nregions;
1308 region++) {
1309 if (vhost_new_umem_range(newumem,
1310 region->guest_phys_addr,
1311 region->memory_size,
1312 region->guest_phys_addr +
1313 region->memory_size - 1,
1314 region->userspace_addr,
1315 VHOST_ACCESS_RW))
1316 goto err;
1317 }
1318
1319 if (!memory_access_ok(d, newumem, 0))
1320 goto err;
1321
1322 oldumem = d->umem;
1323 d->umem = newumem;
1324
1325
1326 for (i = 0; i < d->nvqs; ++i) {
1327 mutex_lock(&d->vqs[i]->mutex);
1328 d->vqs[i]->umem = newumem;
1329 mutex_unlock(&d->vqs[i]->mutex);
1330 }
1331
1332 kvfree(newmem);
1333 vhost_umem_clean(oldumem);
1334 return 0;
1335
1336err:
1337 vhost_umem_clean(newumem);
1338 kvfree(newmem);
1339 return -EFAULT;
1340}
1341
1342long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
1343{
1344 struct file *eventfp, *filep = NULL;
1345 bool pollstart = false, pollstop = false;
1346 struct eventfd_ctx *ctx = NULL;
1347 u32 __user *idxp = argp;
1348 struct vhost_virtqueue *vq;
1349 struct vhost_vring_state s;
1350 struct vhost_vring_file f;
1351 struct vhost_vring_addr a;
1352 u32 idx;
1353 long r;
1354
1355 r = get_user(idx, idxp);
1356 if (r < 0)
1357 return r;
1358 if (idx >= d->nvqs)
1359 return -ENOBUFS;
1360
1361 vq = d->vqs[idx];
1362
1363 mutex_lock(&vq->mutex);
1364
1365 switch (ioctl) {
1366 case VHOST_SET_VRING_NUM:
1367
1368
1369 if (vq->private_data) {
1370 r = -EBUSY;
1371 break;
1372 }
1373 if (copy_from_user(&s, argp, sizeof s)) {
1374 r = -EFAULT;
1375 break;
1376 }
1377 if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) {
1378 r = -EINVAL;
1379 break;
1380 }
1381 vq->num = s.num;
1382 break;
1383 case VHOST_SET_VRING_BASE:
1384
1385
1386 if (vq->private_data) {
1387 r = -EBUSY;
1388 break;
1389 }
1390 if (copy_from_user(&s, argp, sizeof s)) {
1391 r = -EFAULT;
1392 break;
1393 }
1394 if (s.num > 0xffff) {
1395 r = -EINVAL;
1396 break;
1397 }
1398 vq->last_avail_idx = s.num;
1399
1400 vq->avail_idx = vq->last_avail_idx;
1401 break;
1402 case VHOST_GET_VRING_BASE:
1403 s.index = idx;
1404 s.num = vq->last_avail_idx;
1405 if (copy_to_user(argp, &s, sizeof s))
1406 r = -EFAULT;
1407 break;
1408 case VHOST_SET_VRING_ADDR:
1409 if (copy_from_user(&a, argp, sizeof a)) {
1410 r = -EFAULT;
1411 break;
1412 }
1413 if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) {
1414 r = -EOPNOTSUPP;
1415 break;
1416 }
1417
1418
1419 if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr ||
1420 (u64)(unsigned long)a.used_user_addr != a.used_user_addr ||
1421 (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) {
1422 r = -EFAULT;
1423 break;
1424 }
1425
1426
1427 BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE);
1428 BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE);
1429 if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) ||
1430 (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) ||
1431 (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) {
1432 r = -EINVAL;
1433 break;
1434 }
1435
1436
1437
1438
1439 if (vq->private_data) {
1440 if (!vq_access_ok(vq, vq->num,
1441 (void __user *)(unsigned long)a.desc_user_addr,
1442 (void __user *)(unsigned long)a.avail_user_addr,
1443 (void __user *)(unsigned long)a.used_user_addr)) {
1444 r = -EINVAL;
1445 break;
1446 }
1447
1448
1449 if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) &&
1450 !log_access_ok(vq->log_base, a.log_guest_addr,
