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

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
Signed-off-by: default avatarJason Wang <>
Signed-off-by: default avatarMichael S. Tsirkin <>
parent 304ba62f
......@@ -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),
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",
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",
......@@ -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. */
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. */
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);
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