[PATCH 1/4] vhost: Drop variable last_avail_idx in vhost_get_vq_desc()

[Gavin Shan]

The local variable @last_avail_idx is equivalent to vq->last_avail_idx.
So the code can be simplified a bit by dropping the local variable
@last_avail_idx.

No functional change intended.

Signed-off-by: Gavin Shan <gs...@redhat.com>
---
 drivers/vhost/vhost.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 8995730ce0bf..ef7942103232 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2498,14 +2498,11 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 {
        struct vring_desc desc;
        unsigned int i, head, found = 0;
-       u16 last_avail_idx;
        __virtio16 avail_idx;
        __virtio16 ring_head;
        int ret, access;
 
        /* Check it isn't doing very strange things with descriptor numbers. */
-       last_avail_idx = vq->last_avail_idx;
-
        if (vq->avail_idx == vq->last_avail_idx) {
                if (unlikely(vhost_get_avail_idx(vq, &avail_idx))) {
                        vq_err(vq, "Failed to access avail idx at %p\n",
@@ -2514,16 +2511,16 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
                }
                vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
 
-               if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
+               if (unlikely((u16)(vq->avail_idx - vq->last_avail_idx) > 
vq->num)) {
                        vq_err(vq, "Guest moved avail index from %u to %u",
-                               last_avail_idx, vq->avail_idx);
+                               vq->last_avail_idx, vq->avail_idx);
                        return -EFAULT;
                }
 
                /* If there's nothing new since last we looked, return
                 * invalid.
                 */
-               if (vq->avail_idx == last_avail_idx)
+               if (vq->avail_idx == vq->last_avail_idx)
                        return vq->num;
 
                /* Only get avail ring entries after they have been
@@ -2534,10 +2531,10 @@ 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(vhost_get_avail_head(vq, &ring_head, last_avail_idx))) {
+       if (unlikely(vhost_get_avail_head(vq, &ring_head, vq->last_avail_idx))) 
{
                vq_err(vq, "Failed to read head: idx %d address %p\n",
-                      last_avail_idx,
-                      &vq->avail->ring[last_avail_idx % vq->num]);
+                      vq->last_avail_idx,
+                      &vq->avail->ring[vq->last_avail_idx % vq->num]);
                return -EFAULT;
        }
 
-- 
2.44.0