1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2009 Red Hat, Inc.
3 * Copyright (C) 2006 Rusty Russell IBM Corporation
5 * Author: Michael S. Tsirkin <mst@redhat.com>
7 * Inspiration, some code, and most witty comments come from
8 * Documentation/virtual/lguest/lguest.c, by Rusty Russell
10 * Generic code for virtio server in host kernel.
13 #include <linux/eventfd.h>
14 #include <linux/vhost.h>
15 #include <linux/uio.h>
17 #include <linux/miscdevice.h>
18 #include <linux/mutex.h>
19 #include <linux/poll.h>
20 #include <linux/file.h>
21 #include <linux/highmem.h>
22 #include <linux/slab.h>
23 #include <linux/vmalloc.h>
24 #include <linux/kthread.h>
25 #include <linux/cgroup.h>
26 #include <linux/module.h>
27 #include <linux/sort.h>
28 #include <linux/sched/mm.h>
29 #include <linux/sched/signal.h>
30 #include <linux/interval_tree_generic.h>
31 #include <linux/nospec.h>
32 #include <linux/kcov.h>
36 static ushort max_mem_regions
= 64;
37 module_param(max_mem_regions
, ushort
, 0444);
38 MODULE_PARM_DESC(max_mem_regions
,
39 "Maximum number of memory regions in memory map. (default: 64)");
40 static int max_iotlb_entries
= 2048;
41 module_param(max_iotlb_entries
, int, 0444);
42 MODULE_PARM_DESC(max_iotlb_entries
,
43 "Maximum number of iotlb entries. (default: 2048)");
46 VHOST_MEMORY_F_LOG
= 0x1,
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])
52 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
53 static void vhost_disable_cross_endian(struct vhost_virtqueue
*vq
)
55 vq
->user_be
= !virtio_legacy_is_little_endian();
58 static void vhost_enable_cross_endian_big(struct vhost_virtqueue
*vq
)
63 static void vhost_enable_cross_endian_little(struct vhost_virtqueue
*vq
)
68 static long vhost_set_vring_endian(struct vhost_virtqueue
*vq
, int __user
*argp
)
70 struct vhost_vring_state s
;
75 if (copy_from_user(&s
, argp
, sizeof(s
)))
78 if (s
.num
!= VHOST_VRING_LITTLE_ENDIAN
&&
79 s
.num
!= VHOST_VRING_BIG_ENDIAN
)
82 if (s
.num
== VHOST_VRING_BIG_ENDIAN
)
83 vhost_enable_cross_endian_big(vq
);
85 vhost_enable_cross_endian_little(vq
);
90 static long vhost_get_vring_endian(struct vhost_virtqueue
*vq
, u32 idx
,
93 struct vhost_vring_state s
= {
98 if (copy_to_user(argp
, &s
, sizeof(s
)))
104 static void vhost_init_is_le(struct vhost_virtqueue
*vq
)
106 /* Note for legacy virtio: user_be is initialized at reset time
107 * according to the host endianness. If userspace does not set an
108 * explicit endianness, the default behavior is native endian, as
109 * expected by legacy virtio.
111 vq
->is_le
= vhost_has_feature(vq
, VIRTIO_F_VERSION_1
) || !vq
->user_be
;
114 static void vhost_disable_cross_endian(struct vhost_virtqueue
*vq
)
118 static long vhost_set_vring_endian(struct vhost_virtqueue
*vq
, int __user
*argp
)
123 static long vhost_get_vring_endian(struct vhost_virtqueue
*vq
, u32 idx
,
129 static void vhost_init_is_le(struct vhost_virtqueue
*vq
)
131 vq
->is_le
= vhost_has_feature(vq
, VIRTIO_F_VERSION_1
)
132 || virtio_legacy_is_little_endian();
134 #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */
136 static void vhost_reset_is_le(struct vhost_virtqueue
*vq
)
138 vhost_init_is_le(vq
);
141 struct vhost_flush_struct
{
142 struct vhost_work work
;
143 struct completion wait_event
;
146 static void vhost_flush_work(struct vhost_work
*work
)
148 struct vhost_flush_struct
*s
;
150 s
= container_of(work
, struct vhost_flush_struct
, work
);
151 complete(&s
->wait_event
);
154 static void vhost_poll_func(struct file
*file
, wait_queue_head_t
*wqh
,
157 struct vhost_poll
*poll
;
159 poll
= container_of(pt
, struct vhost_poll
, table
);
161 add_wait_queue(wqh
, &poll
->wait
);
164 static int vhost_poll_wakeup(wait_queue_entry_t
*wait
, unsigned mode
, int sync
,
167 struct vhost_poll
*poll
= container_of(wait
, struct vhost_poll
, wait
);
168 struct vhost_work
*work
= &poll
->work
;
170 if (!(key_to_poll(key
) & poll
->mask
))
173 if (!poll
->dev
->use_worker
)
176 vhost_poll_queue(poll
);
181 void vhost_work_init(struct vhost_work
*work
, vhost_work_fn_t fn
)
183 clear_bit(VHOST_WORK_QUEUED
, &work
->flags
);
186 EXPORT_SYMBOL_GPL(vhost_work_init
);
188 /* Init poll structure */
189 void vhost_poll_init(struct vhost_poll
*poll
, vhost_work_fn_t fn
,
190 __poll_t mask
, struct vhost_dev
*dev
)
192 init_waitqueue_func_entry(&poll
->wait
, vhost_poll_wakeup
);
193 init_poll_funcptr(&poll
->table
, vhost_poll_func
);
198 vhost_work_init(&poll
->work
, fn
);
200 EXPORT_SYMBOL_GPL(vhost_poll_init
);
202 /* Start polling a file. We add ourselves to file's wait queue. The caller must
203 * keep a reference to a file until after vhost_poll_stop is called. */
204 int vhost_poll_start(struct vhost_poll
*poll
, struct file
*file
)
211 mask
= vfs_poll(file
, &poll
->table
);
213 vhost_poll_wakeup(&poll
->wait
, 0, 0, poll_to_key(mask
));
214 if (mask
& EPOLLERR
) {
215 vhost_poll_stop(poll
);
221 EXPORT_SYMBOL_GPL(vhost_poll_start
);
223 /* Stop polling a file. After this function returns, it becomes safe to drop the
224 * file reference. You must also flush afterwards. */
225 void vhost_poll_stop(struct vhost_poll
*poll
)
228 remove_wait_queue(poll
->wqh
, &poll
->wait
);
232 EXPORT_SYMBOL_GPL(vhost_poll_stop
);
234 void vhost_work_flush(struct vhost_dev
*dev
, struct vhost_work
*work
)
236 struct vhost_flush_struct flush
;
239 init_completion(&flush
.wait_event
);
240 vhost_work_init(&flush
.work
, vhost_flush_work
);
242 vhost_work_queue(dev
, &flush
.work
);
243 wait_for_completion(&flush
.wait_event
);
246 EXPORT_SYMBOL_GPL(vhost_work_flush
);
248 /* Flush any work that has been scheduled. When calling this, don't hold any
249 * locks that are also used by the callback. */
250 void vhost_poll_flush(struct vhost_poll
*poll
)
252 vhost_work_flush(poll
->dev
, &poll
->work
);
254 EXPORT_SYMBOL_GPL(vhost_poll_flush
);
256 void vhost_work_queue(struct vhost_dev
*dev
, struct vhost_work
*work
)
261 if (!test_and_set_bit(VHOST_WORK_QUEUED
, &work
->flags
)) {
262 /* We can only add the work to the list after we're
263 * sure it was not in the list.
264 * test_and_set_bit() implies a memory barrier.
