Re: [PATCH v3 16/18] vhost: don't bother with copying iovec in handle_tx()
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2015-02-04 09:13:52
Also in:
kvm, virtualization
On Wed, Feb 04, 2015 at 06:40:07AM +0000, Al Viro wrote:
From: Al Viro <viro@zeniv.linux.org.uk> 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>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
quoted hunk ↗ jump to hunk
--- drivers/vhost/net.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 6906f76..d86cc9b 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 !=-- 2.1.4