1451 sizeof *vq->used +
1452 vq->num * sizeof *vq->used->ring)) {
1453 r = -EINVAL;
1454 break;
1455 }
1456 }
1457
1458 vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG));
1459 vq->desc = (void __user *)(unsigned long)a.desc_user_addr;
1460 vq->avail = (void __user *)(unsigned long)a.avail_user_addr;
1461 vq->log_addr = a.log_guest_addr;
1462 vq->used = (void __user *)(unsigned long)a.used_user_addr;
1463 break;
1464 case VHOST_SET_VRING_KICK:
1465 if (copy_from_user(&f, argp, sizeof f)) {
1466 r = -EFAULT;
1467 break;
1468 }
1469 eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
1470 if (IS_ERR(eventfp)) {
1471 r = PTR_ERR(eventfp);
1472 break;
1473 }
1474 if (eventfp != vq->kick) {
1475 pollstop = (filep = vq->kick) != NULL;
1476 pollstart = (vq->kick = eventfp) != NULL;
1477 } else
1478 filep = eventfp;
1479 break;
1480 case VHOST_SET_VRING_CALL:
1481 if (copy_from_user(&f, argp, sizeof f)) {
1482 r = -EFAULT;
1483 break;
1484 }
1485 ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd);
1486 if (IS_ERR(ctx)) {
1487 r = PTR_ERR(ctx);
1488 break;
1489 }
1490 swap(ctx, vq->call_ctx);
1491 break;
1492 case VHOST_SET_VRING_ERR:
1493 if (copy_from_user(&f, argp, sizeof f)) {
1494 r = -EFAULT;
1495 break;
1496 }
1497 ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd);
1498 if (IS_ERR(ctx)) {
1499 r = PTR_ERR(ctx);
1500 break;
1501 }
1502 swap(ctx, vq->error_ctx);
1503 break;
1504 case VHOST_SET_VRING_ENDIAN:
1505 r = vhost_set_vring_endian(vq, argp);
1506 break;
1507 case VHOST_GET_VRING_ENDIAN:
1508 r = vhost_get_vring_endian(vq, idx, argp);
1509 break;
1510 case VHOST_SET_VRING_BUSYLOOP_TIMEOUT:
1511 if (copy_from_user(&s, argp, sizeof(s))) {
1512 r = -EFAULT;
1513 break;
1514 }
1515 vq->busyloop_timeout = s.num;
1516 break;
1517 case VHOST_GET_VRING_BUSYLOOP_TIMEOUT:
1518 s.index = idx;
1519 s.num = vq->busyloop_timeout;
1520 if (copy_to_user(argp, &s, sizeof(s)))
1521 r = -EFAULT;
1522 break;
1523 default:
1524 r = -ENOIOCTLCMD;
1525 }
1526
1527 if (pollstop && vq->handle_kick)
1528 vhost_poll_stop(&vq->poll);
1529
1530 if (!IS_ERR_OR_NULL(ctx))
1531 eventfd_ctx_put(ctx);
1532 if (filep)
1533 fput(filep);
1534
1535 if (pollstart && vq->handle_kick)
1536 r = vhost_poll_start(&vq->poll, vq->kick);
1537
1538 mutex_unlock(&vq->mutex);
1539
1540 if (pollstop && vq->handle_kick)
1541 vhost_poll_flush(&vq->poll);
1542 return r;
1543}
1544EXPORT_SYMBOL_GPL(vhost_vring_ioctl);
1545
1546int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled)
1547{
1548 struct vhost_umem *niotlb, *oiotlb;
1549 int i;
1550
1551 niotlb = vhost_umem_alloc();
1552 if (!niotlb)
1553 return -ENOMEM;
1554
1555 oiotlb = d->iotlb;
1556 d->iotlb = niotlb;
1557
1558 for (i = 0; i < d->nvqs; ++i) {
1559 mutex_lock(&d->vqs[i]->mutex);
1560 d->vqs[i]->iotlb = niotlb;
1561 mutex_unlock(&d->vqs[i]->mutex);
1562 }
1563
1564 vhost_umem_clean(oiotlb);
1565
1566 return 0;
1567}
1568EXPORT_SYMBOL_GPL(vhost_init_device_iotlb);
1569
1570
1571long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
1572{
1573 struct eventfd_ctx *ctx;
1574 u64 p;
1575 long r;
1576 int i, fd;
1577
1578
1579 if (ioctl == VHOST_SET_OWNER) {
1580 r = vhost_dev_set_owner(d);
1581 goto done;
1582 }
1583
1584
1585 r = vhost_dev_check_owner(d);
1586 if (r)
1587 goto done;
1588
1589 switch (ioctl) {
1590 case VHOST_SET_MEM_TABLE:
1591 r = vhost_set_memory(d, argp);
