The shadow used ring's size is the same as the vq's size,
so we shouldn't try more than "vq size" times. Besides,
the element pointed by avail->idx isn't available to the
device, so we will return error when try "vq size" times.
Fixes: 24e4844048e1 ("vhost: unify Rx mergeable and non-mergeable paths")
Fixes: a922401f35cc ("vhost: add Rx support for packed ring")
Signed-off-by: Tiwei Bie <tiwei....@intel.com>
---
lib/librte_vhost/virtio_net.c | 37 ++++++++++++++++-------------------
1 file changed, 17 insertions(+), 20 deletions(-)
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 5d4b97587..3b11b353c 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -415,13 +415,20 @@ reserve_avail_buf_split(struct virtio_net *dev, struct
vhost_virtqueue *vq,
cur_idx = vq->last_avail_idx;
if (rxvq_is_mergeable(dev))
- max_tries = vq->size;
+ max_tries = vq->size - 1;
else
max_tries = 1;
while (size > 0) {
if (unlikely(cur_idx == avail_head))
return -1;
+ /*
+ * if we tried all available ring items, and still
+ * can't get enough buf, it means something abnormal
+ * happened.
+ */
+ if (unlikely(++tries > max_tries))
+ return -1;
if (unlikely(fill_vec_buf_split(dev, vq, cur_idx,
&vec_idx, buf_vec,
@@ -433,16 +440,7 @@ reserve_avail_buf_split(struct virtio_net *dev, struct
vhost_virtqueue *vq,
size -= len;
cur_idx++;
- tries++;
*num_buffers += 1;
-
- /*
- * if we tried all available ring items, and still
- * can't get enough buf, it means something abnormal
- * happened.
- */
- if (unlikely(tries > max_tries))
- return -1;
}
*nr_vec = vec_idx;
@@ -582,11 +580,19 @@ reserve_avail_buf_packed(struct virtio_net *dev, struct
vhost_virtqueue *vq,
avail_idx = vq->last_avail_idx;
if (rxvq_is_mergeable(dev))
- max_tries = vq->size;
+ max_tries = vq->size - 1;
else
max_tries = 1;
while (size > 0) {
+ /*
+ * if we tried all available ring items, and still
+ * can't get enough buf, it means something abnormal
+ * happened.
+ */
+ if (unlikely(++tries > max_tries))
+ return -1;
+
if (unlikely(fill_vec_buf_packed(dev, vq,
avail_idx, &desc_count,
buf_vec, &vec_idx,
@@ -603,16 +609,7 @@ reserve_avail_buf_packed(struct virtio_net *dev, struct
vhost_virtqueue *vq,
avail_idx -= vq->size;
*nr_descs += desc_count;
- tries++;
*num_buffers += 1;
-
- /*
- * if we tried all available ring items, and still
- * can't get enough buf, it means something abnormal
- * happened.
- */
- if (unlikely(tries > max_tries))
- return -1;
}
*nr_vec = vec_idx;
--
2.18.0
