From patchwork Tue Mar 5 22:57:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marc-Andr=C3=A9_Lureau?= X-Patchwork-Id: 10840183 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 74681922 for ; Tue, 5 Mar 2019 23:03:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 628242D05C for ; Tue, 5 Mar 2019 23:03:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 56A482D07A; Tue, 5 Mar 2019 23:03:20 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 06C4F2D05C for ; Tue, 5 Mar 2019 23:03:20 +0000 (UTC) Received: from localhost ([127.0.0.1]:50538 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1J5j-0005hE-8P for patchwork-qemu-devel@patchwork.kernel.org; Tue, 05 Mar 2019 18:03:19 -0500 Received: from eggs.gnu.org ([209.51.188.92]:59067) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1J1h-0002U7-Ae for qemu-devel@nongnu.org; Tue, 05 Mar 2019 17:59:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h1J1g-0008LE-GL for qemu-devel@nongnu.org; Tue, 05 Mar 2019 17:59:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37644) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h1J1g-0008Kx-AK for qemu-devel@nongnu.org; Tue, 05 Mar 2019 17:59:08 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9C5EE8830B for ; Tue, 5 Mar 2019 22:59:07 +0000 (UTC) Received: from localhost (ovpn-112-17.ams2.redhat.com [10.36.112.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id A8F135D96F; Tue, 5 Mar 2019 22:59:01 +0000 (UTC) From: =?utf-8?q?Marc-Andr=C3=A9_Lureau?= To: qemu-devel@nongnu.org Date: Tue, 5 Mar 2019 23:57:29 +0100 Message-Id: <20190305225731.15074-11-marcandre.lureau@redhat.com> In-Reply-To: <20190305225731.15074-1-marcandre.lureau@redhat.com> References: <20190305225731.15074-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 05 Mar 2019 22:59:07 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v5 10/12] libvhost-user: add vu_queue_unpop() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kraxel@redhat.com, mst@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP vhost-user-input will make use of this function to undo some queue pop in case the virtio queue does not have enough room. Signed-off-by: Marc-André Lureau --- contrib/libvhost-user/libvhost-user.h | 14 ++++++++++++++ contrib/libvhost-user/libvhost-user.c | 16 ++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h index b0c798fa1a..01738bf44a 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -459,6 +459,20 @@ void vu_queue_notify(VuDev *dev, VuVirtq *vq); */ void *vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz); + +/** + * vu_queue_unpop: + * @dev: a VuDev context + * @vq: a VuVirtq queue + * @elem: The #VuVirtqElement + * @len: number of bytes written + * + * Pretend the most recent element wasn't popped from the virtqueue. The next + * call to vu_queue_pop() will refetch the element. + */ +void vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem, + size_t len); + /** * vu_queue_rewind: * @dev: a VuDev context diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index fcf5014240..df72d3e440 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -1966,6 +1966,22 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz) return elem; } +static void +vu_queue_detach_element(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem, + size_t len) +{ + vq->inuse--; + /* unmap, when DMA support is added */ +} + +void +vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem, + size_t len) +{ + vq->last_avail_idx--; + vu_queue_detach_element(dev, vq, elem, len); +} + bool vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num) {