1592 break;
1593 case VHOST_SET_LOG_BASE:
1594 if (copy_from_user(&p, argp, sizeof p)) {
1595 r = -EFAULT;
1596 break;
1597 }
1598 if ((u64)(unsigned long)p != p) {
1599 r = -EFAULT;
1600 break;
1601 }
1602 for (i = 0; i < d->nvqs; ++i) {
1603 struct vhost_virtqueue *vq;
1604 void __user *base = (void __user *)(unsigned long)p;
1605 vq = d->vqs[i];
1606 mutex_lock(&vq->mutex);
1607
1608 if (vq->private_data && !vq_log_access_ok(vq, base))
1609 r = -EFAULT;
1610 else
1611 vq->log_base = base;
1612 mutex_unlock(&vq->mutex);
1613 }
1614 break;
1615 case VHOST_SET_LOG_FD:
1616 r = get_user(fd, (int __user *)argp);
1617 if (r < 0)
1618 break;
1619 ctx = fd == -1 ? NULL : eventfd_ctx_fdget(fd);
1620 if (IS_ERR(ctx)) {
1621 r = PTR_ERR(ctx);
1622 break;
1623 }
1624 swap(ctx, d->log_ctx);
1625 for (i = 0; i < d->nvqs; ++i) {
1626 mutex_lock(&d->vqs[i]->mutex);
1627 d->vqs[i]->log_ctx = d->log_ctx;
1628 mutex_unlock(&d->vqs[i]->mutex);
1629 }
1630 if (ctx)
1631 eventfd_ctx_put(ctx);
1632 break;
1633 default:
1634 r = -ENOIOCTLCMD;
1635 break;
1636 }
1637done:
1638 return r;
1639}
1640EXPORT_SYMBOL_GPL(vhost_dev_ioctl);
1641
1642
1643
1644
1645
1646static int set_bit_to_user(int nr, void __user *addr)
1647{
1648 unsigned long log = (unsigned long)addr;
1649 struct page *page;
1650 void *base;
1651 int bit = nr + (log % PAGE_SIZE) * 8;
1652 int r;
1653
1654 r = get_user_pages_fast(log, 1, 1, &page);
1655 if (r < 0)
1656 return r;
1657 BUG_ON(r != 1);
1658 base = kmap_atomic(page);
1659 set_bit(bit, base);
1660 kunmap_atomic(base);
1661 set_page_dirty_lock(page);
1662 put_page(page);
1663 return 0;
1664}
1665
1666static int log_write(void __user *log_base,
1667 u64 write_address, u64 write_length)
1668{
1669 u64 write_page = write_address / VHOST_PAGE_SIZE;
1670 int r;
1671
1672 if (!write_length)
1673 return 0;
1674 write_length += write_address % VHOST_PAGE_SIZE;
1675 for (;;) {
1676 u64 base = (u64)(unsigned long)log_base;
1677 u64 log = base + write_page / 8;
1678 int bit = write_page % 8;
1679 if ((u64)(unsigned long)log != log)
1680 return -EFAULT;
1681 r = set_bit_to_user(bit, (void __user *)(unsigned long)log);
1682 if (r < 0)
1683 return r;
1684 if (write_length <= VHOST_PAGE_SIZE)
1685 break;
1686 write_length -= VHOST_PAGE_SIZE;
1687 write_page += 1;
1688 }
1689 return r;
1690}
1691
1692int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
1693 unsigned int log_num, u64 len)
1694{
1695 int i, r;
1696
1697
1698 smp_wmb();
1699 for (i = 0; i < log_num; ++i) {
1700 u64 l = min(log[i].len, len);
1701 r = log_write(vq->log_base, log[i].addr, l);
1702 if (r < 0)
1703 return r;
1704 len -= l;
1705 if (!len) {
1706 if (vq->log_ctx)
1707 eventfd_signal(vq->log_ctx, 1);
1708 return 0;
1709 }
1710 }
1711
1712 BUG();
1713 return 0;
1714}
1715EXPORT_SYMBOL_GPL(vhost_log_write);
1716
1717static int vhost_update_used_flags(struct vhost_virtqueue *vq)
1718{
1719 void __user *used;
1720 if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags),
1721 &vq->used->flags) < 0)
1722 return -EFAULT;
1723 if (unlikely(vq->log_used)) {
1724
1725 smp_wmb();
1726
1727 used = &vq->used->flags;
1728 log_write(vq->log_base, vq->log_addr +
1729 (used - (void __user *)vq->used),
1730 sizeof vq->used->flags);
1731 if (vq->log_ctx)
1732 eventfd_signal(vq->log_ctx, 1);
1733 }
1734 return 0;
1735}
1736