266 llist_add(&work
->node
, &dev
->work_list
);
267 wake_up_process(dev
->worker
);
270 EXPORT_SYMBOL_GPL(vhost_work_queue
);
272 /* A lockless hint for busy polling code to exit the loop */
273 bool vhost_has_work(struct vhost_dev
*dev
)
275 return !llist_empty(&dev
->work_list
);
277 EXPORT_SYMBOL_GPL(vhost_has_work
);
279 void vhost_poll_queue(struct vhost_poll
*poll
)
281 vhost_work_queue(poll
->dev
, &poll
->work
);
283 EXPORT_SYMBOL_GPL(vhost_poll_queue
);
285 static void __vhost_vq_meta_reset(struct vhost_virtqueue
*vq
)
289 for (j
= 0; j
< VHOST_NUM_ADDRS
; j
++)
290 vq
->meta_iotlb
[j
] = NULL
;
293 static void vhost_vq_meta_reset(struct vhost_dev
*d
)
297 for (i
= 0; i
< d
->nvqs
; ++i
)
298 __vhost_vq_meta_reset(d
->vqs
[i
]);
301 static void vhost_vring_call_reset(struct vhost_vring_call
*call_ctx
)
303 call_ctx
->ctx
= NULL
;
304 memset(&call_ctx
->producer
, 0x0, sizeof(struct irq_bypass_producer
));
305 spin_lock_init(&call_ctx
->ctx_lock
);
308 static void vhost_vq_reset(struct vhost_dev
*dev
,
309 struct vhost_virtqueue
*vq
)
315 vq
->last_avail_idx
= 0;
317 vq
->last_used_idx
= 0;
318 vq
->signalled_used
= 0;
319 vq
->signalled_used_valid
= false;
321 vq
->log_used
= false;
322 vq
->log_addr
= -1ull;
323 vq
->private_data
= NULL
;
324 vq
->acked_features
= 0;
325 vq
->acked_backend_features
= 0;
327 vq
->error_ctx
= NULL
;
330 vhost_reset_is_le(vq
);
331 vhost_disable_cross_endian(vq
);
332 vq
->busyloop_timeout
= 0;
335 vhost_vring_call_reset(&vq
->call_ctx
);
336 __vhost_vq_meta_reset(vq
);
339 static int vhost_worker(void *data
)
341 struct vhost_dev
*dev
= data
;
342 struct vhost_work
*work
, *work_next
;
343 struct llist_node
*node
;
345 kthread_use_mm(dev
->mm
);
348 /* mb paired w/ kthread_stop */
349 set_current_state(TASK_INTERRUPTIBLE
);
351 if (kthread_should_stop()) {
352 __set_current_state(TASK_RUNNING
);
356 node
= llist_del_all(&dev
->work_list
);
360 node
= llist_reverse_order(node
);
361 /* make sure flag is seen after deletion */
363 llist_for_each_entry_safe(work
, work_next
, node
, node
) {
364 clear_bit(VHOST_WORK_QUEUED
, &work
->flags
);
365 __set_current_state(TASK_RUNNING
);
366 kcov_remote_start_common(dev
->kcov_handle
);
373 kthread_unuse_mm(dev
->mm
);
377 static void vhost_vq_free_iovecs(struct vhost_virtqueue
*vq
)
387 /* Helper to allocate iovec buffers for all vqs. */
388 static long vhost_dev_alloc_iovecs(struct vhost_dev
*dev
)
390 struct vhost_virtqueue
*vq
;
393 for (i
= 0; i
< dev
->nvqs
; ++i
) {
395 vq
->indirect
= kmalloc_array(UIO_MAXIOV
,
396 sizeof(*vq
->indirect
),
398 vq
->log
= kmalloc_array(dev
->iov_limit
, sizeof(*vq
->log
),
400 vq
->heads
= kmalloc_array(dev
->iov_limit
, sizeof(*vq
->heads
),
402 if (!vq
->indirect
|| !vq
->log
|| !vq
->heads
)
409 vhost_vq_free_iovecs(dev
->vqs
[i
]);
413 static void vhost_dev_free_iovecs(struct vhost_dev
*dev
)
417 for (i
= 0; i
< dev
->nvqs
; ++i
)
418 vhost_vq_free_iovecs(dev
->vqs
[i
]);
421 bool vhost_exceeds_weight(struct vhost_virtqueue
*vq
,
422 int pkts
, int total_len
)
424 struct vhost_dev
*dev
= vq
->dev
;
426 if ((dev
->byte_weight
&& total_len
>= dev
->byte_weight
) ||
427 pkts
>= dev
->weight
) {
428 vhost_poll_queue(&vq
->poll
);
434 EXPORT_SYMBOL_GPL(vhost_exceeds_weight
);
436 static size_t vhost_get_avail_size(struct vhost_virtqueue
*vq
,
439 size_t event __maybe_unused
=
440 vhost_has_feature(vq
, VIRTIO_RING_F_EVENT_IDX
) ? 2 : 0;
442 return sizeof(*vq
->avail
) +
443 sizeof(*vq
->avail
->ring
) * num
+ event
;
446 static size_t vhost_get_used_size(struct vhost_virtqueue
*vq
,
449 size_t event __maybe_unused
=
450 vhost_has_feature(vq
, VIRTIO_RING_F_EVENT_IDX
) ? 2 : 0;
452 return sizeof(*vq
->used
) +
453 sizeof(*vq
->used
->ring
) * num
+ event
;
456 static size_t vhost_get_desc_size(struct vhost_virtqueue
*vq
,
459 return sizeof(*vq
->desc
) * num
;
462 void vhost_dev_init(struct vhost_dev
*dev
,
463 struct vhost_virtqueue
**vqs
, int nvqs
,
464 int iov_limit
, int weight
, int byte_weight
,
466 int (*msg_handler
)(struct vhost_dev
*dev
,
467 struct vhost_iotlb_msg
*msg
))
469 struct vhost_virtqueue
*vq
;
474 mutex_init(&dev
->mutex
);
480 dev
->iov_limit
= iov_limit
;
481 dev
->weight
= weight
;
482 dev
->byte_weight
= byte_weight
;
483 dev
->use_worker
= use_worker
;
484 dev
->msg_handler
= msg_handler
;
485 init_llist_head(&dev
->work_list
);
486 init_waitqueue_head(&dev
->wait
);
487 INIT_LIST_HEAD(&dev
->read_list
);
488 INIT_LIST_HEAD(&dev
->pending_list
);
489 spin_lock_init(&dev
->iotlb_lock
);
492 for (i
= 0; i
< dev
->nvqs
; ++i
) {
498 mutex_init(&vq
->mutex
);
499 vhost_vq_reset(dev
, vq
);
501 vhost_poll_init(&vq
->poll
, vq
->handle_kick
,
505 EXPORT_SYMBOL_GPL(vhost_dev_init
);
507 /* Caller should have device mutex */
508 long vhost_dev_check_owner(struct vhost_dev
*dev
)
510 /* Are you the owner? If not, I don't think you mean to do that */
511 return dev
->mm
== current
->mm
? 0 : -EPERM
;
513 EXPORT_SYMBOL_GPL(vhost_dev_check_owner
);
515 struct vhost_attach_cgroups_struct
{
516 struct vhost_work work
;
517 struct task_struct
*owner
;
521 static void vhost_attach_cgroups_work(struct vhost_work
*work
)
523 struct vhost_attach_cgroups_struct
*s
;
525 s
= container_of(work
, struct vhost_attach_cgroups_struct
, work
);
526 s
->ret
= cgroup_attach_task_all(s
->owner
, current
);
529 static int vhost_attach_cgroups(struct vhost_dev
*dev
)
531 struct vhost_attach_cgroups_struct attach
;
533 attach
.owner
= current
;
534 vhost_work_init(&attach
.work
, vhost_attach_cgroups_work
);
535 vhost_work_queue(dev
, &attach
.work
);
536 vhost_work_flush(dev
, &attach
.work
);
540 /* Caller should have device mutex */
541 bool vhost_dev_has_owner(struct vhost_dev
*dev
)
545 EXPORT_SYMBOL_GPL(vhost_dev_has_owner
);
547 static void vhost_attach_mm(struct vhost_dev
*dev
)
549 /* No owner, become one */
550 if (dev
->use_worker
) {
551 dev
->mm
= get_task_mm(current
);
553 /* vDPA device does not use worker thead, so there's
554 * no need to hold the address space for mm. This help
555 * to avoid deadlock in the case of mmap() which may
556 * held the refcnt of the file and depends on release
557 * method to remove vma.
559 dev
->mm
= current
->mm
;
564 static void vhost_detach_mm(struct vhost_dev
*dev
)
577 /* Caller should have device mutex */
578 long vhost_dev_set_owner(struct vhost_dev
*dev
)
580 struct task_struct
*worker
;
583 /* Is there an owner already? */
584 if (vhost_dev_has_owner(dev
)) {
589 vhost_attach_mm(dev
);
591 dev
->kcov_handle
= kcov_common_handle();
592 if (dev
->use_worker
) {
593 worker
= kthread_create(vhost_worker
, dev
,
594 "vhost-%d", current
->pid
);
595 if (IS_ERR(worker
)) {
596 err
= PTR_ERR(worker
);
600 dev
->worker
= worker
;
601 wake_up_process(worker
); /* avoid contributing to loadavg */
603 err
= vhost_attach_cgroups(dev
);
608 err
= vhost_dev_alloc_iovecs(dev
);
615 kthread_stop(dev
->worker
);
619 vhost_detach_mm(dev
);
620 dev
->kcov_handle
= 0;
624 EXPORT_SYMBOL_GPL(vhost_dev_set_owner
);
626 static struct vhost_iotlb
*iotlb_alloc(void)
628 return vhost_iotlb_alloc(max_iotlb_entries
,
629 VHOST_IOTLB_FLAG_RETIRE
);
632 struct vhost_iotlb
*vhost_dev_reset_owner_prepare(void)
634 return iotlb_alloc();
636 EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare
);
638 /* Caller should have device mutex */
639 void vhost_dev_reset_owner(struct vhost_dev
*dev
, struct vhost_iotlb
*umem
)
643 vhost_dev_cleanup(dev
);
646 /* We don't need VQ locks below since vhost_dev_cleanup makes sure
647 * VQs aren't running.
