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Commit bfe2bc51 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

vhost: introduce vhost memory accessors 



This patch introduces vhost memory accessors which were just wrappers
for userspace address access helpers. This is a requirement for vhost
device iotlb implementation which will add iotlb translations in those
accessors.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 304ba62f

drivers/vhost/vhost.c

+35 −15
Original line number Diff line number Diff line
@@ -638,6 +638,22 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem, 
	return 1;

}



#define vhost_put_user(vq, x, ptr)  __put_user(x, ptr)



static int vhost_copy_to_user(struct vhost_virtqueue *vq, void *to,

			      const void *from, unsigned size)

{

	return __copy_to_user(to, from, size);

}



#define vhost_get_user(vq, x, ptr) __get_user(x, ptr)



static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to,

				void *from, unsigned size)

{

	return __copy_from_user(to, from, size);

}



static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,

			struct vring_desc __user *desc,

			struct vring_avail __user *avail,
@@ -1143,7 +1159,8 @@ EXPORT_SYMBOL_GPL(vhost_log_write); 
static int vhost_update_used_flags(struct vhost_virtqueue *vq)

{

	void __user *used;

	if (__put_user(cpu_to_vhost16(vq, vq->used_flags), &vq->used->flags) < 0)

	if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags),

			   &vq->used->flags) < 0)

		return -EFAULT;

	if (unlikely(vq->log_used)) {

		/* Make sure the flag is seen before log. */
@@ -1161,7 +1178,8 @@ static int vhost_update_used_flags(struct vhost_virtqueue *vq) 


static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)

{

	if (__put_user(cpu_to_vhost16(vq, vq->avail_idx), vhost_avail_event(vq)))

	if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx),

			   vhost_avail_event(vq)))

		return -EFAULT;

	if (unlikely(vq->log_used)) {

		void __user *used;
@@ -1199,7 +1217,7 @@ int vhost_vq_init_access(struct vhost_virtqueue *vq) 
		r = -EFAULT;

		goto err;

	}

	r = __get_user(last_used_idx, &vq->used->idx);

	r = vhost_get_user(vq, last_used_idx, &vq->used->idx);

	if (r)

		goto err;

	vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx);
@@ -1379,7 +1397,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 


	/* Check it isn't doing very strange things with descriptor numbers. */

	last_avail_idx = vq->last_avail_idx;

	if (unlikely(__get_user(avail_idx, &vq->avail->idx))) {

	if (unlikely(vhost_get_user(vq, avail_idx, &vq->avail->idx))) {

		vq_err(vq, "Failed to access avail idx at %p\n",

		       &vq->avail->idx);

		return -EFAULT;
@@ -1401,7 +1419,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 


	/* Grab the next descriptor number they're advertising, and increment

	 * the index we've seen. */

	if (unlikely(__get_user(ring_head,

	if (unlikely(vhost_get_user(vq, ring_head,

		     &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) {

		vq_err(vq, "Failed to read head: idx %d address %p\n",

		       last_avail_idx,
@@ -1437,7 +1455,8 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 
			       i, vq->num, head);

			return -EINVAL;

		}

		ret = __copy_from_user(&desc, vq->desc + i, sizeof desc);

		ret = vhost_copy_from_user(vq, &desc, vq->desc + i,

					   sizeof desc);

		if (unlikely(ret)) {

			vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",

			       i, vq->desc + i);
@@ -1525,15 +1544,15 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq, 
	start = vq->last_used_idx & (vq->num - 1);

	used = vq->used->ring + start;

	if (count == 1) {

		if (__put_user(heads[0].id, &used->id)) {

		if (vhost_put_user(vq, heads[0].id, &used->id)) {

			vq_err(vq, "Failed to write used id");

			return -EFAULT;

		}

		if (__put_user(heads[0].len, &used->len)) {

		if (vhost_put_user(vq, heads[0].len, &used->len)) {

			vq_err(vq, "Failed to write used len");

			return -EFAULT;

		}

	} else if (__copy_to_user(used, heads, count * sizeof *used)) {

	} else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) {

		vq_err(vq, "Failed to write used");

		return -EFAULT;

	}
@@ -1577,7 +1596,8 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, 


	/* Make sure buffer is written before we update index. */

	smp_wmb();

	if (__put_user(cpu_to_vhost16(vq, vq->last_used_idx), &vq->used->idx)) {

	if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx),

			   &vq->used->idx)) {

		vq_err(vq, "Failed to increment used idx");

		return -EFAULT;

	}
@@ -1609,7 +1629,7 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 


	if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {

		__virtio16 flags;

		if (__get_user(flags, &vq->avail->flags)) {

		if (vhost_get_user(vq, flags, &vq->avail->flags)) {

			vq_err(vq, "Failed to get flags");

			return true;

		}
@@ -1623,7 +1643,7 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
	if (unlikely(!v))

		return true;



	if (__get_user(event, vhost_used_event(vq))) {

	if (vhost_get_user(vq, event, vhost_used_event(vq))) {

		vq_err(vq, "Failed to get used event idx");

		return true;

	}
@@ -1665,7 +1685,7 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
	__virtio16 avail_idx;

	int r;



	r = __get_user(avail_idx, &vq->avail->idx);

	r = vhost_get_user(vq, avail_idx, &vq->avail->idx);

	if (r)

		return false;
@@ -1700,7 +1720,7 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
	/* They could have slipped one in as we were doing that: make

	 * sure it's written, then check again. */

	smp_mb();

	r = __get_user(avail_idx, &vq->avail->idx);

	r = vhost_get_user(vq, avail_idx, &vq->avail->idx);

	if (r) {

		vq_err(vq, "Failed to check avail idx at %p: %d\n",

		       &vq->avail->idx, r);