1737static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)
1738{
1739 if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx),
1740 vhost_avail_event(vq)))
1741 return -EFAULT;
1742 if (unlikely(vq->log_used)) {
1743 void __user *used;
1744
1745 smp_wmb();
1746
1747 used = vhost_avail_event(vq);
1748 log_write(vq->log_base, vq->log_addr +
1749 (used - (void __user *)vq->used),
1750 sizeof *vhost_avail_event(vq));
1751 if (vq->log_ctx)
1752 eventfd_signal(vq->log_ctx, 1);
1753 }
1754 return 0;
1755}
1756
1757int vhost_vq_init_access(struct vhost_virtqueue *vq)
1758{
1759 __virtio16 last_used_idx;
1760 int r;
1761 bool is_le = vq->is_le;
1762
1763 if (!vq->private_data)
1764 return 0;
1765
1766 vhost_init_is_le(vq);
1767
1768 r = vhost_update_used_flags(vq);
1769 if (r)
1770 goto err;
1771 vq->signalled_used_valid = false;
1772 if (!vq->iotlb &&
1773 !access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx)) {
1774 r = -EFAULT;
1775 goto err;
1776 }
1777 r = vhost_get_used(vq, last_used_idx, &vq->used->idx);
1778 if (r) {
1779 vq_err(vq, "Can't access used idx at %p\n",
1780 &vq->used->idx);
1781 goto err;
1782 }
1783 vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx);
1784 return 0;
1785
1786err:
1787 vq->is_le = is_le;
1788 return r;
1789}
1790EXPORT_SYMBOL_GPL(vhost_vq_init_access);
1791
1792static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
1793 struct iovec iov[], int iov_size, int access)
1794{
1795 const struct vhost_umem_node *node;
1796 struct vhost_dev *dev = vq->dev;
1797 struct vhost_umem *umem = dev->iotlb ? dev->iotlb : dev->umem;
1798 struct iovec *_iov;
1799 u64 s = 0;
1800 int ret = 0;
1801
1802 while ((u64)len > s) {
1803 u64 size;
1804 if (unlikely(ret >= iov_size)) {
1805 ret = -ENOBUFS;
1806 break;
1807 }
1808
1809 node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
1810 addr, addr + len - 1);
1811 if (node == NULL || node->start > addr) {
1812 if (umem != dev->iotlb) {
1813 ret = -EFAULT;
1814 break;
1815 }
1816 ret = -EAGAIN;
1817 break;
1818 } else if (!(node->perm & access)) {
1819 ret = -EPERM;
1820 break;
1821 }
1822
1823 _iov = iov + ret;
1824 size = node->size - addr + node->start;
1825 _iov->iov_len = min((u64)len - s, size);
1826 _iov->iov_base = (void __user *)(unsigned long)
1827 (node->userspace_addr + addr - node->start);
1828 s += size;
1829 addr += size;
1830 ++ret;
1831 }
1832
1833 if (ret == -EAGAIN)
1834 vhost_iotlb_miss(vq, addr, access);
1835 return ret;
1836}
1837
1838
1839
1840
1841static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc)
1842{
1843 unsigned int next;
1844
1845
1846 if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT)))
1847 return -1U;
1848
1849
1850 next = vhost16_to_cpu(vq, READ_ONCE(desc->next));
1851 return next;
1852}
1853
1854static int get_indirect(struct vhost_virtqueue *vq,
1855 struct iovec iov[], unsigned int iov_size,
1856 unsigned int *out_num, unsigned int *in_num,
1857 struct vhost_log *log, unsigned int *log_num,
1858 struct vring_desc *indirect)
1859{
1860 struct vring_desc desc;
1861 unsigned int i = 0, count, found = 0;
1862 u32 len = vhost32_to_cpu(vq, indirect->len);
1863 struct iov_iter from;
1864 int ret, access;
1865
1866
1867 if (unlikely(len % sizeof desc)) {
1868 vq_err(vq, "Invalid length in indirect descriptor: "
1869 "len 0x%llx not multiple of 0x%zx\n",
1870 (unsigned long long)len,