649 for (i
= 0; i
< dev
->nvqs
; ++i
)
650 dev
->vqs
[i
]->umem
= umem
;
652 EXPORT_SYMBOL_GPL(vhost_dev_reset_owner
);
654 void vhost_dev_stop(struct vhost_dev
*dev
)
658 for (i
= 0; i
< dev
->nvqs
; ++i
) {
659 if (dev
->vqs
[i
]->kick
&& dev
->vqs
[i
]->handle_kick
) {
660 vhost_poll_stop(&dev
->vqs
[i
]->poll
);
661 vhost_poll_flush(&dev
->vqs
[i
]->poll
);
665 EXPORT_SYMBOL_GPL(vhost_dev_stop
);
667 static void vhost_clear_msg(struct vhost_dev
*dev
)
669 struct vhost_msg_node
*node
, *n
;
671 spin_lock(&dev
->iotlb_lock
);
673 list_for_each_entry_safe(node
, n
, &dev
->read_list
, node
) {
674 list_del(&node
->node
);
678 list_for_each_entry_safe(node
, n
, &dev
->pending_list
, node
) {
679 list_del(&node
->node
);
683 spin_unlock(&dev
->iotlb_lock
);
686 void vhost_dev_cleanup(struct vhost_dev
*dev
)
690 for (i
= 0; i
< dev
->nvqs
; ++i
) {
691 if (dev
->vqs
[i
]->error_ctx
)
692 eventfd_ctx_put(dev
->vqs
[i
]->error_ctx
);
693 if (dev
->vqs
[i
]->kick
)
694 fput(dev
->vqs
[i
]->kick
);
695 if (dev
->vqs
[i
]->call_ctx
.ctx
)
696 eventfd_ctx_put(dev
->vqs
[i
]->call_ctx
.ctx
);
697 vhost_vq_reset(dev
, dev
->vqs
[i
]);
699 vhost_dev_free_iovecs(dev
);
701 eventfd_ctx_put(dev
->log_ctx
);
703 /* No one will access memory at this point */
704 vhost_iotlb_free(dev
->umem
);
706 vhost_iotlb_free(dev
->iotlb
);
708 vhost_clear_msg(dev
);
709 wake_up_interruptible_poll(&dev
->wait
, EPOLLIN
| EPOLLRDNORM
);
710 WARN_ON(!llist_empty(&dev
->work_list
));
712 kthread_stop(dev
->worker
);
714 dev
->kcov_handle
= 0;
716 vhost_detach_mm(dev
);
718 EXPORT_SYMBOL_GPL(vhost_dev_cleanup
);
720 static bool log_access_ok(void __user
*log_base
, u64 addr
, unsigned long sz
)
722 u64 a
= addr
/ VHOST_PAGE_SIZE
/ 8;
724 /* Make sure 64 bit math will not overflow. */
725 if (a
> ULONG_MAX
- (unsigned long)log_base
||
726 a
+ (unsigned long)log_base
> ULONG_MAX
)
729 return access_ok(log_base
+ a
,
730 (sz
+ VHOST_PAGE_SIZE
* 8 - 1) / VHOST_PAGE_SIZE
/ 8);
733 static bool vhost_overflow(u64 uaddr
, u64 size
)
735 /* Make sure 64 bit math will not overflow. */
736 return uaddr
> ULONG_MAX
|| size
> ULONG_MAX
|| uaddr
> ULONG_MAX
- size
;
739 /* Caller should have vq mutex and device mutex. */
740 static bool vq_memory_access_ok(void __user
*log_base
, struct vhost_iotlb
*umem
,
743 struct vhost_iotlb_map
*map
;
748 list_for_each_entry(map
, &umem
->list
, link
) {
749 unsigned long a
= map
->addr
;
751 if (vhost_overflow(map
->addr
, map
->size
))
755 if (!access_ok((void __user
*)a
, map
->size
))
757 else if (log_all
&& !log_access_ok(log_base
,
765 static inline void __user
*vhost_vq_meta_fetch(struct vhost_virtqueue
*vq
,
766 u64 addr
, unsigned int size
,
769 const struct vhost_iotlb_map
*map
= vq
->meta_iotlb
[type
];
774 return (void __user
*)(uintptr_t)(map
->addr
+ addr
- map
->start
);
777 /* Can we switch to this memory table? */
778 /* Caller should have device mutex but not vq mutex */
779 static bool memory_access_ok(struct vhost_dev
*d
, struct vhost_iotlb
*umem
,
784 for (i
= 0; i
< d
->nvqs
; ++i
) {
788 mutex_lock(&d
->vqs
[i
]->mutex
);
789 log
= log_all
|| vhost_has_feature(d
->vqs
[i
], VHOST_F_LOG_ALL
);
790 /* If ring is inactive, will check when it's enabled. */
791 if (d
->vqs
[i
]->private_data
)
792 ok
= vq_memory_access_ok(d
->vqs
[i
]->log_base
,
796 mutex_unlock(&d
->vqs
[i
]->mutex
);
803 static int translate_desc(struct vhost_virtqueue
*vq
, u64 addr
, u32 len
,
804 struct iovec iov
[], int iov_size
, int access
);
806 static int vhost_copy_to_user(struct vhost_virtqueue
*vq
, void __user
*to
,
807 const void *from
, unsigned size
)
812 return __copy_to_user(to
, from
, size
);
814 /* This function should be called after iotlb
815 * prefetch, which means we're sure that all vq
816 * could be access through iotlb. So -EAGAIN should
817 * not happen in this case.
820 void __user
*uaddr
= vhost_vq_meta_fetch(vq
,
821 (u64
)(uintptr_t)to
, size
,
825 return __copy_to_user(uaddr
, from
, size
);
827 ret
= translate_desc(vq
, (u64
)(uintptr_t)to
, size
, vq
->iotlb_iov
,
828 ARRAY_SIZE(vq
->iotlb_iov
),
832 iov_iter_init(&t
, WRITE
, vq
->iotlb_iov
, ret
, size
);
833 ret
= copy_to_iter(from
, size
, &t
);
841 static int vhost_copy_from_user(struct vhost_virtqueue
*vq
, void *to
,
842 void __user
*from
, unsigned size
)
847 return __copy_from_user(to
, from
, size
);
849 /* This function should be called after iotlb
850 * prefetch, which means we're sure that vq
851 * could be access through iotlb. So -EAGAIN should
852 * not happen in this case.
854 void __user
*uaddr
= vhost_vq_meta_fetch(vq
,
855 (u64
)(uintptr_t)from
, size
,
860 return __copy_from_user(to
, uaddr
, size
);
862 ret
= translate_desc(vq
, (u64
)(uintptr_t)from
, size
, vq
->iotlb_iov
,
863 ARRAY_SIZE(vq
->iotlb_iov
),
866 vq_err(vq
, "IOTLB translation failure: uaddr "
867 "%p size 0x%llx\n", from
,
868 (unsigned long long) size
);
871 iov_iter_init(&f
, READ
, vq
->iotlb_iov
, ret
, size
);
872 ret
= copy_from_iter(to
, size
, &f
);
881 static void __user
*__vhost_get_user_slow(struct vhost_virtqueue
*vq
,
882 void __user
*addr
, unsigned int size
,
887 ret
= translate_desc(vq
, (u64
)(uintptr_t)addr
, size
, vq
->iotlb_iov
,
888 ARRAY_SIZE(vq
->iotlb_iov
),
891 vq_err(vq
, "IOTLB translation failure: uaddr "
892 "%p size 0x%llx\n", addr
,
893 (unsigned long long) size
);
897 if (ret
!= 1 || vq
->iotlb_iov
[0].iov_len
!= size
) {
898 vq_err(vq
, "Non atomic userspace memory access: uaddr "
899 "%p size 0x%llx\n", addr
,
900 (unsigned long long) size
);
904 return vq
->iotlb_iov
[0].iov_base
;
907 /* This function should be called after iotlb
908 * prefetch, which means we're sure that vq
909 * could be access through iotlb. So -EAGAIN should
910 * not happen in this case.
912 static inline void __user
*__vhost_get_user(struct vhost_virtqueue
*vq
,
913 void __user
*addr
, unsigned int size
,
916 void __user
*uaddr
= vhost_vq_meta_fetch(vq
,
917 (u64
)(uintptr_t)addr
, size
, type
);
921 return __vhost_get_user_slow(vq
, addr
, size
, type
);
924 #define vhost_put_user(vq, x, ptr) \
928 ret = __put_user(x, ptr); \
930 __typeof__(ptr) to = \
931 (__typeof__(ptr)) __vhost_get_user(vq, ptr, \
932 sizeof(*ptr), VHOST_ADDR_USED); \
934 ret = __put_user(x, to); \
941 static inline int vhost_put_avail_event(struct vhost_virtqueue
*vq
)
943 return vhost_put_user(vq
, cpu_to_vhost16(vq
, vq
->avail_idx
),
944 vhost_avail_event(vq
));
947 static inline int vhost_put_used(struct vhost_virtqueue
*vq
,
948 struct vring_used_elem
*head
, int idx
,
951 return vhost_copy_to_user(vq
, vq
->used
->ring
+ idx
, head
,
952 count
* sizeof(*head
));
955 static inline int vhost_put_used_flags(struct vhost_virtqueue
*vq
)
958 return vhost_put_user(vq
, cpu_to_vhost16(vq
, vq
->used_flags
),
962 static inline int vhost_put_used_idx(struct vhost_virtqueue
*vq
)
965 return vhost_put_user(vq
, cpu_to_vhost16(vq
, vq
->last_used_idx
),
