From patchwork Mon May 21 09:04:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 10414415 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4E155600CC for ; Mon, 21 May 2018 09:09:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 410F028756 for ; Mon, 21 May 2018 09:09:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 35DCC28762; Mon, 21 May 2018 09:09:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CC4CE28756 for ; Mon, 21 May 2018 09:09:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751745AbeEUJEw (ORCPT ); Mon, 21 May 2018 05:04:52 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:54666 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751557AbeEUJEp (ORCPT ); Mon, 21 May 2018 05:04:45 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2504C400E9A7; Mon, 21 May 2018 09:04:45 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-30.pek2.redhat.com [10.72.12.30]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1D2944E68B; Mon, 21 May 2018 09:04:41 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org 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> In-Reply-To: <1526893473-20128-1-git-send-email-jasowang@redhat.com> References: <1526893473-20128-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Mon, 21 May 2018 09:04:45 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Mon, 21 May 2018 09:04:45 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jasowang@redhat.com' RCPT:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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)