1871 sizeof desc);
1872 return -EINVAL;
1873 }
1874
1875 ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect,
1876 UIO_MAXIOV, VHOST_ACCESS_RO);
1877 if (unlikely(ret < 0)) {
1878 if (ret != -EAGAIN)
1879 vq_err(vq, "Translation failure %d in indirect.\n", ret);
1880 return ret;
1881 }
1882 iov_iter_init(&from, READ, vq->indirect, ret, len);
1883
1884
1885
1886 read_barrier_depends();
1887
1888 count = len / sizeof desc;
1889
1890
1891 if (unlikely(count > USHRT_MAX + 1)) {
1892 vq_err(vq, "Indirect buffer length too big: %d\n",
1893 indirect->len);
1894 return -E2BIG;
1895 }
1896
1897 do {
1898 unsigned iov_count = *in_num + *out_num;
1899 if (unlikely(++found > count)) {
1900 vq_err(vq, "Loop detected: last one at %u "
1901 "indirect size %u\n",
1902 i, count);
1903 return -EINVAL;
1904 }
1905 if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) {
1906 vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",
1907 i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);
1908 return -EINVAL;
1909 }
1910 if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) {
1911 vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n",
1912 i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);
1913 return -EINVAL;
1914 }
1915
1916 if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE))
1917 access = VHOST_ACCESS_WO;
1918 else
1919 access = VHOST_ACCESS_RO;
1920
1921 ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
1922 vhost32_to_cpu(vq, desc.len), iov + iov_count,
1923 iov_size - iov_count, access);
1924 if (unlikely(ret < 0)) {
1925 if (ret != -EAGAIN)
1926 vq_err(vq, "Translation failure %d indirect idx %d\n",
1927 ret, i);
1928 return ret;
1929 }
1930
1931 if (access == VHOST_ACCESS_WO) {
1932 *in_num += ret;
1933 if (unlikely(log)) {
1934 log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);
1935 log[*log_num].len = vhost32_to_cpu(vq, desc.len);
1936 ++*log_num;
1937 }
1938 } else {
1939
1940
1941 if (unlikely(*in_num)) {
1942 vq_err(vq, "Indirect descriptor "
1943 "has out after in: idx %d\n", i);
1944 return -EINVAL;
1945 }
1946 *out_num += ret;
1947 }
1948 } while ((i = next_desc(vq, &desc)) != -1);
1949 return 0;
1950}
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960int vhost_get_vq_desc(struct vhost_virtqueue *vq,
1961 struct iovec iov[], unsigned int iov_size,
1962 unsigned int *out_num, unsigned int *in_num,
1963 struct vhost_log *log, unsigned int *log_num)
1964{
1965 struct vring_desc desc;
1966 unsigned int i, head, found = 0;
1967 u16 last_avail_idx;
1968 __virtio16 avail_idx;
1969 __virtio16 ring_head;
1970 int ret, access;
1971
1972
1973 last_avail_idx = vq->last_avail_idx;
1974
1975 if (vq->avail_idx == vq->last_avail_idx) {
1976 if (unlikely(vhost_get_avail(vq, avail_idx, &vq->avail->idx))) {
1977 vq_err(vq, "Failed to access avail idx at %p\n",
1978 &vq->avail->idx);
1979 return -EFAULT;
1980 }
1981 vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
1982
1983 if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
1984 vq_err(vq, "Guest moved used index from %u to %u",
1985 last_avail_idx, vq->avail_idx);
1986 return -EFAULT;
1987 }
1988
1989
1990
1991
1992 if (vq->avail_idx == last_avail_idx)
1993 return vq->num;
1994
1995
1996
1997
1998 smp_rmb();
1999 }
2000
2001
2002
2003 if (unlikely(vhost_get_avail(vq, ring_head,
2004 &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) {