969 #define vhost_get_user(vq, x, ptr, type) \
973 ret = __get_user(x, ptr); \
975 __typeof__(ptr) from = \
976 (__typeof__(ptr)) __vhost_get_user(vq, ptr, \
980 ret = __get_user(x, from); \
987 #define vhost_get_avail(vq, x, ptr) \
988 vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL)
990 #define vhost_get_used(vq, x, ptr) \
991 vhost_get_user(vq, x, ptr, VHOST_ADDR_USED)
993 static void vhost_dev_lock_vqs(struct vhost_dev
*d
)
996 for (i
= 0; i
< d
->nvqs
; ++i
)
997 mutex_lock_nested(&d
->vqs
[i
]->mutex
, i
);
1000 static void vhost_dev_unlock_vqs(struct vhost_dev
*d
)
1003 for (i
= 0; i
< d
->nvqs
; ++i
)
1004 mutex_unlock(&d
->vqs
[i
]->mutex
);
1007 static inline int vhost_get_avail_idx(struct vhost_virtqueue
*vq
,
1010 return vhost_get_avail(vq
, *idx
, &vq
->avail
->idx
);
1013 static inline int vhost_get_avail_head(struct vhost_virtqueue
*vq
,
1014 __virtio16
*head
, int idx
)
1016 return vhost_get_avail(vq
, *head
,
1017 &vq
->avail
->ring
[idx
& (vq
->num
- 1)]);
1020 static inline int vhost_get_avail_flags(struct vhost_virtqueue
*vq
,
1023 return vhost_get_avail(vq
, *flags
, &vq
->avail
->flags
);
1026 static inline int vhost_get_used_event(struct vhost_virtqueue
*vq
,
1029 return vhost_get_avail(vq
, *event
, vhost_used_event(vq
));
1032 static inline int vhost_get_used_idx(struct vhost_virtqueue
*vq
,
1035 return vhost_get_used(vq
, *idx
, &vq
->used
->idx
);
1038 static inline int vhost_get_desc(struct vhost_virtqueue
*vq
,
1039 struct vring_desc
*desc
, int idx
)
1041 return vhost_copy_from_user(vq
, desc
, vq
->desc
+ idx
, sizeof(*desc
));
1044 static void vhost_iotlb_notify_vq(struct vhost_dev
*d
,
1045 struct vhost_iotlb_msg
*msg
)
1047 struct vhost_msg_node
*node
, *n
;
1049 spin_lock(&d
->iotlb_lock
);
1051 list_for_each_entry_safe(node
, n
, &d
->pending_list
, node
) {
1052 struct vhost_iotlb_msg
*vq_msg
= &node
->msg
.iotlb
;
1053 if (msg
->iova
<= vq_msg
->iova
&&
1054 msg
->iova
+ msg
->size
- 1 >= vq_msg
->iova
&&
1055 vq_msg
->type
== VHOST_IOTLB_MISS
) {
1056 vhost_poll_queue(&node
->vq
->poll
);
1057 list_del(&node
->node
);
1062 spin_unlock(&d
->iotlb_lock
);
1065 static bool umem_access_ok(u64 uaddr
, u64 size
, int access
)
1067 unsigned long a
= uaddr
;
1069 /* Make sure 64 bit math will not overflow. */
1070 if (vhost_overflow(uaddr
, size
))
1073 if ((access
& VHOST_ACCESS_RO
) &&
1074 !access_ok((void __user
*)a
, size
))
1076 if ((access
& VHOST_ACCESS_WO
) &&
1077 !access_ok((void __user
*)a
, size
))
1082 static int vhost_process_iotlb_msg(struct vhost_dev
*dev
,
1083 struct vhost_iotlb_msg
*msg
)
1087 mutex_lock(&dev
->mutex
);
1088 vhost_dev_lock_vqs(dev
);
1089 switch (msg
->type
) {
1090 case VHOST_IOTLB_UPDATE
:
1095 if (!umem_access_ok(msg
->uaddr
, msg
->size
, msg
->perm
)) {
1099 vhost_vq_meta_reset(dev
);
1100 if (vhost_iotlb_add_range(dev
->iotlb
, msg
->iova
,
1101 msg
->iova
+ msg
->size
- 1,
1102 msg
->uaddr
, msg
->perm
)) {
1106 vhost_iotlb_notify_vq(dev
, msg
);
1108 case VHOST_IOTLB_INVALIDATE
:
1113 vhost_vq_meta_reset(dev
);
1114 vhost_iotlb_del_range(dev
->iotlb
, msg
->iova
,
1115 msg
->iova
+ msg
->size
- 1);
1122 vhost_dev_unlock_vqs(dev
);
1123 mutex_unlock(&dev
->mutex
);
1127 ssize_t
vhost_chr_write_iter(struct vhost_dev
*dev
,
1128 struct iov_iter
*from
)
1130 struct vhost_iotlb_msg msg
;
1134 ret
= copy_from_iter(&type
, sizeof(type
), from
);
1135 if (ret
!= sizeof(type
)) {
1141 case VHOST_IOTLB_MSG
:
1142 /* There maybe a hole after type for V1 message type,
1145 offset
= offsetof(struct vhost_msg
, iotlb
) - sizeof(int);
1147 case VHOST_IOTLB_MSG_V2
:
1148 offset
= sizeof(__u32
);
1155 iov_iter_advance(from
, offset
);
1156 ret
= copy_from_iter(&msg
, sizeof(msg
), from
);
1157 if (ret
!= sizeof(msg
)) {
1162 if (dev
->msg_handler
)
1163 ret
= dev
->msg_handler(dev
, &msg
);
1165 ret
= vhost_process_iotlb_msg(dev
, &msg
);
1171 ret
= (type
== VHOST_IOTLB_MSG
) ? sizeof(struct vhost_msg
) :
1172 sizeof(struct vhost_msg_v2
);
1176 EXPORT_SYMBOL(vhost_chr_write_iter
);
1178 __poll_t
vhost_chr_poll(struct file
*file
, struct vhost_dev
*dev
,
1183 poll_wait(file
, &dev
->wait
, wait
);
1185 if (!list_empty(&dev
->read_list
))
1186 mask
|= EPOLLIN
| EPOLLRDNORM
;
1190 EXPORT_SYMBOL(vhost_chr_poll
);
1192 ssize_t
vhost_chr_read_iter(struct vhost_dev
*dev
, struct iov_iter
*to
,
1196 struct vhost_msg_node
*node
;
1198 unsigned size
= sizeof(struct vhost_msg
);
1200 if (iov_iter_count(to
) < size
)
1205 prepare_to_wait(&dev
->wait
, &wait
,
1206 TASK_INTERRUPTIBLE
);
1208 node
= vhost_dequeue_msg(dev
, &dev
->read_list
);
1215 if (signal_pending(current
)) {
1228 finish_wait(&dev
->wait
, &wait
);
1231 struct vhost_iotlb_msg
*msg
;
1232 void *start
= &node
->msg
;
1234 switch (node
->msg
.type
) {
1235 case VHOST_IOTLB_MSG
:
1236 size
= sizeof(node
->msg
);
1237 msg
= &node
->msg
.iotlb
;
1239 case VHOST_IOTLB_MSG_V2
:
1240 size
= sizeof(node
->msg_v2
);
1241 msg
= &node
->msg_v2
.iotlb
;
1248 ret
= copy_to_iter(start
, size
, to
);
1249 if (ret
!= size
|| msg
->type
!= VHOST_IOTLB_MISS
) {
1253 vhost_enqueue_msg(dev
, &dev
->pending_list
, node
);
1258 EXPORT_SYMBOL_GPL(vhost_chr_read_iter
);
1260 static int vhost_iotlb_miss(struct vhost_virtqueue
*vq
, u64 iova
, int access
)
1262 struct vhost_dev
*dev
= vq
->dev
;
1263 struct vhost_msg_node
*node
;
1264 struct vhost_iotlb_msg
*msg
;
1265 bool v2
= vhost_backend_has_feature(vq
, VHOST_BACKEND_F_IOTLB_MSG_V2
);
1267 node
= vhost_new_msg(vq
, v2
? VHOST_IOTLB_MSG_V2
: VHOST_IOTLB_MSG
);
1272 node
->msg_v2
.type
= VHOST_IOTLB_MSG_V2
;
1273 msg
= &node
->msg_v2
.iotlb
;
1275 msg
= &node
->msg
.iotlb
;
1278 msg
->type
= VHOST_IOTLB_MISS
;
1282 vhost_enqueue_msg(dev
, &dev
->read_list
, node
);
1287 static bool vq_access_ok(struct vhost_virtqueue
*vq
, unsigned int num
,
1288 vring_desc_t __user
*desc
,
1289 vring_avail_t __user
*avail
,
1290 vring_used_t __user
*used
)
1293 return access_ok(desc
, vhost_get_desc_size(vq
, num
)) &&
1294 access_ok(avail
, vhost_get_avail_size(vq
, num
)) &&
1295 access_ok(used
, vhost_get_used_size(vq
, num
));
1298 static void vhost_vq_meta_update(struct vhost_virtqueue
*vq
,
1299 const struct vhost_iotlb_map
*map
,
1302 int access
= (type
== VHOST_ADDR_USED
) ?
1303 VHOST_ACCESS_WO
: VHOST_ACCESS_RO
;
1305 if (likely(map
->perm
& access
))
1306 vq
->meta_iotlb
[type
] = map
;
1309 static bool iotlb_access_ok(struct vhost_virtqueue
*vq
,
1310 int access
, u64 addr
, u64 len
, int type
)
1312 const struct vhost_iotlb_map
*map
;
1313 struct vhost_iotlb
*umem
= vq
->iotlb
;
1314 u64 s
= 0, size
, orig_addr
= addr
, last
= addr
+ len
- 1;
1316 if (vhost_vq_meta_fetch(vq
, addr
, len
, type
))
1320 map
= vhost_iotlb_itree_first(umem
, addr
, last
);
1321 if (map
== NULL
|| map
->start
> addr
) {
1322 vhost_iotlb_miss(vq
, addr
, access
);
1324 } else if (!(map
->perm
& access
)) {
1325 /* Report the possible access violation by
1326 * request another translation from userspace.
