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 <mst@redhat.com>
Cc: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-12-10 15:00:58 -05:00
Родитель aad9a1cec7
Коммит 98a527aac1
1 изменённых файлов: 5 добавлений и 4 удалений

Просмотреть файл

@ -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 !=