2005 vq_err(vq, "Failed to read head: idx %d address %p\n",
2006 last_avail_idx,
2007 &vq->avail->ring[last_avail_idx % vq->num]);
2008 return -EFAULT;
2009 }
2010
2011 head = vhost16_to_cpu(vq, ring_head);
2012
2013
2014 if (unlikely(head >= vq->num)) {
2015 vq_err(vq, "Guest says index %u > %u is available",
2016 head, vq->num);
2017 return -EINVAL;
2018 }
2019
2020
2021 *out_num = *in_num = 0;
2022 if (unlikely(log))
2023 *log_num = 0;
2024
2025 i = head;
2026 do {
2027 unsigned iov_count = *in_num + *out_num;
2028 if (unlikely(i >= vq->num)) {
2029 vq_err(vq, "Desc index is %u > %u, head = %u",
2030 i, vq->num, head);
2031 return -EINVAL;
2032 }
2033 if (unlikely(++found > vq->num)) {
2034 vq_err(vq, "Loop detected: last one at %u "
2035 "vq size %u head %u\n",
2036 i, vq->num, head);
2037 return -EINVAL;
2038 }
2039 ret = vhost_copy_from_user(vq, &desc, vq->desc + i,
2040 sizeof desc);
2041 if (unlikely(ret)) {
2042 vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
2043 i, vq->desc + i);
2044 return -EFAULT;
2045 }
2046 if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) {
2047 ret = get_indirect(vq, iov, iov_size,
2048 out_num, in_num,
2049 log, log_num, &desc);
2050 if (unlikely(ret < 0)) {
2051 if (ret != -EAGAIN)
2052 vq_err(vq, "Failure detected "
2053 "in indirect descriptor at idx %d\n", i);
2054 return ret;
2055 }
2056 continue;
2057 }
2058
2059 if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE))
2060 access = VHOST_ACCESS_WO;
2061 else
2062 access = VHOST_ACCESS_RO;
2063 ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
2064 vhost32_to_cpu(vq, desc.len), iov + iov_count,
2065 iov_size - iov_count, access);
2066 if (unlikely(ret < 0)) {
2067 if (ret != -EAGAIN)
2068 vq_err(vq, "Translation failure %d descriptor idx %d\n",
2069 ret, i);
2070 return ret;
2071 }
2072 if (access == VHOST_ACCESS_WO) {
2073
2074
2075 *in_num += ret;
2076 if (unlikely(log)) {
2077 log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);
2078 log[*log_num].len = vhost32_to_cpu(vq, desc.len);
2079 ++*log_num;
2080 }
2081 } else {
2082
2083
2084 if (unlikely(*in_num)) {
2085 vq_err(vq, "Descriptor has out after in: "
2086 "idx %d\n", i);
2087 return -EINVAL;
2088 }
2089 *out_num += ret;
2090 }
2091 } while ((i = next_desc(vq, &desc)) != -1);
2092
2093
2094 vq->last_avail_idx++;
2095
2096
2097
2098 BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
2099 return head;
2100}
2101EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
2102
2103
2104void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n)
2105{
2106 vq->last_avail_idx -= n;
2107}
2108EXPORT_SYMBOL_GPL(vhost_discard_vq_desc);
2109
2110
2111
2112int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
2113{
2114 struct vring_used_elem heads = {
2115 cpu_to_vhost32(vq, head),
2116 cpu_to_vhost32(vq, len)
2117 };
2118
2119 return vhost_add_used_n(vq, &heads, 1);
2120}
2121EXPORT_SYMBOL_GPL(vhost_add_used);
2122
2123static int __vhost_add_used_n(struct vhost_virtqueue *vq,
2124 struct vring_used_elem *heads,
2125 unsigned count)
2126{
2127 struct vring_used_elem __user *used;
2128 u16 old, new;
2129 int start;
2130
2131 start = vq->last_used_idx & (vq->num - 1);
2132 used = vq->used->ring + start;
2133 if (count == 1) {
2134 if (vhost_put_user(vq, heads[0].id, &used->id)) {
2135 vq_err(vq, "Failed to write used id");