1331 size
= map
->size
- addr
+ map
->start
;
1333 if (orig_addr
== addr
&& size
>= len
)
1334 vhost_vq_meta_update(vq
, map
, type
);
1343 int vq_meta_prefetch(struct vhost_virtqueue
*vq
)
1345 unsigned int num
= vq
->num
;
1350 return iotlb_access_ok(vq
, VHOST_MAP_RO
, (u64
)(uintptr_t)vq
->desc
,
1351 vhost_get_desc_size(vq
, num
), VHOST_ADDR_DESC
) &&
1352 iotlb_access_ok(vq
, VHOST_MAP_RO
, (u64
)(uintptr_t)vq
->avail
,
1353 vhost_get_avail_size(vq
, num
),
1354 VHOST_ADDR_AVAIL
) &&
1355 iotlb_access_ok(vq
, VHOST_MAP_WO
, (u64
)(uintptr_t)vq
->used
,
1356 vhost_get_used_size(vq
, num
), VHOST_ADDR_USED
);
1358 EXPORT_SYMBOL_GPL(vq_meta_prefetch
);
1360 /* Can we log writes? */
1361 /* Caller should have device mutex but not vq mutex */
1362 bool vhost_log_access_ok(struct vhost_dev
*dev
)
1364 return memory_access_ok(dev
, dev
->umem
, 1);
1366 EXPORT_SYMBOL_GPL(vhost_log_access_ok
);
1368 /* Verify access for write logging. */
1369 /* Caller should have vq mutex and device mutex */
1370 static bool vq_log_access_ok(struct vhost_virtqueue
*vq
,
1371 void __user
*log_base
)
1373 return vq_memory_access_ok(log_base
, vq
->umem
,
1374 vhost_has_feature(vq
, VHOST_F_LOG_ALL
)) &&
1375 (!vq
->log_used
|| log_access_ok(log_base
, vq
->log_addr
,
1376 vhost_get_used_size(vq
, vq
->num
)));
1379 /* Can we start vq? */
1380 /* Caller should have vq mutex and device mutex */
1381 bool vhost_vq_access_ok(struct vhost_virtqueue
*vq
)
1383 if (!vq_log_access_ok(vq
, vq
->log_base
))
1386 /* Access validation occurs at prefetch time with IOTLB */
1390 return vq_access_ok(vq
, vq
->num
, vq
->desc
, vq
->avail
, vq
->used
);
1392 EXPORT_SYMBOL_GPL(vhost_vq_access_ok
);
1394 static long vhost_set_memory(struct vhost_dev
*d
, struct vhost_memory __user
*m
)
1396 struct vhost_memory mem
, *newmem
;
1397 struct vhost_memory_region
*region
;
1398 struct vhost_iotlb
*newumem
, *oldumem
;
1399 unsigned long size
= offsetof(struct vhost_memory
, regions
);
1402 if (copy_from_user(&mem
, m
, size
))
1406 if (mem
.nregions
> max_mem_regions
)
1408 newmem
= kvzalloc(struct_size(newmem
, regions
, mem
.nregions
),
1413 memcpy(newmem
, &mem
, size
);
1414 if (copy_from_user(newmem
->regions
, m
->regions
,
1415 flex_array_size(newmem
, regions
, mem
.nregions
))) {
1420 newumem
= iotlb_alloc();
1426 for (region
= newmem
->regions
;
1427 region
< newmem
->regions
+ mem
.nregions
;
1429 if (vhost_iotlb_add_range(newumem
,
1430 region
->guest_phys_addr
,
1431 region
->guest_phys_addr
+
1432 region
->memory_size
- 1,
1433 region
->userspace_addr
,
1438 if (!memory_access_ok(d
, newumem
, 0))
1444 /* All memory accesses are done under some VQ mutex. */
1445 for (i
= 0; i
< d
->nvqs
; ++i
) {
1446 mutex_lock(&d
->vqs
[i
]->mutex
);
1447 d
->vqs
[i
]->umem
= newumem
;
1448 mutex_unlock(&d
->vqs
[i
]->mutex
);
1452 vhost_iotlb_free(oldumem
);
1456 vhost_iotlb_free(newumem
);
1461 static long vhost_vring_set_num(struct vhost_dev
*d
,
1462 struct vhost_virtqueue
*vq
,
1465 struct vhost_vring_state s
;
1467 /* Resizing ring with an active backend?
1468 * You don't want to do that. */
1469 if (vq
->private_data
)
1472 if (copy_from_user(&s
, argp
, sizeof s
))
1475 if (!s
.num
|| s
.num
> 0xffff || (s
.num
& (s
.num
- 1)))
1482 static long vhost_vring_set_addr(struct vhost_dev
*d
,
1483 struct vhost_virtqueue
*vq
,
1486 struct vhost_vring_addr a
;
1488 if (copy_from_user(&a
, argp
, sizeof a
))
1490 if (a
.flags
& ~(0x1 << VHOST_VRING_F_LOG
))
1493 /* For 32bit, verify that the top 32bits of the user
1494 data are set to zero. */
1495 if ((u64
)(unsigned long)a
.desc_user_addr
!= a
.desc_user_addr
||
1496 (u64
)(unsigned long)a
.used_user_addr
!= a
.used_user_addr
||
1497 (u64
)(unsigned long)a
.avail_user_addr
!= a
.avail_user_addr
)
1500 /* Make sure it's safe to cast pointers to vring types. */
1501 BUILD_BUG_ON(__alignof__
*vq
->avail
> VRING_AVAIL_ALIGN_SIZE
);
1502 BUILD_BUG_ON(__alignof__
*vq
->used
> VRING_USED_ALIGN_SIZE
);
1503 if ((a
.avail_user_addr
& (VRING_AVAIL_ALIGN_SIZE
- 1)) ||
1504 (a
.used_user_addr
& (VRING_USED_ALIGN_SIZE
- 1)) ||
1505 (a
.log_guest_addr
& (VRING_USED_ALIGN_SIZE
- 1)))
1508 /* We only verify access here if backend is configured.
1509 * If it is not, we don't as size might not have been setup.
1510 * We will verify when backend is configured. */
1511 if (vq
->private_data
) {
1512 if (!vq_access_ok(vq
, vq
->num
,
1513 (void __user
*)(unsigned long)a
.desc_user_addr
,
1514 (void __user
*)(unsigned long)a
.avail_user_addr
,
1515 (void __user
*)(unsigned long)a
.used_user_addr
))
1518 /* Also validate log access for used ring if enabled. */
1519 if ((a
.flags
& (0x1 << VHOST_VRING_F_LOG
)) &&
1520 !log_access_ok(vq
->log_base
, a
.log_guest_addr
,
1522 vq
->num
* sizeof *vq
->used
->ring
))
1526 vq
->log_used
= !!(a
.flags
& (0x1 << VHOST_VRING_F_LOG
));
1527 vq
->desc
= (void __user
*)(unsigned long)a
.desc_user_addr
;
1528 vq
->avail
= (void __user
*)(unsigned long)a
.avail_user_addr
;
1529 vq
->log_addr
= a
.log_guest_addr
;
1530 vq
->used
= (void __user
*)(unsigned long)a
.used_user_addr
;
1535 static long vhost_vring_set_num_addr(struct vhost_dev
*d
,
1536 struct vhost_virtqueue
*vq
,
1542 mutex_lock(&vq
->mutex
);
1545 case VHOST_SET_VRING_NUM
:
1546 r
= vhost_vring_set_num(d
, vq
, argp
);
1548 case VHOST_SET_VRING_ADDR
:
1549 r
= vhost_vring_set_addr(d
, vq
, argp
);
1555 mutex_unlock(&vq
->mutex
);
1559 long vhost_vring_ioctl(struct vhost_dev
*d
, unsigned int ioctl
, void __user
*argp
)
1561 struct file
*eventfp
, *filep
= NULL
;
1562 bool pollstart
= false, pollstop
= false;
1563 struct eventfd_ctx
*ctx
= NULL
;
1564 u32 __user
*idxp
= argp
;
1565 struct vhost_virtqueue
*vq
;
1566 struct vhost_vring_state s
;
1567 struct vhost_vring_file f
;
1571 r
= get_user(idx
, idxp
);
1577 idx
= array_index_nospec(idx
, d
->nvqs
);
1580 if (ioctl
== VHOST_SET_VRING_NUM
||
1581 ioctl
== VHOST_SET_VRING_ADDR
) {
1582 return vhost_vring_set_num_addr(d
, vq
, ioctl
, argp
);
1585 mutex_lock(&vq
->mutex
);
1588 case VHOST_SET_VRING_BASE
:
1589 /* Moving base with an active backend?
