From: Al Viro Date: Wed, 10 Dec 2014 20:00:58 +0000 (-0500) Subject: vhost: don't bother with copying iovec in handle_tx() X-Git-Tag: v4.0-rc1~133^2~61^2~2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=98a527aac1eb198dbc4405b800e102563ed8e4dd;p=linux.git vhost: don't bother with copying iovec in handle_tx() just advance the msg.msg_iter and be done with that. Cc: Michael S. Tsirkin Cc: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Al Viro --- diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 6906f76332f4..d86cc9bb9ea4 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -336,7 +336,7 @@ static void handle_tx(struct vhost_net *net) { struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *vq = &nvq->vq; - unsigned out, in, s; + unsigned out, in; int head; struct msghdr msg = { .msg_name = NULL, @@ -395,16 +395,17 @@ static void handle_tx(struct vhost_net *net) break; } /* Skip header. TODO: support TSO. */ - s = move_iovec_hdr(vq->iov, nvq->hdr, hdr_size, out); len = iov_length(vq->iov, out); iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len); + iov_iter_advance(&msg.msg_iter, hdr_size); /* Sanity check */ - if (!len) { + if (!iov_iter_count(&msg.msg_iter)) { vq_err(vq, "Unexpected header len for TX: " "%zd expected %zd\n", - iov_length(nvq->hdr, s), hdr_size); + len, hdr_size); break; } + len = iov_iter_count(&msg.msg_iter); zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN && (nvq->upend_idx + 1) % UIO_MAXIOV !=