2136 return -EFAULT;
2137 }
2138 if (vhost_put_user(vq, heads[0].len, &used->len)) {
2139 vq_err(vq, "Failed to write used len");
2140 return -EFAULT;
2141 }
2142 } else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) {
2143 vq_err(vq, "Failed to write used");
2144 return -EFAULT;
2145 }
2146 if (unlikely(vq->log_used)) {
2147
2148 smp_wmb();
2149
2150 log_write(vq->log_base,
2151 vq->log_addr +
2152 ((void __user *)used - (void __user *)vq->used),
2153 count * sizeof *used);
2154 }
2155 old = vq->last_used_idx;
2156 new = (vq->last_used_idx += count);
2157
2158
2159
2160
2161 if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old)))
2162 vq->signalled_used_valid = false;
2163 return 0;
2164}
2165
2166
2167
2168int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
2169 unsigned count)
2170{
2171 int start, n, r;
2172
2173 start = vq->last_used_idx & (vq->num - 1);
2174 n = vq->num - start;
2175 if (n < count) {
2176 r = __vhost_add_used_n(vq, heads, n);
2177 if (r < 0)
2178 return r;
2179 heads += n;
2180 count -= n;
2181 }
2182 r = __vhost_add_used_n(vq, heads, count);
2183
2184
2185 smp_wmb();
2186 if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx),
2187 &vq->used->idx)) {
2188 vq_err(vq, "Failed to increment used idx");
2189 return -EFAULT;
2190 }
2191 if (unlikely(vq->log_used)) {
2192
2193 log_write(vq->log_base,
2194 vq->log_addr + offsetof(struct vring_used, idx),
2195 sizeof vq->used->idx);
2196 if (vq->log_ctx)
2197 eventfd_signal(vq->log_ctx, 1);
2198 }
2199 return r;
2200}
2201EXPORT_SYMBOL_GPL(vhost_add_used_n);
2202
2203static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
2204{
2205 __u16 old, new;
2206 __virtio16 event;
2207 bool v;
2208
2209
2210
2211 smp_mb();
2212
2213 if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) &&
2214 unlikely(vq->avail_idx == vq->last_avail_idx))
2215 return true;
2216
2217 if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
2218 __virtio16 flags;
2219 if (vhost_get_avail(vq, flags, &vq->avail->flags)) {
2220 vq_err(vq, "Failed to get flags");
2221 return true;
2222 }
2223 return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT));
2224 }
2225 old = vq->signalled_used;
2226 v = vq->signalled_used_valid;
2227 new = vq->signalled_used = vq->last_used_idx;
2228 vq->signalled_used_valid = true;
2229
2230 if (unlikely(!v))
2231 return true;
2232
2233 if (vhost_get_avail(vq, event, vhost_used_event(vq))) {
2234 vq_err(vq, "Failed to get used event idx");
2235 return true;
2236 }
2237 return vring_need_event(vhost16_to_cpu(vq, event), new, old);
2238}
2239
2240
2241void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
2242{
2243
2244 if (vq->call_ctx && vhost_notify(dev, vq))
2245 eventfd_signal(vq->call_ctx, 1);
2246}
2247EXPORT_SYMBOL_GPL(vhost_signal);
2248
2249
2250void vhost_add_used_and_signal(struct vhost_dev *dev,
2251 struct vhost_virtqueue *vq,
2252 unsigned int head, int len)
2253{
2254 vhost_add_used(vq, head, len);
2255 vhost_signal(dev, vq);
2256}
2257EXPORT_SYMBOL_GPL(vhost_add_used_and_signal);
2258
2259
2260void vhost_add_used_and_signal_n(struct vhost_dev *dev,
2261 struct vhost_virtqueue *vq,
2262 struct vring_used_elem *heads, unsigned count)
2263{
2264 vhost_add_used_n(vq, heads, count);
2265 vhost_signal(dev, vq);
2266}
2267EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n);