1590 * You don't want to do that. */
1591 if (vq
->private_data
) {
1595 if (copy_from_user(&s
, argp
, sizeof s
)) {
1599 if (s
.num
> 0xffff) {
1603 vq
->last_avail_idx
= s
.num
;
1604 /* Forget the cached index value. */
1605 vq
->avail_idx
= vq
->last_avail_idx
;
1607 case VHOST_GET_VRING_BASE
:
1609 s
.num
= vq
->last_avail_idx
;
1610 if (copy_to_user(argp
, &s
, sizeof s
))
1613 case VHOST_SET_VRING_KICK
:
1614 if (copy_from_user(&f
, argp
, sizeof f
)) {
1618 eventfp
= f
.fd
== VHOST_FILE_UNBIND
? NULL
: eventfd_fget(f
.fd
);
1619 if (IS_ERR(eventfp
)) {
1620 r
= PTR_ERR(eventfp
);
1623 if (eventfp
!= vq
->kick
) {
1624 pollstop
= (filep
= vq
->kick
) != NULL
;
1625 pollstart
= (vq
->kick
= eventfp
) != NULL
;
1629 case VHOST_SET_VRING_CALL
:
1630 if (copy_from_user(&f
, argp
, sizeof f
)) {
1634 ctx
= f
.fd
== VHOST_FILE_UNBIND
? NULL
: eventfd_ctx_fdget(f
.fd
);
1640 spin_lock(&vq
->call_ctx
.ctx_lock
);
1641 swap(ctx
, vq
->call_ctx
.ctx
);
1642 spin_unlock(&vq
->call_ctx
.ctx_lock
);
1644 case VHOST_SET_VRING_ERR
:
1645 if (copy_from_user(&f
, argp
, sizeof f
)) {
1649 ctx
= f
.fd
== VHOST_FILE_UNBIND
? NULL
: eventfd_ctx_fdget(f
.fd
);
1654 swap(ctx
, vq
->error_ctx
);
1656 case VHOST_SET_VRING_ENDIAN
:
1657 r
= vhost_set_vring_endian(vq
, argp
);
1659 case VHOST_GET_VRING_ENDIAN
:
1660 r
= vhost_get_vring_endian(vq
, idx
, argp
);
1662 case VHOST_SET_VRING_BUSYLOOP_TIMEOUT
:
1663 if (copy_from_user(&s
, argp
, sizeof(s
))) {
1667 vq
->busyloop_timeout
= s
.num
;
1669 case VHOST_GET_VRING_BUSYLOOP_TIMEOUT
:
1671 s
.num
= vq
->busyloop_timeout
;
1672 if (copy_to_user(argp
, &s
, sizeof(s
)))
1679 if (pollstop
&& vq
->handle_kick
)
1680 vhost_poll_stop(&vq
->poll
);
1682 if (!IS_ERR_OR_NULL(ctx
))
1683 eventfd_ctx_put(ctx
);
1687 if (pollstart
&& vq
->handle_kick
)
1688 r
= vhost_poll_start(&vq
->poll
, vq
->kick
);
1690 mutex_unlock(&vq
->mutex
);
1692 if (pollstop
&& vq
->handle_kick
)
1693 vhost_poll_flush(&vq
->poll
);
1696 EXPORT_SYMBOL_GPL(vhost_vring_ioctl
);
1698 int vhost_init_device_iotlb(struct vhost_dev
*d
, bool enabled
)
1700 struct vhost_iotlb
*niotlb
, *oiotlb
;
1703 niotlb
= iotlb_alloc();
1710 for (i
= 0; i
< d
->nvqs
; ++i
) {
1711 struct vhost_virtqueue
*vq
= d
->vqs
[i
];
1713 mutex_lock(&vq
->mutex
);
1715 __vhost_vq_meta_reset(vq
);
1716 mutex_unlock(&vq
->mutex
);
1719 vhost_iotlb_free(oiotlb
);
1723 EXPORT_SYMBOL_GPL(vhost_init_device_iotlb
);
1725 /* Caller must have device mutex */
1726 long vhost_dev_ioctl(struct vhost_dev
*d
, unsigned int ioctl
, void __user
*argp
)
1728 struct eventfd_ctx
*ctx
;
1733 /* If you are not the owner, you can become one */
1734 if (ioctl
== VHOST_SET_OWNER
) {
1735 r
= vhost_dev_set_owner(d
);
1739 /* You must be the owner to do anything else */
1740 r
= vhost_dev_check_owner(d
);
1745 case VHOST_SET_MEM_TABLE
:
1746 r
= vhost_set_memory(d
, argp
);
1748 case VHOST_SET_LOG_BASE
:
1749 if (copy_from_user(&p
, argp
, sizeof p
)) {
1753 if ((u64
)(unsigned long)p
!= p
) {
1757 for (i
= 0; i
< d
->nvqs
; ++i
) {
1758 struct vhost_virtqueue
*vq
;
1759 void __user
*base
= (void __user
*)(unsigned long)p
;
1761 mutex_lock(&vq
->mutex
);
1762 /* If ring is inactive, will check when it's enabled. */
1763 if (vq
->private_data
&& !vq_log_access_ok(vq
, base
))
1766 vq
->log_base
= base
;
1767 mutex_unlock(&vq
->mutex
);
1770 case VHOST_SET_LOG_FD
:
1771 r
= get_user(fd
, (int __user
*)argp
);
1774 ctx
= fd
== VHOST_FILE_UNBIND
? NULL
: eventfd_ctx_fdget(fd
);
1779 swap(ctx
, d
->log_ctx
);
1780 for (i
= 0; i
< d
->nvqs
; ++i
) {
1781 mutex_lock(&d
->vqs
[i
]->mutex
);
1782 d
->vqs
[i
]->log_ctx
= d
->log_ctx
;
1783 mutex_unlock(&d
->vqs
[i
]->mutex
);
1786 eventfd_ctx_put(ctx
);
1795 EXPORT_SYMBOL_GPL(vhost_dev_ioctl
);
1797 /* TODO: This is really inefficient. We need something like get_user()
1798 * (instruction directly accesses the data, with an exception table entry
1799 * returning -EFAULT). See Documentation/x86/exception-tables.rst.
1801 static int set_bit_to_user(int nr
, void __user
*addr
)
1803 unsigned long log
= (unsigned long)addr
;
1806 int bit
= nr
+ (log
% PAGE_SIZE
) * 8;
1809 r
= pin_user_pages_fast(log
, 1, FOLL_WRITE
, &page
);
1813 base
= kmap_atomic(page
);
1815 kunmap_atomic(base
);
1816 unpin_user_pages_dirty_lock(&page
, 1, true);
1820 static int log_write(void __user
*log_base
,
1821 u64 write_address
, u64 write_length
)
1823 u64 write_page
= write_address
/ VHOST_PAGE_SIZE
;
1828 write_length
+= write_address
% VHOST_PAGE_SIZE
;
1830 u64 base
= (u64
)(unsigned long)log_base
;
1831 u64 log
= base
+ write_page
/ 8;
1832 int bit
= write_page
% 8;
1833 if ((u64
)(unsigned long)log
!= log
)
1835 r
= set_bit_to_user(bit
, (void __user
*)(unsigned long)log
);
1838 if (write_length
<= VHOST_PAGE_SIZE
)
1840 write_length
-= VHOST_PAGE_SIZE
;
1846 static int log_write_hva(struct vhost_virtqueue
*vq
, u64 hva
, u64 len
)
1848 struct vhost_iotlb
*umem
= vq
->umem
;
1849 struct vhost_iotlb_map
*u
;
1850 u64 start
, end
, l
, min
;
1856 /* More than one GPAs can be mapped into a single HVA. So
1857 * iterate all possible umems here to be safe.
1859 list_for_each_entry(u
, &umem
->list
, link
) {
1860 if (u
->addr
> hva
- 1 + len
||
1861 u
->addr
- 1 + u
->size
< hva
)
1863 start
= max(u
->addr
, hva
);
1864 end
= min(u
->addr
- 1 + u
->size
, hva
- 1 + len
);
1865 l
= end
- start
+ 1;
1866 r
= log_write(vq
->log_base
,
1867 u
->start
+ start
- u
->addr
,
1885 static int log_used(struct vhost_virtqueue
*vq
, u64 used_offset
, u64 len
)
1887 struct iovec iov
[64];
1891 return log_write(vq
->log_base
, vq
->log_addr
+ used_offset
, len
);
1893 ret
= translate_desc(vq
, (uintptr_t)vq
->used
+ used_offset
,
1894 len
, iov
, 64, VHOST_ACCESS_WO
);
1898 for (i
= 0; i
< ret
; i
++) {
1899 ret
= log_write_hva(vq
, (uintptr_t)iov
[i
].iov_base
,
1908 int vhost_log_write(struct vhost_virtqueue
*vq
, struct vhost_log
*log
,
1909 unsigned int log_num
, u64 len
, struct iovec
*iov
, int count
)
1913 /* Make sure data written is seen before log. */
1917 for (i
= 0; i
< count
; i
++) {
1918 r
= log_write_hva(vq
, (uintptr_t)iov
[i
].iov_base
,
1926 for (i
= 0; i
< log_num
; ++i
) {
1927 u64 l
= min(log
[i
].len
, len
);
1928 r
= log_write(vq
->log_base
, log
[i
].addr
, l
);
1934 eventfd_signal(vq
->log_ctx
, 1);
1938 /* Length written exceeds what we have stored. This is a bug. */
1942 EXPORT_SYMBOL_GPL(vhost_log_write
);
1944 static int vhost_update_used_flags(struct vhost_virtqueue
*vq
)
1947 if (vhost_put_used_flags(vq
))
1949 if (unlikely(vq
->log_used
)) {
1950 /* Make sure the flag is seen before log. */
1952 /* Log used flag write. */
1953 used
= &vq
->used
->flags
;
1954 log_used(vq
, (used
- (void __user
*)vq
->used
),
1955 sizeof vq
->used
->flags
);
1957 eventfd_signal(vq
->log_ctx
, 1);
1962 static int vhost_update_avail_event(struct vhost_virtqueue
*vq
, u16 avail_event
)
1964 if (vhost_put_avail_event(vq
))
1966 if (unlikely(vq
->log_used
)) {
1968 /* Make sure the event is seen before log. */
1970 /* Log avail event write */
1971 used
= vhost_avail_event(vq
);
1972 log_used(vq
, (used
- (void __user
*)vq
->used
),
1973 sizeof *vhost_avail_event(vq
));
1975 eventfd_signal(vq
->log_ctx
, 1);
1980 int vhost_vq_init_access(struct vhost_virtqueue
*vq
)
1982 __virtio16 last_used_idx
;
1984 bool is_le
= vq
->is_le
;
1986 if (!vq
->private_data
)
1989 vhost_init_is_le(vq
);
1991 r
= vhost_update_used_flags(vq
);
1994 vq
->signalled_used_valid
= false;
1996 !access_ok(&vq
->used
->idx
, sizeof vq
->used
->idx
)) {
2000 r
= vhost_get_used_idx(vq
, &last_used_idx
);
2002 vq_err(vq
, "Can't access used idx at %p\n",
2006 vq
->last_used_idx
= vhost16_to_cpu(vq
, last_used_idx
);
2013 EXPORT_SYMBOL_GPL(vhost_vq_init_access
);
2015 static int translate_desc(struct vhost_virtqueue
*vq
, u64 addr
, u32 len
,
2016 struct iovec iov
[], int iov_size
