vhost: move memory pointer to VQs

commit 2ae76693b8bcabf370b981cd00c36cd41d33fabc
    vhost: replace rcu with mutex
replaced rcu sync for memory accesses with VQ mutex locl/unlock.
This is correct since all accesses are under VQ mutex, but incomplete:
we still do useless rcu lock/unlock operations, someone might copy this
code into some other context where this won't be right.
This use of RCU is also non standard and hard to understand.
Let's copy the pointer to each VQ structure, this way
the access rules become straight-forward, and there's
no need for RCU anymore.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 2bc8f298a4e7..971a760af4a1 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -374,7 +374,7 @@ static void handle_tx(struct vhost_net *net)
                               % UIO_MAXIOV == nvq->done_idx))
                         break;
 
-                head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
+                head = vhost_get_vq_desc(vq, vq->iov,
                                          ARRAY_SIZE(vq->iov),
                                          &out, &in,
                                          NULL, NULL);
@@ -506,7 +506,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
                         r = -ENOBUFS;
                         goto err;
                 }
-                r = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
+                r = vhost_get_vq_desc(vq, vq->iov + seg,
                                       ARRAY_SIZE(vq->iov) - seg, &out,
                                       &in, log, log_num);
                 if (unlikely(r < 0))