From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [RFC PATCH net-next 01/12] vhost_net: introduce helper to initialize tx iov iter Date: Mon, 21 May 2018 17:04:22 +0800 Message-ID: <1526893473-20128-2-git-send-email-jasowang@redhat.com> References: <1526893473-20128-1-git-send-email-jasowang@redhat.com> Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: mst@redhat.com, jasowang@redhat.com Return-path: In-Reply-To: <1526893473-20128-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Signed-off-by: Jason Wang --- drivers/vhost/net.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index c4b49fc..15d191a 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -459,6 +459,26 @@ static bool vhost_exceeds_maxpend(struct vhost_net *net) min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2); } +static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter, + size_t hdr_size, int out) +{ + /* Skip header. TODO: support TSO. */ + size_t len = iov_length(vq->iov, out); + + iov_iter_init(iter, WRITE, vq->iov, out, len); + iov_iter_advance(iter, hdr_size); + /* Sanity check */ + if (!iov_iter_count(iter)) { + vq_err(vq, "Unexpected header len for TX: " + "%zd expected %zd\n", + len, hdr_size); + return -EFAULT; + } + len = iov_iter_count(iter); + + return len; +} + /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */ static void handle_tx(struct vhost_net *net) @@ -521,18 +541,10 @@ static void handle_tx(struct vhost_net *net) "out %d, int %d\n", out, in); break; } - /* Skip header. TODO: support TSO. */ - 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 (!msg_data_left(&msg)) { - vq_err(vq, "Unexpected header len for TX: " - "%zd expected %zd\n", - len, hdr_size); + + len = init_iov_iter(vq, &msg.msg_iter, hdr_size, out); + if (len < 0) break; - } - len = msg_data_left(&msg); zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN && !vhost_exceeds_maxpend(net) -- 2.7.4