, int access
)
2018 const struct vhost_iotlb_map
*map
;
2019 struct vhost_dev
*dev
= vq
->dev
;
2020 struct vhost_iotlb
*umem
= dev
->iotlb
? dev
->iotlb
: dev
->umem
;
2025 while ((u64
)len
> s
) {
2027 if (unlikely(ret
>= iov_size
)) {
2032 map
= vhost_iotlb_itree_first(umem
, addr
, addr
+ len
- 1);
2033 if (map
== NULL
|| map
->start
> addr
) {
2034 if (umem
!= dev
->iotlb
) {
2040 } else if (!(map
->perm
& access
)) {
2046 size
= map
->size
- addr
+ map
->start
;
2047 _iov
->iov_len
= min((u64
)len
- s
, size
);
2048 _iov
->iov_base
= (void __user
*)(unsigned long)
2049 (map
->addr
+ addr
- map
->start
);
2056 vhost_iotlb_miss(vq
, addr
, access
);
2060 /* Each buffer in the virtqueues is actually a chain of descriptors. This
2061 * function returns the next descriptor in the chain,
2062 * or -1U if we're at the end. */
2063 static unsigned next_desc(struct vhost_virtqueue
*vq
, struct vring_desc
*desc
)
2067 /* If this descriptor says it doesn't chain, we're done. */
2068 if (!(desc
->flags
& cpu_to_vhost16(vq
, VRING_DESC_F_NEXT
)))
2071 /* Check they're not leading us off end of descriptors. */
2072 next
= vhost16_to_cpu(vq
, READ_ONCE(desc
->next
));
2076 static int get_indirect(struct vhost_virtqueue
*vq
,
2077 struct iovec iov
[], unsigned int iov_size
,
2078 unsigned int *out_num
, unsigned int *in_num
,
2079 struct vhost_log
*log
, unsigned int *log_num
,
2080 struct vring_desc
*indirect
)
2082 struct vring_desc desc
;
2083 unsigned int i
= 0, count
, found
= 0;
2084 u32 len
= vhost32_to_cpu(vq
, indirect
->len
);
2085 struct iov_iter from
;
2089 if (unlikely(len
% sizeof desc
)) {
2090 vq_err(vq
, "Invalid length in indirect descriptor: "
2091 "len 0x%llx not multiple of 0x%zx\n",
2092 (unsigned long long)len
,
2097 ret
= translate_desc(vq
, vhost64_to_cpu(vq
, indirect
->addr
), len
, vq
->indirect
,
2098 UIO_MAXIOV
, VHOST_ACCESS_RO
);
2099 if (unlikely(ret
< 0)) {
2101 vq_err(vq
, "Translation failure %d in indirect.\n", ret
);
2104 iov_iter_init(&from
, READ
, vq
->indirect
, ret
, len
);
2105 count
= len
/ sizeof desc
;
2106 /* Buffers are chained via a 16 bit next field, so
2107 * we can have at most 2^16 of these. */
2108 if (unlikely(count
> USHRT_MAX
+ 1)) {
2109 vq_err(vq
, "Indirect buffer length too big: %d\n",
2115 unsigned iov_count
= *in_num
+ *out_num
;
2116 if (unlikely(++found
> count
)) {
2117 vq_err(vq
, "Loop detected: last one at %u "
2118 "indirect size %u\n",
2122 if (unlikely(!copy_from_iter_full(&desc
, sizeof(desc
), &from
))) {
2123 vq_err(vq
, "Failed indirect descriptor: idx %d, %zx\n",
2124 i
, (size_t)vhost64_to_cpu(vq
, indirect
->addr
) + i
* sizeof desc
);
2127 if (unlikely(desc
.flags
& cpu_to_vhost16(vq
, VRING_DESC_F_INDIRECT
))) {
2128 vq_err(vq
, "Nested indirect descriptor: idx %d, %zx\n",
2129 i
, (size_t)vhost64_to_cpu(vq
, indirect
->addr
) + i
* sizeof desc
);
2133 if (desc
.flags
& cpu_to_vhost16(vq
, VRING_DESC_F_WRITE
))
2134 access
= VHOST_ACCESS_WO
;
2136 access
= VHOST_ACCESS_RO
;
2138 ret
= translate_desc(vq
, vhost64_to_cpu(vq
, desc
.addr
),
2139 vhost32_to_cpu(vq
, desc
.len
), iov
+ iov_count
,
2140 iov_size
- iov_count
, access
);
2141 if (unlikely(ret
< 0)) {
2143 vq_err(vq
, "Translation failure %d indirect idx %d\n",
2147 /* If this is an input descriptor, increment that count. */
2148 if (access
== VHOST_ACCESS_WO
) {
2150 if (unlikely(log
&& ret
)) {
2151 log
[*log_num
].addr
= vhost64_to_cpu(vq
, desc
.addr
);
2152 log
[*log_num
].len
= vhost32_to_cpu(vq
, desc
.len
);
2156 /* If it's an output descriptor, they're all supposed
2157 * to come before any input descriptors. */
2158 if (unlikely(*in_num
)) {
2159 vq_err(vq
, "Indirect descriptor "
2160 "has out after in: idx %d\n", i
);
2165 } while ((i
= next_desc(vq
, &desc
)) != -1);
2169 /* This looks in the virtqueue and for the first available buffer, and converts
2170 * it to an iovec for convenient access. Since descriptors consist of some
2171 * number of output then some number of input descriptors, it's actually two
2172 * iovecs, but we pack them into one and note how many of each there were.
2174 * This function returns the descriptor number found, or vq->num (which is
2175 * never a valid descriptor number) if none was found. A negative code is
2176 * returned on error. */
2177 int vhost_get_vq_desc(struct vhost_virtqueue
*vq
,
2178 struct iovec iov
[], unsigned int iov_size
,
2179 unsigned int *out_num
, unsigned int *in_num
,
2180 struct vhost_log
*log
, unsigned int *log_num
)
2182 struct vring_desc desc
;
2183 unsigned int i
, head
, found
= 0;
2185 __virtio16 avail_idx
;
2186 __virtio16 ring_head
;
2189 /* Check it isn't doing very strange things with descriptor numbers. */
2190 last_avail_idx
= vq
->last_avail_idx
;
2192 if (vq
->avail_idx
== vq
->last_avail_idx
) {
2193 if (unlikely(vhost_get_avail_idx(vq
, &avail_idx
))) {
2194 vq_err(vq
, "Failed to access avail idx at %p\n",
2198 vq
->avail_idx
= vhost16_to_cpu(vq
, avail_idx
);
2200 if (unlikely((u16
)(vq
->avail_idx
- last_avail_idx
) > vq
->num
)) {
2201 vq_err(vq
, "Guest moved used index from %u to %u",
2202 last_avail_idx
, vq
->avail_idx
);
2206 /* If there's nothing new since last we looked, return
2209 if (vq
->avail_idx
== last_avail_idx
)
2212 /* Only get avail ring entries after they have been
2218 /* Grab the next descriptor number they're advertising, and increment
2219 * the index we've seen. */
2220 if (unlikely(vhost_get_avail_head(vq
, &ring_head
, last_avail_idx
))) {
2221 vq_err(vq
, "Failed to read head: idx %d address %p\n",
2223 &vq
->avail
->ring
[last_avail_idx
% vq
->num
]);
2227 head
= vhost16_to_cpu(vq
, ring_head
);
2229 /* If their number is silly, that's an error. */
2230 if (unlikely(head
>= vq
->num
)) {
2231 vq_err(vq
, "Guest says index %u > %u is available",
2236 /* When we start there are none of either input nor output. */
2237 *out_num
= *in_num
= 0;
2243 unsigned iov_count
= *in_num
+ *out_num
;
2244 if (unlikely(i
>= vq
->num
)) {
2245 vq_err(vq
, "Desc index is %u > %u, head = %u",
2249 if (unlikely(++found
> vq
->num
)) {
2250 vq_err(vq
, "Loop detected: last one at %u "
2251 "vq size %u head %u\n",
2255 ret
= vhost_get_desc(vq
, &desc
, i
);
2256 if (unlikely(ret
)) {
2257 vq_err(vq
, "Failed to get descriptor: idx %d addr %p\n",
2261 if (desc
.flags
& cpu_to_vhost16(vq
, VRING_DESC_F_INDIRECT
)) {
2262 ret
= get_indirect(vq
, iov
, iov_size
,
2264 log
, log_num
, &desc
);
2265 if (unlikely(ret
< 0)) {
2267 vq_err(vq
, "Failure detected "
2268 "in indirect descriptor at idx %d\n", i
);
2274 if (desc
.flags
& cpu_to_vhost16(vq
, VRING_DESC_F_WRITE
))
2275 access
= VHOST_ACCESS_WO
;
2277 access
= VHOST_ACCESS_RO
;
2278 ret
= translate_desc(vq
, vhost64_to_cpu(vq
, desc
.addr
),
2279 vhost32_to_cpu(vq
, desc
.len
), iov
+ iov_count
,
2280 iov_size
- iov_count
, access
);
2281 if (unlikely(ret
< 0)) {
2283 vq_err(vq
, "Translation failure %d descriptor idx %d\n",
2287 if (access
== VHOST_ACCESS_WO
) {
2288 /* If this is an input descriptor,
2289 * increment that count. */
2291 if (unlikely(log
&& ret
)) {
2292 log
[*log_num
].addr
= vhost64_to_cpu(vq
, desc
.addr
);
2293 log
[*log_num
].len
= vhost32_to_cpu(vq
, desc
.len
);
2297 /* If it's an output descriptor, they're all supposed
2298 * to come before any input descriptors. */
2299 if (unlikely(*in_num
)) {
2300 vq_err(vq
, "Descriptor has out after in: "
2306 } while ((i
= next_desc(vq
, &desc
)) != -1);
2308 /* On success, increment avail index. */
2309 vq
->last_avail_idx
++;
2311 /* Assume notifications from guest are disabled at this point,
2312 * if they aren't we would need to update avail_event index. */
2313 BUG_ON(!(vq
->used_flags
& VRING_USED_F_NO_NOTIFY
));
2316 EXPORT_SYMBOL_GPL(vhost_get_vq_desc
);
2318 /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
2319 void vhost_discard_vq_desc(struct vhost_virtqueue