2268
2269
2270bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq)
2271{
2272 __virtio16 avail_idx;
2273 int r;
2274
2275 if (vq->avail_idx != vq->last_avail_idx)
2276 return false;
2277
2278 r = vhost_get_avail(vq, avail_idx, &vq->avail->idx);
2279 if (unlikely(r))
2280 return false;
2281 vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
2282
2283 return vq->avail_idx == vq->last_avail_idx;
2284}
2285EXPORT_SYMBOL_GPL(vhost_vq_avail_empty);
2286
2287
2288bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
2289{
2290 __virtio16 avail_idx;
2291 int r;
2292
2293 if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY))
2294 return false;
2295 vq->used_flags &= ~VRING_USED_F_NO_NOTIFY;
2296 if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
2297 r = vhost_update_used_flags(vq);
2298 if (r) {
2299 vq_err(vq, "Failed to enable notification at %p: %d\n",
2300 &vq->used->flags, r);
2301 return false;
2302 }
2303 } else {
2304 r = vhost_update_avail_event(vq, vq->avail_idx);
2305 if (r) {
2306 vq_err(vq, "Failed to update avail event index at %p: %d\n",
2307 vhost_avail_event(vq), r);
2308 return false;
2309 }
2310 }
2311
2312
2313 smp_mb();
2314 r = vhost_get_avail(vq, avail_idx, &vq->avail->idx);
2315 if (r) {
2316 vq_err(vq, "Failed to check avail idx at %p: %d\n",
2317 &vq->avail->idx, r);
2318 return false;
2319 }
2320
2321 return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx;
2322}
2323EXPORT_SYMBOL_GPL(vhost_enable_notify);
2324
2325
2326void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
2327{
2328 int r;
2329
2330 if (vq->used_flags & VRING_USED_F_NO_NOTIFY)
2331 return;
2332 vq->used_flags |= VRING_USED_F_NO_NOTIFY;
2333 if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
2334 r = vhost_update_used_flags(vq);
2335 if (r)
2336 vq_err(vq, "Failed to enable notification at %p: %d\n",
2337 &vq->used->flags, r);
2338 }
2339}
2340EXPORT_SYMBOL_GPL(vhost_disable_notify);
2341
2342
2343struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type)
2344{
2345 struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL);
2346 if (!node)
2347 return NULL;
2348 node->vq = vq;
2349 node->msg.type = type;
2350 return node;
2351}
2352EXPORT_SYMBOL_GPL(vhost_new_msg);
2353
2354void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head,
2355 struct vhost_msg_node *node)
2356{
2357 spin_lock(&dev->iotlb_lock);
2358 list_add_tail(&node->node, head);
2359 spin_unlock(&dev->iotlb_lock);
2360
2361 wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM);
2362}
2363EXPORT_SYMBOL_GPL(vhost_enqueue_msg);
2364
2365struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
2366 struct list_head *head)
2367{
2368 struct vhost_msg_node *node = NULL;
2369
2370 spin_lock(&dev->iotlb_lock);
2371 if (!list_empty(head)) {
2372 node = list_first_entry(head, struct vhost_msg_node,
2373 node);
2374 list_del(&node->node);
2375 }
2376 spin_unlock(&dev->iotlb_lock);
2377
2378 return node;
2379}
2380EXPORT_SYMBOL_GPL(vhost_dequeue_msg);
2381
2382
2383static int __init vhost_init(void)
2384{
2385 return 0;
2386}
2387
2388static void __exit vhost_exit(void)
2389{
2390}
2391
2392module_init(vhost_init);
2393module_exit(vhost_exit);
2394
2395MODULE_VERSION("0.0.1");
2396MODULE_LICENSE("GPL v2");
2397MODULE_AUTHOR("Michael S. Tsirkin");
2398MODULE_DESCRIPTION("Host kernel accelerator for virtio");
2399