From patchwork Fri Mar 3 17:24:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 13159174 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3A87EC7EE2F for ; Fri, 3 Mar 2023 17:26:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pY99i-0008W0-Mq; Fri, 03 Mar 2023 12:25:18 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pY99h-0008Tv-VM for qemu-devel@nongnu.org; Fri, 03 Mar 2023 12:25:17 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pY99g-0005ZW-58 for qemu-devel@nongnu.org; Fri, 03 Mar 2023 12:25:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677864315; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jq+BQ8eQ8jCCD6tjr6K9FCoUwxsrU+yilWsq6RAnpEQ=; b=jHXMtykd2NVXb33xwbFe8faOffOk6s0fIjKIUlqSC7BYjROsaMOtJKZB0yDsjLuUVhkL90 7EbEhWfpASx/PQZ/vQG3Oy+Yyj4iih6Fo+BggMQGWnRCy4PL0W67irfczZ+pIA6SNl6UXG bPlEZMYdqQj520JrDakDuqjOTk1Xirk= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-539-o64UYtENOLSWLAw5xE0bAQ-1; Fri, 03 Mar 2023 12:25:07 -0500 X-MC-Unique: o64UYtENOLSWLAw5xE0bAQ-1 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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1CD761C05AF7; Fri, 3 Mar 2023 17:25:03 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.194.107]) by smtp.corp.redhat.com (Postfix) with ESMTP id 383C9440D8; Fri, 3 Mar 2023 17:25:00 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: Laurent Vivier , "Michael S. Tsirkin" , Gautam Dawar , Lei Yang , Harpreet Singh Anand , Shannon Nelson , Liuxiangdong , Cindy Lu , Parav Pandit , Zhu Lingshan , virtualization@lists.linux-foundation.org, Eli Cohen , si-wei.liu@oracle.com, longpeng2@huawei.com, Jason Wang , alvaro.karsz@solid-run.com, Stefan Hajnoczi , Stefano Garzarella , "Gonglei (Arei)" Subject: [PATCH v5 04/14] vdpa: rewind at get_base, not set_base Date: Fri, 3 Mar 2023 18:24:35 +0100 Message-Id: <20230303172445.1089785-5-eperezma@redhat.com> In-Reply-To: <20230303172445.1089785-1-eperezma@redhat.com> References: <20230303172445.1089785-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org At this moment it is only possible to migrate to a vdpa device running with x-svq=on. As a protective measure, the rewind of the inflight descriptors was done at the destination. That way if the source sent a virtqueue with inuse descriptors they are always discarded. Since this series allows to migrate also to passthrough devices with no SVQ, the right thing to do is to rewind at the source so the base of vrings are correct. Support for inflight descriptors may be added in the future. Signed-off-by: Eugenio Pérez Acked-by: Jason Wang --- v4: * Use virtqueue_unpop at vhost_svq_stop instead of rewinding at vhost_vdpa_get_vring_base. --- hw/virtio/vhost-shadow-virtqueue.c | 8 ++++++-- hw/virtio/vhost-vdpa.c | 11 ----------- 2 files changed, 6 insertions(+), 13 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 515ccf870d..8361e70d1b 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -694,13 +694,17 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq) g_autofree VirtQueueElement *elem = NULL; elem = g_steal_pointer(&svq->desc_state[i].elem); if (elem) { - virtqueue_detach_element(svq->vq, elem, 0); + /* + * TODO: This is ok for networking, but other kinds of devices + * might have problems with just unpop these. + */ + virtqueue_unpop(svq->vq, elem, 0); } } next_avail_elem = g_steal_pointer(&svq->next_guest_avail_elem); if (next_avail_elem) { - virtqueue_detach_element(svq->vq, next_avail_elem, 0); + virtqueue_unpop(svq->vq, next_avail_elem, 0); } svq->vq = NULL; g_free(svq->desc_next); diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index 5cfa9d5d27..1550b1e26a 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -1170,18 +1170,7 @@ static int vhost_vdpa_set_vring_base(struct vhost_dev *dev, struct vhost_vring_state *ring) { struct vhost_vdpa *v = dev->opaque; - VirtQueue *vq = virtio_get_queue(dev->vdev, ring->index); - /* - * vhost-vdpa devices does not support in-flight requests. Set all of them - * as available. - * - * TODO: This is ok for networking, but other kinds of devices might - * have problems with these retransmissions. - */ - while (virtqueue_rewind(vq, 1)) { - continue; - } if (v->shadow_vqs_enabled) { /* * Device vring base was set at device start. SVQ base is handled by