*vq
, int n
)
2321 vq
->last_avail_idx
-= n
;
2323 EXPORT_SYMBOL_GPL(vhost_discard_vq_desc
);
2325 /* After we've used one of their buffers, we tell them about it. We'll then
2326 * want to notify the guest, using eventfd. */
2327 int vhost_add_used(struct vhost_virtqueue
*vq
, unsigned int head
, int len
)
2329 struct vring_used_elem heads
= {
2330 cpu_to_vhost32(vq
, head
),
2331 cpu_to_vhost32(vq
, len
)
2334 return vhost_add_used_n(vq
, &heads
, 1);
2336 EXPORT_SYMBOL_GPL(vhost_add_used
);
2338 static int __vhost_add_used_n(struct vhost_virtqueue
*vq
,
2339 struct vring_used_elem
*heads
,
2342 vring_used_elem_t __user
*used
;
2346 start
= vq
->last_used_idx
& (vq
->num
- 1);
2347 used
= vq
->used
->ring
+ start
;
2348 if (vhost_put_used(vq
, heads
, start
, count
)) {
2349 vq_err(vq
, "Failed to write used");
2352 if (unlikely(vq
->log_used
)) {
2353 /* Make sure data is seen before log. */
2355 /* Log used ring entry write. */
2356 log_used(vq
, ((void __user
*)used
- (void __user
*)vq
->used
),
2357 count
* sizeof *used
);
2359 old
= vq
->last_used_idx
;
2360 new = (vq
->last_used_idx
+= count
);
2361 /* If the driver never bothers to signal in a very long while,
2362 * used index might wrap around. If that happens, invalidate
2363 * signalled_used index we stored. TODO: make sure driver
2364 * signals at least once in 2^16 and remove this. */
2365 if (unlikely((u16
)(new - vq
->signalled_used
) < (u16
)(new - old
)))
2366 vq
->signalled_used_valid
= false;
2370 /* After we've used one of their buffers, we tell them about it. We'll then
2371 * want to notify the guest, using eventfd. */
2372 int vhost_add_used_n(struct vhost_virtqueue
*vq
, struct vring_used_elem
*heads
,
2377 start
= vq
->last_used_idx
& (vq
->num
- 1);
2378 n
= vq
->num
- start
;
2380 r
= __vhost_add_used_n(vq
, heads
, n
);
2386 r
= __vhost_add_used_n(vq
, heads
, count
);
2388 /* Make sure buffer is written before we update index. */
2390 if (vhost_put_used_idx(vq
)) {
2391 vq_err(vq
, "Failed to increment used idx");
2394 if (unlikely(vq
->log_used
)) {
2395 /* Make sure used idx is seen before log. */
2397 /* Log used index update. */
2398 log_used(vq
, offsetof(struct vring_used
, idx
),
2399 sizeof vq
->used
->idx
);
2401 eventfd_signal(vq
->log_ctx
, 1);
2405 EXPORT_SYMBOL_GPL(vhost_add_used_n
);
2407 static bool vhost_notify(struct vhost_dev
*dev
, struct vhost_virtqueue
*vq
)
2412 /* Flush out used index updates. This is paired
2413 * with the barrier that the Guest executes when enabling
2417 if (vhost_has_feature(vq
, VIRTIO_F_NOTIFY_ON_EMPTY
) &&
2418 unlikely(vq
->avail_idx
== vq
->last_avail_idx
))
2421 if (!vhost_has_feature(vq
, VIRTIO_RING_F_EVENT_IDX
)) {
2423 if (vhost_get_avail_flags(vq
, &flags
)) {
2424 vq_err(vq
, "Failed to get flags");
2427 return !(flags
& cpu_to_vhost16(vq
, VRING_AVAIL_F_NO_INTERRUPT
));
2429 old
= vq
->signalled_used
;
2430 v
= vq
->signalled_used_valid
;
2431 new = vq
->signalled_used
= vq
->last_used_idx
;
2432 vq
->signalled_used_valid
= true;
2437 if (vhost_get_used_event(vq
, &event
)) {
2438 vq_err(vq
, "Failed to get used event idx");
2441 return vring_need_event(vhost16_to_cpu(vq
, event
), new, old
);
2444 /* This actually signals the guest, using eventfd. */
2445 void vhost_signal(struct vhost_dev
*dev
, struct vhost_virtqueue
*vq
)
2447 /* Signal the Guest tell them we used something up. */
2448 if (vq
->call_ctx
.ctx
&& vhost_notify(dev
, vq
))
2449 eventfd_signal(vq
->call_ctx
.ctx
, 1);
2451 EXPORT_SYMBOL_GPL(vhost_signal
);
2453 /* And here's the combo meal deal. Supersize me! */
2454 void vhost_add_used_and_signal(struct vhost_dev
*dev
,
2455 struct vhost_virtqueue
*vq
,
2456 unsigned int head
, int len
)
2458 vhost_add_used(vq
, head
, len
);
2459 vhost_signal(dev
, vq
);
2461 EXPORT_SYMBOL_GPL(vhost_add_used_and_signal
);
2463 /* multi-buffer version of vhost_add_used_and_signal */
2464 void vhost_add_used_and_signal_n(struct vhost_dev
*dev
,
2465 struct vhost_virtqueue
*vq
,
2466 struct vring_used_elem
*heads
, unsigned count
)
2468 vhost_add_used_n(vq
, heads
, count
);
2469 vhost_signal(dev
, vq
);
2471 EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n
);
2473 /* return true if we're sure that avaiable ring is empty */
2474 bool vhost_vq_avail_empty(struct vhost_dev
*dev
, struct vhost_virtqueue
*vq
)
2476 __virtio16 avail_idx
;
2479 if (vq
->avail_idx
!= vq
->last_avail_idx
)
2482 r
= vhost_get_avail_idx(vq
, &avail_idx
);
2485 vq
->avail_idx
= vhost16_to_cpu(vq
, avail_idx
);
2487 return vq
->avail_idx
== vq
->last_avail_idx
;
2489 EXPORT_SYMBOL_GPL(vhost_vq_avail_empty
);
2491 /* OK, now we need to know about added descriptors. */
2492 bool vhost_enable_notify(struct vhost_dev
*dev
, struct vhost_virtqueue
*vq
)
2494 __virtio16 avail_idx
;
2497 if (!(vq
->used_flags
& VRING_USED_F_NO_NOTIFY
))
2499 vq
->used_flags
&= ~VRING_USED_F_NO_NOTIFY
;
2500 if (!vhost_has_feature(vq
, VIRTIO_RING_F_EVENT_IDX
)) {
2501 r
= vhost_update_used_flags(vq
);
2503 vq_err(vq
, "Failed to enable notification at %p: %d\n",
2504 &vq
->used
->flags
, r
);
2508 r
= vhost_update_avail_event(vq
, vq
->avail_idx
);
2510 vq_err(vq
, "Failed to update avail event index at %p: %d\n",
2511 vhost_avail_event(vq
), r
);
2515 /* They could have slipped one in as we were doing that: make
2516 * sure it's written, then check again. */
2518 r
= vhost_get_avail_idx(vq
, &avail_idx
);
2520 vq_err(vq
, "Failed to check avail idx at %p: %d\n",
2521 &vq
->avail
->idx
, r
);
2525 return vhost16_to_cpu(vq
, avail_idx
) != vq
->avail_idx
;
2527 EXPORT_SYMBOL_GPL(vhost_enable_notify
);
2529 /* We don't need to be notified again. */
2530 void vhost_disable_notify(struct vhost_dev
*dev
, struct vhost_virtqueue
*vq
)
2534 if (vq
->used_flags
& VRING_USED_F_NO_NOTIFY
)
2536 vq
->used_flags
|= VRING_USED_F_NO_NOTIFY
;
2537 if (!vhost_has_feature(vq
, VIRTIO_RING_F_EVENT_IDX
)) {
2538 r
= vhost_update_used_flags(vq
);
2540 vq_err(vq
, "Failed to disable notification at %p: %d\n",
2541 &vq
->used
->flags
, r
);
2544 EXPORT_SYMBOL_GPL(vhost_disable_notify
);
2546 /* Create a new message. */
2547 struct vhost_msg_node
*vhost_new_msg(struct vhost_virtqueue
*vq
, int type
)
2549 struct vhost_msg_node
*node
= kmalloc(sizeof *node
, GFP_KERNEL
);
2553 /* Make sure all padding within the structure is initialized. */
2554 memset(&node
->msg
, 0, sizeof node
->msg
);
2556 node
->msg
.type
= type
;
2559 EXPORT_SYMBOL_GPL(vhost_new_msg
);
2561 void vhost_enqueue_msg(struct vhost_dev
*dev
, struct list_head
*head
,
2562 struct vhost_msg_node
*node
)
2564 spin_lock(&dev
->iotlb_lock
);
2565 list_add_tail(&node
->node
, head
);
2566 spin_unlock(&dev
->iotlb_lock
);
2568 wake_up_interruptible_poll(&dev
->wait
, EPOLLIN
| EPOLLRDNORM
);
2570 EXPORT_SYMBOL_GPL(vhost_enqueue_msg
);
2572 struct vhost_msg_node
*vhost_dequeue_msg(struct vhost_dev
*dev
,
2573 struct list_head
*head
)
2575 struct vhost_msg_node
*node
= NULL
;
2577 spin_lock(&dev
->iotlb_lock
);
2578 if (!list_empty(head
)) {
2579 node
= list_first_entry(head
, struct vhost_msg_node
,
2581 list_del(&node
->node
);
2583 spin_unlock(&dev
->iotlb_lock
);
2587 EXPORT_SYMBOL_GPL(vhost_dequeue_msg
);
2589 void vhost_set_backend_features(struct vhost_dev
*dev
, u64 features
)
2591 struct vhost_virtqueue
*vq
;
2594 mutex_lock(&dev
->mutex
);
2595 for (i
= 0; i
< dev
->nvqs
; ++i
) {
2597 mutex_lock(&vq
->mutex
);
2598 vq
->acked_backend_features
= features
;
2599 mutex_unlock(&vq
->mutex
);
2601 mutex_unlock(&dev
->mutex
);
2603 EXPORT_SYMBOL_GPL(vhost_set_backend_features
);
2605 static int __init
vhost_init(void)
2610 static void __exit
vhost_exit(void)
2614 module_init(vhost_init
);
2615 module_exit(vhost_exit
);
2617 MODULE_VERSION("0.0.1");
2618 MODULE_LICENSE("GPL v2");
2619 MODULE_AUTHOR("Michael S. Tsirkin");
2620 MODULE_DESCRIPTION("Host kernel accelerator for virtio");